The URL can be used to link to this page

Home My WebLink About1 Creeks, Water Quality, USGS MapsAppendix B Region's Watersheds Unified Stormwater Design Guidelilnes City of College Station City of Bryan February 2007 SECTION IX APPENDIX B -REGION'S WATERSHEDS Table B-2 Minimum Floor Elevations Along Selected Named Regulatory Watercourses Reference Section II, Paragraph C1-b , page 8of18 Regulatory Channel Reach Elevation Watercourse Above From To Base Flood Bee Creek (Main Bee Creek Trib. B Texas Ave. 3 feet Watercourse) Bee Creek Trib . "A" Walsh Ave . Main Bee Creek below* 2 feet East Bypass South Fork Trib . "B' FM 2818 4 feet above Welsh Ave. FM 2818 at Rio Main Bee Creek 2 feet Bee Creek Trib . "B'' Grand North Fork Trib. "B" at South Fork Trib. "B'' FM 2818 and at near Welsh Ave . 2 feet Southwest Parkway South Fork Trib. "B'' Bee Creek Trib. "B" 2 feet at Wellborn Road Lick Creek Graham Road Alum Creek confluence 3 feet South Fork of Lick First trib. above CS Main Lick Creek 3 feet Creek city limits Spring Creek Confluence of North Main Lick Creek 3 feet and South Forks North Fork of Upper limits Confluence with South 3 feet Spring Creek Fork South Fork of Upper limits Confluence with North 3 feet Spring Creek Fork STORMWATER DESIGN GUIDELINES Effective February 2007 Page 3 of 24 APPENDIX B : REGION 'S WATERSHEDS As Revised ___ _ SECTION IX APPENDIX B -REGION'S WATERSHEDS Table B-1 Detention Requirements by Watershed and Watershed Reach Reference Section II , Paragraph B, page 2of18 Watershed Channel Reach Detention For Flood Name From To Control Alum Creek Carter Creek SH 6 Not Required SH 6 Upstream Required Carter Creek Texas Avenue Not Required Texas Avenue Southwest Parkway , Evaluate Bee Creek Welsh , Deacon Southwest Parkway , Upstream Required Welsh , Deacon Carter Creek Quail Hollow, SH 6 Not Required Briar Creek Quail Hollow, SH 6 E. Villa Maria Evaluate E. Villa Maria Upstream Required Wickson Creek Cole Lane Not Required Brushy Creek Cole Lane Elmo Weedon Road Evaluate Elmo Weedon Road Upstream Required Carter Creek E. 291h Street Not Required Burton Creek E. 291" Street E. Villa Maria Evaluate E. Villa Maria Upstream Required Carters Creek Navasota River Upstream Evaluate Cottonwood Burton Creek FM 2818 Evaluate Branch FM 2818 Upstream Required Carter Creek Boonville Road Not Required Hudson Creek Boonville Road Miramont Evaluate Miramont Upstream Required Navasota River Greens Prairie Road Not Required Lick Creek Greens Prairie Road SH 6 Evaluate SH6 Upstream Evaluate Little Wikson Wickson Creek Dilly Shaw Tap Road Evaluate Creek Dilly Shaw Tap Road Upstream Required Navasota River Peach Creek Road Not Required Peach Creek Peach Creek Road Upstream 14,000 feet Evaluate 14,000 ft. above Peach Upstream Required Creek Spring Creek Lick Creek SH 6 Evaluate SH 6 Upstream Required STORMWATER DESIGN GUIDELINES Effective February 2007 Page 1 of24 APPENDIX B: REGION 'S WATERSH E DS As Revised ___ _ SECTION IX APPENDIX B -REGION'S WATERSHEDS Table B-1 (continued) Detention Requirements by Watershed and Watershed Reach Reference Section II, Paragraph B1, page 2 of 18 Watershed Channel Reach Detention Name For Flood From To Control Wickson Creek Green Branch Loop , Evaluate Steep Hollow Easterling Drive Branch Green Branch Loop, Upstream Required Easterling Drive Still Creek Thompsons Creek FM 2818 Evaluate FM 2818 Upstream Required Thompsons Thompsons Creek N. Texas Avenue Evaluate Branch N . Texas Avenue Upstream Required Thompsons Brazos River SH 21 Not Required Creek SH 21 Thompsons Branch Evaluate Thompsons Branch Upstream Required Brazos River SH47 Not Required Turkey Creek SH47 W . Villa Maria Drive Evaluate W . Villa Maria Drive Upstream Required Brazos River Unnamed Road off White Not Required Creek Road White Creek Unnamed Road off FM 2818 Evaluate White Creek Road FM 2818 Upstream Required Carter Creek Dartmouth Street Not Required Wolf Pen Dartmouth Street George Bush Drive at Evaluate Creek Texas Avenue George Bush Drive at Upstream Required Texas Avenue STORMWATER DESIGN GUIDELINES Effective February 2007 Page 2 of 24 APPENDIX B: REGION 'S WATERSHEDS As Revised ___ _ SECTION IX APPENDIX B -REGION'S WATERSHEDS 14,000 7,000 0 -- WAlERSHED 1 ALUM CREEK 2 BEE CREEK J BRIAR CREEK 4 BRUSHY CREEK S BURTOll CREEK 6 CARTERS CREEK 7 COTTOllWOOD BRAllCH I HUDSOll CREEK 9 LICK CREEK 1t LITTLE WICKSOll CREEK 11 PEACH CREEK 12 SPRlllG CREEK 1J STEEP HOLLOWBRAll CH 14 ST ILL CREEK 15 THOMPSOllS BRAllCH 16 THOMPSOllS CREEK 17 TURKEY CREEK 11 WHllES CREEK 19 WICKSOll CREEK 2t WOLF PEii CREEK Figure B-1: Watersheds of Bryan I College Station Region STORMWATER DESIGN GUIDELINES Effective February 2007 Page 4 of 24 APPENDIX B: REGION'S WATERSHEDS As Revised ____ _ SECTION IX APPENDIX B -REGION'S WATERSHEDS Figure B-2: Alum Creek Watershed Area STORMWATER DESIGN GUIDELINES Effective February 2007 Page 5 of 24 APPENDIX B : REGION 'S WATERSHEDS As Revised ___ _ SECTION IX APPENDIX B -REGION'S WATERSHEDS 0 2,600 5,200 Figure B-3: Bee Creek Watershed Area STORMWATER DESIGN GUIDELINES Effective February 2007 Page 6 of 24 APPENDIX B: REGION 'S WATERSHEDS As Revised ___ _ SECTION IX APPENDIX B -REGION'S WATERSHEDS Figure B-4: Briar Creek Watershed Area STORMWATER DESIGN GUIDELINES Effective February 2007 Page 7 of 24 APPENDIX B: REGION 'S WATERSHEDS As Revised ___ _ SECTION IX APPENDIX B -REGION'S WATERSHEDS 0 3 ))00 6 ))00 Figure B-5: Brushy Creek Watershed Area STORMWATER DESIGN GUIDELINES Effective February 2007 Page 8 of 24 APPENDIX B: REGION 'S WATERSHEDS As Revised ___ _ SECTION IX APPENDIX B -REGION'S WATERSHEDS ~Feet 0 1 ,BOO 3.600 7,200 Figure B-6: Burton Creek Watershed Area STORMWATER DESIGN GUIDELINES Effect ive February 2007 Page 9 of 24 APPENDIX B : REGION 'S WATERSHEDS As Revised ___ _ SECTION IX APPENDIX B -REGION'S WATERSHEDS 0 6j)OO 12,000 Figure 8-7: Carters Creek Watershed Area STORMWATER DESIGN GUIDELINES Effective February 2007 Page 10 of24 APPENDIX B: REGION 'S WATERSHEDS As Revised ___ _ SECTION IX APPENDIX B -REGION'S WATERSHEDS ~Fee t 0 2,400 4 ,800 9p00 Figure B-8: Conttonwood Branch Watershed Area STORMWATER DESIGN GUIDELINES Effective February 2007 Page 11 of 24 APPENDIX B : REGION 'S WATERSHEDS As Rev ised ___ _ SECTION IX APPENDIX B -REGION'S WATERSHEDS 0 1 ,50 0 3 .ODO Figure 8-9: Hudson Creek Watershed Area STORMWATER DESIGN GUIDELINES Effective February 2007 Page 12 of 24 APPENDIX B: REGION 'S WATERSHEDS As Revised ___ _ SECTION IX APPENDIX B -REGION'S WATERSHEDS I , I re ~-/ Gj / Figure B-10: Lick Creek Watershed Area STORMWATER DESIGN GUIDELINES Effective February 2007 Page 13 of 24 APPENDIX B : REGION 'S WATERSHEDS As Revised ___ _ SECTION IX APPENDIX B -REGION'S WATERSHEDS ~Feet 0 2 ,250 4 ,5 00 9 0 00 Figure B-11: Little Wickson Creek Watershed Area STORMWATER DESIGN GUIDELINES Effective February 2007 Page 14 of24 APPENDIX B: REGION 'S WATERSHEDS As Revised ___ _ SECTION IX APPENDIX B -REGION'S WATERSHEDS / 0 4,050 8,100 Figure B-12: Peach Creek Watershed Area STORMWATER DESIGN GUIDELINES Effective February 2007 Page 15 of 24 APPENDIX B: REGION 'S WATERSHEDS As Rev ised ___ _ SECTION IX APPENDIX B -REGION'S WATERSHEDS Figure B-13: Spring Creek Watershed Area STORMWATER DESIGN GUIDELINES Effective February 2007 Page 16 of 24 APPENDIX B: REGION 'S WATERSHEDS As Revised ---- SECTION IX APPENDIX B -REGION'S WATERSHEDS ~Fee t 0 2,250 4,5 00 9/)00 Figure 8-14: Still Creek Watershed Area STORMWATER DESIGN GUIDELINES Effective February 2007 Page 17 of24 APPENDIX B: REGION 'S WATERSHEDS As Revised ___ _ SECTION IX APPENDIX B -REGION'S WATERSHEDS 0 1,900 3,800 Figure B-15: Steep Hollow Branch Watershed Area STORMWATER DESIGN GUIDELINES Effective February 2007 Page 18 of 24 APPENDIX B: REGION 'S WATERSHEDS As Revised ___ _ SECTION IX APPENDIX B -REGION'S WATERSHEDS ~F eet 0 2 .250 4,500 9/)00 Figure B-16: Thompsons Branch Watershed Area STORMWATER DESIGN GUIDELINES Effective February 2007 Page 19 of24 APPENDIX B: REGION 'S WATERSHEDS As Revised ___ _ SECTION IX APPENDIX B -REGION'S WATERSHEDS ~Fe e t 0 4,250 8 .500 17 ,000 Figure B-17: Thompsons Creek Watershed Area STORMWATER DESIGN GUIDELINES Effective February 2007 Page 20 of 24 APPENDIX B: REGION 'S WATERSHEDS As Revised ___ _ SECTION IX 0 2POO 4P OO APPENDIX B -REGION'S WATERSHEDS Fee t BPO O Figure 8-18: Turkey Creek Watershed Area STORMWATER DESIGN GUIDELINES Effective February 2007 Page 21 of 24 APPENDIX B : REGION 'S WATERSHEDS As Revised ___ _ SECTION IX 0 2,250 4,500 APPENDIX B -REGION'S WATERSHEDS Feet gpoo I Figure B-19: Whites Creek Watershed Area STORMWATER DESIGN GUIDELINES Effective February 2007 Page 22 of 24 APPENDIX B: REGION'S WATERSHEDS As Revised ___ _ SECTION IX APPENDIX B -REGION'S WATERSHEDS ~Feet 0 6))00 12,000 24 ,000 Figure B-20: Wickson Creek Watershed Area STORMWATER DESIGN GUIDELINES Effective February 2007 Page 23 of 24 APPENDIX B: REGION 'S WATERSHEDS As Revised ____ _ SECTION IX APPENDIX B -REGION'S WATERSHEDS 0 1 ,650 3 ,300 Figure B-21: Wolf Pen Creek Watershed Area STORMWATER DESIGN GUIDELINES Effective February 2007 Page 24 of 24 APPENDIX B: REGION 'S WATERSHEDS As Revised ___ _ Appendix C Computational Information Unified Stormwater Design Guidelines City of College Station City of Bryan February 2007 This guide is published under a grant provided by the United States Environmental Protection Agency, Region 6. Authori- zation for use or reproduction of any original material (unless obtained from other sources) is freely given. The TNRCC would appreciate acknowledgement. The TNRCC gratefully acknowledges the EPA's Streamwalk Manual for some of the material used in the streamwalk checklist. For additional information about this guide, please call the Watershed Assessment and Planning Section of the TNRCC at 512- 239 -4594. The TNRCC is an equal opportunity/affirmative action employer. The agency does not discriminate on the basis of race, color, religion , national origin , sex, disability, age , sexual orientat ion, or veteran status. O e,Printed on recycled paper with soy based ink . ~ Watershed Owner's Stream walk Guide Gl-2 18 Texas Natural Resource Conservation Commission Nonpoint Source Program Team • 5196 nonpoint source pollution -refers to pollution that is 1) generated by diffuse land use activities , not by identifi- able facilities (point sources); 2) conveyed to water ways through natural processes such as storm runoff or groundwater seepage, rather than by deliberate , controllable discharges; and 3) controllable by changes in land management or process practices percolation -the movement of water through the pores or spaces of sub-surface soil layers perpendicular -at a right angle to a given line or plane precipitation -a deposit on the earth of rain , mist , hail, sleet, or snow redds -the spawning grounds or nests of various fishes riffles -a shallow extending across a streambed and causing broken water spawning -the production or deposit of eggs by an aquatic organism topography -the art or practice of graphic representa- tion on maps or charts of the natural and man-made features of a region in a way that shows their relative positions and elevations transpiration -the direct transfer of water from the leaves of living plants to the atmosphere watershed -the land area from which water drains toward a common body of water in a natural basin vector -a quantity that has magnitude and direction, represented by a direct line segment whose length represents the magnitude and whose orientation represents the direction We are not victims of the world we see, rather we are victims of how we see the world. The very quality of your life depends on your attitude, and attitude is al- ways a choice. -Rachelle Breslow Watershed Owner's Streamwalk Guide The Streamwalk Guide is designed to help people interested in water quality learn more about their local streams and how human use of the water and surrounding land affects that quality. Your Streamwalk Leader will cover the items in this guide before you head out to look at your stream. The guide is intended to reinforce what you hear during Streamwalk training, to be a companion on the walk , and for your review after you have completed your observations. And you can use the guide to share what you 've learned with friends or neighbors . The goals of conducting the Streamwalk are to: • educate people about the relationship between streams and watersheds, • educate people about the activities in a water- shed that affect water quality, • encourage people to get involved in local efforts to protect water quality, • interest people in volunteering to collect data on water quality in their own areas, and • have fun learning about water quality. You will learn about current water quality issues, how to read a topographic map, how to map your watershed, how land use affects water quality, and what signs to look for in your stream that can alert you to water quality problems. What you do with the information you learn is limited only by your imagination. The things you see today might lead to all kinds of activities, like creek cleanups, tree plant- ing, storm drain stenciling projects, renovation of empty lots, or development of a nature trail, just to name a few. It's your water. Additional Notes: Additional Notes: Water and Water Quality We all know how important water is to our daily existence -we must have good drinking water simply to survive. But we also use it in many other ways which we may take for granted, like cooking, bathing , cleaning our houses and cars, fishing, swimming, boating, and countless others. Govern- ment regulation seeks to preserve water quality for all of these uses. But regulation alone is not enough. According to the Environmental Protec- tion Agency {EPA), 80 percent of the pollution in our water today comes from pollutants washed off the land and into nearby streams whenever it rains. This form of pollution is called nonpoint source pollution because it comes from many different places, rather than a single, identifiable discharge {point source pollution). By learning how our activities affect the water and how we can change our habits to protect it, each of us can make an important contribution to protecting this most valuable of resources . When water quality professionals refer to water quality, they are talking about the chemical, physical, and biological characteristics of water which make it suitable or unsuitable for the uses that people wish to make of it . The same water may be acceptable for one purpose, but not for another. Some things about water quality are evident from simple observation, and those are the things you 'll be looking for on your Streamwalk. First, let's become familiar with the definition of a watershed. Watersheds The EPA defines a watershed as "a geographic area in which water, sediments, and dissolved materials drain into a common outlet." A watershed can be big or small, ranging in size from a neighborhood and its nearby creek to the very large land area that drains into a coastal bay. The topography, or "lay," of the land determines the boundaries of a particular watershed. A ridge or other elevated land area separates one watershed from another. For example, in the United States, all land west of the Continental Divide drains to the Pacific, and all land to the east drains to the Atlantic. Each of these two watersheds is composed of numerous smaller watersheds. In your Streamwalk, you will be concerned with the watershed immediately surrounding your stream. When it rains, water flows overland and through soils, recharging underground water supplies and draining into nearby streams (see illustration). Everything that happens in the watershed can contribute to what ends up in the stream. Impuri- ties such as sediments, oil and grease, and bacteria are picked up in the water flow and deposited in the nearby stream. The concentration of these impurities, and the speed and amount of water flowing to the stream, affect the stream's water quality. In natural areas, such as forests, the veg- etation slows the flow of water over the land, filtering some of the impurities and decreasing erosion. In these areas as much as half of the rainfall is absorbed into the ground, becoming ground water. In urban areas, many vegetated surfaces are replaced with impervious cover, like a parking lot or a rooftop, which does not allow the Additional Notes: Additional Notes: water to soak into the ground, causing it to flow more swiftly downhill toward the stream. This in- creased water flow can lead to flooding and erosion, and allows more pollutants to reach the water. In many urban areas, less than one third of the rainfall is absorbed into the ground. The Hydrologic Cycle The hydrologic cycle is the natural pathway that water foUows as it moves through the ecosphere in its various forms. Water moves into the atmosphere from the earths swface through evaporation or transpiration. Water vapor condenses in the atmosphere, and retums to the swface in the form of precipitation. When precipitation falls to the ground, it is absorbed into the ground, or runs over or through the earth into nearby streams, lakes, or under- ground water supplies. Heat energy from the sun and gravity supply the energy that keeps the water moving from one stage to another in the cycle. The hydrologic cycle has neither beginning nor end,· it is the constant recycling of the earths water supply. Land Use and Nonpoint Source Pollution Obviously, human activities affect what happens to the water. Contaminants resulting from our use of the land can run off into nearby streams and become nonpoint source (NPS) pollution in the water. NPS pollution comes from a variety of sources. Some of those sources and their effects are : •excess fertilizers, herbicides, and insecticidesfrom residential areas, which can cause excessive growth of aquatic vegetation, which in turn can lead to a depletion of oxygen necessary for other aquatic life; • oil, grease, and other toxic chemicals from roadways and parking lots , or from household chemicals that have been improperly disposed of, which can contaminate the food chain with long-term effects on wildlife and human health ; • sediment from erosion caused by poorly managed lots or construction sites , which can smother aquatic life and increase the costs of operating water supply reservoirs ; and • bacteria and nutrients from pets or faulty septic systems , which can also lead to excessive aquatic growth and depletion of oxygen in the water. During your Streamwalk, you will learn to recognize some of the warning signs of stream degradation. Some of the things to look for are: • Water clarity -Does the water appear green or foamy? Is there a multicolored oily sheen? The green color may indicate an overabundance of algae. Foam usually indicates excess detergents. A multi-colored sheen can indicate oil or grease. Additional Notes: • Odor -Do you detect any strange smells, like the odor of rotten eggs or the smell of chlorine? A rotten egg smell (sulfur) usually indicates sewage pollution. A musky odor can indicate the prese nce of untreated sewage or excessive algal growth and decay. The smell of chlorine may indicate excessive chlorination of treated waste water. A bitter or acrid odor may indicate industrial wastes. • Erosion -Do you see any undercut banks or gullies? Does the water appear cloudy? These signs show the effects of sediments from erosion. • Aquatic and plant life -Do you see fish, insects, and healthy plants? Do you see pools where fish can live? Do you see a great deal of algae? These signs tell you whether the water is healthy enough to support aquatic life . Healthy vegetation along the stream bank helps filter water entering the stream. • Debris -What kinds of trash do you see - small cups or cans , tires , cars, couches , machines? What kinds of land use do you see in or near the stream which could be contributing this trash or litter? Some possible sources are construction sites , parking lots , roads or bridges , residential areas, commercial and industrial sites, or recreational uses . Getting Prepared for Your Stream walk Before you go out, you must first choose a stream to look at, decide how you will get there, make a map of the stream's watershed, and assemble your tools. Choosing Your Stream When choosing your stream, you need to consider access. How will you get to the stream? If you must cross private property to get to the stream, be sure to get permission from the landowner first. You will also want to consider the terrain -is it gentle enough for your safety and your level of fitness? Will you run into any insurmountable obstacles, like steep waterfalls? Choose a stream that you are inter- ested in, perhaps one in your own neighborhood. Assembling Your Tools You don't really need a lot of tools to do your Streamwalk, but here's a list of things that will come in handy: • Copies of the section of the topo map that shows your Streamwalk area • Comfortable rubber boots, or two pairs of comfortable shoes • Snag or thorn-proof clothing • Work gloves ~~ • Insect repellent and sunscreen ~ :•, • Your Streamwalk Guide and data forms • Clipboard or portfolio Congratulations! You've completed your Streamwalk, and taken an important step toward improving your environ- ment, because the first step in improving water quality is to link people to their streams and watersheds. YOU can make a big difference -be part of the solution to water pollution. In nature there is neither praise nor blame, but there are consequences. A Few Final Notes on Collecting Data Don't be afraid to take too many photos or draw too many pictures -these will help you remem- ber what you saw, and will also help water qual- ity professionals respond to any areas of concern that you discover. Write detailed descriptions of what you see. If you decide to start regular monitoring of your stream, you'll want to go at least four times a year, at each of the different seasons, and the descriptions and pictures will help you keep track of how the stream changes over time. While you are collecting the data, make sure that you are part of the solution , not part of the problem. Remember not to leave any trash be- hind. Try to avoid walking in the stream or disturbing the natural vegetation next to the stream. If you do have to walk in the stream, be alert for spawning areas, and stay out of them. Spawning areas , or redds , will look like a round or elliptical area of clean gravel about 1-3 feet long. These redds are especially active in the spring. As for the data itself, record only what you see, not what you have seen in the past. There are no right or wrong answers. So relax, and have fun. • Pencils and extra blank paper • Tape measure • Camera and film in a waterproof bag If you won 't be close to home or to a residential area , you may also want to carry a change of clothes, a flashlight , a water bottle or canteen, and a small first aid kit. Mapping Your Watershed This will help you determine which part of your stream you wish to monitor and how you will gain access. The best map to use is a topographic map for your area. If you get a U.S. Geographical Survey (USGS) map , it will show elevations, waterways, buildings and roads. These are usually available at local sporting goods stores, for about $4.00. Find your stream on the topo map, and mark the downstream outlet of your watershed, or the fur - thest point downstream in which you are interested. Mark the flow direction of your stream and other water bodies on the map. To determine whether one stream is flowing to or from another, compare the elevation of the land features around the streams. Then look for the contour lines that indicate the highest points around the stream. Connect these points, following ridges and crossing slopes at right angles to contour lines. This line forms the water- shed boundaries. Reading a Topographical Map Topographical maps show land features with standard symbols and colors. The works of man - schools, houses , roads -are in black. Unimproved roads are shown by double broken lines, improved roads by solid double lines. Water features -streams, rivers, bays, and oceans -are in blue. Green is used to indicate wooded areas, white is used for clearings, and pink or yellow is used to show urbanized or built- up areas. The shape and elevation of the land surface are shown by contour lines, in brown. Figures 1 and 2 illustrate contour lines for ridges and valleys. I'\ l(f ltJ M.1$D The LJ..shape I I I t . points to lower I I 11 .. A~ afevation I I f / \!P-..__ I l ... " ,,..-' . -I "_., ,.....--... \ _. ..,....,,. ........ ~i"I ..... __ ..... RIDGE SIGNARJRE Figure I VAll.EV SIGNARJRE Figure2 Contour lines are abstract devices for representing the third dimension on a two-dimensional map. There are key rules which govern their use on topo- graphical maps. • Contours always occur Jn pairs. Contours that indicate a ridge will always close; there- seaweed) can point to a problem such as too much fertilizer entering the water from land areas upstream. Note any colors, odors, foams, sheens, algae, or scum: 16. Activities in the stream Are there recreational activities in the stream? Do livestock have unrestricted access to the stream? Do you see obvious paths that animals or people use to reach the stream? Note any activities in the stream: 1 7. Discharging pipes Are there pipes with visible openings dumping fluids or water into the stream? Note them, even if you cannot tell what they are discharging or where they originate. Do you see other pipes or ditches entering the stream that are not discharg- ing? Make a note of their locations. D Actively discharging pipes D Ditches Notes: D Other pipes 13 . Fish and insects Do you see any fish or insects? If you know the names of the fish or insects, make a note of them. Mark only what you see, not what you suspect. Fish Dyes D no Notes: Insects Dyes D no ~~~~~~~~~~~~~~~~~~- 14. Adjacent land uses As discussed, adjacent land use has a big impact on the quality of the stream. Indicate what types of land use you see. D Residential D Roads/Bridges D Construction D Agricultural D Recreational D Other -describe below Other: 15 . Conditions • Color and Odor -A rotten-egg smell can indi- cate the presence of sewage leaks, especially if it is accompanied by excessive algal growth. • Foam or Sheen -Foam or sheen can be a natu- ral occurrence or evidence of a problem. For example, an iridescent sheen can come from rotting leaves or from some upstream pollutant. If you are not sure of the source, simply note what you observe. •Algae or scum floating or covering rocks- Evidence of scum or algae (very tiny plants that can color the water green or can resemble fore, on a map, if you cross a 50-foot contour mov- ing uphill, you must cross another 50-foot contour when making the transition to a downhill direction, as shown in Figure 3. • Contours never cross. Contour lines never cross unless an overhanging ledge is indicated. The situa- tion shown in Figure 4 may occur on a topographical map, but if it should occur on a site plan, it is sus- pect. Figure4 • Contours have equal vertical separation. Contour lines always indicate equal change in vertical mea- sure. In some unusual cases, maps are made with intermediate contours, but these are carefully marked and should be noted in the map legend. Figure 5 illustrates this equal separation. Figures • All contour lines close on themselves. All contour lines will close someplace on the face of the earth, even though they may not appear to on an indi- vidual map. Figure 6 shows this law; the 10-, 11-, and 12-foot contours appear not to close on the map, when in fact they do close in an area that is not included on the map. Figure6 • Contours do not merge, or split. Since contours must always occur in pairs, and always ultimately close, they cannot merge as shown at the top of Figure 7. Contours must always be continuous and close on themselves_ -... ---:~----::.-___ zo ?17----,,,.,... --cia_------~-__ -z4 "-s----<-----~---zo " -----,,,.,, zo--:-_____ --__ .-WWI.JG- -------_-:_-:_-----~ fO----,......--) ---_Zif "~:...:::..:_ (~-:.,-:::==~: 'i':I ---/ p· 7 -zo---------iz1&1-1T igure • The steepest slope is a line perpendicular to the contour. This principle is illustrated in Figure 8. Water will always flow along the line of steepest slope. The steepest slope is indicated by vector a; vector b shows a gentler slope. Figure 8 9. Overhead canopy This is the amount of vegetation that overhangs the stream. It offers protection and refuge areas for fish and other organisms, shading the stream and keeping the water cool , and providing launching areas for insects that might fall into the river. Estimate how much of the river is overhung by grasses, shrubs, and trees. Measurements in this category may vary by season. 0 0-25 % 0 25 -50 % 0 50 -75 % 0 75 -100% 10. Artificial bank protection Note any modifications you see to the banks , such as retaining walls built of concrete or rock. Esti- mate the percentage of modification. 0 0-25 % 0 25 -50 % 0 50-75 % 0 75 -100% 11. Logs or woody debris and organic debris Logs and woody debris can slow or divert water to provide important fish habitat such as pools and hiding places. The presence of organic matter in the stream can be both good and bad. Dumped grass clippings would not be good for the stream health. Naturally falling leaves and twigs can be beneficial. 0 None 0 Occasional 0 Common 12. Trash & floatables This category applies to man-made debris in the stream. Note the type of debris you observe . 0 None 0 Occasional 0 Common 7 . Width of vegetative buff er around the stream The natural vegetated area on either side of the stream, also called the riparian area, forms the natural habitat, along with the stream itself. This vegetation shades the water, holds the soil in place, adds nutrients to the stream in the form of leaves, and provides habitat for streamside wildlife. Left -looking downstream (ft) ------- Right -looking downstream (ft) ______ _ 8. Streamside vegetation Streamside vegetation plays an important role in molding the stream environment. On your data sheet, mark all the categories which apply. Conifer. A cone bearing, evergreen tree or shrub, such as a pine tree. Deciduous. A tree which sheds its foliage at the end of the growing season. Small trees or shrubs. Conifers or deciduous trees less than 20 feet tall. Grasses. Any of numerous plants with narrow leaves, jointed stems, and spikes or clusters of inconspicuous flowers. none/ sparse occasional common Conifers D D D Deciduous D D D Shrubs D D D Grasses D D D Take a Streamwalk Safety First The first rule of safety is to always work with some- one else. Remember that Texas has many plant and animal species that may be troublesome to humans, and be on the lookout for poison ivy, poison oak, nettles, snakes, ticks, and irate dogs. Always assume that the water is not safe to drink. Do not walk on unstable banks; this is unsafe for you, and could speed erosion. Try not to walk in the stream. When you do have to cross the stream, look for shallow water, and remember that stream beds can be very uneven and slippery. Never attempt to cross streams that are swift or above the knee in depth. Be careful around streamside vegetation. These plants provide habitat for many aquatic animals -don't step on their homes. The Streamwalk Now you're ready. You have the knowledge and the equipment. So what are you looking for? 1. Weather The amount of recent rainfall can affect flow, clar- ity, and amount of water in the stream, so it is important to know how long ago it rained and how much rain fell at that time. Rainfall reports are available in the local newspaper, or you can call your local weather service. Rainfall amount, inches, last 24 hrs ------ 2. Stream water measurements Describe the stream at your site in terms of width and depth. Indicate if your response is measured or estimated. It is best to estimate if taking mea- surements will disturb habitat or stream banks, or require that you wade in deep water. Never at- tempt to cross the stream in high flows -your safety comes first. Depth (ft) ---- Width (ft) ---- D measured D estimated D measured D estimated 3. Stream channel & cross-section shape Describe the shape of the stream using the figures provided on your data sheet. If you are unable to see the shape of the bottom and banks, select the figure that seems closest to what you observe. You can base your estimate on the flow of water --the slower the water in the middle of the stream, the flatter the bottom. D o~o M 4. Water clarity How clear is the water? Data on water clarity is used to determine if sediment pollution is present. Cloudy water can be the result of natural sedimen- tation or of land use in the surrounding watershed. Are stream banks eroded? Too much sediment can adversely affect habitat conditions for fish and macroinvertebrates. D Clear D Cloudy 5. Water flow: pools and riffles The variety of flow in relation to depth creates habitat to support fish and invertebrate life. This variety can be seen in the form of pools and riffles. Pools are areas that are deeper than adjacent water, and supply feeding, resting, and spawning areas for fish. Pools are slow, deep water. Riffles and runs are areas where water flow is faster than in adjacent areas. Riffles are shallow, fast water; runs are deep, fast water. D Pools and riffles or runs present 6. Stream bottom Indicate the most common type of material on the stream bottom. Silt/clay/mud. This substrate has a sticky, cohesive feeling. The particles are fine. The spaces between the particles hold a lot of water, making the sedi- ments behave like ooze. Sand. Sand is made up of tiny particles of rock. It feels soft underfoot. Gravel. A gravel stream bottom is made up of rock particles ranging from quarter-inch pebbles to rocks of about 2 inches. Cobbles. The majority of rocks on this type of stream bottom are between 2 and 10 inches. The average size is about that of a grapefruit. Boulders. Most of the rocks on the bottom will be large, greater than 10 inches in diameter. Bedrock This kind of stream bottom is solid rock. D Silt/clay/mud D Gravel D Boulders D Sand D Cobbles D Bedrock Did You Know? ... that USDA has a "N ational Conservation Buffer Initiative" that · uses grasses , forbs, and trees to protect and enhance all the resources on a farm? ... that the potential for water to be contaminated by nonpoint source pollution (whethe r from urban housing development, industrial parks , agricultural fields) can be reduced by buffer strips and riparian areas between the pollution source and the water course? ... that riparian areas depend on a dynamic equilibrium between erosion and deposition of sediment in the aquatic system and these processes are profoundly influenced by the condition and management of the surrounding watershed? ... that riparian areas are sensitive to natural and construction disturbances and flood impacts, but are resilient and can recover rapidly when properly managed? ... that an estimated one-third of U.S. riparian areas border water courses that pass through agricultural lands? ... that riparian areas support economic activities that take place far beyond the bounds of the riparian zone (fo r example, North American salmon fishery)? ... that Iowa State University research found that 10-foot-wide buffer strips remove 70 percent of the upland sediment from runoff, and that 48 percent of the herbicide runoff from ra in is filtered out on relatively small slopes and small areas? Riparian Area Trends and Disruptions L and use practices have directly af- fected the quality and quantity of riparian areas in the United States. Es- timates of riparian acreage vary, and there has been no systematic effort to characterize their extent and distribu- tion. One estimate suggests that there may have been as much as 121 million acres of riparian habitat in the 48 States. Today about one-third of that amount exists across the United States and these remaining riparian areas tend to be fragmented and unevenly distributed , which has a decremental effect on wildlife sustainability (Swift, 1984). (For further discussion on re- gional distinctions in riparian areas, see Issue Brief 12 , Regional Distinc- tions and Disturbances.) Nevertheless, management opportunities exist to re- store , maintain, and enhance riparian areas to increase the goods and ser- vices provided by these ecosystems. Riparian areas have been disrupted by several forms of natural and human management. These disturbances have modified the natural hydrologic perfor- mance of a watershed and associated riparian areas. Natural erosion and deposition processes in the watersh ed shape the riparian area and determine its compo- sition, structure , and productivity. Disturbances caused by flooding, fire, wind , and wildlife-induced alterations to water ecosystems (buffalo, elk, bea- ver dams, wildlife trampling of streambanks and overgrazing) are natural effects on the riparian zone. Natural processes such as flooding or significant amounts of rain are dy- namic natural occurrences nee ded to create or maintain fish habitat and bal- ance in the riparian area. Water management activities sig- nificantly affect the riparian community. Dams and other flood control or water management struc- tures (levees, stream channelization , impoundments) may be the most in- fluential as they can alter the hydrology significantly. Changes in the natural patterns of flooding re- duce sediment inflows necessary to replenish shorelines, eliminate back-channel habitat for fish species, and alter the ability of the native plant communities to compete effec- tively with invasive or nonnative species that altered the hydrology. In the Southwest, flood control struc- tures and upstream impoundments may be responsible for transforming the native mesquite-cottonwood-wil- low communities into mesquite- saltcedar and for reducing the ecosystem's richness and complexity. Saltcedar, a nonnative invader, is a phreatophyte (water consuming) plant that will dry up a small stream or underground fed body of water Riparian areas provide food, water, and cover for wildlife and domesticated animals, pro- vide s hade and food, and reduce water temperature for aquatic ecosystems . They remove sedi- ment from the water flowing through them, act as sponges to hold water in streambanks to provide a higher water table and a more stable streamflow, protect streambanks and reduce erosion, and help dissipate the energy of floodwater. (For more information on values and func- tions of riparian areas, see Issue Brief 11 , RiparianAreas: Unique- ness, Puncti.orls , and Values.) NRCS/RCA Issue Brief 13 and make it impossible for oth er fa- vorable and productive plants to become established. The expansion of the saltcedar foothold alo ng the lower Co lorado River correlates di- r ectly with major dam construction on the river in the early to mid-1900 's. Clearing veg etation and land conversion for housing , industrial , commercial, and road construction have been the most common distur- bances of riparian areas over the past 50 years (fig. 1). In creased sedimen- tation from land clearing is detri- mental to water quality and can smother aquatic and riparian vegeta- Riparian Areas Management tion . Land conversion can narrow the riparian zone ; in troduce disturbances from traffic (including automobile ex- haust); and alter the microclimate. Road and railroad construction may, in fact , have more criti cal and lo nger lasting impacts on a rip arian area than any other type of disturbance . Much of the Nation's ground transpor- tation network has been developed along the historical routes of naviga- tion streams and rivers . Agricultur e and timber opera- tions can affect the integrity of riparian areas directly and indirectly. Logging or the pulling of farm equip- December 1997 drain the water table that previously had supported riparian vegetation. Water diversion to support irrigated agriculture and other industries may reduce streamflow and its reliability, depriving riparian areas of n eeded moisture . In many of the Nation's riv- ers us ed for irrigation, the return water is degraded by agricultural contaminants and sediment: irrigation-induced salinity, agricul- tural ch emicals , and animal waste . Restoring and Managing Riparian Areas ment to the stream edge Figure 1. Land conve rsion for housing, roads, and com-removes vegetation- mercia/ uses are common disturba nces in ripa rian areas contributing excessive Most riparian area conservation an d production management practices are able to r estor e riparian areas for multiple benefits that are long-term an d productive. They may be man- aged as buffers to protect the adjacent watercourse , maintain the hydrologic and ecologi cal integrity of streambanks a nd channels, and pro- vide for productive agriculture as well as urban , industrial, and recre- ation industries. Numerous manage- ment practices exist that blend co n- servation and land use to maintain riparian a r eas . These management practices can be applied to the water- course, the riparian area itself, or the upland area, or all t hree , that can be linked by the drainage basin (fig. 2). 2 Riparian habitat lost I-- - - - -- -~ I I Upland Zone Conserv ation tillage Crop rotati on Pestic ide m anagement (IPM) Buff e r strips N utr ie nt m a nagement Set-backs and zoning I I I I I I I I I Riparian Zone Enric hme nt plantings Strea mbank stab ili zation Bu ffer strips sediment to the system, and reducing water infil- tration and groundwater recharge . Liv estock graz- ing, using improved practices, can reduce the denuding of rip arian veg- etation, compacting of soils , widening or incis- ing of stream chann els , and changing of the streambank structure. Excessive channel inci- sion can intercept and Water Course M ai ntai n instream flow Manage da ms a nd div ersions to approxim ate natu ral flow vari ati on Enha nce aquatic habitat (long, we irs) Riparian Zone Fe nci ng to manage liv estock access Enrichm ent pl a nti ng s Strea mb ank stabi lization Buffer strip s Upland Zone Grazing manageme nt Buffer strip s Nutrie nt managemen t Set-backs and zoning NRCS/RCA Issue Brief 13 Ri parian Areas Management December 1997 Implications for Management The eight riparian area e xamples, located throughout the United States , illustrate how these conservation and production management practices achieve both environmental and economic benefits . All of the examples are based on actual p h otographs. Image a is a photograph of an existing riparian area. Images b or c , or both, are ei- ther photographs or computer-based simulations of conservation and production management practices applied to a riparian area, resulting in environmental and economic benefits. NRCS uses this computer simulation tech- nology to provide landowners and communities with better conservation planning and technical assistance . Rangeland Productivity and Wildlife Habitat Restoration Conservatio n and p roduction goal s: Restore riparian area productivity and habitat diversity to improve livestock production, wildlife numbers , and wa- ter availability as well as reduce erosion and sediment. B efore con servation : Image I a (Sep- tember 1976). Overgrazing has denuded the riparian vegetation , wid- ened the stream channel, cut down the streambank that induced erosion, and decreased habitat diversity, wildlife populations , and water availability. Conservation improvements: Image lb (August 1985 ). Controlled access fencing was installed to implement a prescribed grazing management system that allows properly timed and con- trolled access of livestock to the riparian area. Environmental and economic hen-· efits: Nine years later the stream channel has deepened, water quantity has increased , length of flow has in- creased, and a more diverse riparian vegetation has been re-established, causing wildlife populations (deer, elk , birds, and fish) to rebound and nearby rangeland vegetation to improve . Live- sto ck carrying capacity remained constant over the 9 years. Source: USDA , Forest Service photo- graphs of U.S . Bureau of Land Management, Texas Creek , Colorado. Image 1a Image 1b 3 NRCS/RCA Issue Brief 13 R iparian Areas Management _ Riparian Streambank Restoration Conservation and production goals: Restore rip a ri an area productivity and dive rsity to improve wildlife h a bitat a nd population , reduce streambank d e- terio ration and erosion , and maintain livestock production . Before conservati o n : Image 2a. Ranch operations fed 400 head of live - stock in a 200-to 3 00-acr e riparian pasture a long th e East Fork Big Spring Cr ee k , Mon tana, from No ve mber to May. Th e c r eek provided the only so urce of stockwater ; streambank trampling , compaction , and eros ion were severe. Conservation impr ovements: Image 2b. Federal and State grants fund ed the fencing off of the c reek and the drilling of a well n earby as a source for stockwater as an a lte rnative to con- tro ll e d access to the c r eek. Along severely eroded o uter bends of the cr eek, 4 0-to 50-foot ponderosa pine trees were cabled to stabilize eros ion ; 1 ,5 00 willow cu ttings w er e obtained from n earby stand s and planted along th e eroded sectio ns of the creek. Environmental a nd econ omi c b e n - efits: After 5 years, the cable d ponderosa pine tree area was filled with sedim ent and healthy h e rbaceous. cover. Veg etativ e growth improve d wa- te r quality, which also contributes to · wildlife species diversity. The esth etic an d associated stewardship values im- prove d significantly. Al so, it was no longer n ecessary to c hop ice fo r a so urce of stockwater in the winte r, or to retrieve liv estock that may fall into the ice-covered c r eek. Source: Ripari a n Grazing Successes on Mo ntan a Ran c h es, NR CS-befo re and after photographs . 4 lmage2a Image 2b December 1997 NRCS/RCA Issue Brief 13 Riparian Areas Management Integrating Diversity in Livestock Feeding Habitats Conservation and production goals: Restore streambank integrity, improve habitat in unmanaged area between feedlot and stream, filter animal wastes, and contin ue livestock feeding operations at current levels . Before conservation: Image 3a. Feed- lot waste entering the stream had potential for degrading water quality, r educing wildlife and fish h a bitat diver- s ity, increasing streambank erosion , and harboring undesirable weeds in ungrazed areas. Conservation improvements: Image 3b. A simple pond was constructed that inter cepts and biologically filters feed- lot runoff; streambank grass was established that stabilized the bank and r e duced e ro s ion. Seeding of native grasses and trees improved habitat and species div ersity a long with the streambank vegetation. Grazing of hay can be used as a management tool to maintain pla nt vigor and in crease nutri- ent uptake. Environment and economic ben- efits: Water quality is improve d as wetlands recycl e feedlot nutrie nts. Streambank erosion is reduced. Tree habitat, native flowers and grasses, and wetlands increase nesting opportuni-. ties of songbirds and other species ; air c urrents from trees dissipate odors , and a cooler mi cro climate is the result of trees, water, and a n abundance of grasses. F ee dlo t production and man- agement are not changed . Source: NR CS photograph, Papillion, Nebraska Feedl ot; a nd image process- ing. Image 3a Image 3b December 1997 5 NRCS/RCA Issue Brief 13 Riparian Areas Management Woodland, Riparian Forest, and Agriculture Conservation and p rod uction goals: Create larger riparian forested buffer areas (corridors/blocks) and woodland for species diversity; integrate with hayland and cropland production; and in cr ease pastureland production. B efore con servation: Image 4a. Habi- tat loss , degradation , and fragmentation from agricultural devel- opment. Uncontrolled cattle access to riparian zone caused streambank ero- sion and in cr eased runoff. All contri buted to degradation of water quality and loss of biodiversity. Conservatio n improvem ents: Image 4 b. Prescribed grazing management system t hat consists of properly timed and controlled access of livestock to the riparian a r eas improves vegetative growth in riparian areas and reduces streambank erosion. Rotational grazing increases forage production. Establish- ment of larger forested blo c ks for habitat on farmland increases species diversity. E n vironm ent and e conomi c b e n- efits: Prescribed grazing management is designed to increase both wildlife species diversity and grazing potential. This management also improved water quality and aquatic habitat through controlling stream access. Larger for- ested areas and forested riparian areas reduce d stream and air temperatures, and they increased wildlife biodiversity and species mi gration, woodland pro- duction, a nd r ecreation benefits from bird-watching , hunting , and fishing. Th e conserv ation production goal is to diversify income opportunities from the production of livesto ck , hay, crop, forests , and wildlife. Source: NRCS photo, Virginia; and im- age processing. 6 Image 4a Image 4b Dece m ber 1997 .r NRCS/RCA Issue Brief 13 Riparian Areas Management Riparian Areas and Intensive Agriculture Conservation and production goals: Establish a riparian zone/corri- dor to filter nutrient and pesticide run off, catch sediment, and provide habitat for terrestrial and aquatic spe- cies . Maintain an intensive agricultural production system while improving the esthetic and steward- s hip values of the landowner. B efore conservation: Im age 5a. Farm operations cropping adjacent to stream edge resulted in nutrients, pes- ticides , and sediment from the field and streambank erosion directly en- tering the stream . Lack of a riparian zone significantly affects habitat di- versity. Conservation improvements: Im- age 5b. Establishing a streambank grassed buffer (native and other) fil- ters nutrients and other agricultural elements , reduces streambank ero- sion, and provides habitat diversity. Image 5c. A forested buffer better fil- ters agric ultural nutrient runoff, holds sediment, in creases water infiltration, and provides additional species habi- tat. Conservation goal is to provide for a diversity of income from trees, wildlife, and agriculture. Environmental and economic b e n - efits: Water quality is improved by filtering and up take of nutrients, sedi- ment, and pesticides by the riparian zone. Erosion is reduced by streambank stabilization. Habitat di- versity improvements include wildlife , ne sting opportunities, fishin g , bird- watching, hunting, and other recreational opportuniti es . Esthetic and stewardship values are realized by the landown er and t h e community. Additional crop yields of 20 percent result from adde d soil moisture from trapped snow. Also , the land place d in grass and forest buffers in creases ground water supplies . Source: NRCS photo, Midwest ; and im age processing. Image Sa Image Sb Image Sc December 1997 7 NRCS/RCA Issue Brief 13 Riparian Areas Management Pasture Grazing and Riparian Restoration Conservation and production goals: Restore water's edge, provide for h ealthy productive riparian areas, and maintain grazing land. Before conservation: Image 6a. Un- controll ed livestock access to water in ponds resulted in water 's edge (ponds , lakes, and streams) erosion and bank deterioration . Continuous livestock ac- cess to the water also caused a loss of riparian areas and dire ct runoff of nu- trients into the water body. Conservation improvements: Im age 6b. Prescribed grazing management system (rotations, season of use , length of use , timing) and fenc in g re- sult in water's edge bank restoration . Shrubs and trees can r estore them- selves in a prescribed grazing management system . Environmental and economic ben- efits: Healthy productive vegetation consisting of grasses a nd shrubs a long the water's edge reduces bank erosion and sedim entation, and filters app lied and naturally distributed nutrients from the runoff. Vegetation increases the bio di ve r sity fo r wildlife s h elter, food so urces, and nesting opportuni- ties. Prescribed grazing m a n agem ent provides t he potential for increased livestock production that is balanced · with land's productive capacity. Also, li vestock has access to much cleaner stoc kwater. Source: NRCS photographs, Vermont ; and image processing. 8 Image 6a Image 6b December 1997 NRCS/RCA Issue Brief 13 Riparian Areas Management December 1997 Rangeland, Cropland, Forested Riparian Riverine System Conservation and production goals: Restore forested riparian area in an e n- trenched riverine system that has adjacent terraces of productive range- land and cropland. B efore conservation: Image 7a. Ranch, crop, and woodland production removed substantial amounts of forests/wood- lands , which resulted in fragmentation of the riparian zones and losses of aquatic and terrestrial h abitat and diver- sity. Crop production erosion and nutrient runoff contributed to water quality degradation. Liv estock de nuded river terraces, trampled streambanks, and increased erosion and sedimenta- tion in the river. Conservation improvements: Image 7b. Prescribed grazing system (rota- tional grazing, timing and length of access to the ri ver, and seasonal use) re- stores rangeland production , reduces rangeland erosion, reduces terrace and riv erbank erosion, and minimizes tram- pling of riverbanks especially during vulnerable seasons. Forest establi s h- ment over several landowners ' lands restores larger forested corridors and blocks for habitat diversity. Forested ri- parian buffers filter and u se rangeland and cropland nutrient runoff and hold sediment. Environment and economic b e nefits: Water quality is improved by establish- ing riparian zones and controlling live stock 's access to the river; by fi lter- ing runoff of nutrients, pesticides, and sediment from cropland; and by reduc- ing livestock trampling of the riverbank. Prescribed grazing management r esults in reduced acres of barren river terraces and knolls/hills ; increased plant vigor, production, and diversity; and r e duced erosion. Wildlife habitat is more diverse , plentiful, and in larger blocks for corri- dor and migratory opportunities leading to more hunting and recreation opportu- nities (bird-watching, fishing, camping). Aquatic and fish habitat improves from reduced stream temperatures and better Image la Image lb organic food sources from the riparian zones. Woodland production in for- ested riparian areas partly offsets t h e lo sses of potential inc ome r ealized from decreased crop production; how- ever, easements or compensation fo r r etirement of hi ghly productive all uvi al floodplain cropland appear lik ely be- cause a major livestock feed source is eliminated. Sources: NRCS photograph , James River, SD; and image processing . 9 NRCS/RCA Issue Brief 13 Riparian Areas Management Bayou and Watershed Riparian Management Conservation and production goals: Stabilize natural barriers affected by forces of nature and humans to main- tain riparian areas and a productive aquatic fishery enterprise. B efore conservation: Image Sa. Boat traffic (recreation and industry) caused bank slumping and erosion that re- duced water quality; and receding waters from hurricane surges and high tide caused blowouts that result in losses in interior (landside) wetlands. Invasions of noxious exotic weeds such as chicken trees (Chinese tallow tree) reduced plant diversity, site resil- ience, and wildlife habitat. Conservation impro vements: Image Sb. A bank back slope is created against grade to divert water from run- ning down the channel's side s lope. Giant cutgrass is planted at the toe of the slope with coconut fiber mats used as an interim measure to reduce ero- sion and bank slumping. A pipe drop structure is installed downstream to prevent blowouts. E nvironmental and econ o mic b e n- efits: Land-side stabilization increases habitat diversity for wetland species. Water-side stabilization improves the water quality and habitat of the estuar- ies , fisheries , crabbing, and shrimp · industries . Plus , the water tables are higher, which benefits most of the aquatic species. Bank stabilization al- lows maintaining an interior wetland system that reduces hurricane surge damage , increases wildlife habitat, and prevents growth of noxious exotic spe- cies , while the cutgrass reduces erosion and wa ter energy from water traffic on the banks. Source : NRCS photographs , Bayou Queue De Tortue , LA . 10 Image Ba Image Sb December 1997 NRCS/RCA Issue Brief 13 Riparian Areas Management Partnerships for Managing Riparian Areas USDA provides technical and cost share assistance to promote manage- ment of riparian areas through several programs , including the Con- servation Reserve Program (CRP), the Wetland Res e rve Program (WRP), and the Stewardship Incentive Pro- gram (SIP). Other Federal and State agencies, as well as private sector groups, are also involved in efforts to co nserve and restore riparian areas. The American Forestry and Paper As- sociation, with 400 corporate members accounting for 84 percent of paper production, 50 percent of solid wood production , and 90 per- cent of industrial forest land use in the United States, has adopted Sus- tainable Forestry Initiative Principles and Guidelines . Members agree to es- tablish riparian protection for all perennial streams and lakes and con- tribute funding for water quality research. Size limitations are in place for clear-cutting. Clear-cutting adja- cent areas is prohibited until vegetation begins to re-emerge. The Wildlife Habitat Council, composed of 100 corporations that are collabo- ratively managing 340,000 acres, is enhancing riparian areas and wet- lands through the Waterways for Wildlife program to promote wildlife habitat on corporate lands . Some projects are employing natural assistance in improving riparian habi- tat. For example , the Wood River Resource Conservation and Develop- ment (RC&D) area in Idaho is releasing beavers at appropriate riv- erine sites to manage erosion and improve the extent and quality of ri- parian vegetation. In the RC&D area, the downcutting action of the streams had altered the native grass-sedge ri- parian vegetation to a sagebrush- dominated community. Beaver dams can raise the water table and change the composition of the riparian com- munity in beneficial ways ; where beavers are active, the vegetation has returned to a lush grass-sedge com- munity capable of produc ing greater livestock and wildlife benefits. Multiple Benefits Managing riparian areas can yield a variety of benefits for the landowner and the public at large. Healthy ripar- ian areas are reservoirs of biological diversity that reduce risks to water quality and can support certain eco- nomic activities, such as bird-watching, hunting, fishing , boat- ing, and grazing. Riparian areas contain specialized plant and animal communities and provide essential wildlife habitat and biological corridors for migrations. The complexity of the riparian veg- etation has direct implications for species diversity. For example , breeding bird populations in South- western riparian habitats are larger than in any of the surrounding sparse vegetation of upland habitat. Other species, such as frogs, lizards , turtles, and salamanders, are largely restricted to riparian habitats . Healthy riparian zones, in the North- west and elsewhere, also improve the conditions of the associated aquatic ecosystem, promoting development of critical habitat for many important native fish species (Atlantic salmon, coho, chinook, sockeye, native brook trout). Riparian areas can reduce the poten- tial adverse impacts of upland development on the quality of the aquatic ecosystem. A healthy riparian zone can act as a buffer, trapping sediments and taking up nutrients, and transforming or sequestering chemicals contained in runoff. The stabilizing influence of the riparian zone also mediates the effects of high water p e riods on upland ecosystems, promoting infiltration of excess wa- ter and buffering the effects of flood water. Well-maintained riparian areas contribute to stabilizing water avail- ability for the riparian community and associated watercourses. The contributions of riparian areas to maintaining fish and wildlife popula- tions and healthy watercourses increase the opportunities for recre- ation and other economic activities. December 1997 The quality of hunting , fishing , boat- ing (canoeing, rafting), and bird-watching , among others, all de- pends in part on the health of the riparian system. For example , in the Northeast, the riparian zone is criti- cal overwintering habitat for deer, which is essential for maintaining the deer population that is so attractive to hunters. Other riparian-dependent economic activities do not even oc- cur in or near the riparian zone. For example, salmon on the west and east coasts of the United States de- pend on the aquatic habitat developed adjacent to riparian areas; however, these fish are caught in the open ocean far away from the ripar- ian area. Clearly, the influence of the riparian area and the importance of maintaining its health reach far be- yond the often narrow band that it occupies along watercourses. Did You Know? ... that North Carolina research s hows buffer stri ps or riparia n areas as na rr ow as 14 feet removed 80 percent of the sediment-bound nutri- ents a nd 50 percent in a 1-to 2-inch storm event , but their effectiveness is directly related to slope and area drained? ... that USDA , farm , and conserva- tion organizations are working together in the "National Conserva- tion Buffer Initiative" to use grasses , forb s, and trees to protect and en- hance all the resources on a farm so pro du cers ca n use their bes t land for food production and put marginal land to good use too? ... that recreation, if not properly managed , can promote soi l erosion and compaction, destroy natural plan t di versity and structure, and disturb wildlife in a riparian area? ... that riparian area health disrupted by nature or humans can recover rapid ly in the absence of additional human or natural disturbance? 11 NRCS/RCA Issue Brief 13 Riparian Areas Management December 1997 Suggested Readings Krueper, D.J. 1993. Effects ofland use practices on western riparian ecosystems. In Status and Management of Neotropi- cal Migratory Birds; Estes Park , Colorado, D.M. Finch and P.W. Stangel (eds.). U.S. Department of Agriculture , Forest Service General Tech Report RM-2 29 Meehan, WE., F.R . Swanson, and J .R. Sedell. 1977 . Influences of riparian vegetation on aquatic ecosystems with particular Krzysik , A.J . 1990. Biodiversity in riparian communities and watershed management, In Watershed Planning and Analysis in Action, R.E. Riggins , E .B. Jones, R. Singh, and P.A. Rechard (eds.). American Society of Civil Engineers, New York reference to salmonid fishes and their food supply. In Impor- tance , Preservation , and Managem ent of Riparian Habitat: A symposiwn; Tucson , Arizona, R.R. Johnson and D.A. Jon es, technical coordinators. U.S. Department of Agriculture , Forest Service General Technical Report RM-43 Montgomery, G.L. 1996. Riparian Areas : Reservoirs of Diversity. U.S. Department of Agriculture, Natural Reso urces Conservation Service, Working Paper No. 13 Lowrance, R., R. Leonard , and J . Sheridan. 1985 . Managing riparian ecosystems to co ntrol nonpoint source pollution. Journal of Soil and Water Conservation 40:87-91 Swift, B.L., 1984 . Statu s of Riparian Ecosystems in the United States. Water Resour ces Bulletin 20:223228 Thomas, J.W., C. Maser, and J.E. Rodlek. 1979. Riparian Zones: Manci , K.M. 1989 . Riparian Ecosyste m Creation and Resto ra- tion: A literature summary. Bio . Report 89 (20), U.S. Fish and Wildlife Service, Washington , DC Wildlife Habitats in Managed Forests . J.W. Thomas , technical editor. U.S. Department of Agriculture , Forest Service, Agricul- ture Handbook No . 533 The United States Department of Agriculture , through the Natural Resources Conservation Service, is preparing an environmental scan of the status, conditions, and trends of natural resources on America's non-Federal land, as required by the Soil and Water Resources Con- servation Act of 1977 (RCA), Public Law 95-192 . The appraisal will help guide the updating of the National Conservation Program, which di- rects USDA's natural resource conservation policies and pro- grams. Six other USDA agencies and 10 non-USDA agencies are full partners in this effort. Resource analysis and assessments are ongoing funcitons of the Natu- ral Resources Conservation Service. These assessments play an U.S. Department of Agriculture Natural Resources Con servation Service Natural Resources Inv entory Divi sio n P.O . Box 2890 Washington, DC 200 13 important role in how we keep the public and policymakers informed about emerging conservation and environmental issue , develop plans to conserve our natural resources, and design programs to provide na- tional leadership for the conser- vation of natural resources on America 's private lands. For addi- tional information about this or other NRCS resource assessments publications, contact the Director of the Resource Assessment and Stra- tegic Planning Division, USDA , Natural Resources Conservation Service, P.O . Box 2890, Washington, D.C .2001 3 For additional information on the NRCS cultural resources program, see our web.site at: http://www. nhq. nrcs . usda.gov/BCS/bcs .htm/ The United States Department of Ag- riculture (USDA) prohibits discrimi- nation in its programs on the basis of race, color, national origin, sex, reli- gion, age, disability, political beliefs, and marital or familial status. (Not all prohibited bases apply to all pro- grams.) Persons with disabilities who require alternate means for communi- cation of program information (Braille, large print, audiotape, etc.) should contact the USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint, write the Secre- tary of Agriculture , U.S. Department of Agriculture, Washington, DC , 20250, or call 1-800-245-6340 or (202) 720-1127 (TDD). USDA is an equal opportunity employer. Bu lk Rate Postage and Fees Pai d USDA-NR CS Permit No. G-267 S/1Eff!S Urban Subwate rsh ed Re sto r ation Manual Series .... --·-. . --~ - ; An Integrated Framework to Restore CENTER FOR ~!ilfE~S~[~ PROTECTION Manual 1 Small Urban Water ed Version 1.0 March 2004 page 7 page 19 page 33 page 38 page 38 page 39 page 39 page 43 page 44 page 45 page 50 Ph oto Acknowledgments USDA NRCS www.metrokc.go v Fairfax County, VA USDANRCS Eric Livings ton Roger Bann erman http ://in. water. usgs .govl ri ve rl USDANRCS Ft. Wor th Departm ent of Environm enta l Management www.cabq.gov/solidwastel g reenwst.html www.cityschoo ls .com/wa lkergrantlfsts /aboutprograrn.html Urban Subwatershed Restoration Manual No. 1 An Integrated Framework to Restore Small Urban Watersheds Version 1.0 Prepared by: Tom Schueler Center for Watershed Protection 8390 Main Street, 2nd Floor Ellicott City, MD 21043 www.cwp.org vvww .s torrn wate rc e nt er.ne t Prepared for: Office of Water Management U.S. Environmental Protection Agency Washington, D.C . March 2004 Copyright ©2004 by the Center for Watershed Protection. Material may be quoted provided credit is given. Printed in the United States of America on recycled paper. Foreword Urban watershed restoration has recently evolved into a growing and sophisticated practice. Two decades ago, the number of watershed restoration efforts could be counted on one hand ; now they number in the hundreds , with many more starting each year. With each new effort, more experience is gained, and the practice of restoring urban watersheds becomes ever more sophisticated and effective. We have learned many les so ns so far: that restoration is technically challenging, takes many years to complete, and requires broad partnerships to build the dozens or even hundreds of restoration practices needed for a small watershed. While urban watershed restoration is extremely challenging, it is also exceptionally rewarding to make a real difference in the quality of our home waters. This manual series was written for a broad audience with an interest in the methods and techniques to restore small urban watersheds, including planners, engineers, agency staff, watershed groups, and environmental consultants. The manuals distill our experience acquired in many different watershed restoration settings over the past two decades into a single package. During this time, we have sought to continuously refine, test and expand both our restoration practices and our subwatershed assessment tools. We sincerely hope that these manuals will help guide your efforts to successfully restore urban watersheds in your community. Urban Subwatershed Restoration Manual 1 Many thanks are extended to three external reviewers who carefully looked over drafts of this manusc ript. They include Derek Booth, University of Washington Center for Water and Watershed Research ; Bill Stack, City of Baltimore Department of Public Works; and Thomas Davenport, national nonpoint source expert for the U.S. Environmental Protection Agency. Much of this material was first presented at our inaugural Watershed Restoration Institute in September 2003, and the common sense feedback from institute participants is also keenly appreciated. Many Center staff contributed to the development of this manual, including Ted Brown, Anne Kitchell, Chris Swann, Karen Cappiella, Hye Yeong Kwon, Jennifer Zielinski, and Stephanie Sprinkle. The hard work, diligent research and practical insights of this outstanding team is reflected throughout the manual. In addition, Tiffany Wright and Heather Holland cannot be thanked enough for their able assistance in editing, proofing and producing this manual. Finally, we would like to acknowledge the patience, insights and flexibility of our EPA project officer, Robert Goo, during the two years it took to produce this manual series under a cooperative agreement with US EPA Office of Water CP- 82981501. Sincerely, Tom Schueler Director of Watershed Research and Practice Center for Watershed Protection Foreword Foreword ii Urban Subwatershed Restoration Manual 1 About the Restoration Manual Series This is the first of a series of 11 manuals on techniques to restore small urban watersheds. The entire series of manuals was written by the Center for Watershed Protection to organize the enormous amount of information needed to restore small urban watersheds into a format that can easily be accessed by watershed groups, municipal staff, environmental consultants and other users. The contents of the manuals are organized as follows. Manual 1 : An Integrated Framework to Restore Small Urban Watersheds The first manual introduces the basic concepts and techniques of urban watershed restoration , and sets forth the overall framework we use to evaluate subwatershed restoration potential. The manual emphasizes how past subwatershed alterations must be understood in order to set realistic expectations for future restoration. Toward this end, the manual presents a simple subwatershed classification system to define expected stream impacts and restoration potential. Next, the manual defines seven broad groups of restoration practices, and describes where to look in the subwatershed to implement them. The manual concludes by presenting a condensed summary of a planning approach to craft effective subwatershed restoration plans. Manual 2: Methods to Develop Restoration Plans for Small Urban Watersheds The second manual contains detailed guidance on how to put together an effective plan to restore urban subwatersheds. The manual outlines a practical, step-by-step approach to develop, adopt and implement a subwatershed plan in your community. Within each step, the Urban Subwatershed Restoration Manual 1 manual presents a variety of desktop analysis, field assessment, and stakeholder invol vement methods used to make critical restoration management dec isions. The next seven manuals provide specific guidance on how to identify, design, and construct the seven major groups of watershed restoration practices . Each of these "practice" manuals describes the range of techniques used to implement each practice, and provides detailed guidance on subwatershed assessment methods to find, evaluate and rank candidate sites. In addition, each manual provides extensive references and links to other useful resources and websites to design better restoration practices. The seven manuals are organized as follows. Manual 3: Storm Water Retrof it Practices The third manual focuses on storm water retrofit practices that can capture and treat storm water runoff before it is delivered to the stream. The manual describes both off-site storage and on-site retrofit techniques that can be used to remove storm water pollutants, minimize channel erosion, and help restore stream hydrology. The manual then presents guidance on how to assess retrofit potential at the subwatershed level, including methods to conduct a retrofit inventory, assess candidate sites, screen for priority projects, and evaluate their expected cumulative benefit. The manual concludes by offering tips on retrofit design , permitting, construction, and maintenance considerations in a series of 17 retrofit profile sheets. Foreword iii Foreword iv Manual 4: Stream Repair and Restoration Practices The fourth manual concentrates on practices used to enhance the appearance, stabi lity, structure, or function of urban streams . The m anual offers guidance on three broad approaches to urban stream restoration : stream cleanups , stream repairs, and more sophisticated comprehensive restoration designs. The ma nu al em ph asizes the powerful and relentless forces at work in urban streams, which must always be carefully evalu ated in r estoration and design . Next, the manual presents g uidance on ho w to set appropriate restoration goals for your stream, and how to c hoo se the best combination of stream restoration techniques to meet them. The manual also outlines methods to assess stream restoration potential at the subwatershed level, including basic stream reach analysis, more detailed project investigations, and priority restoration project screenings. The manual concludes by offering practical advice to help design, pennit, construct and maintain stream restoration practices in a series of more than 30 profile sheets . Manual 5: Riparian Management Practices The fifth manual examines practices to restore the quality of forests and wetlands within the remaining stream corridor and/or flood plain. It begins by describing four site preparation techniques that may be needed to make a site more suitable for planting, and then profiles four planting techniques for the riparian zone, based on its intended management use . The manua l presents several methods to assess riparian restoration potential at the sub watershed level, inc ludin g basic stream corridor analysis, detailed site investigations , and screening factors to choose priority reforestation projects . The manual concludes by reviewing effective site preparation and planting techniq ues in a series of eight riparian reforestation profile sheets. Manual 6: Discharge Prevention Practices The sixth manual covers practices used to prevent the entry of sewage and other pollutant discharges into the stream from pipes and spills. The manual describes a vari ety of techniques to find, fix and prevent these discharges that can be caused by illicit sewage connections, illicit business connections, fai lin g sewage lines, or industrial/transport spills . The manual a lso briefly prese nts desktop and field m ethods to assess the severity of illicit discharge problems in your subwatershed. Lastly, the manual profiles 12 different "forensic" methods to detect and fix illicit discharges . Manual 7: Pervious Area Management Practices The seventh manual reviews subwatershed practices that can improve the quality of upland perv ious areas, which include techniques to reclaim land, revegetate upland areas, and restore natural area remnants. When broadly appli ed, these techniques can improve the capacity of these lands to a bsorb rainfall and sustain healthy plant growth and cover. This bri ef manual also outlines methods to assess the potential for these techniques at both the site and subwatershed scale. Manual 8: Pollution Source Control Practices Pollution source control practices reduce or prevent pollution from residential neighborhoods or stonn water hotspots . Thu s, the eighth manual focuses on a wide range of stewardship and pollution prevention practices that can be employed in subwatersheds. The manual presents several methods to assess subwatershed pollution sources in order to develop and target e ducation a nd/or enforcement efforts that can prevent or reduce polluting behaviors and operations . The manual outlines more than 100 different "carrot" and "stick" options that can be used for this purpose. Lastly, the manual presents Urban Subwatershed Restoration Manual 1 profile sh eets that describe 22 specific stewardship practices for residential neighborhoods, and 15 pollution prevention techniques for control of storm water hotspots . Manual 9: Municipal Practices and Programs The ninth manual focuses on municipal programs and practices that can directly support subwatershed restoration efforts. The five broad areas include improved street and storm drain maintenance practices, development/redevelopment standards, stewardship of public land, delivery of municipal stewardship services, and watershed education and enforcement. This last "practice" manual presents guidance on how municipalities can use these five programs and practices to promote subwatershed restoration goals. The manual also contains a series of profile sheets that recommends specific techniques to implement effective municipal practices and programs. The series concludes with two user's manuals that explain how to perform field assessments to discover subwatershed restoration potential in the stream corridor and upland areas . Manual l 0: The Unified Stream Assessment: A User's Manual The Unified Stream Assessment (USA) is a rapid technique to locate and evaluate problems and restoration opportunities within the urban stream corridor. The tenth manual is a user's guide that describes how to perform USA, and interpret the data collected to determine the stream corridor restoration potential for your subwatershed. Urban Subwatershed Restoration Manual 1 Manual 11 : The Unified Subwatershed and Site Reconnaissance: A User's Manual The last manual examines pollution sources and restoration potential within upland areas of urban subwatersheds. The manual provides detailed guidance on how to perform each of its four components -the Neighborhood Source Assessment (NSA), Hotspot Source Investigation (HSI), Pervious Area Assessment (PAA) and the analysis of Streets and Storm Drains (SSD). Together, these rapid surveys help identify upland restoration projects and source control to consider when devising subwatershed restoration plans. Individual manuals in the series are scheduled for delivery throughout 2004, and each will be available for free downloading for a period of six months. After this window expires, they can be ordered online or as hard copies from the Center for a nominal charge. Be sure to check our website, www.cwp.org, to find out when each manual will be available and how it can be accessed. Foreword v Foreword vi Urban Subwatershed Restoration Manual 1 Table of Contents Table of Contents Foreword .................................................................................................................................... i About the Restoration Manual Series ........................................................................................ ii i Table of Contents ..................................................................................................................... vii Introduction ............................................................................................................................... l Chapter l : Organizing to Restore Urban Watersheds ............................................................. 3 l .1 Getting the Terminology Right ............................................................................... 3 l .2 Trends Driving Growth in Urban Watershed Restoration ......................................... 4 1.3 Many Different Goals Guide Urban Watershed Restoration .................................. 6 l .4 The Role of Stakeholders in Watershed Restoration ............................................... 8 l .5 Organizing Stakeholders Into Action ................................................................... 13 Chapter 2: The Alteration of Urban Subwatersheds .............................................................. 15 2.1 Conversion to Impervious Cover ........................................................................ 15 2.2 Construction of Sewer, Water, and Storm Water Infrastructure ............................. 17 2.3 Intensive Management of Pervious Areas ........................................................... 17 2.4 Fragmentation of Natural Area Remnants ........................................................... 18 2 .5 Interruption of the Stream Corridor ...................................................................... 18 2.6 Encroachment and Expansion in the Flood Plain ................................................ 19 2.7 Increased Population Density .............................................................................. 20 2.8 Increased Density of Storm Water Hotspots ......................................................... 20 Chapter 3: Impacts of Urbanization on Streams .................................................................. 21 3.1 Changes to Stream Hydrology ............................................................................ 23 3.2 Physical Alteration of the Stream Corridor ........................................................... 25 3.3 Degradation of Stream Habitat ........................................................................... 27 3.4 Decline in Water Quality ...................................................................................... 29 3.5 Loss of Aquatic Diversity ....................................................................................... 32 3.6 Summary ............................................................................................................. 35 Chapter 4: The Range of Subwatershed Restoration Practices ............................................ 3 7 4.1 Storm Water Retrofit Practices .............................................................................. 3 7 4.2 Stream Restoration ............................................................................................... 39 4 .3 Riparian Management ........................................................................................ 41 4.4 Discharge Prevention Practices ........................................................................... 44 4 .5 Pervious Area Management ................................................................................ 45 4.6 Pollution Source Control Practices ....................................................................... 46 4 .7 Municipal Practices and Programs ..................................................................... 49 4 .8 Choosing the Right Combination of Restoration Practices for a Subwatershed ............................................................................................. 50 Urban Subwatershed Restoration Manual 1 vii Table of Contents Chapter 5: Envisioning Restoration ....................................................................................... 55 5 .1 The Remnant Stream Corridor ............................................................................. 55 5 .2 Existing Storm Water Infrastructure ....................................................................... 56 5.3 Open Municipal Land ......................................................................................... 57 5.4 Natural Area Remnants ....................................................................................... 57 5.5 Road Crossings and Highway Rights-of -Way ....................................................... 57 5 .6 Large Parking Lots ................................................................................................ 58 5. 7 Storm Water Hotspots ........................................................................................... 60 5 .8 Residential Neighborhoods ................................................................................. 60 5.9 Large Institutional Land Owners ........................................................................... 60 5.10 The Sewer System ............................................................................................... 62 5 .11 Streets and Storm Drain Inlets ............................................................................. 62 5 .12 Summary ............................................................................................................ 62 Chapter 6: A Framework for Small Watershed Restoration .................................................. 65 Step l : Develop Watershed Restoration Goals ........................................................... 6 7 Step 2: Screen for Priority Subwatersheds ................................................................... 68 Step 3: Evaluate Restoration Potential ........................................................................ 69 Step 4: Conduct Detailed Restoration Assessment ..................................................... 70 Step 5: Assemble Projects into Plan ............................................................................ 71 Step 6: Determine Whether Subwatershed Plan Meets Watershed Goals .................. 72 Step 7: Implement Plan .............................................................................................. 73 Step 8: Measure Improvements Over Time ................................................................. 74 Summary ........................................ ; ............................................................................ 75 Appendix A: Derivation of Predictions for the Impervious Cover Model ............................... A-1 Appendix B: Organization of Restoration Technique Profile Sheets for the Manual Series ................................................................................................. B-1 References ............................................................................................................................. R-1 List of Tables l . Selected Results of National Survey of Municipal Watershed Restorat ion Activity ........ 6 2. Hydrologic Predictions According to the ICM ............................................................... 25 3. ICM Predictions Concerning Physical Alteration of the Urban Stream Corridor ............ 26 4 . Stream Habitat Predictions According to the ICM ......................................................... 28 5. Water Quality Predictions According to the ICM ........................................................... 30 6. Predictions on Aquatic Diversity According to the ICM ........... -...................................... 34 7. Eleven Places to Envision Restoration in a Subwatershed ............................................. 55 viii Urban Subwatershed Restoration Manual 1 Table of Contents List of Figures l . The Stream Corridor and Upland Areas in Urban Subwatersheds .................................. 4 2. General Classification of Watershed Restoration Goals ................................................. 7 3 . Four Types of Stakeholders Involved in Watershed Restoration Plans ............................. 9 4 . The Agency Stakeholder Pyram id .................................................................................. 9 5. The Public Stakeholder Pyramid ..................................................................................... l l 6 . The Partner Stakeholder Pyramid .................................................................................... l l 7 . The Funder Stakeholder Pyramid .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. l 2 8 . Six Urban Subwatersheds With Progressively Greater Impervious Cover ........................ 16 9. Distribution of Natural Area Remnants in a Non-Supporting Subwatershed ................... 18 l 0. Stream Interruption in a Non-Supporting Subwatershed ................................................ 19 l l . Five Groups of Stream Impacts Associated with Urban Subwatersheds ......................... 22 12 . Representation of the Impervious Cover Model (ICM) ................................................... 23 13. Comparison of Urban and Rural Hydrographs ............................................................... 24 14 . Loss of Riparian Forest Continuity in an Impacted Subwatershed .................................. 26 15. Contrast in Habitat Features Between Rural and Non-Supporting Streams .................... 28 16. Ten Major Categories of Pollutants Found in Urban Storm Water Runoff ........................ 29 l 7. Relationship Between Subwatershed IC and Aquatic Insect Diversity ........................... 33 18 . Seven Groups of Practices Used to Restore Urban Watersheds ..................................... 38 19. Example of a Storage Retrofit Pond ............................................................................... 39 20 . The Seven Basic Types of Stream Repair Techniques .................................................... 40 21 . Example of Comprehensive Stream Restoration Approach .......................................... 42 22 . Four Strategies to Establish Vegetation in the Riparian Area ......................................... 43 23 . Pollution Source Control Opportunities in Residential Neighborhoods .......................... 47 24 . Investigating Potential Storm Water Hotpots .................................................................. 48 25. General Feasibility of Retrofit Practices at Different Levels of Subwatershed IC ........... 51 26 . General Ability to Meet Subwatershed Goals at Different Levels of Subwatershed IC ............................................................................... 53 27. Envisioning Restoration in the Remnant Stream Corridor ............................................... 56 28 . Envision ing Restoration Within Existing Storm Water Infrastructure ................................. 57 29 . Envisioning Restoration on Open Municipal Lands ........................................................ 58 30. Envisioning Restoration in Natural Area Remnants ........................................................ 59 31 . Envisioning Restoration at Road Crossings and Rights-of-Way ...................................... 59 32 . Envisioning Restorat ion in Large Parking Lots ................................................................. 60 33. Envisioning Restoration for Storm Water Hotspots ........................................................... 61 34. Envisioning Restoration in Res idential Neighborhoods .................................................. 61 35 . Envisioning Restoration on Large Parcels of Institutional Land ...................................... 61 36. Envisioning Restoration in the Sewer System .................................................................. 62 3 7 . Envisioning Restoration on Streets and Storm Drain Inlets .............................................. 63 38 . Overview of the Eight-Step Framework to Restore Urban Watersheds ........................... 65 39. Detailed Steps and Tasks Involved in the Restoration Planning Process ....................... 66 Urban Subwatershed Restoration Manual 1 ix Table of Contents x Urban Subwatershed Restoration Manual 1 Introduction This Manual presents the basic concepts used to restore urban streams, and outlines an integrated and practical framework for assessing restorat ion potential in small urban watersheds. The Manual is organized into six chapters: Chapter 1 : Organizing to Restore Urban Watersheds This chapter introduces the basic concepts of organizing people to restore a local watershed. It begins by defining the language used to talk about watersheds and their restoration . Next, it explores national trends that are driving the rapid growth of urban watershed restoration efforts , as well as the diverse local issues that prompt restoration . Together, these national trends and local issues shape the unique restoration goals that guide local restoration efforts. These goals often prescribe a desired level of improvement in watershed health, as measured by a combination of physical, hydrologic, chemical, ecological or social indicators. Chapter I makes a strong case for defining these indicators in specific, measurable ways so that restoration progress can be tracked and monitored . Chapter I a lso describes the fo ur basic gro ups of stakeholders that must be engaged in local watershed restoration efforts: the public, agencies, watershed partners, and potential funders. As all of these stakeholders must interact to develop and implement an effective local restoration plan, the chapter concludes by describing how to build stakeholder involvement into the restoration planning process. Chapter 2: Alteration of Urban Subwatersheds Effective restoration requires a keen understanding of how a subwatershed has been altered in the past. This chapter reviews eight Urban Su b watersh e d Restoration M anua l 1 major subwatershed alterations that influence urban streams and their prospects for restoration . Alterations include the conversion of land to impervious cover; construction of sewer, water and storm drain infrastructure; management of pervious areas; fragmentation of natural area remnants ; interruption of the stream corridor; expansion and encroachment of the floodplain; increased population density; and the creation of pollution hotspots . Chapter 3: Impacts of Urbanization on Streams Given a knowledge of the intensity of subwatershed development, recent urban stream research can help set rea listic expectations for urban restoration. This chapter presents stream research within the context of the Impervious Cover Model (ICM). From a restoration standpoint , the ICM groups urban streams into three categories based on how much impervious cover exists in the subwatershed: impacted streams, non- supporting strea ms and urban drainage . The ICM is then used to develop specific quantitative or narrative predictions for stream indicators for each of the three stream categories. These predictions define the severity of current stream impacts and the prospects for their future restoration. Predictions are made for five major types of urban stream impacts: changes in stream hydrology, alteration of the stream corridor, stream habitat degradation, declining water quality and loss of aquatic diversity. Water qua lity impacts are further subdivided into predictions concerning eutrophication, exceedance of bacterial standards, aquatic life toxicity, sediment contamination, and trash and debris loading. Intro duction In troduction 2 Chapter 4: Range of Availab le Subwatershed Restoration Pract ices This chapter introduces the seven major groups of restoration practices used to restore urban subwatersheds. Four groups of practices ar e generally applied within the remaining stream corridor: storm water retrofits , stream restoration , riparian management, and discharge prevention practices . Three groups of practices can be applied in the upland areas of a subw atershed, including pervious area management, pollution source control, and improved municipal practice (although some on-site storm water retrofits can also be installed in upland areas). The cha pter describes the many different restoration techniques and discusses how they contribute to subwatershed restoration goals . The chapter concludes with guidance on choosing the right combination of practices to meet specific restoration goals , in the context of the actual restoration potential of the subwatershed . Chapter 5: Envisioning Restoration Urban restoration is both an art and a science, and it takes some skill to imagine the possibilities for effective watershed re storation . This short chapter provides insight on how to envision the prospects for effective restoration at the subwatershed level , and outlines some key subwatershed characteristics that create these opportunities . This chapter describe s 11 subwatershed features that offer opportunities for subwatershed restoration practices . The actual desktop and field assessment methods used to find these restoration opportunities are described in greater detail in Manuals 2, 10, and 11. Chapter 6 : A Framework to Guide Subwatershed Restoration The last chapter introduces an eight-step process to develop and implement sub watershed re storation plans . Each step may include tasks involving desktop analysis, rapid field assessment, stakeholder invol vement and management products. The eight-step framework can be used as a guide to de velop , adopt, implement and track subwaters hed restoration plans . Manual 2 provides more detail on the specific tasks and methods that can be used in subwatershed restoration planning framework. The next seven manuals provide more detailed guidance on each of the seven types of watershed re storation practices: Manual 3: Storm Water Retrofit Practices Manual 4 : Stream Repair Practices Manual 5: Riparian Management Practices Manual 6: Di scharge Prevention Practices Manual 7: Pervious Area Management Practices Manual 8: Pollution Source Control Practices Manual 9: Municipal Practices and Programs Each of these manuals describes techniques to de s ign and implement each restoration practice, and provides detailed guidance on site and subwatershed a ssessment methods. In addition , the manuals provide extens ive references to other helpful resources for the design and construction of effective restoration practices. The final two manuals outline field methods to assess su bwatershed restoration potential: Manual 10: The Unified Stream As sessment (USA) Manual 11 : The Unified Subwatershed and Site Reconnaissance (USSR) Urba n Subwatershed Res toration Man ual 1 Chapter 1: Organizing to Restore Urban Watersheds Chapter 1 : Organizing to Restore Urban Watersheds Each watershed restoration partnership is unique , both in terms of the goals that guide it and the stakeholders that participate in it. The five parts of this chapter explore how to organize the partnerships needed to effectively restore urban watersheds . The first part of Chapter 1 defines the basic terminology used to talk about watersheds and restoration. The second part examines the key trends driving the rapid growth in urban watershed restoration in communities across the country. The third part explores possible goals that can guide watershed restoration efforts and outlines how communities can develop the most appropriate and achievable goals. The fourth part describes the broad groups of stakeholders that must be involved in restoration plan development, while the fifth part outlines practical strategies for organizing stakeholders toward a common purpose . l .1 Getting the Terminology Right The words "urban," "watershed" and "restoration" can mean many things to many people, and when they are combined, it can be a recipe for confusion. So , from the outset, we want to carefully define how each of these terms is used throughout this manual. Urban is defined as any watershed or subwatershed with more than 10 % total impervious cover. Watersheds are land areas that drain surface and groundwater to a downstream water body, such as a river, lake or estuary. Watershed drainage areas are large, ranging from 20 to 100 square miles or more . Given their size, they may encompass many political jurisdictions, contain a mix of land uses (forest, agricultural, rural , suburban, urban), and have a broad range of pollution sources. Each watershed is composed of a number of smaller watersheds called "subwatersheds." Urban Subwatershed Restoration Manual 1 Subwatersheds, as a general rule of thumb , have a drainage area of five to 10 square miles or less , and are the primary restoration unit in the context of this manual. The small size of subwatersheds makes them ideal restoration candidates for several reasons. First, subwatersheds can be rapidly mapped and assessed for restoration potential in a matter of months, with an initial restoration strategy following soon after. The small scale of a subwatershed a lso allows restoration practices to be designed, constructed and assessed within a few years. Also, most subwatersheds are contained within a single political jurisdiction, making it easier to coordinate local stakeholders. In our view, watershed restoration can only be effectively implemented at the subwatershed scale, although many subwatersheds may require restoration to achieve watershed goals. Each urban subwatershed is drained by a network of perennial streams, each of which can be classified based on its relative order in the network. For example, a small stream with no tributaries or branch es is defined as a first order stream. When two first order streams combine, they form a second order stream. Similarly, when two second order streams join, they create a third order stream, and so on . Given their relatively small drainage area , most urban subwatersheds only contain streams that range from first to third order. The health of these smaller headwater streams is the major foc us of urban restoration efforts. The stream co rridor and upland areas are the two parts of a subwatershed. Stream corridors include the existing network of stream channels and the lands that surround them . Upland areas include the remaining subwatershed area that drains to the stream corridor. The relationship between the stream corridor and upland areas is depicted in Figure 1. As sub watersheds urbanize, both the length and width of the stream corridor decline, and upland areas begin to dominate the landscape. 3 Chapter 1: Organizing to Restore Urban Watersheds 4 Restoration is used throughout this manual in its broadest sense, and is defined as the application of any combination of restoration practices that can improve stream health, as measured by improvements in physical, hydrological, chemical , ecological or social indicators of stream quality. Alternative terms such as "recovery," "repair," "rehabilitation," or "enhancement" were considered, but found inadequate . However, the use of the term "restoration" does not imply that full ecological restoration of an urban streams is always possible. Restoration practice is used to describe the seven broad groups of practices used to restore urban subwatersheds. Four groups of restoration practices -storm water retrofits, stream restoration, riparian management and discharge prevention -are generally applied within the urban stream corridor. The remaining three groups of practices - pollution source control, pervious area management and municipal stewardship - are normally applied to upland areas of a subwatershed. Stakeholders are defined as any agency, organization or individual involved in or affected by the decisions made in a subwatershed restoration plan. From a practical standpoint, it helps to think of four broad groups of stakeholders in each restoration effort: agencies , the public, watershed partners and potential funders. Each of these four stakeholder groups is further defined later in this chapter. 1.2 Trends Driving Growth in Urban Watershed Restoration The remarkable growth in urban watershed restoration efforts has been fueled by several intersecting trends affecting thousands of communities across the nation: the need to control nonpoint source pollution, new regulatory mandates, increased municipal restoration capability, growth in urban watershed organizations, and greater public expectations for cleaner and greener neighborhoods . Need to Control Nonpolnt Pollution Sources Most communities have clamped down on point sources of pollution to the furthest extent possible (e.g., sewage treatment plants and industrial discharges). Despite a multi-billion dollar investment over the last three decades , Urban Subwatershed Restoration Manual 1 however, many urban streams and rivers still do not meet water quality standards and continue to experience severe habitat degradation. Consequently, communities are now shifting their control efforts to reduce nonpoint sources of pollution in order to meet clean water goals. In urban watersheds, nonpoint source control usually means better treatment of urban storm water runoff, which is best accomplished at the watershed or subwatershed scale. Emerging Regulatory Drivers A series of state and federal regulations are also prompting many communities to restore their urban watersheds. For example, when urban waters do not meet water quality standards prescribed under the Clean Water Act, agencies must develop pollutant reduction plans that show how these standards can be attained in the future. These plans, known as Total Maximum Daily Loads (or TMDLs), may require communities to implement restoration practices to reduce nonpoint source pollutant loads by specific amounts over a defined timetable. In addition, many communities are now regulated under EPA's storm water NPDES permit program, which covers pollutants discharged from municipal storm drain systems. The municipal permit program applies to communities with populations of more than 50,000. Under these permits, communities must demonstrate that they have local programs to manage storm water, detect and eliminate illicit discharges, prevent pollution, and educate and involve the public. Larger communities are also responsible for monitoring the quality of their storm water runoff. A few states have even gone so far as to stipulate that a fixed percentage of each community must be restored during each permit cycle . As a result, many of the local programs required under municipal NPDES storm water permits support stronger local restoration programs (CWP, 2003). Communities may also engage in watershed restoration to comprehensively address numerous other federal environmental Urban Subwatershed Restoration Manual 1 Chapter 1: Organizing to Restore Urban Watersheds mandates , control programs, and policies. Examples include the EPA minimum measures to control combined sewer overflows (CSOs) and sanitary sewer overflows (SSOs), as well as source control measures that may be required under the Safe Drinking Water Act. Other federal agencies also encourage a watershed approach. A notable example is the National Flood Insurance Program (FEMA), which encourages watershed-based solutions to local flooding problems. In addition, watershed efforts to recover salmon populations in the Pacific Northwest have been prompted by the Endangered Species Act. Similar efforts have been triggered in the Texas hill country to protect the endangered Barton Springs salamander. Many federal agencies actively promote watershed restoration through new grant programs that support research and demonstration of wetland restoration, stream restoration , nonpoint source control and urban forestry practices. Communities often find it a challenge to integrate the many state and federal regulatory drivers into a coherent whole, since they operate over many different watershed units and address multiple environmental endpoints. Urban watershed restoration planning offers a useful framework for this integration . Increased Local Restoration Capability In recent years, communities have greatly expanded the type and scope of their watershed restoration activities. For example, the Center recently surveyed more than 50 communities of all sizes to measure their current activity in urban watershed restoration. The average community had engaged in at least 10 of the 17 core restoration programs recommended as part of a local Smart Watersheds Program (CWP, 2004). Table 1 presents some of the interesting highlights from the survey. As can be seen, at least half of the communities reported some level of activity in many areas of urban watershed restoration. This finding suggests that more staff, programs, funding and mapping are available to support urban watershed restoration than ever before, and communities are rapidly acquiring more 5 Chapter 1: Organizing to Restore Urban Watersheds Small Watershed Plann ing 55 Subwatershed GIS Mapping 80 Rapid Stream Assessment 49 Storm Water Retrofitting 53 Stream Restoration 51 Discharge Prevention 63 Urban Forestry 49 Watershed Education 65 Hotspot Pollution Prevention 35 Public Involveme nt 71 Note : 50 + comm unities surveyed, with populations ranging from 25,000 to 2,000,000. Restoration activity tended to be slightly higher in communities with larger populations and in those covered by Phase I storm water NPDES permits. For complete survey results, consult CWP 2004 6 practical skills and experience to implement restoration practices. At the same time, the survey revealed that most local restoration efforts were still in an experimental or demonstration stage, and few communities had systematically integrated their restoration efforts at the subwatershed scale. Growth In Urban Watershed Organizations The recent growth of nonprofit watershed groups has also been impressive . More than 4 ,000 watershed groups are now established across the country, along with an equal number of land trusts, smart growth and "friends of' organizations. A majority of these groups are located in suburban or urban watersheds (CWP, 2002). The number, sophistication, and expectations of urban watershed groups have all increased sharply in recent years. These groups can exert considerable pressure to get communities to do a better job in restoring their urban watersheds . While urban watershed groups may often be impatient for results, they are becoming more effective advocates for local restoration . Public Demand for Better Local Environment Urban and suburban residents are concerned about the overall quality oflife in their neighborhoods , and these concerns often extend beyond healthier streams. Residents are concerned about issues such as greenways, flooding, waterfront improveme nts , aesthetics, trash, and neighborhood revitalization. In addition, the public has a stronger awareness about local stream quality, and actively participates in both personal and watershed stewardship activities . The net effect is that the public is demanding better stream protection, and expects their community concerns to be fully integrated within the watershed restoration planning process. l .3 Many Different Goals Guide Urban Watershed Restoration No two urban watershed restoration efforts are ever alike. Each restoration effort has its own unique goals, which are shaped by the watershed scale, various restoration "drivers" and stakeholder input. This section reviews the impressive di versity of goals driving local watershe d restoration efforts across the country. A sample of watershed restoration goals is depicted in Figure 2; most communities choose multiple goals to guide their watershed plan. In general, most re storation goals can be lumped into one of four broad categories: water quality, physical/ hydrological condition, biological diversity and community concerns. Watershed restoration goals may be oriented to ward the stream, the stream corridor, or upland areas, or some combination of all three . In addition, local restoration goa ls frequently differ in ambition. For example, some communities set goals with prevention in mind, e.g ., simply to keep something bad from happeni ng, like a pollution spi ll , flood damage , or sewage overflows. Other communities seek to systematically repair a problem (or set of problems) in the stream or its corridor, such as an eroding bank, a fish barrier or an inadequate forest buffer. The most ambitious communities Urban Subwatershed Restoration Manual 1 Chapter 1: Organizing to Restore Urban Watersheds set goals to improve conditions within the stream or its corridor. These communities seek a defined and measurable improvement for a desired indicator in stream health by comprehensively applying many restoration practices across a subwatershed . The choice of whether to set goals to prevent, repair or improve problems depends on the actual restoration opportunities within a subwatershed. These opportunities depend on at least three subwatershed factors: percent impervious cover, the length of intact stream corridor, and the fraction of the subwatershed that can be effectively treated by restoration practices . Consequently, communities often need to reconcile broad watershed restoration goals with the limited restoration potential of the many subwatersheds that comprise it. The balance between proposing ambitious goals at the watershed level and the ability to realistically achieve them in individual subwatersheds is a major theme of this manual. • Reduce pollutants of concern (e .g . TSS, N, P, Zn, Cu, hydrocarbons , pesticides) • Prevent illegal discharges/spills • Meet water quality standards • Reduce sediment contamination • Allow water contact recreation • Protect drinking water supply Restore aquatic diversity • Restore wetlands/natural areas • Expand forest cover • Restore/reintroduce species (e.g . salmon) • Improve fish passage • Enhance wildlife habitat • Remove invasive species • Keep shellfish beds open Enhance riparian areas • Increase groundwater recharge • Reduce channel erosion • Reclaim stream network • Reduce flood damage • Reconnect floodplain • Restore physical habitat • Protect municipal infrastructure • Eliminate trash/debris • Create greenways/waterfront access/open space • Revitalize neighborhoods • Improve aesthetics/beautification • Increase citizen awareness • Improve recreation opportunities • Increase fishing opportunities Urban Subwatershed Restoration Manual 1 7 Chapter 1: Organizing to Restore Urban Watersheds 8 1 .4 The Role of Stakeholders in Watershed Restoration While restoration is driven by the goals of those that care for the watershed, aligning the efforts and resources of stakeholders towards common goals is critical to the adoption and implementation of any restoration plan . Ideally, the goals and vision for the watershed should be developed early in the restoration process , based on input from a broad group of stakeholders. Consequently, you need to know the key stakeholders in the watershed , and include them in virtually every step of the restoration process. The term stakeholder is loosely defined as any agency, organization, or individual that is involved in or affected by the decisions made in a watershed plan . In theory, this definition includes just about everybody; in reality, it merely refers to those folks that actually show up to speak their mind. Not all stakeholders are equal, however. In a literal sense, each has a different stake in the outcome of the plan, and is expected to perform a different role in the watershed restoration effort . Each comes to the table with varying degrees of watershed awareness , concern and/or expertise. Stakeholders al so have different preferences as to how, when , and in what manner they want to be involved in the process. As a result, the outreach methods used to educate and inform stakeholders must be carefully calibrated to match their different levels of knowledge and understanding. For example, some stakeholders are daytime professionals expected to be at the table because of their job duties , whereas others are "night-timers" donating their time and experti se . Effective watershed managers recognize the wide diversity in stakeholders , and structure their planning process to provide multiple options and opportunities for involvement. Stakeholders usually fall into one of four distinct groups that interact to produce restoration plans , as shown in Figure 3. The four groups include the public, agencies, watershed partners and potential funders. Conceptually, stakeholder in volvement can be viewed as a pyramid, with expanding levels of involvement. The base of the pyramid contains the greatest number of stakeholders, many of whom are initially unaware of watershed problems and their potential role in restoration . The awareness and involvement of stakeholders becomes progressively greater toward the top of the pyramid . Stakeholders found at the apex of the pyramid represent key decision-makers , and are generally considered the champions for restoration . The next section describes each of the four stakeholder groups in more detail. Agency Stakeholders Local government has primary responsibility for urban watershed restoration. In reality, these responsibilities are usually spread over a wide assortment of bureaus , departments , agencies and divisions that rarely coordinate much with each other. As a result, it is useful to think of all these individuals and units as occupying different levels of the stakeholder pyramid (Figure 4). The apex of the pyramid consists of the elected officials and the lead local restoration agency that are the champions of restoration , and who act to coordinate the actions of all other units of local government. Elected officials are critical stakeholders since they must vote to approve budgets for restoration plans . The next tier consists of agencies that deal directly with local environmental issues or services, followed by agencies that own or control land where restoration practices may be constructed (e .g., schools, parks, etc .). The next rung is occupied by local agencies that may not initially perceive restoration as a core part of their mission. A good example is a local planning and zoning authority that can contribute to subwatershed restoration by adopting better development standards for infill and redevelopment. The bottom of the pyramid consists of state and f ederal agencies that regulate water quality or protect natural resources. These agencies are critical, since they may need to approve permits for restoration practices or even Urban Subwatershed Restoration Manual 1 Chapter 1: Organizing to Restore Urban Watersheds Restoration Plan Figure 3: Four Types of Stakeholders Involved in Watershed Restoration Plans Local Environmental Agencies Mayor; Council; Planning Commission Department of Public Works ; Department of Enviro nmental Protection Planning Department; Community Forestry; Conservation District r-~~~~~~~~~~~~---..,--~~~~~--. Land owning or Land Re gu lati ng Agencies State and Federal Agencies Schools and Parks ; Planning and Zoning Authority '--~~~~~~~~~~~~~~~~~~--->..~~~~~~· State DEP/DNR; EPA ; Corps of Engineers Figure 4: The Agency Stakeholder Pyramid Dozens of local, state and even federal agency stakeholders need to be involved to coordinate effective local restoration planning. Urban Subwatershed Restoration Manual 1 9 Chapter 1: Organizing to Restore Urban Watersheds 10 approve the restoration plan itself (e.g., in the case of a TMDL). Some agencies can also lend staff expertise and provide monitoring and mapping data to support the restoration effort. The Public The public is a major stakeholder in every watershed restoration effort, although as individuals they may be unaware of this role. Indeed, watershed awareness and activism varies considerably among the public, and can be best understood in terms of a pyramid (Figure 5). The general public make up the bottom of the pyramid, and initially possess a low level of watershed awareness or involvement. Indeed, much of what they know about watersheds comes from the local paper or evening news. Increasing the awareness of the general public is important, given that the collective impact of their individual actions can improve or degrade watershed health. The next level of the pyramid is occupied by the receptive public. As voters, they may support stronger local environmental initiatives, and might be willing to change daily behaviors to protect the watershed, such as installing rain barrels , planting trees or picking up after their pets. Education, outreach and direct municipal services may often be needed to improve personal stewardship among the receptive public. The next subset is the adjacent public, which includes people that live near the stream corridor and will be positively or negatively affected by any restoration practices constructed within it. Since they have such a direct stake in the outcome of restoration, this group must be continuously informed as to how restoration practices will influence their neighborhood and property values. The activist public occupies the next rung on the pyramid. This group consists of community leaders in neighborhood associations, civic groups , garden clubs, recreational enthusiasts, and the like. While watershed restoration may not be their main mission, the activist public often recognizes its potential benefits for the community. Enlisting the activist public in the restoration cause can be very important, given the strong influence they exert both in the community and on the local political process . The apex of the pyramid is occupied by watershed groups that are organized to advocate for urban watersheds and help implement local restoration plans. Few subwatersheds possess such a group at the beginning of the restoration process, but they should always have one at the end. Watershed Partners The watershed partners stakeholder group consists of non-local government partners that are expected to perform many important roles in watershed restoration. Figure 6 depicts the diversity of watershed partners involved in local restoration . Responsible parties include utilities whose activities or discharges are regulated by permit or ordinance . The goal is to align their pollution control efforts with the goals for watershed restoration . Local media are also valuable watershed partners, since they have the best means to broadcast information about watershed restoration to the general public through local television, community newspaper and radio. Restoration requires a lot of expertise, and local advisors are the stakeholders that can bring it to the table. Examples of local advisors include engineers, environmental consultants , local scientists and educators. In addition, many non-profit organizations and regional planning agencies can contribute data and expertise to the watershed restoration effort . Loca l busin esses and landown ers can be voluntary watershed partners, although they often start with a low level of awareness or may be suspicious of potential regulation . However, it is very important to enlist their cooperation to improve stewardship on the lands they own and the operations they control. Urban Subwatershed Restoration Manual 1 Chapter 1: Organizing to Restore Urban Watersheds Activist Public Adjacent Public Receptive Public Watershed Organizations Neighborhood Associations; Civic Groups; Garden Clubs; Greenway Coalitions; Anglers' Groups ; Recreation/Hiking Group Property owners near proposed restoration project sites Community Leaders; PT As ; Schools ; Churches; Interested Citizens; Voters General Public Everyone who lives and works '------------------------~----in the watershed Figure 5: The Public Stakeholder Pyramid Public stakeholders are not monolith1c, but can be stratified on the basis of thelf awareness, stewardship act1v1t1es , and interest in participating in the local watershed restoration process . Local Media Local Advisors Local Businesses and Landowners NPDES Regulated Dischargers ; Local Utilities Engineers; Environmental Groups and Consultants ; Local Scientists; Educators; Non- Profits; Regional Planning Agencies Chamber of Commerce; Private Schools; Colleges/Universities; Industry ; Builder/Developers; Real Estate Companie Figure 6: The Partner Stakeholder Pyramid Many different partners comprise this diverse stakeholder group asked to perform many roles in watershed restoration , including implementing pollution controls, spreading the restoration message, providing expertise, and integrating restoration goals into their normal operations. Urban Subwatershed Restoration Manual 1 11 Chapter 1: Organizing to Restore Urban Watersheds 12 Funders Funding partners are the stakeholders expected ~o finance watershed restoration at some point m the future . The diversity of funding stakeholders can also be viewed in terms of a pyramid (Figure 7). The top of the pyramid is occupied by local government who has the primary responsibility to finance restoration especially during the early planning stages . The most common local revenue streams are operating budgets, capital budgets and storm water .utilities. Most communities are already spending more money than they think on restoration activities, although these costs are frequently spread across many different agency budgets. Clearly, the agency heads, budget experts, and elected officials that control local purse strings are important individual stakeholders, and they need to be continuously educated on how restoration benefits the community and why the restoration investment is justified. Private The next two levels on the funding pyramid are occ.upied by state and federal funding sources, which can provide grants, loans or direct technical services to supplement local restoration investments . State and federal funding stakeholders usually get many more funding requests than they can meet so it is important to emphasize why the loc~l watershed should be a top priority for funding and to demonstrate the width and breadth of the local restoration partnership. The last rung of the pyramid is occupied by private funding sources. This diverse group of funders includes foundations, corporations, and individuals that can provide supplemental funding for selected restoration tasks . Private funding sources like to give to people, and see on-the-ground results at the community scale. Consequently, they tend to support grassroots watershed organizations rather than local governments. All funding stakeholders should be viewed as investors, and shou ld be continuously updated about the costs of restoration and the benefits it provides to the community. Agency Heads ; Budget Experts; Elected Officials State Environmental Agency (grants); State Resource Protections (grants) EPA; Corps ofEngineers; Fish and Wildlife Service Foundations; Corporations; Individuals Figure 7: The Funder Stakeholder Pyramid This group of stakeholders constitutes the major investors in local watershed restoration . Stakeholders near the top of the pyramid usually provide the greatest share of overall funding, but a targeted education strategy is always needed to cultivate each group of potential investors . Urban Subwatershed Restoration Manual 1 1 .5 Organizing Stakeholders Into Action There is no single path to successfully involve all four stakeholder groups in the watershed re storation process . Howe ver, it is a good p actice to invol ve them early and often, and particularly when setting the goals that drive the re storation effort . Manual 2 presents a series of methods for involving each of the four stakeholder groups during each step of the restoration process . Each method seeks to achieve a unique purpose, is targeted to a different combination of stakeholders, and employs customized outreach techniques . The ultimate goal is to organize stakeholders to create a strong partnership that can attract political support for the re storation plan . Urban Subwatershed Restoration Manual 1 Chapter 1: Organizing to Restore Urban Watersheds Stakeholder involvement helps ensure that the restoration plan is reali stic, scientifically sound , and reflects community values and desires . When the right mix of stakeholders agrees on clear and measurable goals, it can create a powerful impetus to guide restoration decision s. Many cons ider watershed restoration to primarily be a technical endeavor, and it is certainly true that many technical skills are needed . In practice, ho wever, successful restoration is mostly about organizing people and resources around common goals . Many non-technical skills must be learned to make restoration happen, such as coordination, communication, outreach and leadership. 13 Chapter 1: Organizing to Restore Urban Watersheds 14 Urban Subwatershed Restoration Manual 1 Chapter 2: The Alteration of Urban Subwatersheds Chapter 2: The Alteration of Urban Subwatersheds The current state of an urban stream reflects past alterations to its subwatershed. These past subwatershed alterations must be fully understood before you can begin to make sense of an urban stream, set restoration goals or even think about prescribing the right restoration practices. This chapter reviews the ways in which hundreds of past human alterations collectively transform the character of urban subwatersheds into a complex mosaic of pervious and impervious areas, both of which are extensively modified by humans. Subwatersheds are progressively transformed and disturbed over the course of many decades or even centuries. Subwatersheds experience at least eight major alterations that are significant from the standpoint of restoration: 1. Conversion to Impervious Cover 2. Construction of Sewer, Water, and Storm Water Infrastructure 3 . Intensive Management of Pervious Areas 4. Fragmentation of Natural Area Remnants 5. Interruption of the Stream Corridor 6 . Encroachment and Expansion in the Flood Plain 7. Increased Population Density 8. Increased Density of Storm Water Hotspots Urban Subwatershed Restoration Manual 1 2 .1 Conversion to Impervious Cover The cycle begins with the clearing of forests, farms and wetlands, which are replaced by rooftops, roads , parking lots and other forms of impervious cover (IC). By our definition , urban subwatersheds can range from 10 to nearly 100% IC . The imprint of the built environment on subwatersheds of progressively greater impervious cover is clearly evident in Figure 8. Impervious cover fundamentally alters the hydrology of urban subwatersheds by generating increased storm water runoff and reducing the amount of rainfall that soaks into the ground. Impervious cover is also the best indicator to measure the intensity of subwatershed development and predict the severity of impacts to the remaining stream network (CWP, 2003). 15 Chapter 2 : The Alteration of Urban Subwatersheds a) 10% Impervious Cover c) 30% Impervious Cover d) 50% Impervious Cover e) 60% Impervious Cover Figure 8: Six Urban Subwatersheds With Progressively Greater Impervious Cover The imprint of IC 1s clearly evident m these six aerial photos of small urban subwatersheds with progressively greater IC . Note how both the stream network and comdor are d1m1mshed at higher levels of IC. Subwatershed IC is a key variable to assess the prospects for stream restoration. 16 Urban Subwatershed Restoration Manual 1 2. 2 Construction of Sewer, Water, and Storm Water Infrastructure Urban subwatersheds are serviced by an enormous network of underground water, sewer, and storm drain pipes . Hundreds of miles of pipes can be found in a subwatershed as small as five square miles. Each kind of pipe has a pervasive influence on the subwatershed and can also severely constrain the location of restoration practices . For example, sanitary sewer pipes often parallel the stream network and can become a source of sewage leaks and overflows. In other cases, sewer pipes can capture groundwater that would otherwise sustain stream flow. Since sewers often cross the stream network, they can a lso become barriers to fish migration . Even the network of pipes that supplies water to homes can influence the subwatershed . Depending on their age and condition, water di stri bution pipes can lose 10 or even 20% of their water volume to the stream. Urban subwatersheds also possess an extensive network of storm drain pipes that deliver storm water flows rapidly and efficiently to the stream. This efficiency comes at an environmental cost, as storm drains increase downstream floods and deli ver pollutants entrained in storm water runoff. Storm drains "short circuit" natural riparian areas, which reduces their effectiveness in removing pollutants . Storm drain pipes can also cause severe localized erosion at their outfalls, unles s they are extensively armored. Urban Subwatershed Restoration Manual 1 Chapter 2 : The Alteration of Urban Subwatersheds 2.3 Intensive Management of Pervious Areas When subwatersheds are viewed from the air, areas of impervio us cover are seen interspersed within a larger matrix of pervious areas. Most of the remaining pervious areas have been highly disturbed in the past and few retain the soil and vegetation qualities they once possessed. The most fundamental change is caused by the disturbance of native soils . Progressive cycles of development and redevelopment involve wholesale earthmoving; erosion or removal of topsoil; compaction of subsoils; and the filling of depressions, wetlands and natural rainfa ll storage areas. Consequently, the soils of urban pervious areas often lack the fertility, tilth, and recharge characteristics of their non -urb an counterparts (Schueler, 2000). From a practical standpoint, the hydrology of many urban pervious areas is more similar to impervious areas than natural ones. The vegetative cover of pervious areas ranges from bare earth to urban forest, but the majority is managed as turf grass or lawn. Most pervious areas are continuously mowed to arrest the natural pattern of vegetative succession . Whi le there is some tree cover in most urban subwatersheds, most urban "forest" has less than 50% canopy coverage (American Forests, 2001). As a result, urban forests lack the structure and understory of their rural counterparts, and are often dominated by non- native trees , shrubs and vines . 17 Chapter 2: The Alteration of Urban Subwatersheds 18 2.4 Fragmentation of Natural Area Remnants A few isolated fragments of forests and wetlands always seem to persist in urban subwatersheds. A typical pattern is depicted in Figure 9, which shows the distribution of forest and wetland remnants in the Watts Branch subwatershed located in suburban Maryland. Often , natural area remnants are located in areas that were extremely difficult to develop (e.g., steep slopes), were abandoned and have since regrown, or grew up over time within parks, cemeteries and public open space. In other situations, subwatershed alterations cause changes in local hydrology that unintentionally create new urban wetlands. Common examples include old ponds , backwaters behind road crossings, and abandoned earthworks . Although of relatively recent origin, these wetlands may receive some protection under state or federal wetland protection statutes. Forest and wetland remnants are often isolated and have little or no connection with other natural habitats or the stream corridor. Typically, natural area remnants have a greater proportion of edge habitats compared to core habitats. Natural area remnants are particularly susceptible to invasions of non-native species of both plants and animals, and it is not uncommon for invasive species to become numerically dominant. Natural area remnants are also stressed by storm water runoff and urban heat island effects. As disturbed and isolated as they are , natural area remnants have intrinsic value as examples of nature in the city, and may present excellent opportunities for restoration in their own right. 2 .5 Interruption of the Stream Corridor Some kind of stream corridor remains in all but the most extremely developed subwatersheds, if for no other reason than it is usually too expensive to totally enclose all streams in pipes. The stream corridor that remains , however, is highly interrupted (i.e., it is frequently crossed, culverted, channelized, ditched, enclosed, armored or otherwise "improved"). Each of these types of interruptions can be found in the Maiden's Urban Subwatershed Restoration Manual 1 Chapter 2 : The Alteration of Urban Subwatersheds ". :r I [ I '1:Tl'l\ll i;d Stfl"a lll Open \:h an nc C h a nnelized P1p~·J LargL· sturmJrarn pip..: Sto rmd rni n o utfa ll Ro ad Crossing Figure 1 O: Stream Interruption in a Non-Supporting Subwatershed This stream network of this Baltimore (MO) subwatershed has been extensively interrupted by road crossings, extended culverts, channelization and other engineering "improvements" over many decades. Most first order streams are not shown on the map because they have been enclosed by storm drains. Stream interruption is an important factor in determining fish passage , channel erosion, and aquatic habitat suitability. Choice subwatershed located in Baltimore, MD (Figure l 0). The subwatershed has about 40 % impervious cover and experiences extensive channel alteration and interruption throughout its headwaters and main stem. In many ways , it rese mbles a broken pipe more than a stream network. 2.6 Encroachment and Expansion in the Flood Plain The natural flood plain has always been an attractive but dangerous area in which to build , and communities have historically proceeded with development in these areas . In order to protect buildings from flood damage , landowners have incrementally modified the flood plain to allow development. The most common modification has been to fill the flood Urban Subwatershed Restoration Manual 1 plain with earth to provide a higher platform for buildings . While the fill may provide local relief to landowners, it also sharply reduces the capacity of the flood plain and exacerbates downstream flooding problems. Other flood contro l remedies such as channelization, levees, and armoring produce similar effects . In addition, the frequent stream crossings found in urban subwatersheds can encroach on the flood plain. Undersized bridges or culverts that cross the flood plain may also reduce the ca pacity of the flood plain to handle flood waters. Even if encroachment never occurred, urban flood plains will always expand in response to upstream development. Urban subwatersheds produce hi gher peak flooding rates; consequently, urban flood plains must expand to accommodate these higher flows . Both the height and width of the urban flood plain increase, so that when floods occur, more property is subject to inundation. Indeed, many urban subwatersheds are experiencing flood plain expansion, while at the same time they are lo sing flood plain capacity due to encroachment. Flood damages are the inevitable res ult. 19 Chapter 2: The Alteration of Urban Subwatersheds 20 2.7 Increased Populat ion Density Urban subwatersheds are home to many humans, pets and wildlife. Each of these populations can directly generate pollutants , such as bacteria or nutrients that can move from the subwatershed to the stream. Humans, presumably the most intelligent of the three groups, make daily decisions that can either improve or degrade conditions in a subwatershed. Negative choices such as dumping, littering, over-fertilizing or not picking up after a dog can directly diminish stream quality when these actions are mu ltiplied many times over. On the other hand, positive choices such as installing rain barrels , adopting streams or planting trees can improve stream quality, particularly when they occur on a widespread basis . Thus, the collective attitudes , awareness and behaviors of subwatershed residents determine whether pollution will be generated or prevented. 2.8 Increased Density of Storm Water Hotspots The density of storm water pollution hotspots increases as subwatersheds become more intensively developed. Hotspots are defined as commercial, industrial, institutional, municipal, and transport-related operations that tend to produce higher levels of storm water pollution, or present a higher potential risk for spills, leaks and ill egal discharges . The nature and distribution of storm water hotspots is different in each urban subwatershed, but there are always quite a few of them, many of which are quite small. Considerable detective work is needed to find storm water hotspots and to prevent potential pollution discharges that can impair downstream water quality. Together, these eight subwatershed alterations diminish the quality of streams and downstream waters. The next chapter reviews how these alterations impact streams, and how they can be predicted on the basis of subwatershed impervious cover. Urban Subwatershed Restoration Manual 1 Chapter 3: Impacts of Urbanization on Streams Chapter 3: Impacts of Urbanization on Streams This chapter summarizes recent research on the impact of urbanization on stream quality for subwatersheds with more than l 0% impervious cover (IC). In general , changes in stream quality can be tracked according to five broad indicators : 1. Changes to stream hydrology 2. Physical alteration of the stream corridor 3 . Stream habitat degradation 4. Declining water quality 5. Loss of aquatic diversity Figure 11 outlines different stream impacts that can occur within each indicator category (CWP, 2003). This chapter describes how urban stream quality is related to subwatershed IC , and how stream restoration can be assessed within the context of the Impervious Cover Model (ICM). Impervious cover is often used as a general index of the intensity of subwatershed development and the presumed severity of the seven other subwatershed alterations discussed in the last chapter. The relationship between subwatershed IC and stream quality indicators can be predicted by the ICM, which is based on hundreds of research studies on first to fourth order urban streams (CWP, 2003). It is important to keep in mind that the ICM is a guide and not a guarantee: ICM stream indicator predictions are general, and will not apply to every stream within the ICM classification. Urban streams are notoriously variable, and factors such as gradient, stream order, stream type, age of subwatershed development, and past management practices can and will make some streams depart from these predictions. In general, subwatershed IC causes a continuous but variable decline in most stream indicators in a stream category. Therefore, the severity of impacts tends to be greater at the high end of the IC range within each stream category. The ICM is a s imple tool that identifies three classifications of urban streams, according to their current health and future restoration potential (Figure 12). The three types of streams are as fo llows : Impacted Streams have between l 0 and 25% subwatershed IC, and show clear signs of declining stream health. Most indicators of stream health fa ll in the fair range, although some reaches may still be rated as being of good quality. These streams often exhibit the greatest restoration potential since they experience only moderate degradation, have an intact stream corridor, and usually have enough land available in the subwatershed to install restoration practices. No n-Supporting Streams range between 25 and 60% subwatershed IC, and no longer support their designated uses 1, as defined by hydrology, channel stability, habitat, water quality and biological indicators. Subwatersheds at the lower end of the IC range (25 to 40%) may show promise for partial restoration , but are so altered that they normally cannot attain pre-development cond itions for most indicators . In some circumstances, streams in the upper range of the non-supporting category (40 to 60% IC) may show some potential for stream restoration. In most circumstances , however, the primary restoration goals are to reduce pollutants, improve the stream corridor, or enhance community amenities. 1 Th e term '"des ignated uses" has a regu latory co nn ecti on with respect to th e Clea n Wat er Act. in term s of a water body s capacity to support fishin g. swimming, and oth er hum an uses as determined by co mplian ce with applica ble wa ter quality standards and narrative biologica l criteria. Urban Subwatershed Restoration Manual 1 21 Chapter 3: Impacts of Urbanization on Streams 22 Increased annual storm water runoff Diminished baseflow (in some streams) Increased peak discharge for 100-year storm event Increased frequency of bankfull flooding Stream enclosure/modification Loss of riparian forest continuity Stream interruption Floodplain disconnection Increased stream crossings Channel enlargement Greater annual sediment yield Declining stream habitat indexes Diminished large woody debris Increased summer stream temperatures Higher concentrations of pollutants in storm water runoff Eutrophication Exceedance of water contact bacteria standards Potential toxicity to aquatic life Contaminated sed iments Fish consumption advisories Higher loads of trash/debris Decline in aquatic insect diversity Increase in pollutant-tolerant species Decline in fish diversity Loss of capacity to support trouUsalmon Declining riparian plant diversity Urban Subwatershed Restoration Manual 1 Chapter 3: Impacts of Urbanization on Streams Urban Drainage refers to streams that have subwatersheds with more than 60 % IC and where the stream corridor has essentially been eliminated or physically altered to the point that it functions merely as a conduit for flood waters . Water quality indicators are consistently poor, channels are highly unstable and both stream habitat and aquatic diversity are rated as very poor or are eliminated altogether. Thus , the prospects to restore aquatic diversity in urban drainage are extremely limited, although it may be possible to achieve significant pollutant reductions. This chapter presents some quantitative predictions as to how specific stream indicators behave within the three stream categories of the ICM. These predictions help diagnose the severity of stream impacts, set realistic goals for restoration, and may be helpful in the design of restoration practices in the stream corridor. The scientific basis for deriving the ICM predictions is documented in Appendix A. Good Fair Poor 10% 25 % 3 .1 Changes to Stream Hydrology The combination of IC, storm drain pipes, compacted soils , and altered flood plains dramatically changes the hydrology of urban streams. During storms , urban watersheds produce a greater volume of storm water runoff and deliver it more quickly to the stream compared to rural watersheds. As a consequence, urban streams have a distinct hydrograph, as shown in Figure 13. The urban stream hydrograph has a much higher and earlier peak discharge rate, compared to rural or undeveloped streams . In addition, stream flow drops abruptly after storms, and often steadily declines during dry weather due to a lack of groundwater recharge. This basic hydrologic response occurs during every storm, but the effect is most pronounced during smaller, more frequent storms . Non-Supporting 40% 60% 100% Watershed Impervious Cover Figure 12: Representation of the Impervious Cover Model (ICM) The ICM illustrates the relationship between subwatershed IC and expected stream quality, and defines three broad urban subwatershed categories-impacted streams, non-supporting streams and urban drainage. The prospects and strategies for restoration are often markedly different for each of the three subwatershed categories. Urban Subwatershed Restoration Manual 1 23 Chapter 3: Impacts of Urbanization on Streams 24 Large I Storm t I I I Higher and M ore /\ .,._ Rapid Peak Di s c h a rge I \ Small Storm --Pr e ·dcvcloprnent -~ -Post -development w ~ I I I \ More Runoff Volume ~ Lo we r and L ess , I Rapid Pea k ~ / \ I \ a: 3: 0 ...J \ .._ :;: <( w a: .... Hrgh er Basctlow I f / \ \ \ Gradual /Recession / I V> -------/~ ----- TIME - Figure 13: Comparison of Urban and Rural Hydrographs A hydrograph shows the rate of flow in a stream over time after a rainfall event. The hydrograph of an urban subwatershed (dashed /me) is compared to a rural subwatershed (solid /me). Note the higher and earlier peak discharge that occurs in the urban subwatershed. Source : Schueler, 1987 Consequently, urban streams experience an increased frequency and magnitude of flooding. Frequent flash flooding occurs after intense rain events and often causes chronic flood damage. The increased frequency of flooding from smaller storm events often has the greatest impact on streams, as it transports sediments and causes channel erosion. Another hydrologic impact that may sometimes occur is a reduction in stream flows after extended dry weather periods. Urban headwater streams can dry out during droughts due to a lack of groundwater recharge. In other urban streams, however, dry weather stream flows may actually increase because of additional water flows from irrigation, water leaks , or sewer exfiltration in the subwatershed. Much of the tap water supply delivered in the subwatershed actually originates in other subwatersheds. Thus , when residents or businesses use tap water for irrigation or outdoor washing, some fraction of this imported "return" water reaches the storm drain system and eventually returns to the stream itself. Indeed, urban return water can substantially increase dry weather stream flow in arid and semiarid regions. The severity of changes in urban stream hydrology can be predicted by the ICM, as described in Table 2. Impacted streams exhibit substantial changes in their hydrology, compared to undeve loped or rural streams, with increased runoff, flashier hydrographs and more frequent bankfull flooding. While the hydrology changes are pronounced, it may still be possible to minimize them through a combination of upstream storage retrofit practices . Non-supporting streams are much more dominated by urban storm water runoff, with the frequency and magnitude of flooding increasing by as much as an order of magnitude . It may still be possible to partially compensate for changes in stream hydrology through a combination of upstream retrofit practices, but the sheer volume of storm water runoff makes it difficult to manage or treat the entire subwatershed. Often, the best that can be done is to shift hydrologic indicators from non- supporting to the impacted category. As the name implies , urban drainage is completely dominated by storm water runoff, and these streams retain few elements of their original "natural" hydrology. Indeed, urban drainage essentially behaves as a conduit for urban storm water. Given the prodigious volume of storm water produced and the limite d space available to store it, it is often Urban Subwatershed Restoration Manual 1 Ch a p ter 3 : Im p a cts of Urbanizatio n o n Streams impossible to meaningfully improve hydrological indicators for urban drainage. It may still be possible to prevent flood damage from extreme storms in urban drainage , but these efforts may require significant alterations to the existing stream corridor. 3.2 Physical Alteration of the Stream Corridor Urban stream corridors are profoundly altered by land development, and the severity of the alteration can be generally predicted based on subwatershed IC . Major alterations include storm drain enclosure, cu lverts , flood plain encroachment, clearing and mowing, road and sewer crossings, and various engineering "improvements" designed to fix the stream (and its flood waters) in the desired place. Cumulatively, these improvements can greatly reduce the length of the stream channel network within urban subwatersheds, with a disproportionate loss of smaller headwater streams that are enclosed by pipes, channelized or culverted. Dams , pipelines, bridges and other stream crossings also create many potential fish barriers that prevent resident and/ or anadromous fish from moving freely through the stream network. Consequently, spawning success often declines sharply in urban streams. Forest or natural cover along the stream corridor is frequently lost after subwatershed development or is confi ned to a narrow strip. In many cases, the forest buffers that remain are cleared and managed as turf. The progressive reduction in the continuity of natural buffers along the stream corridor has many detrimental consequences to stream ecology and aesthetics. The degree of forest buffer loss in the urban stream corridor is exemp lified by the Hospital Branch subwatersbed near Lewisburg , TN (Figure 14). While Hospital Branch has only 20% IC, less than ha lf of its stream network bas an adequate forest buffer. The quality of the remaining forest buffer in the urban stream corridor is often degraded by invasive p lants, dumping and encroachment. The degree of physical alteration of the urban stream corridor can be forecast in the context of the ICM, as shown in Table 3. Impacted streams often experience moderate interruption of the stream corridor, some loss of headwater stream channels an d moderate loss of forest buffers . Because the stream corridor alterations are relatively modest in most impacted subwatersheds, they can often be directly restored using practices such as fish barrier removal, stream daylighting or riparian reforestation . Stream corridors of non-supporting streams experience major alteration, with significant loss of headwater streams and forest buffers, severe flood plain encroachment, and frequent stream interruption . The alterations may be Jess severe, however, if a community has historically regulated its flood plains or reserved land in the stream valleys for parks. Table 2: Hydrologic Predictions According to the ICM ' ICM Stream Classification Stream Hydrology Indicator Impacted Non-Supporting Urban Dra inage Storm Water Runoff as a 10to 30 % 25 to 60 % 60to 90 % Fraction of Annual Rainfall 1 Ratio of Peak Discharge 100 Year Stormb 1.1to1.5 1.5 to 2 2 to 3 Frequency of Bankfull Flood 1.5 to 3 per year 3 to 7 per year 7 to 10 pe r year Eventsc Notes : a) Stonn water ru noff in undeve lo ped streams range s from 2 to 5%. b) The ratio for undeveloped strea ms for the 100-year storm is 1.0. Ratios are often much greater for storm events of lower return frequency. cl Pre-develooment bankfull fl ood frequency is about 0. 5 oer year, or about one bankfull flood every two yeam . Urban Sub watershe d Re sto ratio n Man ual 1 25 Chapter 3: Impacts of Urbanization on Streams 26 Given the extent of alterations in non- supporting streams, it is often difficult to fully restore the entire stream corridor, although it is often possible to find some individual stream reache s within the subwatershed where the stream corridor can be repaired or restored. Subwatersheds classified as urban drainage are essentially conduits for storm water and posse ss a stream corridor with few natural features. Typically, most first and second order streams are enclosed or channelized; much of the stream corridor is eliminated or confined to a narrow strip; and forest buffers are few and far between . The stream corridor that does remain is often intensively managed for recreation or flood control. Thus, the prospects to restore the stream corridor are limited in urban drainage subwatersheds. Some opportunities may exist to mitigate flooding Table 3: ICM Predictions Concerning Physical Alteration of the Urban Stream Corridor Stream Corridor ICM Stream Classification Alteration Factor Impacted Non-Supporting Urban Drainage Fraction of Original Stream Network 60 to 90% 25 to 60% 10 to 30% Remaining a Fraction of Riparian Forest Buffer Intact b 50 to 70% 30 to 60% less than 30% Stream Crossings c 1 to 2 per stream mile 2 to 10 per stream mile No stream to cross Notes: a) Undeveloped streams typically have 90 to 100% of original stream network remaining . b) Undeveloped streams normally have 80 to 100% of riparian forest buffer intact. c) Rural streams usually have less than one crossing per stream mile . Urban Subwatershed Restoration Manual 1 problems, restore a natural area remnant or create a greenway linking the remaining fragments of intact stream corridor. There may also be selected opportunities to restore higher order streams and rivers that escaped enclosure. 3.3 Degradation of Stream Habitat The increased magnitude and frequency of storm water flows give urban streams more power to transport sediment and cause channel erosion. Most urban streams respond by enlarging their channel cross-section to accommo date the increased flows. Channel enlargement occurs through a combination of widening or down-cutting, depending on the stream type. The cross-section of the current channel can be two to 10 times larger than the pre-development channel, although the full adjustment process may take many decades to complete. Consequently, channel erosion is severe in urban streams, and causes extensive damage to both public infrastructure and private property. The active phase of urban channel erosion greatly increases the sediment supply to urban streams. Urban streams commonly transport two to 10 times more sediment than rural streams. As this sediment moves through the stream, it exerts a strong influence on the streambed, causing many alternating cycles of sediment deposition and erosion. When increased sediment transport is combined with active channel erosion and frequent flooding , it isn't surprising that many habitat features are simplified or eliminated in urban streams (Figure 15). Typically, the normal low-flow channel becomes extremely shallow and variable, and pool and riffie structure is lost. Individual habitat elements such as large woody debris, pools, channel sinuosity, meanders , and undercut banks are sharply diminished. The materials of the streambed tum over frequently, and fine sediments become embedded within coarser- grained bed materials. As a result, the highly unstable and embedded streambed becomes less suitable for fish spawning . Urban Subwatershed Restoration Manual 1 Chapter 3: Impacts of Urbanization on Streams Stream habitat is typically measured by examining a composite of individual habitat metrics thought to contribute to habitat quality. Based on these assessments, most urban streams are consistently ranked as having "poor" to "fair" stream habitat. Few urban streams are ever classified as having "good" or "excellent" habitat ratings. Finally, urban streams tend to have warmer summer temperatures than undeveloped streams, with mean temperatures increasing by two to 10 degrees Fahrenheit. Much of the stream warming is caused by the heat island effect ofIC, but can be intensified by impoundments and the loss of streamside forest cover. In many regions of the country, urban stream warming makes it difficult to support trout, salmon and other cold-water adapted species. The ICM predicts the nature and extent of habitat degradation, which can help craft realistic strategies to restore or repair urban streams (Table 4). Impacted streams typically possess "fair" habitat, although "good" habitat conditions may be encountered at the lower range of IC . The potential to restore many habitat elements in impacted streams is often good , if the stream corridor remains intact and upstream retrofits are built. Under these conditions, it may even be possible to systematically restore habitat throughout the stream network of an impacted subwatershed. Non-supporting subwatersheds consistently experience severe erosion, extensive habitat degradation and frequent interruption of the remaining stream network. For these reasons, many practitioners doubt that full ecological restoration is possible within non-supporting streams (Konrad, 2003). Still, important structural and functional stream elements can be repaired, particularly if upstream retrofits create more stable hydrological conditions. Consequently, "restoration" within this class of streams involves practices that repair a specific stream problem at a defined point or reach within the stream network, which may or may not have associated ecological benefits. Common stream repairs include stabilizing eroding streambanks, removing fish barriers, 27 Chapter 3: Impacts of Urbanization on Streams A . Refe ren ce Stream B. Urban Stream Figure 15: Contrast in Habitat Features Between Rural and Non-Supporting Streams These photos compare typical habitat features in urban and rural streams , with respect to bank stability. sediment deposition, channel enlargement, and npanan cover. Also, note the difference in the depth and wetted perimeter of the base flow channel between the two streams. Table 4: Stream Habitat Predictions According to the ICM Stream ICM Stream Classification Habitat Indicator Impacted Non-Supporting Urban Drainage Ultimate Channel Enlargement 1.5 to 2.5 2 .5 to 6 6 to 12 Ratio a times larger times larger times larger Sediment Yieldb 2 to 5 5 to 10 possibly lower times qreater times qreater Typical Stream Habitat Score c fair , but variable consistently poor poor, often absent Presence of Large Woody Debris 2 to 3 pieces per scarce absent d 100 feet Increased Summer Stream Temperatures e 2 to 4 degrees F 4 to 8 degrees F 8 +degrees F Notes a) Ultimate channel cross-section compared to pre -development cross-section . b) Compared to stable rural stream . c) As computed by EPA Rapid Bioassessment Inde x or QHI . d) Forested stre ams ha ve 5 to 15 pieces of LWD per 100 feet of stream . e) Compared to shaded rural stream . 28 Urban Subwatershed Restoration Manual 1 preventing channel incision or recreating in- stream habitat. Subwatersheds classified as urban drainage have extremely poor stream habitat in the few place s where it has not been physically eliminated. Consequently, the prospects for restoring the structure and function of the urban drainage channels are very poor, although some individual reaches may show some restoration potential. In addition, habitat improvements or stream repairs may still be possible on larger streams and small rivers that may have escaped significant alteration. 3.4 Decline in Water Quality Just about any pollutant deposited from the atmosphere or generated within a subwatershed is likely to be washed off in urban storm water runoff (Figure 16). Consequently, storm water runoff contains a wide range of pollutants that can degrade local or downstream water quality. A recent summary of national median concentrations for more than 20 pollutants frequently detected in storm water runoff is provided in Appendix A. Pollutant concentrations tend to vary with each storm event, and may also vary based on the prevailing land use, region of the country, and type of precipitation. In general, however, the unit area pollutant load delivered to a stream always increases in direct proportion to subwatershed IC. Pollutant reduction is usually a major goal of most watershed restoration efforts. The basic strategy is to determine which pollutants are causing the water quality problems of greatest concern, isolate their major sources in the subwatershed, and then apply a combination of restoration practices to treat runoff to reduce these pollutant levels. A comprehensive review of the concentrations, sources and water quality impacts of 10 major storm water pollutants found in urban storm water can be found in CWP, 2003. These pollutants include sediment, nutrients , trace metals, hydrocarbons, bacteria, organic carbon, pesticides, deicers , and trash and debris . Urban Subwatershed Restoration Manual 1 Chapter 3: Impacts of Urbanization on Streams The severity of water quality problems in urb an streams can be reliably predicted with knowledge of subwatershed IC. From the perspective of the ICM , it is important to examine five common water quality problems : eutrophication, exceedance of bacteria standards, aquatic life toxicity, sediment and fish tissue contamination, and trash and debris loads (Table 5). Eutroph/cation High levels of phosphorus and nitrogen in urban storm water runoff can cause eutrophication in streams and contribute to algal blooms in downstream lakes and estuaries. The annual nutrient load produced by urban subwatersheds can be as much as six times higher than rural ones, making it difficult to completely reverse the symptoms of eutrophication. Impacted subwatersh eds generate comparatively modest nutrient loads , and it may be possible to reduce these loads to rural background levels through widespread implementation of restoration practices. Achieving nutrient reduction goals in non- supporting subwatersh eds is more problematic. The crux of the problem is that nutrient loads in these subwatersheds are two to four times greater than rural subwatersheds, yet current 29 Chapter 3: Impacts of Urbanization on Streams 30 Table 5: Water Quality Predictions According to the ICM Water ICM Stream Classification Quality Indicator Impacted Non-Supporting Urban Drainage Annual Nutrient 1 to 2 times higher 2 to 4 times higher 4 to 6 times higher Load a than rural backqround than rural background than rural backqround Violations Continuous violations Continuous violations Frequent violations during wet weather; during wet weather, of Bacteria Standards b during wet weather Episodic violations during frequent violations during dry weather dry weather Aquatic Life Moderate potential for High potential for acute Toxicity c Acute toxicity rare acute toxicity during toxicity during dry and some storms and spills wet weather Contaminated Sediments enriched but Sediment contamination Contamination should be Sediments not contaminated likely, potential risk of presumed bioaccumulation Potential risk of Fish Advisories d Rare bioaccum ulation Should be presumed Trash and Debris e 1 to 2 tons 2 to 5 tons 5 to 10 tons per square mile per square mile per square mile Notes a) Annual load of phosphorus or nitrogen produced by a rural subwatershed. b) Rural stream might violate standards during 10 to 20% of storms. c) Acute toxicity would be very rare in a rural stream. d) Enrichment in comparison to sediment quality of rural stream . e) Based on trash loading estimates from various CA , MD, and NY trash studies and TMDLs . restoration practices can generally only reduce nutrient load by about 40 to 60% (even assuming that the subwatershed is fully treated with retrofits and source controls). Nevertheless, nutrient reduction efforts may still be warranted in non-supporting subwatersheds as one part of a comprehensive watershed-wide nutrient reduction strategy. The disparity between the nutrient load produced and the capacity to reduce it is even greater in subwatersheds classified as urban drainage . Given the intensity of development in urban drainage subwatersheds, it is often a challenge to find enough feasible retrofit sites to get full treatment of all nutrient sources. Still , nutrient reduction may still make sense in an urban drainage subwatershed if it cost- effectively contributes to a watershed-wide reduction strategy. Bacterial Contamination Fecal coliform bacteria levels found in storm water runoff routinely exceed water qu a lity standards, thereby limiting or preventing water contact recreation, shellfish harvesting or swimming in urban waters during and after storm events. Bacteria levels can sometimes violate water quality standards during dry weather periods as a result of sewage leaks, overflows or illicit discharges . The degree to which bacteria impairs designated uses in urban waters is a direct function of IC and can be interpreted in the light of the ICM (Schueler, 1999). Streams within impacted subwatersheds will frequently violate bacteria standards during some storm events, but usually support water contact recreation during dry weather periods, particularly at the lower end of the IC range. Often, impacted streams can reliably meet standards when storm water retrofit and bacterial source controls are applied to the subwatershed. Streams in non-supporting subwatersheds continuously violate standards during wet weather conditions unless favorable dilution or mixing conditions are present. Non-supporting streams may al so episodically violate bacteria standards during dry weather periods, as a result of sewage leaks and overflows . Bacteria standards can seldom be attained in non- Urban Subwatershed Restoration Manual 1 supporting streams during wet weather conditions even with extensive subwatershed treatment. The main reason is that bacteria concentrations are so high that they would require a 99% removal rate in order to achieve standards. Such a high level of treatment cannot be achieved with current restoration practices (Schueler, 1999). However, if bacteria sources are found and eliminated from the sewer and storm drain network, standards may be achievable during dry weather conditions. Subwatersheds that are classified as urban drainage continuously violate bacteria standards during wet weather conditions and frequently violate them during dry weather, as well. Given the sheer number and diversity of bacteria sources , it is not realistic to expect compliance with bacteria standards in urban drainage "streams." However, bacteria source controls may still be warranted if they contribute to a larger watershed bacteria- reduction strategy. Aquatic Life Toxicity Storm water runoff contains concentrations of copper, chlorine, zinc, cadmium, lead , hydrocarbons , and deicers that can potentially be toxic to aquatic life in urban streams . In addition, numerous pesticides have been detected during storm flow and dry weather flow within urban streams , including several known to cause mortality in aquatic life. Other toxins may enter urban streams as a result of spills, accidents, leaks and illicit discharges from storm water hotspots , which produce higher levels of storm water' pollution and/or present a higher risk for spills , leaks and illicit discharges. In general, the number and diversity of storm water hotspots increase with the intensity of subwatershed development. Consequently, the risk of potential toxicity to aquatic life can be interpreted within the context of the ICM. Most scientists agree that acute toxicity to aquatic life is rare in impacted streams, although others suggest that some pollutants mi ght cause chronic toxicity. Pollutant level s in urban storm water are typically below the Urban Subwatershed Restoration Manual 1 Chapter 3: Impacts of Urbanization on Streams thresholds for acute toxicity, although they may exceed sta ndards for brief periods of time . The greatest risk of aquatic life toxicity in impacted streams is from spills, accidents and discharges . This risk can be sharply reduced if pollution prevention practices are implemented at storm water hotspots in impacted subwatersheds . Non-supporting subwatersheds exhibit moderate potential for acute toxicity during some storms and spill e vents . The toxins of greatest concern will often vary in non- supporting subwatersheds, and depend on the prevailing mix of land use and hotspots. The risk of potential toxicity to aquatic life in non- supporting streams can be reduced ifretrofit and pollution prevention practices are widely applied across the subwatershed. The issue of toxicity in urban drainage is often moot, since other stressors have already diminished the diversity of aquatic life (i .e., sensitive fish and insect species are often eliminated). Pollution prevention practices and retrofits may be warranted in urban drainage subwatersheds if they reduce toxin loads to downstream aquatic ecosystems . Sediment Contamination Many pollutants are attached to sediments borne in storm water runoff, which are eventu'ally deposited in slow-moving waters such as lakes , rivers, estuaries and wetlands. Urban sediments have a diagnostic signature of contamination, with enriched levels of copper, cadmium, lead, mercury, zinc, organic carbon, hydrocarbons and pesticides. In addition, long- banned compounds such as DDT, dieldrin , and PCBs are often detected in urban sediments . The effect of sediment contamination on aquatic life is poorly documented, but clear evidence exists that metals, pesticides and hydrocarbons bioaccumulate in larger fish and other aquatic life in urban streams . For example, the USGS (2001) found that 100 % of fish sampled in urban streams had detectable levels of pesticide in their tissues. Even more troubling was the finding that 20% of the fish tissue samples exceeded recommended levels for fish-eating wildlife (such as raccoons, 31 Chapter 3: Impacts of Urbanization on Streams 32 kingfishers, ospreys and eagles). Pollutant level s in fish tissue may sometimes exceed action levels set to protect human health in highly urban subwatersheds. When the se occur, health authorities issue advisories to pre vent or restrict fish consumption from local waters. The severity of sediment contamination can be evaluated within the context of the ICM. Sediment contamination is usually not a major problem for impacted subwatershe ds , although deposited sediments will usually contain higher levels of trace metal s and hydrocarbons than would be found in a rural stream. The potential for sediment contamination and subsequent bioaccumulation in fish and other aquatic life is much greater in non-supporting subwatersheds. The risk is greatest for lakes, coves and waterfronts that are small in relation to the area of their contributing non-supporting subwatershed. In general , it should be presumed that bottom sediments from urban drainage subwatersheds will be contaminated with some pollutants, and that these may bioaccumulate within whatever remains of the fish community. Consequently, human consumption of fish from urban drainage subwatersheds should be avoided. Trash and Debris Large quantities of litter, trash and debris wash through the storm drain system into streams and receiv ing waters. Often, the problem is exacerbated by illegal dumping. While trash and debri s are an uns ightly annoyance in other settings, they are a major problem in urban subwatersheds. The prodigious loads of trash and debris generated by urban subwatersheds can diminish the scenic character of urban waters and waterfronts, interfere with des ignated uses such as swimming or boating, and severely detract from public attitudes about stream quality. While trash is often noticed, it is seldom measured in urban streams. Recent preliminary estimates of trash generation rates for urban streams range from one to 10 tons of trash and debri s per square mile of urban subwatershed (see Appendix A). Trash and debris loads appear to be related to subwatershed IC . Within the context of the ICM, the following predictions can be made with respect to trash and debris and its management. Trash is noticeable in impacted subwatersheds, and often concentrates in de bris jams and backwaters. However, generation rates are relatively modest, particularly ifthe impacted subwatershed is primarily residential. Cleanups and education can make a real difference in the appearance of impacted streams, as long as they are frequently repeated . Tra sh can become a moderate to severe problem within non-supporting and urban drainage sub waters heds . The higher rate of trash generation means that creeks, shorelines, and waterfronts will receive a significant load of trash and debris after every major storm. Even regular stream cleanups may not keep pace with this increased supply. Additional measures such as booms, catch basin clean outs, litter enforcement, storm drain stenciling, dump ster management or the operation of trash skimmers may be needed to control the trash problem. 3 .5 Loss of Aquatic Diversity The decline in physical, hydrologic and water quality indicators collectively dimini shes the quality and quantity of available habitat in urban steams. As a result, urban streams experience reduced aquatic diversity, a shift toward more pollution-tolerant species, and a progress ive lo ss of ecosystem structure and function (CWP, 2003). This trend is exemplified by aquatic insects, which often form the base of the stream food chain in many streams in North America. In general, aquatic insect diversity decline s as subwatershed IC increases. A typical example of this relationship is provided in Figure 17, which compares aquatic insect diversity scores for a large number of subwatersheds with different IC in suburban Northern Virginia. While some scatter is always seen in such data, the trend toward reduced aquatic insect di ve rsity with progressively greater IC is clearly evident. Urban Subwatershed Restoration Manual 1 Chapter 3: Impacts of Urbanization on Streams Under current patterns of development, urban streams lose their potential to have "good" or "excellent" aquatic insect diversity at about 20 % subwatershed IC, and lose the potential to achieve "fair" diversity scores at about 30% subwatershed IC. This basic pattern in aquatic insect diversity has been reinforced by more than 20 urban stream studies (CWP, 2003). Other researchers have noted that habitat-or pollution-sensitive species are eliminated from the aquatic insect community in highly urban watersheds. The most common method used to assess this change is the EPT index, which looks at the proportion of sensitive stonefly, mayfly and caddisfly species found in the aquatic insect community (Table 6). A similar decline is also observed for fish diversity in urban streams. Sharp drops in fish diversity scores are universally reported for urban streams, with the best index scores ranging from "fair " to "very poor." The health of the fish community is also diminished, with lesions and bioa ccum ulation commonly lOO • --·~·-.--------- .'I. reported. The fish community in urban streams also tends to be dominated by pollution- tolerant or non-native species. Sensitive fish species that require cold water or a clean stream bed usually disappear as subwatershed IC increases. Consequently, it is difficult to maintain a self- sustaining trout or salmon population in many urban streams. Likewise, poor stream bed quality and frequent stream interruption make urban streams a poor spawning environment for anadromous fish that move from estuaries or the oceans to spawn. Although urban stream ecology remains a very young science, researchers have discovered that important functional elements of stream ecosystems are altered by subwatershed development (Paul and Meyer, 2001; Palmer et al ., 2002; Meyer and Couch, 2001). For example , stream researchers have found that in-stream processes such as leaf pack decay, nutrient uptake, retention time and carbon processing occur at different rates in urban 80 --------<>--------~~_.;_~~::.;I:i.._:~_:_.....s:..;...,;::.._~~~~ -::::: - .. • 60 • 40 • • • ---~-~-----"""~---• • • i • . . 20 • • .. • . . .. 0 0 IO 20 30 40 50 Pc n :c nl I mix· rviou.-. ncss Fairfax Co, VA Figure 17: Relationship Between Subwatershed IC and Aquatic Insect Diversity This is one of many studies that shows the decline in aquatic insect diversity as a function of subwatershed IC (Fairfax County, 2000). While there is always some variability in aquatic insect data , note how diversity scores rarely exceed 60% B-IBI or "fair'' once subwatershed IC exceeds 20%. Urban Subwatershed Restoration Manual 1 33 Chapter 3: Impacts of Urbanization on Streams 34 Table 6: Predictions on Aquatic Diversity According to the ICM Aquatic ICM St ream Classification Dive rsi ty Impa cted No n-Supporting Urban Drai na ge In dica tor Aq uatic Insect fair to good poor very poor Diversity a EP T Ta xa b 40 to 70% 20 to 50% 0 to 20% Fish Dive rsity c fair to good poor very poor T rout o r Sa lm on d limited potential temporary use only no potential Ri paria n Pla nt stressed, with simplified c ommunity isolated remnants; reduced native plant Diversity diversity with many exotic species dominated by exotics Notes a) As measured by Benthic Index of Biotic Integrity. Scores for rural streams normally range from "good" to "very good." b) Aquatic insect metric that looks at sensitive stonefly, caddisf/y and mayfly species; values shown are percent of score for undeveloped reference stream or a "put and take " fishery c) As measured by fish Index of Biotic Integrity. Scores for rura l streams typically range from "good" to "excellent." d) Ability to maintain a self-reproducing population. e) As comp ared to flood plain forest or wetlands plant communit y adjacent to rural strea m. streams compared to rural or undeveloped ones. It is too early to tell how these changes in ecosystem function will influence the prospects for urban stream restoration. An important but frequently overlooked aspect of stream corridor biodiversity is the simplification of plant diversity in the flood plains and wetlands. Both plant communities suffer from filling and encroachment, and remaining fragments continue to be disturbed by increased water fluctuations, falling water tables, exotic plants, deer browsing and human disturbance. Consequently, wetland and flood plain plant communities often experience significant changes in species composition, with increased invasive or exotic species, declining regeneration of native species, and longitudinal shifts in species along the stream corridor (Brush and Zipperer, 2002; Groffrnan et al. 2003). The loss of aquatic diversity in the urban stream corridor can be interpreted in the light of the ICM (Table 6). As with other indicators, impac ted streams experience a fairly moderate decline in aquatic diversity, with diversity scores consistently ranking as "fair" to "good." Thus, prospects for partial recovery are good if restoration practices can be applied comprehensively to both the stream corridor and upland areas of the subwatershed . It may even be possible to partially restore a trout, salmon or anadromous fishery, particularly at the Low end of the IC range of impacted streams. Full restoration of aquatic diversity in non- supporting streams is probably an elusive goal, given the many different stressors affecting the stream and its flood plain. Most diversity indicators are solidly in the "poor" range for non-supporting streams. If restoration practices are comprehensively applied across a non- supporting subwatershed, it might be possible to shift the communities into the "fair" range, but it is doubtful whether "good" or "excellent" diversity can ever be attained . Impro ve d diversity is possible, however, if success is defined in the context of a "good" urban stream instead of an unattainable high quality undeveloped stream. For example, while it may be impossible to support a self- sustaining trout population in a non-supporting stream, it may be possible to support a "put and take" trout fishery with annual stocking. Similarly, it may still make sense to remove fish barriers in non-supporting streams, even if actual spawning success will vary greatly from year to year. Urba n Subwatershed Resto ra tion Manual 1 Subwatersheds classified as urban drainage ha ve "poor" to "very poor" aquatic diversity in the portions of the stream network that still support stream habitat. As noted earlier, urban drainage is frequently interrupted, which makes natural recolonization difficult or impossible. Consequently, prospects for restoring much aquatic diversity in urban drainage is extremely limited, although some individual stream reaches may show modest restoration potential. The best candidates are larger streams and small rivers that may have escaped significant alteration and natural area remnants along the stream corridor. Urban Subwatershed Restoration Manual 1 Chapter 3 : Impacts of Urbanization on Streams 3.6 Summary The ICM sets benchmarks that define stream quality expectations for each of the three urban stream categories. As such, the ICM can generally predict the severity of stream impacts, and set realistic goals for subwatershed restoration. It bears repeating that the ICM is a guide and not a guarantee . Some urban streams will depart from these expectations, and these outliers are often of considerable interest when it comes to restoration design. The next chapter reviews the full range of restoration practices that can be used to compensate for the impact of subwatershed development. 35 Chapter 3: Impacts of Urbanization on Streams 36 Urban Subwatershed Restoration Manual 1 Ch apter 4 : The Ran ge of Subwa tershed Restoration Practices Chapter 4: The Range of Subwatershed Restoration Practices The term "restoration practice" is defined as the application of structural or non-structural techniques in urban subwatersheds to improve stream health, as measured by improvements in physical, hydrological, chemical , ecological or social indicators . At least 130 different techniques can potentially be used to restore urban subwatersheds. These restoration practices can be broadly classified into seven major groups, which are reviewed in this chapter (Figure 18): 1. Storm Water Retrofit Practices 2. Stream Repair Practices 3. Riparian Management Practices 4. Discharge Prevention Practices 5. Pervious Area Management Practices 6. Pollution Source Control Practices 7. Municipal Practices and Programs The choice of which combination of practices to apply depends on your restoration goals, along with the restoration potential and development intensity within your subwatershed. In general, the first four types of restoration practices are applied to the remaining stream corridor. The remaining three restoration practices are usually applied to upland areas in the subwatershed, although some on-site storm water retrofits can also be installed in upland areas. This chapter describes each major group of restoration practices, briefly reviews the specific strategies and techniques for implementing them, and discusses how restoration practices can meet subwatershed restoration goals . Urban Sub wa ters hed Re stora tion Manua l 1 4. l Storm Water Retrofit Practices Storm water retrofits are structural practices installed within the stream corridor or upland areas to capture and treat storm water runoff before it is delivered to the stream. Storm water retrofits are the primary practice for restoring subwatersheds, since they can remove and/or treat storm water pollutants , minimize channel erosion, and help restore stream hydrology. Retrofits can be further classified by the subwatershed area they treat. Storage retrofits , such as ponds, wetlands, filtering and infiltration practices , can typically treat subwatershed areas ran g ing from five to 1,000 acres . On-site retrofits capture runoff from individual source areas , such as rooftops, parking lots and street sections . Residential on-site retrofits are designed to treat areas as small as a few hundred square feet, whereas nonresidential retrofits normally serve areas up to two acres in size. Manual 3 provides extensive guidance on 17 different retrofit techniques that can be app lie d in urban su bwatersheds; a summary list is provided in Appendix B. storage Retrofits A typical example of a storage retrofit is the pond/wetland system constructed within an older detention pond shown in Figure 19. This retrofit was designed to remove pollutants from storm water runoff, reduce downstream channel erosion, and provide local wild life habitat. A s the name implies, storage retrofits may require several acre-feet of storage to effective ly perform their restoration function . Therefore, the best sites for storage retrofits are found within exist ing detention ponds, a bove roadway embankments and cu lverts, within highway rights-of-way, within large parking 37 Chapter 4 : The Range of Subwatershed Restoration Practices 38 • Storage retrofits On-site non-residential retrofits • On-site residential retrofits • Stream clean-ups • Stream repair practices • Comprehensive restoration practices • Site preparation • Active reforestation • Park or greenway plantings • Natural regeneration • Riparian wetland restoration Finding, fixing or preventing : • Illicit sewage connections • Commercial and industrial illicit connections • Failing sewage lines • Industrial and transport spills • Land reclamation • Upland revegetation/reforestation • Management of natural area remnants • Residential source control • Hotspot source control • Street and storm drain practices • Best practices for development/ redevelopment • Stewardship of public land • Municipal stewardship programs • Watershed education and enforcement lots , and at golf courses. New storage retrofits can also be constructed at existing storm water outfalls , if enough adjacent land is available to provide the required storage. Many storage retrofits must be constructed within a subwatershed to meet restoration or treatment goals. The process of finding and evaluating candidate sites for storage retrofits is known as a "retrofit inventory." In general, site constraints and land availability make it impossible to obtain full treatment with storage retrofits across a subwatershed, but it is often possible to find enough storage to reduce pollutant loads to meet many subwatershed goals. On-site Nonresidential Retrofits Commercial, industrial and institutional sites can also provide opportunities to treat storm water runoff. The objective of nonresidential on-site retrofits is to capture and treat storm water from larger rooftops, parking lots, and other source areas. Common examples include the construction of bioretention islands within existing parking lots, green roofs, and storm water planters to treat rooftop runoff. Often, on-site nonresidential retrofits are often combined with storage retrofits to achieve comprehensive treatment across a subwatershed. Urban Subwatershed Restoration Manual 1 On-site Residential Retrofits Rain barre ls and rain gardens are common examples of on-site residential retrofit practices. On-site retrofits are typically installed on individual homes or yards to store or infiltrate runoff from rooftops , driveways or yards . On -site retrofits promote infi ltration, which can reduce storm water runoff, treat storm water pollutants at their source , and increase groundwater recharge . Because each individual on-site retrofit treats such a small area, dozens or hundreds are needed to make a measurable difference at the subwatershed level. Consequently, widespread homeowner implementation of on-site retrofits requires targeted education, technical assistance and financial subsidies . On-site retrofits are often combined with storage retrofits to increase the extent of subwatershed treatment. Urban Subwatershed Restoration Manual 1 Chapter 4 : The Range of Subwatershed Restoration Practices 4. 2 Stream Restoration Stream restoration practices include a large group of techniques used to enhance the appearance, structure or function of urban streams. These practices range from simple stream cleanups and basic stream repairs to extreme ly sophisticated stream restoration techniques. Stream restoration practices are often combined with storm water retrofits and riparian management practices to meet subwaters hed restoration goals. Manual 4 provides detailed g uid ance on 33 different stream restoration techniques that can be app li ed in urban subwatersheds; a summary list is provided in Appendix B . Stream Cleanups These techniques involve regular pickup and disposal of trash , debris , litter, and rubble from the stream or its corridor, usually with volunteer help. While stream c leanups are often cosmetic and temporary, they are extreme ly effective tools for involving and educating the public about urban stream degradation . In addition, public attitudes toward urban creeks are often influenced by the presence or absence of trash and debris . We ll-organized and frequent stream cleanup programs can remove impressive quantities of trash and debris from the stream corridor, thus preventing its movement to downstream waters. 39 Chapter 4 : The Range of Subwatershed Restoration Practices 40 Urban Subwatershed Restoration Manual 1 Stream Repair Techniques Techniques from this large group repair a specific stream problem at a defined point or stream reach. The primary goal may be to stabilize an eroding stream bank, remove a fish barrier, day light a storm water pipe, create in- stream fish habitat, or control channel incision (Figure 20). Stream repair techniques can be classified by primary design objective: · Hard bank stabilization · Soft bank stabilization · Grade control · Flow deflection · In-stream habitat enhancement · Flow diversion · Fish barrier remova l Stream repair techniques are inherently limited by their in-stream location, which may result in the treatment of symptoms but not the underlying causes. Comprehensive Restoration Practices This technique takes a more sophisticated and comprehensive approach toward stream restoration. The goal is to design a more natural geometry and habitat structure for the stream channel and banks consistent with its current hydro logy and sediment transport dynamics. The broad objectives for these techniques are to restore more natural channel morphology and improve habitat conditions for aquatic life. This may entail natural channel design, dechannelization, or multiple applications of many individual stream repair techniques . Urban subwatersheds are an extreme ly challenging environment for comprehensive stream restoration, given the dynamic changes in hydrology and sediment transport caused by upstream development. A stable channel fom1 that still experiences altered hydrology and sediment transport may not be hospitable to native aquatic species. Urban Sub watersh e d Restoration M anual 1 Chapter 4 : The Range of Subw a te rshed Restoration Pra ctices Whether the ultimate goal of comprehensive stream restoration is recovering a trout or salmon population or enhancing fish diversity, meeting this goal requires integrating stream restoration efforts w ith other restoration practices in the stream corridor and subwatershed . An excellent example of a comprehensive approach to stream restoration is Wheaton Branch in Montgomery County, Maryland (Figure 21 ). 4.3 Riparian Management Riparian management practices involve eight basic techniques to restore the q uality of forests and wetlands withi n the remaining stream corridor. The overall goal of riparian management is to improve the continuity of streamside vegetation to maximize the many benefits that buffers provide (e.g., pollutant removal, shading, large woody debris , etc.). Given that urban stream corridors are heavi ly used and have multiple owners, many individual riparian management projects may need to be linked together to create a better riparian zone. Each riparian management project must be designed to address the unique stresses and disturbances that occur within the urban stream corridor, and maximize storm water infiltration and subsequent pollutant removal. Manual 5 offers detailed guidance on eight riparian management techniques to revegetate the stream corridor; a summary list is provided in Appendix B. Site Preparation While there may be many potential reforestation sites in the urban stream corridor, they are often highly impacted by dumping, soil compaction, hill-s lope erosion, mowing, invasive plants and other disturbances. Site preparation is us uall y needed to make a riparian site suitable for successful revegetation or reforestation. Site preparation techniques 4 1 Chapter 4: The Range of Subwatershed Restoration Practices 42 include remova l of trash and rubble, control of invasive plant species, restoration of urban soils, control of hill-slope erosion, and the capture and distribution of storm water evenly across the riparian zone . Once sites are adequately prepared, they can be revegetated to improve the quality and functional value of the streamside zone, based on the intended management use of the stream corridor. Four basic strategies for revegetating the riparian zone are shown in Figure 22 and described below. +Q l><l <I -xxx ' Severe erosk)n gully (corrected and convey in storm drain pipe) \\<0 \\ \) \\ <0 -J '--:::::::i --\\ D = Placed rlp rap = lmbricated rip rap = Root wad placement "" Random bouider placement • Ooubte wing deflector = Single wing deflector '"' Log drop structure = Brush bundle "" Reforestation \\I\\ \ \ 1) _.1 \\) ---D \ \ 1J I D _)} 0 ;; I o // Active Reforestation These planting techniques are designed to maximize the ecological benefits of a forested flood plain by creating a mature and self- sustaining native plant community. Parks or Greenways These plantings are applied when the stream corridor is used for recreational activities such as hiking, biking or nature enjoyment. The Urban Subwatershed Restoration Manual 1 planting plans within these park or greenway settings seek to expand natural vegetative cover while still accommodating the needs of park users. Natural Regeneration This technique allows vegetation to grow back in the stream corridor by stopping mowing operations. Although natural regeneration is simple and inexpensive, it can take a long time to establish a mature streamside forest along the stream corridor. Natural regeneration may also result in a plant communi ty that could be dominated by invasive or exotic plant species . Urban Subwatershed Restoration Manual 1 Chapter 4 : The Range of Subwatershed Restoration Practices Riparian Wetland Restoration These techniques are used to enhance or re store d egraded wetland communiti es found along th e flood plain. Wetlands are frequently assoc iated with stream corridors because of the close hydro logic connection of the stream with its flood plain. In urb an subwatersheds, however, the stream and its flood plain may become disconnected . This occ urs when the elevat ion of the stream channel drops due to severe channel erosion, which leaves the flood plain wet lands high and dry (Groffman et al, 2003). Consequently, riparian wetland restorat ion can involve engineering techniques 43 Chapter 4: The Range of Subwatershed Restoration Practices 44 to reconnect the stream with its flood plain or redirect urban storm water generated from outside the stream corridor to create surface wetlands . 4.4 Discharge Prevention Pract ices Discharge prevention practices prevent sewage and other pollutants from entering the stream from illicit discharges, sewage overflows, or industrial and transport spills . Discharges can be continuous, intermittent, or transitory, and depending on the volume and type , can cause extreme water quality problems in a stream. Sewage discharges can directly affect public health (bacteria), while other discharges can be toxic to aquatic life (e.g ., oil, chlorine, pesticides, and trace metals). Discharge prevention focuses on four types of discharges that can occur in a subwatershed, as described below. Illicit Sewage Discharges Sewage can get into urban streams when septic systems fail or sewer pipes are mistakenly or illegally connected to the storm drain pipe network. In other cases, "straight pipes" discharge sewage to the stream or ditch without treatment, or sewage from RVs or boats is illegally dumped into the storm drain network. Research has shown that sewage is the most common type of illicit discharge in most communities (Brown et al., 2004). These discharges can be detected by screening storm water outfalls with dry weather flow for water quality parameters that indicate suspected sewage contamination. More detailed diagnostic tests a e often needed to trace the problem up the pipe network and iso late the specific home or business connection that is discharging sewage or septage. Commercial and Industrial Illicit Discharges Some businesses mistakenly or illegally use the storm drain network to dispose of liquid wastes that can exert a severe water quality impact on streams . Examples include shop drains that are connected to the storm drain system; improper disposal of used oil, paints, and solvents; and disposal of untreated wash water or process water into the storm drain system. A large number of commercial, industrial, institutional, municipal, and transport-related sites have the potential to generate these discharges on an in termittent or transitory basis . Brown et al. (2004) and Manual 8 provide detailed guidance on how to identify generating sites, and describe education and enforcement methods for eliminating illicit discharges. Falling Sewer Lines Sewer lines often follow the stream corridor, where they may leak, overflow or break, sending sewage direct ly to the stream. The frequency of failure depends on the age, condition and capacity of the existing sanitary sewer system. The vigilance of the local sewer authority is also important to minimize failure . Regular inspection of sewer lines, prompt response to overflows and leaks, and ongoing repairs to the sewer infrastructure can sharply reduce sewage discharge. Urb an Subwa te rsh e d Restoration Manual 1 Industrial and Transport Spills Tanks rupture , pipelines break, accidents cause spills, and morons dump pollutants into the storm drain system. It is only a matter of time before these events occur in most urban subwatersheds, allowing potentially hazardous materials to mo ve through the storm drain network and reach the stream. Since spills are unpredictable, they can only be managed by maintaining an emergency response system that quickly reacts to spills and contains the damage. Spill response plans are needed for storm water hotspots , many industrial sites, and the road system of the subwatershed. Manual 6 provides general guidance on the range of techniques to find, fix or prevent all four types of discharge s in an urban subwatershed. A condensed list of the discharge prevention techniques profiled in the manual can a lso be found in Appendix B. 4 .5 Pervious Area Management Municipalities often own or manage as much as 10 % of total subwatershed area in parks, open lands, golf courses, schools and tax delinquent parcels . Some of these areas are prime candidates for land reclamation, which impro ves soil quality by amending it to increase its capacity to infiltrate rainfall, and create better conditions for healthy plant growth . Manual 7 offers guidance on eight pervious area management techniques ; Appendix B provides a condensed summary list. Urban Sub watershe d Restoratio n M anual 1 Chapter 4: The Range of Subwatershed Restoration Practices land Reclamation Because urban soils are extremely compacted, they often have poor vegetative cover and infiltration capabilities . Consequently, many pervious areas in urban subwatersheds produce more storm water runoff and sediment than undeveloped areas. Land reclamation seeks to restore soil quality on tracts of land that are vacant, abandoned or unused, or within individual yards. This technique includes compost and other soil amendments, tilling, and aeration. In many ways, land reclamation practices are similar to rain gardens and other residential on-si te retrofit practices. Land reclamation is a relatively new urban restoration technique, and its subwatershed benefits can only be realized when it is widely implemented across a subwatershed. Upland Revegetation Once soil quality has been restored, trees or other forms of native cover can be planted to measurably increase overall forest cover within a subwatershed. The canopy interception and infiltration created by expanded forest cover can improve stream hydrology and reduce the urban heat island effect. It should be noted that prairie, meadows or grasslands may be the idea l native vegetative cover in some regions of the country. In any event, revegetation must be conducted at a widespread scale in a subwatershed to provide measurable hydrologic and water quality benefits . 45 Chapter 4 : The Ra n ge of Subwatershed Restoration Practices 46 Management of Natural Area Remnants This practice enhances the quality of remaining forest fragments, wetlands and other natural area remnants in the upland areas of the subwatershed. Like their counterparts along the stream corridor, natural area remnants are frequently impacted by dumping, soil compaction, erosion, invasive plants and storm water runoff. This practice usually invo lves an eco logical assessment of the natural area remnant to identify key stressors, followed by a restoration plan to improve its ecological structure and function. 4.6 Pollution Source Control Practices Source control is a broad restoration practice that seeks to prevent pollution from residential neighborhoods or storm water hotspots. Which source control practices are applied depends on the pollutants of concern and the major pollutant source areas identified in the watershed. Source control practices focus educational, enforcement, and technical resources on changing the resident behaviors or business operations that are causing the pollution. Manual 8 provides extensive in fo rmation on 2 1 stewardship practices that can be applied in residential neighborhoods , along with 15 poll ution prevention techniques used to control storm water hotspots . A list of source control practices profiled in the manual can be found in Appendix B . Residential Stewardship Subwatershed residents engage in many beh av iors that can influence stream quality. You may want to focus on changing negative behavi ors such as over-fertilizing, oil dumping, littering, or excessive car washing and pesticide use. Alternative ly, your focus may be on encouraging positive b ehavi ors such as tree p lanting, properly disposing of household hazardous wastes , and picking up after pets. In either case , residential stewardship involves designing a targeted education campaign that deli ve rs a specific message and changes resident behavior (Swann, 2000). Often, the educational campaign is supported by incentives and the provision of convenient municipal services such as free compost for soil amendments, free lawn soil testing , advice on nontox ic ways to dea l with pests, or oil recycling directories . To devise an effective neighborhood stewardship program, it is important to understand the range of homeowner behaviors that contribute to storm water pollution . Since each neighborhood has its own distinctive character, it is helpful to assess homeowner behaviors and pollution sources at the neighborhood scale (Figure 23). The Neigh borhood Source Assessment (NSA) component of the USSR survey, described in Manual 11, systematically examines five common pollution source areas in every neighborhood: Overall Neighborhood Character: What is the average age, lot size and construction activity within the neighborhood? Are there septic systems tha t could become a po ll ution source? Is there an active homeowner or civic association to help with outreach? La wn and Yard Practices: What proportion of lawns in the neighborhood is intensively managed from the standpoint of fertilization, Urban Sub wa ters h e d Restoration Manua l 1 Chapter 4: The Range of Subwatershed Restoration Practices pesticide use, and irrigation? What opportunities exist in the yards to expand natural landscaping, tree canopy, and backyard composting? Rooftops: Are the rooftops directly connected to the storm drain system, and, if so, what is the potential to disconnect, capture or treat rooftop runoff? Sidewalks, Driveways and Curbs: Are pollutants, pet waste, or organic matter accumulating on these surfaces? What can be inferred about driveway cleaning, car maintenance and other housekeeping practices in these areas? Stewardship of Common Areas : Is community open space present in the neighborhood in the form of storm water ponds, buffers, flood plains, forest conservation areas, or Common Areas ·. . ,- .Rooftops .. streetscapes,? If so, what are the prevailing vegetative management, maintenance and housekeeping practices in these common areas? Most subwatersheds contain multiple neighborhoods that can differ sharply in both the potential severity of their pollution sources and opportunities for neighborhood restoration. Hotspot Source Control This restoration practice involves applying pollution prevention practices at commercial, industrial, institutional, municipal, and transport-related sites that are suspected or confirmed storm water hotspots. Pollution prevention practices may be legally required under local or state storm water permits at many of these hotspots. While dozens of ..... Sidewalks , \ Driveways , and Curbs ' \ Yards and Lawns .· .· Figure 23: Pollution Source Control Opportunities in Residential Neighborhoods Nearly two dozen pollution source control opportunities can exist within a residential neighborhood. They can be systematically evaluated by looking at lawns and yard practices, rooftop connections, the condition of sidewalks, driveways and curbs, and the management of any common areas. Urb an Subwatershe d Re sto ration Man ual 1 47 Chapter 4: The Range of Subwatershed Restoration Practices 48 pollution prevention technique s are available, managers must identify the unique combination of techniques that will address the actual pollution problems encountered at each s ite . Thus, the first step in hotspot source control involves a thorough investigation of storm water problems , spill risks, and pollution sources at the site. A Hotspot Source Investigation (HSI) evaluates current operations with respect to six potential pollution so urces (Figure 24): Vehicular Sources: Are vehicles washed , fueled , repaired, or stored at the site that could serve as a potential source of pollution ? Material Handling: Are pollutants being stored or loaded outside where they may be exposed to rainfall? Waste Management: Can any wastes produced at the site ge t into the storm drain system? (e.g., trash dumpsters, used oil , product disposal). ' ' Turf Waste ·,, · Stora,ge/· Physical Plant Practices : Do any of the maintenance practices for the building and parking lots ha ve the potential to pollute storm water? Turf and Landscaping: Are the fertilizers or pesticides used to maintain the grounds a potential pollution source? Miscellan eous Sources: Are there unique operations at the si te that can produce pollution? (e.g., marinas, swimming pools, and golf courses) A unique combination of pollution prevention practices is prescribed for each storm water hots pot based on the HSI. This prescription may in volve structural and nonstructural techniques , along with the employee training needed to make them happen . Guidance on conducting an HSI can be found in Manual 11 . Vehicle Fueling Urban Subwatershed Restoration Manual 1 4. 7 Municipal Practices and Programs Municipalities can play at least six pivotal roles in subwatershed restoration . First, communities maintain much of the physical infrastructure in a subwatershed, including roads, sewers, and storm drain systems . In many cases, communities can reduce or prevent pollutants from entering the subwatershed by changing their infrastructure maintenance policies. Second, maintenance practices set the rules governing how development and redevelopment proceed. When crafted properly, these rules can active ly promote better development practices that support long-term subwatershed restoration goals. Third, municipalities are usually a significant landowner in most subwatersheds, and can practice better stewardship on the lands they own or control. Fourth, municipalities operate certain facilities that are well-known storm water hotspots. Common examples include solid waste facilities, public works yards, fleet storage lots and maintenance depots. Many of these operations are required to implement source control or pollution prevention practices (see Practice 6). Fifth, municipalities can act as the direct service provider to help residents and businesses practice better stewardship. Examples include local programs to conveniently dispose of yard wastes, used oil or household hazardous wastes. Lastly, municipalities can play a strong role in both education and enforcement to promote better stewardship by residents and businesses. More guidance on municipal practices and programs that can support subwatershed restoration can be found in Manual 9; a condensed list is presented in Appendix B . Urban Subwatershed Restoration Manual 1 Chapter 4: The Range of Subwatershed Restoration Practices street and storm Drain Practices Municipalities own and maintain much of the road and storm drain infrastructure in a subwatershed. Routine maintenance practices such as road and bridge repairs, snow removal and road salting can cause storm water pollution unless employees are properly trained on best practices. On the other hand , municipal maintenance practices such as street sweeping, catch basin cleanouts, and streetscaping can help remove pollutants from subwatersheds. The degree of pollutant reduction depends on how frequently and systematically each practice is implemented across a subwatershed. Best Practices for Development or Redevelopment Urban subwatersheds undergo a continual process of development and redevelopment. Indeed, it has been estimated that an urban subwatershed wi ll completely redevelop over a 50 year timeline (GVSDD, 2002), presenting an excellent long-term opportunity to retrofit better storm water practices during the redevelopment process. By crafting better criteria for development and redevelopment, communities can actively promote "smart site practices" that support long-term subwatershed restoration goals. Smart site practices are innovative techniques to create green space and creatively treat storm water at redevelopment and infill sites (Kwon, 2001). They can be app lied to both private and public sector redevelopment projects in highly urban subwatersheds. 49 Chapter 4 : The Range of Subwatershed Restoration Practices 50 Stewardship of Public Land It is not uncommon for a municipality to own or control as much as 10 % of all the land within a subwatershed, when all of the parks , sc hool s, golf courses , rights of way, easements, open space, municipal buildings and tax delinquent parcels are combined. Even more land m ay be owned or controlled by loca l uti liti es or state and federal agencies. While this land reserve is quite large, it is widely dispersed and managed by many entities for many different purpo ses. This restoration practice seeks to educate municipal landowners about subwatershed restoration goals and enlist them as partners in the restoration effort. The partners who manage the lands held in publi c trust can improve their land steward ship and provide demonstration s ites for both stream corridor and subwatershed restoration practices . An example of public land s stewardship is the reforestation of the gro und s of a local middle school. Municipal Stewardship Programs Municipalities provide many direct services that can improve stewardship by residents and businesses alike. Some of these programs may be required under their NPDES stonn water permit or by state regulation, while others are local initiatives to increase local watershed awareness. Examples of municipal steward ship include programs organized to do the fo ll owing: · Enforce illegal dumping · Stencil storm drain s · Adopt a stream · Collect household ha zardous wastes · Collect use d oil for recycling · Provide lawn care advice · Provide soil te stin g or compost · Di sconnect re sidential rooftops · Insp ect septic systems · Citizen hotline s These programs are intended to make each act of personal stewardship as easy and convenient as pos si ble to achieve the greatest pollutant reduction for the su bwatershed. Stewardship pro grams require a carefully targeted ed ucation campaign to increase participation , as well as an efficient and timely delivery service. Watershed Education and Enforcement Municipalities can wiel d both carrots and sticks to promote pollution prevention practices and re spond to severe water quality problems . Municipal education efforts can include basic outreach, subsidies, di sco unts , and recognition progra ms. Enforcement methods can include inspections , new regulations , certification, and civil enforcement proceedings. The full range of carrots and sticks availab le to a municipality is de scri bed in Manua l 8. 4.8 Choosing the Right Combination of Restoration Practices for a Subwatershed The range of practices that can potentially restore urban subwatersheds is impre ss ive , but also daunting . From a planning standpoint, subwatershed restoration potential is basically governed by the size of the remaining stream corridor, and the amount of subwatershed area that can be effectively treated. Since both factors are closely related to impervious cover, a general sense of restoration potential can be inferred from the subwatershed ICM c lassification. The basic relationship is presented in Figure 25, which shows how subwatershed IC influences the feasibility of implementing re storation practices . The chart indicates the degree to which a given restoration technique can be implemented across each ICM Urban Subwatershed Restoration Manual 1 Chapter 4 : The Range of Subwatershed Restoration Practices Restoration Practice Subwatershed Impervious Cover 10 to 25% 25 to 40% 40 to 60% 60 to 100% Storm Water Retrofit Practices Storage Retrofit • @ On-s ite Non-Residential Retrofits • • On-s ite Residential Retrofits • • Stream Restoration Practices Stream Clean-ups • • Stream Repairs • @ Comprehensive Restoration @ 0 Riparian Management Practices Site Preparation • @ Active Reforestation • • Park/G reenway Plantings • @ Natural Regeneration • @ Riparian Wetland Restoration • @ Discharge Prevention Practices Illicit Sewage Connections • • Other Illicit Connections @ • Failing Sewage Lines • • Industrial and Transport Spills @ • Pervious Area Management Practices Land Reclamation Upland Revegetation Natural Area Remnant Mana ement • • • • • • Pollution Source Control Practices Residential Source Controls • • Hotspot Source Controls @ • Municipal Practices and Programs Street and Storm Drain Cleaning @ @ Best Practices for Redevelopment • • Stewardship of Public Land • • Mun ic ipal Stewardship Programs • • Education and Enforcement KEY 0 @ @ @ @ 0 @ @ • • • • @ @ @ • • @ • @ • • Technique is normally feasible and can be widely applied across subwatershed @ Technique is often feasible , depending on subwatershed characteristics x 0 0 x 0 x x x x x x • • • • 0 0 0 @ • • • 0 • 0 Individual sites can be found , but widespread implementation across subwatershed is limited I "' I ... ... • I -I • • -I Figure 25: General Feasibility of Retrofit Practices at Different Levels of Subwatershed IC This chart provides general guidance on the subwatershed conditions where the restoration techniques can be most widely applied. Actual restoration potential should always be assessed in the field, but the ability to widely implement some restoration techniques is often limited in the most intensely developed subwatersheds, due to lack of available land in the stream corridor or upland areas. Urban Subwatershed Restoration Manual 1 51 Chapter 4 : The Range of Subwa tershed Restoration Practices 52 subwatershed category. Note that the non- supporting subwatershed category has been divided into a lower range (25 to 40% IC) and an upper range (40 to 60 % IC). As can be seen, restoration practices become less feasible as subwatershed IC increases. This is particularly true for stream corridor restoration practices such as storm water retrofits, stream restoration and riparian reforestation . All seven restoration practices are potentially feasible within impacted subwatersheds , and many of these practices continue to be feasible in the lower range of the non-supporting category. Obviously, their actual feasibi lity cannot be determined until systematic desktop and field surveys are conducted in a subwatershed. By contrast, stream corridor restoration practices are seldom feasible in the upper range of non-supporting subwatersheds ( 40 to 60 % IC) and are rarely feasible in urban drainage subwatersheds. These subwatersheds may be suitable for up land practices that reduce or prevent pollution, such as discharge prevention, municipal practices , and pollution source controls . The feasibility of restoration practices strongly influences the ability to meet various water quality, biological and social goals in each class of subwatershed. Figure 26 illustrates the general ability to meet various goals at different levels of subwatershed imperviousness . The chart is based on past experience assessing restoration potential in many subwatersheds across the country, and is only intended as a general planning guide, as exceptions can and will occur. Still , the chart is a useful framework for analyzing how impervious cover influences the ability to meet subwatershed goals. Restoration Goals for Impacted Subwatersheds Impacted subwatersheds usually have the greatest restoration potential, since they experience only moderate stream degradation, have an intact stream corridor, and normally have enough land available in the subwatershed to install restoration practices . Consequently, many restoration goals can be achieved in impacted subwatersheds, assuming that enough feasible retrofit sites can be found to assure widespread treatment. If this can be done, it may be possible to set goals to actually improve physical , biological and water quality indicators for impacted subwatersheds , particularly at the low end of its IC range. Thus, it m ay be possible to systematically restore habitat throughout the stream network , reduce pollutant loads to rural background levels, meet water contact recreation standards during dry weather periods, partially recover aquatic diversity, and possibly even restore a fishery. Simi larly, it is reasonable to expect that many community goals , such as stream corridor enhancement, can still be achieved in impacted subwatersheds. Restoration Goals for Non-supporting Subwatersheds Fewer restoration goals can be achieved in non-supporting subwatersheds, although some subwatersheds at the lower end of the IC range (25 to 40% IC) may show promise for partial restoration if they can be extensively treated with retrofits and pollution source controls . The primary restoration goal in many non- supporting subwatersheds is to reduce pollutant loads by comprehensively applying storage and on-site retrofits , discharge prevention, source control and municipal practices. Full restoration of aquatic diversity can be an elusive goal, although it may be possible to find some individual stream reaches that can be repaired . In addition, it may still be possib le to meet community goals for the stream corridor, such as recreation, flood control , and aesthetics. Urban Sub wa ters hed Restoration Manual 1 Chapter 4 : The Range of Subwatershed Restoration Practices Percent Subwatershed Impervious Cover Subwatershed Restoration Goals 10 to 25 25 to 40 40 to 60 60 to 100 Water Quality Reduce pollu tants of concern • • • @ Prevent illegal discharges/spills @ • • @ Meet water quality standards • @ 0 x Reduce sediment contamination • • @ x Allow water contact recreation • • @ x Protect drinking water supply @ 0 x x Biological Restore aqua tic diversity • @ x x Restore wetlands/natural areas • @ @ x Expand forest cover • • • @ Restore/reintroduce species • @ x x Improve fish passages • • @ x Enhance wild life habitat • • @ x Remove invasive species • • x x Keep shellfish beds open @ x x x Enhance riparian areas • • @ 0 Phys ic al/Hydrological Inc rease groundwater recharge • @ @ x Reduce channel erosion • @ x x Reclaim stream network • @ x x Reduce flood damage • • @ 0 Reconnect with floodplain • @ x x Restore physical habitat • 0 x x Protect municipal infrastructure • • @ @ Community Eliminate trash/debris • • • • Create greenways/waterfront access/open • • • @ s ace Revitalize neighborhoods • • • • Im prove aesthetics/beautification • • • • Increase citizen awareness • • • • Improve recreation • • • • Increase angling opportunities • • @ x • Goal can often be achieved in many subwatersheds @ Goal can be achieved in some subwatersheds depending on degree of treat ment 0 Goal can possibly be achieved in unusual circumstances x Goal generally not achievable Figure 26: General Ability to Meet Subwatershed Goals at Different Levels of Subwatershed IC This planning chart indicates how subwatershed impervious cover influences the degree of potential treatment, and ultimately the ability to meet specific subwatershed goals. Actual treatment potential for any subwatershed should always be determined through desktop analyses and field assessments. The chart simply indicates that the some restoration goals or objectives cannot always be attained in the most intensely developed subwatersheds , due to inadequate levels of treatment. Urban Subwatershed Restoration Manual 1 53 Chapter 4: The Range of Subwatershed Restoration Practices 54 Restoration Goals for Urban Drainage Subwatersheds Given the intensity of development in urban drainage subwatersheds, it is hard to find enough feasible retrofit sites to meet most biological goals . Thus, the prospects for restoring aquatic diversity or stream habitat in urban drainage subwatersheds are extremely limited, although some individual reaches may show modest restoration potential. Some opportunities may exist to mitigate flooding problems , restore natural area remnants or create greenways to link remaining fragments of intact stream corridor. It is also possible to achieve incremental reductions in downstream pollutant export in urban drainage subwatersheds, although it may not be realistic to expect major water quality improvements within the "streams" themselves . The next two chapters describe the methods used to discover the actual restoration potential for all three types of subwatersheds. Urban Subwatershed Restoration Manual 1 Chapter 5: Envisioning Restoration Chapter 5: Envisioning Restoration The most important skill in urban watershed restoration is an ability to envision restoration opportunities within the stream corridor and upland areas. It takes a practiced eye to find these possibilities in a landscape dominated by the built environment. Still, many good restoration opportunities can be discovered. This brief chapter describes how and where to find restoration opportunities in your subwatershed. Subwatersheds are a complex mosaic of both impervious and pervious cover. The best restoration opportunities are usually found in the remaining pervious areas . As much as three to 5% of subwatershed area may be needed to locate enough restoration practices to repair or improve stream conditions . Further, this land must be located in the right place and be controlled by willing landowners . Lastly, restoration sites are distributed across dozens and sometimes hundreds of small parcels within a subwatershed . While a quick glance at a city map might make this land requirement seem unattainable in most impacted and non- supporting subwatersheds, many excellent restoration opportunities can be discovered with a practiced eye, some imagination, and a lot of detailed map work. The process of discovering these opportunities is called "envisioning restoration ," and consists of two basic techniques : intensively analyzing maps and aerial photographs, and conducting a rapid reconnaissance of actual conditions in the subwatershed. Both techniques are as much a skill as a science, and certainly no computer model can do the same jobs. Detailed methods for systematically envisioning restoration are outlined in Manuals 2, 10, and 11 . Table 7 summarizes the 11 places to envision restoration in any subwatershed, and the remainder of the chapter reviews key features to look for in the stream corridor and its subwatershed. Urban Subwatershed Restoration Manual 1 5. l The Remnant Stream Corridor The first place to explore is the remaining stream corridor (Figure 27). Normally, the stream corridor comprises about three to 5% of the total area of an unde veloped subwatershed, but it can be much smaller in highly urban subwatersheds due to encroachment. Indeed, the stream corridor can be eliminated in some ultra-urban subwatersheds . Still, the stream corridor is the first place to envision restoration . Regrettably, the urban stream network is poorly portrayed on most maps, and many first and second order streams are not shown. Stream interruptions, crossings and channel alterations are not depicted, and the width and condition of the stream corridor are seldom delineated with any accuracy (indeed, it is usually shown on maps as undefined white space between buildings, streets and parking lots). Aerial photographs that show current vegetative condition are the best tool for defining the approximate boundaries of the stream corridor. Table 7: Eleven Places to Envision Restoration in a Subwatershed 1. Remnant Stream Corridor 2 . Existing Storm Water Infrastructure 3. Open Municipal Land 4. Natural Area Remnants 5 . Road Crossings and Rights-of-way 6 . Large Parking Lots 7 . Storm Water Hotspots 8. Residential Neighborhoods 9. Large Parcels of Institutional Land 10 . Sewer Network 11 . Streets and Storm Drains 55 Chapter 5: Envisioning Restoration 56 While maps and photos are a starting point, the stream corridor can only be truly seen by wa lkin g the entire stream network. The Unified Stream Assessment (USA), described in Manual 10, has been developed as a tool to systematically evaluate the remaining stream area. The stream corridor is an important place to envision restoration because it is the transition zone between the upland storm drain network and the urban stream. Within this narrow zone, there is often enough available land to install restoration practices to repair or improve stream conditions. These include storage retrofits, riparian management and discharge prevention practices 5.2 Existing Storm Water Infrastructure The next place to envision restoration in a subwatershed is the existing storm water infrastructure (Figure 28). Each subwatershed has a vast network of catch basins, storm drains, outfall pipes, detention ponds, flood ways and storm water practices that convey storm water. The existing storm water system is attractive for restoration for two reasons. First, as much as 3% of total subwatershed area may be devoted to the storm water system (although often at the expense of the existing stream corridor). Second, since land is already devoted to storm water management, it is much easier to get approval from owners to retrofit it. The restoration potential of a storm water infrastructure depends largely on its age . Storm water systems constructed prior to 1970 are mostly underground, with limited surface land devoted to flood control projects. Systems from 1970 to 1990 were often built with storm water detention ponds designed to control peak flood discharges. Detention ponds, which are often quite large, greatly add to the surface land available for potential restoration, and are always a favorite target for storage retrofits . Systems designed over the last decade reflect th e growi ng trend toward the treatment of storm water quali ty, and may contain dozens of storm wate r treatment practices of all different sizes and types. The surface land area devoted to storm water practices can consume as much as three to 5% of subwatershed area, depending on local storm water criteria. These newer practices are a particularly attractive retrofitting target. A good map of the urban storm water pipe system is extremely helpful , if available. Several location s on these maps deserve close scrutiny: outfalls where storm water pipes di scharge, open land adjacent to these outfalls, and any surface land devoted to storm water detention and/or treatment. These lo cations are Urban Subwatershed Restoration Manual 1 prime candidates for storage retrofits and stream daylighting practices. Storm water outfalls are also the starting point to look for illicit discharges that may be flowing through the storm drain system. In reality, the storm water pipe network is poorly mapped in most communities, and often reflects a confusing blend of pipes and structures built in many different eras. So once again, field reconnaissance is necessary to see how it actually works. In practice, the many routes that storm water travels to get to the stream corridor must be traced by working up from each storm drain outfall. 5.3 Open Municipal Land The next place to envision restoration is in large parcels of open municipal land, such as parks, public golf courses, schools, rights-of- way or protected open space (Figure 29). Municipal lands are attractive areas for restoration because of their large size and ownership. While municipal lands are managed for different purposes, portions of each parcel may be good candidates to creatively locate all seven restoration practices. In addition, open lands are easy to distinguish on either aerial photographs or tax maps, and are easy to confirm in the field. Urban Subwatershed Restoration Manual 1 Chapter 5: Envisioning Restoration 5.4 Natural Area Remnants The next place to envision restoration is in the larger natural area remnants in the subwatershed (Figure 30). Forest and wetland fragments are frequently located near the stream corridor, and the larger contiguous parcels are hard to miss when looking at an aerial photograph or resource inventory map. Larger remnants and their adjacent margins always deserve close scrutiny in the field. A two-acre size thresho ld is often used to select parcels for field ana ly sis. Natural area remnants are not a preferred location for intrusive restoration practices (such as a large storage retrofit), but may be good targets for fores t or wetland restoration. In addition, the possibility of expanding natural areas or linking them to the stream corridor or other remnants should always be considered. 5.5 Road Crossings and Highway Rights-of-Way Road crossings and rights-of-way are always worth exploring for restoration opportunities (Figu re 31 ). Stream crossings are quite easy to spot on aerial photos or regular maps. Two specific areas of the map shou ld be located: the points where roads cross the stream corridor, and large rights-of-way, such as cloverleaf interchanges and highway access ramps . 57 Chapter 5: Envisioning Restoration 58 Each road crossing presents both a problem and an opportunity. Bridges and culverts that cross the corridor are always suspected barriers to fish migration, but they may also unintentionally act as a useful grade control in a rapidly incising stream. Also , road designers like to maintain grade when crossing streams, so they often build earthen embankments across the flood plain to approach the bridge and culvert. In very sma ll streams, these crossings can be modified to provide temporary storage and treatment of storm water upstream of the crossing. Lastly, road crossings often provide the best access to the stream corridor for stream assessments, c leanups and construction equipment. Larger highways often have fairly large parcels of unu sed land near interchanges in the form of cloverleafs and approach ramps. These parcels can be an ideal location both for storage retrofits and reforestation, because they receive polluted runoff from the highway and generally serve no other purpose. 5.6 Large Parking Lots Large parking lots really stand out in an aerial photograph or land use map (Figure 32) and are of great interest for several reasons . First, they produce more storm water runoff and pollution on a unit area basis than any other land use in a subwatershed. As such, they are obvious targets for on-site or storage retrofits. Second, large parking lots generally signal the presence of large clusters of commercial , industrial or institutional lands often associated with storm water hotspots . While these areas can be easily identified from a desktop, it is usually necessary to visit each one to determine its actual potential for retrofitting or source control. In particular, it is important to assess how storm water is currently handled in the parking lot, and look for unused land adjacent to the lot that may be suitable for a retrofit. Urban Subwatershed Restoration Manual 1 Chapter 5 : Envisioning Restoration Urban Subwatershed Restoration Manual 1 59 Chapter 5: Envisioning Restoration 60 5. 7 Storm Water Hotspots The next place to envision restoration is in the many storm water hotspots in a subwatershed . Storm water hotspots are the commercial, industrial, institutional , municipal, and transport-related land uses that tend to produce higher levels of storm water pollution, or present a higher risk for spills , leaks and illicit discharges (Figure 33). The number, type and distribution of storm water hotspots vary enormously between subwatersheds . Hotspots are exceedingly hard to find, and many are quite small and out of the way. Maps and aerial photos are of little value in finding them; instead, they can be found by searching databases that contain standard business codes or permits, or by driving the entire subwatershed looking for them, or both . The USSR, described in Manual 11 , was designed to find these elusive hotspots and target appropriate pollution prevention practices. 5.8 Residential Neighborhoods Residential neighborhoods are the next place to envision restoration. They are easy to see on a map, but must be visited to be truly understood (Figure 34). Each residential neighborhood has a distinctive character in terms of age , lot size, tree cover, lawn size, and general upkeep. In addition, neighborhoods tend to be rather homogenous when it comes to resident behavior, awareness and participation in restoration efforts. Each unique neighborhood characteristic directly affects the ability to widely implement residential restoration practices, s uch as on-site retrofits and residential stewardship practices. In general, it is not easy to discern neighborhood characteristics from a map or even an aerial photograph. Instead, the Neighborhood Source Assessme nt (NSA) component of the USSR can be used to collect quantitative data on neighborhood characteristics to determine their restoration potential. 5. 9 Large Institutional Land Owners Large institutional land owners have the last remaining land worth prospecting for restoration potential in a subwatershed (Figure 35). Examp les include hospitals, colleges, corporate parks, private go lf courses, cemeteries and private schools. Inspection of aerial photos may reveal that institutions have und eruti li zed areas on their grounds with restoration potential. These sites can be problematic, since it may be hard to expend local funds to improve private lan ds. Also , some landowners may be reluctant to bear the cost and maintenance burden associated with restoration projects. However, other Urban Subwatershed Restoration Manual 1 Chapter 5: Envision ing Restoration Urban Subwatershed Restoration Manual 1 61 Chapter 5 : Envisioning Restoration 62 institutional landowners are actively involved in the community and may be willin g to partner in restoration efforts. 5.10 The Sewer System The sewer system is always an important place to envision restoration potential, although it is intrinsically difficult to see since most of it is located underground (Figure 36). Most communities have good maps of their sewer pipe networks, although older portions may be much less reliable . The key factor to determine is whether the sewer system is a source of sewage discharges to the stream corridor that it often parallels. The severity of sewage discharge depends on the age, condition, and capacity of the sewer network . In addition, urban watersheds are not always fully sewered; some are partly served by existing or relict septic systems, which can be a source of pollution . 5.11 Streets and Storm Drain Inlets The last area to envision restoration potential includes the street surfaces and storm drain inlets of a subwatershed (Figure 37). Pollutants tend to accumulate on street surfaces and curbs, and may be temporarily trapped within storm drain catch basins and sumps. These storage areas often represent the last chance to remove pollutants and trash before they wash into the stream . Municipal maintenance practices , such as street sweeping , catch basin clean-outs and storm drain stenciling, can potentially remove some fraction of the se pollutants , under the right conditions. These municipal practices are particularly well-suited for highly urban subwatersheds that have many streets, but few other feasible restoration options . While good street maps are almost always available , accurate maps of storm drain inlet locations can be much harder to find. The Streets and Storm Drains (SSD) component of the USSR helps to qualitatively assess the degree of actual pollutant accumulation within streets, curbs and catch basins in the subwatershed. The SSD also looks at feasibility factors , such as parking, traffic, access and pavement condition, that will determine if street sweeping or catch basin clean-outs will be effective or practical in a particular subwatershed. 5.12 Summary This chapter described how and where to search for restoration potential in urban subwatersheds. Each subwatershed has a different combination of opportunities and thus different restoration potential. The next chapter describes a framework for translating these possibilities into a realistic subwatershed plan. Urban Subwatershed Restoration Manual 1 Chapter 5 : Envisioning Restoration Urban Subwatershed Restoration Manual 1 63 Chapter 5 : Envisioning Restoration 64 Urban Subwatershed Restoration Manual 1 Chapter 6 : A Framework for Small Watershed Restoration Chapter 6: A Framework for Small Watershed Restoration This chapter outlines a framework to guide you through actions needed to develop, adopt, implement and track a small watershed restoration plan. Deve loped over the last decade, this general framework app li es to urban subwatersheds , but can also be applied at the watershed level. The framework is particularly useful for organizing the many different tasks needed to produce effective watershed restoration plans, regardless of whether the plan is prepared by a municipality, watershed group, private consultant, or a combination of all three. The eight steps of the framework are shown in Figure 38. As many as four different tasks are needed to complete each step, including a desktop analysis, field assessment, stakeho ld er involvement and management product (Figure 39). Desktop analysis tasks help organize, map and interpret subwatershed information to make better restoration decisions . Rapid field assessment occurs in both the stream corridor 8 . Monitor, rev ise , go to next subwatershed 7 . Implement subwatershed plan 6 . Assess whether plan meets watershed goals Guals \ ·.,··· ,·. 'b \, . ' __.. ·( 5. Assemble projects into watershed plan and subwatershed, and is used to identify restoration opportuniti es, design and rank individual restoration projects, and measure improvements in stream health. Stakeholder involvement helps identify stakeholders and structure their invo lvement in the restoration planning process . Lastly, management products document key decisions made during each step of restoration plan development. This chapter provides a condensed overview of the planning framework; Manual 2 provides much greater detail on the specific methods used in each step . You should regard the framework as a starting point to structure your efforts, and adapt it to fit your unique goals, budget constraints and partners. For example, if you have already decided which subwatershed(s) to restore , you should skip steps 1 and 2 . Also, whi le our approach outlines the simplest, fastest and least expensive way to perform each task, you may choose more sophisticated methods in order to justify the community investment in watershed restoration . Go•I• ' ·, 1. Choose initial watershed goals 2. Screen most restorable watersheds 3. Evaluate subwatershed res toration potential 4. Investigate individual restorat ion projects Figure 38: Overview of the Eight-Step Framework to Restore Urban Watersheds Urban Subwatershed Restoration Manual 1 65 Chapter 6 : A Framework for Small Watershed Restoration 66 Step 1: Develop Watershed Restoration Goals Step 2: Screen Priority Subwatersheds Step 3: Evaluate Restoration Potential Step 4: Conduct Detailed Restoration Assessment Step 5: Assemble Projects into Plan Step 6: Determine if Subwatershed Plan Meets Watershed Goals Step 7 : Implement Plan Step 8: Measure Im provements OverTime KEY A-1 Needs and Capabilities Assessmenl A-2 Comparat ive Subwatershed Analysis A-3 Desktop Subwatershed Analysis A-4 Desktop Analys is of Individual Re storation Projects A-5 Ranking of Priorily Projects A-6 Subwatershed Treatment Analysis A-7 Design and Construction of Restoration Projects A-8 Plan Tracking and Assessment D Analysis S-1 + + Existing Data Analysis S-2 + + S-3 +/\~ bV + S-4 Stream Corridor Investigation + + + S-8 + 1-1 1-2 ~3 6\J 0 Stream Subwate rshed Stake holder Assessment Inve stig atio n Involvement Figure 39: Detailed Steps and Tasks Involved in the Restoration Planning Process P-1 Watershed Goals P-2 Priority Sub- watershed List P-3 In itial Sub- wate rs hed Strate11Y P-4 Sub- wate rshed Restoration Inventory P-5 Oran Sub- watershed Restoration Plan P-6 Implemen- tation Strategy P-7 0 P-8 Sob- weil:ershed lmprovemert 0 Outcome Each step in the planning process usually has its own associated desktop analysis, field assessment, stakeholder involvement, or management product. Urban Subwatershed Restoration Manual 1 A-1 8-1 Step 1: Develop Need s and + Watershed Capabi lities Restoration Assess ment Existing Goals Data Analysis Step l : Develop Wa tershed Re stor ati on Goals It is surprising how many watershed restoration efforts have started with neither clear agreement on the specific goals and objectives they are expected to accomplish, nor a thorough understanding of available planning resources . Therefore, this issue should be addressed as early as possible to set clear expectations for watershed restoration. A-1 Needs and Capabilities Assessment (NCA) This desktop analysis helps evaluate the factors driving local restoration and find available resources to make it happen . A needs and capabilities assessment (NCA) examines two areas . The first part comprehensively analyzes federal and state "regulatory drivers" that influence watershed restoration, including the alphabet soup ofTMDLs, MS4 NPDES Permits, CSO, SSO, SWDA, ESA, FEMA, among others. The second part analyzes existing municipal capabilities and resources for watershed restoration . This usually entails an agency-by-agency review of existing staff, programs, funding and mapping resources that can potentially be applied to watershed restoration . Both assessments are best conducted on a watershed-wide or municipal scale, in cooperation with regional stakeholders. S-1 Existing Data Analysis This task answers the question : "What is already known about the watershed?" In many cases, a wealth of watershed monitoring and mapping data has been produced over the years, which can help define critical water resource problems. Consequently, this task involves an extensive analysis of historical water quality and biological monitoring data within the watershed, as well as a search for any available mapping and GIS resources . While good Urban Su b watershed Restoration M anual 1 + Chapter 6 : A Framework for Small Watershed Restoration 1-1 P-1 Watershed Goals watershed information usually exists, the challenge is to locate it and critically evaluate its quality. The data analysis usually requires an intensive search of academic institutions, federal databases , regional GIS centers , state and local agencies , and non-governmental organizations . If sound data is not available, then additional monitoring or research may be needed to establish goals . The end product is a baseline assessment that describes water quality and habitat problems across the watershed or municipality. J-1 Achieving Consensus on Goals Goal- setting requires extensive stakeholder input to identify important community interests and issues that will drive the watershed restoration effort. Under this task, forums are created to find out what the public thinks about urban watersheds and what issues they want incorporated in the restoration plan. Recurr~ng issues include recreation , greenways, floodmg , waterfront and neighborhood revitalization, enforcement, and cleanups, in addition to water quality and habitat. By li stening to all fou~ groups of stakeholders, it is possible to gam broad agreement on the overall goals that will drive local watershed restoration efforts. P-1 Wat e rsh ed Goals and Objectives The management product of this task is the definition of clear, measurable goals that command broad public support to guide the watershed re storation process . Assuming that consensus on these goals can be reached, it is helpful to produce a watershed agreement, a memorandum of understanding or similar directive that establishes interim goals for watershed restoration that can be executed by elected offici a ls , key stakeholders and/or senior agency leaders. These agreements can raise the profile of watershed restoration and ensure greater inter-agency coordination later in the process . 67 Chapter 6: A Framework for Small Watershed Restoration 68 Step 2: Screen Priority Subwatersheds A-2 Comparative Subwatershed Ana lysis + Step 2: Screen for Priority Subwatersheds S-2 The second step of the framework selects priority subwatersheds within the watershed that show the most promise for effective restoration. This step can be skipped ifthe subwatershed(s) have already been selected. A -2 Comparative Subwatershed Analysis It is re latively easy to quickly screen the most promising subwatersheds from a desktop , assuming that basic GIS layers are available. The first step is to subdivide the watershed to delineate subwatersheds that are typically about one to five square miles in area. In the second step, important stream corridor and subwatershed metrics are derived from GIS data to "discriminate" among subwatersheds. At the stream corridor leve l, key metrics include channel density, stream corridor area, and stream assessment data . For upland areas, key variables include the subwatershed impervious cover, public land , detached residential housing , industrial lands , natural area remnants, and the presence or absence of storm water practices. Each of these factors can be weighted and analyzed in a simple spreadsheet model to rank the comparative restoration potential for each subwatershed. S-2 Rapid Baseline Assessment Some communities may want to collect more monitoring data to characterize water quality, habitat or biological conditions across its subwatersheds, although this can be both expensive and time-consuming. The basic approach is to establish a network of fixed stations where stream parameters are rapidly measured to indicate current aquatic health within all subwatersheds . These subwatershed "indicators" can be used to track how a stream may respond to future subwatershed restoration + 1-2 P-2 Priority Sub- watershed List efforts. Examples inc lud e the Rapid Stream Assessment Technique (RSAT), Rapid Bioassess ment Protocol (RBP), dry or wet weather water quality sampling, and fish shocking. The basic objective of a baseline assessment is to get data within a few months that can be incorporated into the comparative subwatershed analysis. J-2 Watershed Outreach Once again, it is important to involve key stakeholders in the process of choosing priority subwatersheds, since strong public support is often instrumental in successfu l restoration (particularly when organized community or watershed groups exist). Effective watershed outreach efforts at this stage include workshops, community meetings, field trips, and watershed maps . Efforts should be made to condense watershed issues into an accessible and understandable format. Watershed outreach efforts can increase public understanding about local watershed problems, set realistic expectations and may even recruit new stakeholders to the cause. Stakeholders can also play a role in devising the weighting factors for s ub watershed ranking to maximize overall support. P-2 Subwatershed Priority List The management product associated with this step is simple: a decision on which sub watersheds to work on first. It is often helpful to produce a technical memo documenting the ranking system used to derive the priority subwater.shed li st to justify why restoration efforts are bemg deferred in other subwatersheds. Urban Subwatershed Re st oration Manual 1 Chapter 6: A Framework for Small Watershed Restoration A-3 S-3 1-3 P-3 Step 3: Evaluate Restoration Potential Desktop Subwatershed Analys is +/\ ~+ ~v In itia l Sub- wate rs hed Strategy Step 3: Evaluate Restoration Potential The third step is a systematic assessment of potential restoration opportunities within the stream corridor and subwatershed, and involves five important tasks. A-3 Des ktop Subwatershed Assessment It is important to compile basic subwatershed information and generate base maps for stream corridor and subwatershed assessments prior to going out in the field. This first phase of desktop analysis characterizes current subwatershed characteristics, plans routes and establishes stream survey reaches. Extra time spent in the office can save a lot of time out in the field. The second phase of desktop analysis occurs after the field assessments and stakeholder involvement tasks are completed. This phase assembles, implements and analyzes subwatershed data to devise an initial re storation strategy. S-3a Unified Stream Assessment (USA) The USA is a rapid assessment of all surface drainage in a subwatershed to identify problems and restoration opportunities within the stream corridor. The USA evaluates eight stream impacts or conditions, including storm water outfalls, severe erosion, impacted buffers , utility crossings, trash and debris, stream crossings, channel modifications and mi scellaneous features. The running su~ey relies on GPS mapping, digital photos and reach analysis to identify potential sites for individual retrofit, stream restoration discharge preve ntion or riparian man;gement ~rojects . The data compiled from USA surveys 1s then analyzed to evaluate the restoration potential of the stream corridor (see Manual 10). Urban Subwatershed Restoration Manual 1 S-3b Unified Subwatershed and Site Reco nnaissance (USSR) The USSR is a companion survey that explores pollution sources and restoration opportunities in the upland areas of a subwatershed. During a USSR survey, a team drives all roads in the subwatershed , evaluates neighborhood conditions, and assesses all open spaces larger than two acres . The USSR profiles current practices in residential neighborhoods, the condition of streets and storm drains , and the potential for on-site retrofits. It is also used to confirm the location and severity of storm water hotspots . Finally, the USSR creates an inventory of upland sites for potential reforestation or natural area restoration. Data collected from the USSR is then analyzed to evaluate strategies such as improved retrofits, source control , pervious area management and municipal practice in the subwatershed. 1-3 Stakeholder Identification and Outreac h In this task, all of the potential stakeholders that li ve or work in the subwatershed are identified a group that may include individuals from civi~ groups, churches, neighborhood associations , schools , institutional landowners businesses and other organizations. These i;dividuals ' should be actively recruited to participate in future stakeholder meetings . Some stakeholders can be identified during the USSR, but additional networking is usually needed to get the right people to the table. P-3 Initial Subwatershed Res toration Strategy This step produces a great deal of initial data on restoration options and opportunities in the subwatershed. The management product for this step is a quick analysis of subwatershed data to de vise an initial restoration strategy. This initial strategy is often accompanied by a scope of work outlining detailed restoration investigations to pursue in subsequent steps . 69 Chapter 6: A Framework for Small Watershed Restoration 70 Step 4 : Conduct Detailed Restoration Assessment A-4 De s kt op Ana lys is of Ind ivi dual Re storation Projects + Step 4: Conduct Detailed Restoration Assessment S-4 The fourth step of the framework involves assessing the feasibility of individual restoration projects in the subwatershed or stream corridor. A-4 Desktop Analysis of Projects This desktop task develops detailed concept designs for individual restoration projects identified during the initial subwatershed restoration strategy. Project data from detailed site investigations is then used to work up concept designs for the most feasible and effective restoration projects in the subwatershed. Some upl and restoration practices, such as source control and municipal practices, are developed and refined at the desktop level. Each candidate project is then evaluated with regard to feasibility, design constraints, estimated cost and potential restoration benefits. Planning and design information for individual restoration projects are then organized into spreadsheets and/or GIS for subsequent analysis in the next step . S-4a Stream Corridor Project Investigations This task gathers the field and/or engineering data needed to develop workable concept designs for individual restoration projects in the stream corridor. Depending on the initial restoration strategy, this may entail one or more of the following : · Retrofit Reconnaissance Inventory · Stream Restoration Investigation · Riparian Management Investigation · Discharge Prevention Investigation The goal of each investigation is to acquire _ enough data to develop a basic concept design for each restoration project. 1-4 + P-4 Sub- w aters hed Re storation Inventory S-4b Upland Project Investigations This task involves a series of detailed site assessments to develop workable plans or programs to control upland pollutant sources and/or restore . pervious areas in the subwatershed . Dependmg on the initial restoration strategy, this may entail one or more of the following investigations: · Hotspot Compliance Inspections ·Natural Area Remnant Studies · Pervious Area Management Inventory These rapid investigations are used to either develop a basic concept design for each project or determine effective program delivery. I-4 Managing Stakeholder Input The first community stakeholder meeting should report on the early results of subwatershed analyses and get initial feedback from the "nighttime" stakeholders that live and work in the subwatershed. While evening meetings are a common way of soliciting involvement, other methods such as Saturday subwatershed tours , websites, mailings, or stream walks can also be used to solicit involvement. All of these involvement methods can help elicit the issues and concerns stakeholders want to incorporate into the subwatershed plan . P-4 Subwatersh ed Restoration Inventory The management product associated with this step is an inventory of feasible restoration projects for the subwatershed that addresses restoration goals and objectives set at the watershed level. Urban Subwatershed Restoration Manual 1 Step 5: Assemble Projects into Plan A-5 Ranki ng of Priority Proj ect s + Step 5: Assemble Projects into Plan The fifth step transforms the restoration inventory into a draft subwatershed plan that recommends the most cost-effective combination of restoration projects and programs to meet subwatershed goals . Key tasks of this step include project ranking, neighborhood consultation and plan writing . A-5 Project Evaluation and Ranking This task involves a detailed evaluation and ranking of the whole range of projects and programs in the restoration inventory. Each project or group of projects is ranked according to subwatershed area treated , cost, feasibility, environmental benefits , public acceptance and other key implementation factors . The exact ranking factors and their corresponding wei ghts are unique to each subwatershed and should reflect overall restoration goa ls and stakeholder input. The ranking is typically done through spreadsheet analysis, and the results are used to select the package of projects to recommend for final design . In some cases, additional field survey or subwatershed data may be needed to support project evaluation. Urban Subwatershed Restoration Manual 1 Chapter 6 : A Framework for Small Watershed Restoration 1-5 P-5 Ora n Sub- w at ershe d Res toratio n Plan J-5 N e ig hborh ood Consultation Storm water retrofits and other restoration products can si gnificantly alter a local landscape that has been around for years. Residents often have le g itimate concerns about access, safety, mosquitoes , weeds , vermin , tree loss and other issues related to a particular restoration project. Consequently, it is wise to get input from adjacent stakeholders and respond to their concerns early in the design process. Forums and field trips to notify adjacent re s idents about proposed projects are always a good investment. P-5 Draft Sub wate rsh ed Res toration Plan The management outcome of this task is a concise subwatershed plan with specific re commenda tions for implementing restoration projects and programs , along with a subwatershed management map. A good subwatershed plan need not be long or complex . Instead, it should be written with the punch of a newspaper article, and clearly specify the "what," "why," "when," "where ," and "how much" of the recommended combination of restoration projects. 71 Chapter 6 : A Framework for Small Watershed Restoration 72 Step 6: Determine if Subwatershed Plan Meets Watershed Goals A-6 Sub watershed Treatment Analys is + Step 6: Determine Whether Subwatershed Plan Meets Watershed Goals This is perhaps the most frequently overlooked step in watershed restoration : determining whether or not the subwatershed plan can meet watershed goals . In some cases, models and predictive tools to make this determination may not exist In these cases, plan success can only be measured by future monitoring in the su bwatershed, and the subwatershed restoration plan becomes its own experiment In other cases, however, predictive models can be used to determine whether the plan will meet restoration goals . Some communities may elect to pursue this step concurrently with the development of the draft subwatershed plan . A-6 Subwatershed Treatment Analysis If watershed restoration goa ls are oriented toward hydrology or water quality, there are several good desktop models for estimating the plan 's watershed treatment and associated pollutant reduction . Manual 2 describes how to apply the Watershed Treatment Model (WTM) to quantify the pollutant reduction achieved by the subwatershed restoration plan, and provides references for other subwatershed 1-6 P-6 Implemen- tation Strategy assessment tools. Fewer predictive models exist to evaluate restoration goa ls geared to improving habitat or aquatic biodiversity. 1-6 Ex ternal Plan R e vi e w An important element of plan evaluation is review and input from the subwatershed stakeholders, who help ensure the plan meets the unique needs of both the subwatershed and the community. Generally, review of the draft plan involves at least one additional stakeholder meeting. P-6 Implementation Strategy It is extremely useful during this step to begin thinking about what it will take to get the plan adopted and how it might be funded over time. Since watershed plans compete against many other municipal expenditures, it is helpful to develop an implementation strategy for navigating the plan through the political and bureaucratic system . Two management tasks are assoc iated with this step . The first is to make a persuasive case that the subwatershed plan is worth the community investment, and the second is to create an organized campaign for presenting that case to the influential members of the community. This campaign should target elected officials, regulators, local media, state and federal funders, and the activist public. Urban Subwatershed Restoration Manual 1 Step 7: Implement Plan A-7 De sign and Construction of Reslorotion Projects Step 7: Implement Plan + This step deals with the many complex tasks involved in the final design, public review and adoption of the plan. A-7 Design of Restoration Projects Much of the time and expense in the subwatershed planning process is expended for the final design, engineering and permitting of individual restoration projects . Since many different projects and programs will be implemented in the subwatershed plan, you will need to anticipate how to "deliver" restoration projects (i.e., how to sequence design, construction, inspection, maintenance and monitoring within budget constraints). Particular emphasis shou ld be placed on getting the most accurate project cost estimates possible, so that the total cost of the plan can be established and phased over time. [Note: In some cases, additional field or subwatershed data may be needed to support final design, such as geotechnical surveys. In other cases, a community may wish to adopt the final subwatershed plan before commencing with final design of restoration projects (A -7).] Urban Subwatershed Restoration Manual 1 Chapter 6 : A Framework for Small Watershed Restoration 1-7 P-7 r::\ ~ 1-7 Expanding Implementation Partn erships While it may seem redundant to have another round of stakeholder involvement, it is important to get formal support and endorsement of the final plan. The goal is to transform stakeholders into partners, and create a broad community coalition to attract the political support needed to get reliable funding for plan implementation. P-7 Adopt Final Plan There is no universal method for final plan adoption, given that the political process , partnership structure, and budgetary system are unique in every community. The basic management product in this step is to work through the existing process to adopt the plan, and define a short-and long- term funding strategy to implement it It is important to keep in mind that many communities cannot obligate operating funds beyond the current budget year (although they may be able to sequence capital projects over a longer time frame). 73 Chapter 6: A Framework for Small Watershed Restoration 74 Step 8: Measure Improvements Over Time A-8 Plan Tracking and Assessment S-8 Step 8: Measure Improvements Over Time Urban restoration is such a new field that each restoration plan is basica lly its own experiment. As a result, it is important to institute tracking and monitoring systems to measure improvements in subwatershed indicators over time. These systems can include internally tracking the delivery of restoration projects in a subwatershed, as well as monitoring stream indicators at sentinel monitoring stations. Performance monitoring of individual restoration projects can be tracked to improve the design of future restoration practices . Information gathered from each of these tracking systems is used to revise or improve the restoration plan ove r a five-to seven-year cycle. A -8 Tra cking and Plan Implem entation Few people fully comprehend the complexity of delivering a large group of restoration projects within a small subwatershed . It is a good idea to use a spreadsheet or GIS system to track project implementation data such as project construction, inspection , maintenance and performance. Project tracking data chronicles progress made in subwatershed implementation, and can isolate management problems to improve the delivery of future restoration projects. S-8A Se ntinel Monitoring Stations In this task, fixed, long-term sentinel stations are established to measure trends in selected aquatic indicators over many years (preferably at the same locations monitored during the initial baseline assessment). Sentinel monitoring is perhaps the best way to determine how streams are actually re s ponding to subwatershed restoration . Few communities have the resources to continuously maintain a 1-8 + P-8 Sub- w eter shed Improvement long-te rm monitoring program, but the existence of sentinel stations ensures that the right indicators are measured at the same place s when money is available for monitorin g. S-8B Project Monitoring Restoration practices are often experimental, and it is important to measure whether restoration projects are really working as they were designed to. As a result, communities may want to invest in performance monitoring of individual restoration projects to improve future designs . Such monitoring can be relatively simple (ob serv ing the success of a reforestation project) or extremely complex and expensive (measuring the pollutant reduction of a storm water retrofit or the biological response to a comprehensive stream restoration project). I-8 Ongoing Management Structure Full implementation of subwatershed restoration plans usually takes a minimum of three years, and often as many as 10. Therefore, it is critical to find a way to sustain momentum for subwatershed restoration over such an extended period. The preferred method is to create a small watershed organization or interagency committee to advocate for the plan and handle ongoing education, outreach and public involvement tasks. Ideally, such a group should be created much earlier in the process (or may have already existed). The key point is that the watershed advocacy function must be sustained and supported throughout the implementation stage, and often well beyond . P-8 Subwatersh ed Improvement The management outcome of thi s step is fairly simple : a measurable improvement in the indicators used to define subwatershed quality. If expected improvements have not occurred, a re-assessment of either the subwatershed restoration plan or expectations for meeting watershed goals may be required. Urban Subwatershed Restoration Manual 1 Summary This chapter presents an ideal framework to guide and organize the small watershed restoration planning pro cess . In reality, every community will end up with its own peculiar planning process reflective of its diverse watersheds, uniqu e goals, funding sources, partners and pri or experience. The key point is that each community shou ld develop a clear and understandable process to translate plans into action . The next manual , M ethods to Develop Restoration Plans for Sma ll Urban Watersheds, presents different options to help c reate an effective planning process . Urban Subwatershed Restoration Manual 1 Chapter 6 : A Framework for Small Watershed Restoration 75 Chapter 6 : A Framework for Small Watershed Restoration 76 Urban Subwatershed Restoration Manual 1 Ap p e ndix A : Derivation of Predictions fo r the Impervious Cover Model Appendix A: Derivation of Predictions for the Impervious Cover Model The third chapter of this manual presents quantitative predictions as to how 22 specific stream corridor indicators behave in the context of the Impervious Cover Model (ICM). These general predictions are intended to diagnose the severity of stream impacts, set realistic goals for restoration, and plan and design restoration practices in the stream corridor. This Appendix outlines the current research supporting the ICM, with particular reference to the impacted (I), non-supporting (NS) and urban drainage ( UD) stream categories. It begins with a general discussion about the limitations and caveats of the ICM, and then explores how specific quantitative or narrative predictions were derived for each of the 22 stream corridor indicators. The section describes how each indicator was defined, measured or computed, and the baseline condition against which it is compared. Next, the research, models , and other evidence used to support predictions are described. Remarks are also made about the utility of each indicator in urban subwatershed restoration planning and design. Lastly, we comment on our confidence in the accuracy and reliability of the individual indicator predictions of the ICM. In some cases , the predictions are merely untested hypotheses, while others are solidly grounded in science and engineering . Where possible, we recommend ways these predictions could be improved or narrowed through further urban subwatershed research . Urban Subwatershed Restoration Manual 1 This appendix is organized into seven sections : A . Summary of the ICM and its Use in Subwatershed Restoration Planning B . Derivation of Hydro logic Predictions for the ICM C . Derivation of ICM Predictions for Physical Alteration of the Urban Stream Corridor D . Derivation of Urban Stream Habitat Predictions for the ICM E. Derivation of Urban Water Quality Predictions for the ICM F. Derivation of Aquatic Diversity Predictions for the ICM G Summary A: Summary of the ICM and its Use in Subwatershed Restoratio n Planning The ICM organizes a series of testable hypotheses about how stream corridor indicators respond to greater subwatershed impervious cover (IC). It is used to classify three types of urban streams based on subwatershed IC: impacted, non-supporting and urban drainage . We have not included any predictions for sensitive streams (that have less than 10% IC), because they do not meet our definition of urban subwatershed, and are often predicted better by other subwatershed metrics (CWP, 2003). The ICM applies to small streams, from first to fourth order, with a contributing subwatershed area of less than 10 square miles. ICM predictions are general , and may not apply to every stream within the proposed classifications. Urban streams are notoriously variable, and factors such as gradient, stream order, stream type, age of subwatershed development, and past land use can and will make some streams depart from these predictions . Indeed, these "outlier" streams are A-1 Appendix A : Derivation of Predictions for the Impervious Cover Model A-2 extremely interesting from the standpoint of restoration . In general, su bwatershed IC causes a continuous but variable decline in most stream corridor indicators . Consequently, the severity of individual indicator impacts tends to be greater at the upp er end of the IC range for each stream category. The ICM does not explicitly address the influence of past subwatershed treatment or the effect of future subwatershed restoration practices. This is not currentl y much of a limitation since few urban subwatersheds have been comprehensively treated and/or restored to date . Indeed, Manual 2 presents a sequence of monitoring and modeling methods to measure how individual stream indicators might respond to sub watershed treatment. It should also be noted that limi ted evidence exists to define indicator behavior in the upper range of NS stream category and the entire UD category. More systematic research is needed on these highly urban streams, which have received scant attention despite the fact they are the most polluted, impaired and degraded of any stream category. For comparative purposes, a baseline condition is provided to give a general sense of the maximum possible improvement in the indicator that might be achieved by su bwatershed restoration (although this degree of improvement cannot be attained in all urban subwatersheds). The baseline condition helps assess and quantify realistic goals and objectives for sub waters hed restoration . In general , the base line condition is defined as a stream located in a rural subwatershed in good con dition. Rural land use is considered to be a sub watershed that contains a mix of forest , pasture, and crops; has not experienced extensive channel modification; has an intact riparian forest buffer; and lacks major point sources of pollution. Lastly, whi le the ICM is quite useful, it is obviously not the only factor to consider in urban subwatershed restoration planning. Other subwatershed metrics , such as turf or pervious cover, stream corridor condition, age and condition of sewer system, stream interruption, hotspot density, and age of development are all extreme ly useful to define opportunities and constraints for subwatershed restoration . B: Derivation of Hydrologic Predictions for the ICM 1. Influence of Storm Water Runoff Definition and measurement of indicator This indicator is defined by the su bwatershed runoff coefficient or Rv, which measures the fraction of annual rainfall vo lume that is converted into storm water runo ff. It is measured by simultaneous ly sampling the vo lume of rainfa ll and storm water runoff produced at a single catchment over multiple (20+) storm events. Baseline condition The annual vo lume of storm water runoff produced by an undeve loped rural subwatershed . Prior research has establi shed that the Rv ranges from 0.02 to 0.07, depending on soils, slope and geology of the rural sub watershe d monitored. Reference used to derive The Rv vs . IC relationship is presented in Figure 1.2 in Schueler (1987), which examined 44 urban catchments monitored in the U.S. during the EPA NURP program. Uti lity in restoration planning and design The Rv is a fundamental indicator of the degree of hydrologic alteration within a subwatershed, and is also u se d to estimate pollutant loadings (which are a direct function of subwatershed IC). The Rv relationship is a lso used in retrofit design to estimate the size and storage volume required for these practices . Comments The Rv vs. IC relationship is we ll documented , and has been directly incorporated into many wide ly-used engineering hydrology models . 2. Flood Plain Expansion Definition and computation of indicator This indicator is defined as the ra tio of the current peak discharge rate to the pre-development Urban Subwatershed Restoration Manual 1 Appendix A: Derivation of Predictions for the Impervious Cover Model peak discharge rate produced during a 100-year rainfall event at a specific point of interest within the subwatershed (expressed in units of cubic feet per second, or cfs). This ratio is a useful index of the probable expansion of the flood plain within the existing stream corridor. 1n practice, the ratio is computed by applying detailed hydrology models to estimate the peak discharge rates for current conditions, which are a function of current subwatershed IC, soil types, and hydraulic conditions in the stream channel and flood plain. The models are then run again to simulate pre-development conditions in the subwatershed, and the ratio of the two current and pre-development peak discharge rates is then computed. Baseline condition compared to The 100-year peak discharge rate for pre-development conditions is usually modeled assuming the subwatershed has a rural land use mix (e.g., forest, pasture and crops) and does not have a storm drain collection system. For comparison purposes, the index or ratio for an unde ve lop ed rural subwatershed is one. References used to derive Sauer et al. (1983) and Hollis (1975) established the initial relationship. The basic modeling tools to predict 100-year peak discharge rates for pre- development and current development conditions have advanced considerably since then, but the newer hydrologic models still give the same basic results in most urban subwatersheds (USGS, 1996). Utility in restoration planning and design The index helps define the degree of flood plain expansion in the stream corridor. High index values indicate that flooding problems may be severe in the stream corridor, and could suggest that older stream crossings may lack sufficient capacity to handle increased flood waters. The peak discharge ratio also helps estimate the maximum stress and current velociti es that stream repair practices will be exposed to. Comments The relationship between IC and 100-year peak discharge rate ratios are reasonably well established, but several other subwatershed factors can also strongly influence this indicator. These factors include Urban Subwatershed Restoration Manual 1 the type and age of storm drains, the age of subwatershed development, and the existing hydraulic capacity of both the stream channel and its flood plain. 3. Bankfull Flooding Frequency Definition and computation of indicator This indicator is defined as the number of flow events that comp letely fill the cross-sectional area of the pre-development channel in an average year of rainfall. Continuous hydro logic simulation models are often used to derive this statistic, by comparing bankfull flood frequency based on current subwatershed conditions against the frequency computed for assumed rural, pre-development conditions. Baseline condition compared to In rural watersheds, the bankfull flood frequency is about 0.5 events per year, or roughly one bankfull flood event every two years. References used to derive The basic relationship was developed by Leopold ( 1968, 1994) and a simple model to relate bankfull flooding frequency to subwatershed IC was advanced in Figure B-3 , Appendix B "Bankfull Flooding Frequency Analysis" by Schueler ( 1987). Data from Konrad and Booth (2002) and Nehrke and Roesner (2002) were also helpful in characterizing the relationship. Utility in restoration planning and design This indicator helps assess the potential severity of stream bank erosion and habitat degradation within an urban subwatershed. Bankfull flooding frequency can also be reduced when upstream storage retrofits are constructed within a subwatershed, so it is often used to plan the location and required storage of upstream storm water retrofit practices to protect the channe l. In addition, bankfull flooding frequency has considerable value in stream repair design. Comments The actual bankfull discharge can change over time in an urban subwatershed, as the cross-sectional area of the stream channel gradually enlarges to accommodate increased storm water flows (see indicator# 7). Therefore, this indicator will be less accurate A-3 Appendix A: Derivation of Predictions for the Imper vious Cover Model A-4 in older subwatersheds where channel incision and enlargement have already increased th e capacity of the channel to accommodate pre- development bankfull flood di scharge rates . Stream order may also be important in defining bankfull flooding frequency in urban streams. Palmer et al. (2003) observed the greatest increase in bankfull flooding frequency occurred in first and second streams, and was attenuated to some degree in third and fourth order streams. C: Derivation of ICM Predictions for Physical Alteration of the Urban Stream Corridor 4. stream Enclosure/Modification Definition and measurement of indicator This indicator is defined as the fraction of the pre- development stream network that remains intact, expressed in terms of total length (miles) or stream density (miles/square mile). This indicator is derived by comparing the length of the historical stream network (derived from historical maps or photos) to its current stream length (determined from GIS analysis or field assessment). Baseline condition compared to Rura l streams that have 90 to 100% of the original stream network remaining, although some may have experienced greater modification because of past agricultural drainage, flood control or channelization "improvements." References used to derive The predictions are primarily based on anecdotal evidence, although several studies have documented that individual urban subwatersheds lose considerable stream dens ity at high levels of deve lopment (Dunne and Leopold, 1978 and NVRC, 2001 ). As a practical consideration, very few biological or habitat indicators are reported above 50 to 60% subwatershed IC, which indirectly suggests that this level of IC may be the breakpoint where natural stream channels are enclosed or channelized. Utility in restoration planning and de sign This indicator can help define general opportunities to daylight streams, and is also a good measure of the loss of headwater streams that are important in stream ecology. Comments The age and intensity of deve lopment in a subwatershed can also be very important in defining this stream corridor indicator. For example , recent ly developed subwatersheds could potentially be subject to les s stream enclosure/modification because of wetland permitting and/or stream buffer requirements . 5. Riparian Forest Continuity Definition and meas urement of indicator This indicator is defined as the fraction of the exi sting perennial stream network th a t possesses an intact forest buffer of an appropriate width (e .g., 50 feet on either side of channe l). Riparian forest continuity, or RFC can be directly measured by the Unified Stream As sessment (Manual 2) or through a GIS analysis of aerial photographs of a su bwatershed. Baseline condition compared to Rural streams typically have an intact riparian fore st buffer along about 80 to 100% of their stream corridor, according to regional surveys by Jones et al. ( 1997). Riparian forest continuity, howeve r, can be quite variable in some rural subwatersheds, depending on the prevailing ri parian ma nagement p ractices used by adjacent farmers and ranchers . References used to derive Only one study has defined the behav ior of RFC over a broad range of subwatershed IC (Homer e t al., 1997), but the Center has consistently seen the sharp decline in RFC during fie ld work in highly urban s ubwatersheds . Utility in restoration planning and desi gn Riparian forest continuity is an extremely important indicator of s ubwatershed with high potential to reforest or improve management of the stream corridor. RFC is also a good indicator to measure progress made in riparian reforestation at the subwatershed leve l. Urban Sub wa te rsh e d Restoration M an ual 1 Appendix A: Derivation of Predictions for the Impervious Cover Model Comments Historical stream corridor management actions can also be extremely important to explain RFC behavior within indi v idual subwatersheds. For example, past decisions to locate stream valley parks, re gulate the flood plain or require stream buffers during development can all strongly influence RFC. 6. Stream Interruption Definition and measurement of indicator This indicator is defined as the average number of stream crossings per stream mile in a subwatershed, and can be measured during the Unified Stream Assessment (Manual 2) or through careful GIS analysis of subwatershed aerial photos. Baseline condition compared to Rural streams usually have less than one crossing per stream mile , according to an extensive national GIS watershed analysis by Jones et al. (1997). References used to derive Only one study has explored the relationship between IC and the number of stream crossings in urban subwatersheds (May et al., 1997), although our field experience, drawn from many urban watershed assessments, suggests that it is a robust relationship . Utility in restoration planning and design The number of stream crossings can be used to determine urban fishery resource potential, with an emphasis on the potential severity of barriers to fish migration in a subwatershed. In addition, the number of hard crossings can be useful to locate potential storage retrofit sites in the stream corridor, and to identify existing grade controls that may locally moderate stream bank erosion in the stream network. Comments While that this indicator relationship seems robust, it has not been systematically studied across the full range of IC, particularly in the NS and UD categories . Indeed , stream crossings are probably irrelevant in UD subwatersheds, for the simple reason that there are no streams left to cross . Urban Subwatershed Restoration Manual 1 D: Derivation of Urban Stream Habitat Predictions for the ICM 7. Channel Enlargement Ratio Definition and measurement of indicator This indicator of expected channel enlargement is defined as the ratio of the ultimate stream channe l cross-sectional area compared to the pre-development cross-sectional area, averaged for multiple stream reaches in a subwatershed. Channel enlargement can be measured, if both current and historical cross-sectional data are avai lable for stream channels, and can be modeled if extensive geomorphic data is available. Baseline condition compared to A rural stream of the same geomorphic type that has stable banks, which is defined as having a ratio of one. References used to derive The basic relationship has been proposed by Caraco (2001); MacRae and DeAndrea (1999); MacRae (1996); and Hammer (1972). Both Bledsoe (2001) and Booth and Henshaw (2001) observed that the power of IC to predict stream channel en largement is not particularly great at low to moderate levels of subwatershed development (5 to 15% IC), and argued that many other subwatershed and geomorphic variables complicate the enlargement prediction in these subwatersheds. On the other hand, the Center 's field assessments clearly indicate that progressively greater bank instability and enlargement are common for both the NS and UD stream categories . Uti lity in restoration planning and design The channel enlargement indicator is a good index of bank stability along the stream corridor, as well as the likely degree of habitat impairment in the stream. A general understanding of expected channel enlargement is also quite helpful when designing stream repair and restoration practices. Comments More research is needed to assess the degree of channe l enlargement that occurs A-5 Appendix A : Derivation of Predictions for the Impervious Cover Model A-6 in the NS and UD stream categories. It is also quite likely the age of development will be an important s ubwatershed factor, s ince the channel enlargement process may take decades to fully manifest itself in many urban streams. 8. Sediment Supply to stream Definition and mea surement of indicator The indicator is defined by the ratio of the annua l sediment yie ld produced from an urban subwatershed compared to a rural one, expressed in terms of mass per unit area per year (e.g ., tons/square mile/yr). The sediment yie ld indicator reflects the delivery of greater urban sediment loads caused by accelerated stream bank and channel erosion. Long-term sediment and flow monitoring are need ed to compute the subwatershed sediment yield, which has been done at a few small er USGS gage sites . Baseline condition compared to A stable rura l stream of the same geomorphic type and subwatershed area. References used to deri ve The fact that individual urban subwatersheds have higher unit area sediment yields compared to rural subwatersheds has been established by Barton (2003); Trimble (1997); and Dartiguenave et al. (1997). To date, no studie s have tracked this indicator over the broad range of imperviou s cover encompassed by the ICM . In addition, the potential for reduced urban sediment yie lds because of extensive stream enclos ur e/ modification has not been investigated, but could be very important in UD subwatersheds. Utility in restoration p lanning and de s ign This indicator is important to assess a subwatershed's contribution to downstream sediment loads, as we ll as predicting internal sediment dynamics within the stream channel. Sediment yield can be used to forecast the future loss of capacity in storage retrofits and stream repair practices due to sediment deposition. Comments The general prediction is reasonab ly strong, but is complicated by the evolution process of urban stream channels . More research on the unit area sediment yield data over the range of IC covered by the ICM wou ld be helpful , particularly for channels that are naturally adjusting and those that are channe li zed/enclosed. 9. Typical Stream Habitat Score Definition and measurement of indicator This indicator is defined by the average stream habitat score sampled in multiple stream reaches in an urban su bwatershed, compared to a rural sub watershed. Stream habitat scores are frequently measured by the EPA rapid habitat assessment protocol (Barbour et al., 1999) or equivalent habitat assessment method . Base line condition compared to A rural stream in good condition (i.e., with stable banks and intact riparian zone) typically has "good" or "very good" habitat index scores. As Wang et al. (2001) notes , however, habitat scores may be lower in some rural streams with poor riparian management practices . References used to derive A detailed review of the general relationship between IC and stream habitat is provided in CWP (2003). Most stream researchers have only looked at the relationship between 5 and 25% subwatershed IC (Morse 2001 and Wang et al. 2001). Consequently, very littl e systematic data is available to characterize stream habitat quality within the upp er range of the NS streams and the entire UD category. Once again, the Center 's field assessments indicate that habitat quality is consistently poor to very poor in these streams. Utility in restoration planning and design In- stream habitat scores are a u se ful indicator to assess fishery restoration potential in urban subwatersheds , and can be used to track restoration progress . Comments More subwatershed research is needed to characterize habitat quality in NS and UD streams in order to refine the predictions. Urban Subwatershed Restoration Manual 1 Appendix A : Derivation of Predictions for the Impervious Cover Model 10. Presence of Large Woody Debris Definition and measurement of indicator Large woody debris (LWD) in the stream channel is a good measure of both structural stream habitat and the interaction of the stream with its riparian zone. Large diameter wood in contact with the stream can be measured in the field over several reaches within a subwatershed. The composite score is expressed as the average number of LWD pieces encountered over a unit stream length. Baseline condition compared to Rural stream, with intact forested riparian zone, averaging five to 15 LWD pieces per 100 feet of stream reach (Fox et al., 2003). References used to derive Most urban subwatershed LWD data has been gathered for Pacific Northwest streams with subwatershed IC ranging from 0 to 40% (May et al. 1997; Fox et al., 2003; Finkebine et al., 2000). No systematic data has been collected for NS streams at the upper end of its IC range, and for the entire UD category, although the Center's field assessments indicate that LWD is scarce or absent in these highly urban streams . Utility in restoration planning and design LWD is helpful in assessing fishery resource potential , habitat quality, and the degree of interaction between the stream and riparian zone. Comments More regional research is needed to assess LWD frequency for both the NS and UD stream categories . 11. Increased Summer Stream Temperatures Definition and measurement of indicator This indicator is defined as the increase in average maximum summer stream temperature compared to a comparable rural stream draining the same subwatershed area. The warming effect is often referred to as the delta- T and can be monitored using continuous or simultaneous water temperature probes in the stream during the summer months. Urban Subwatershed Restoration Manual 1 Baseline condition compared to Average summer stream temperature for a rural stream that has an intact riparian canopy to provide shade. References used to derive The primary data on the IC vs. stream temperature relationship was first proposed by Galli (1990). The relationship is a lso indirectly supported by urban heat island research conducted by Cheung (2002), who found a one degree F increase in summer surface air temperature for each 10% increment in local IC , when the presence of adjacent water and forest cover was controlled. Confounding factors include effect of cold water springs (Kilham and Steffy, 2002), stream canopy, and the presence of storm water ponds in a subwatershed. Still , there is a strong physical basis for the IC /stream temperature relationship up to about 60% sub watershed IC. No stream temperature data could be found for UD subwatersheds, whose extensive below- ground drainage could potentially have a coo lin g effect on summer stream temperatures. Uti lity in restoration planning and design Stream temperature is an important indicator to determine fishery resource potential (e.g., ability to support trout, salmon or sensitive aquatic insect species). Comments More research is needed to refine stream temperature predictions for the NS and UD stream categories . E: Derivation of Urban Water Quality Predictions for the ICM 12. Annual Nutrient Load Definition and computation of indicator This indicator is defined as the annual unit area mass storm water loading of phosphorus and/or nitrogen produced by an urban subwatershed compared to a rural one . Nutrient loads can be computed for any urban subwatershed using the Simple Method (Schueler, 1987), given a reliable estimate of subwatershed IC and median event mean concentrations for the range of land uses present (Table A-1 ). A-7 Appendix A : Derivation of Predictions for the Impervious Cover Model Table A-1: National Summary of Pollutant Concentrations in Storm Water Runoff All Data Residential Commercial Industrial Freeway #of storms sampled 3756 1069 497 524 185 Median Event Mean Concentrations EMC (mg/I or ppm) Suspended Solids 58 48 43 77 99 Dissolved Solids 80 71 77 92 78 BOD5 8.6 9.0 11 .9 9 8 COD 53 55 63 60 100 Fecal coliforms # 5081 7750 4500 2500 1700 Fecal streptococci# 17 ,000 24,000 10,800 13,000 17 ,000 Nitrate-N 0 .6 0.6 0.6 0.7 0.28 TKN 1.4 1.4 1.6 1.4 2.0 Total Nitrogen 2 .00 2.00 2 .2 2.1 2.3 Total Phosphorus 0 .27 0.3 0.22 .26 0.25 Dissolved P 0.12 0.17 0.11 0.11 0.20 Oil and Grease 4 3.1 4 .7 4 8 Median Event Mean Concentrations EMC (ug/I or ppb) Total Cadmium* 1.0 0.5 0.9 2 .0 1.0 Total Chromium 7 .0 4 .6 6 .0 15 8.3 Total Copper 16 11 .1 17 22 35 Total Cyanide* 5.0 5.0 0.1 5.9 nd Total Lead 16 11 .1 18 25 25 Total Mercury* 0.2 0 .2 0 .2 0.1 0.2 Total Nickel* 8 5.4 7 16 9 Total Zinc 116 73 150 210 200 Fluoranthrene * 6 3 6 3.8 nd Phenanthrene * 3.95 1.7 4.1 9 nd Pyrene * 5.2 2 .2 5 .0 7.2 nd Source : Pitt et al. 2003 Notes : Medians are of detected values . An asterisk indicates constituent was undetected in more than half of all storm events . A# indicates bacteria measured in counts per 100 ml. A -8 Urban Subwatershed Restoration Manual 1 Appendix A: Derivation of Predictions for the Impervious Cover Model Baseline condition compared to The annual load of phosphorus or nitrogen produced by a rural subwatershed, which has been defined regionally in the National Water Quality Assessment by the USGS (2001 ). The term "rural" refers to a mix of forest , pastures and crops; note that subwatersheds with extensive row crop or livestock operations can produce much higher nutrient loads. References used to derive The general relationship between storm water nitrogen loading rates and subwatershed IC has been proposed by Schueler and Caraco (2001 ). A sim ilar relationship between storm water phosphorus loading rates and subwatershed IC has been presented by Caraco and Brown (2001, Table 4) and Caraco (2001, Figure 1). The nutrient load indicator does not include any nutrients from wastewater discharges (either permitted or illicit), which are often found in NS and UD subwatersheds and could possibly increase annual nutrient loads . Utility in restoration planning and design Nutrient loads can be a useful indicator to measure progress toward nutrient reduction efforts in subwatersheds where downstream eutrophication is a management concern. Various modeling tools can be used to estimate the effect of various restoration practices to reduce subwatershed nutrient loading rates. Manual 2 in this series describes how the Watershed Treatment Model can be used for this purpose. Comments Pitt et al. (2003) has published extensive summaries of storm water runoff monitoring data that establish reliable estimates of nutrient event mean concentrations over a wide range of subwatershed IC in many regions of the country. Therefore, our confidence in the accuracy of urban nutrient load predictions is fairly high , although we are less confident in the estimates of rural nutrient loads used as the baseline condition . Urban Subwatershed Restoration Manual 1 13. Exceedance of Bacteria Standards Definition and measurement of indicator This indicator is defined as the frequency that bacteria standards for water contact recreation are exceeded during wet weather and/or dry weather flow events in urban subwatersheds , as measured either by fecal coliform or E. coli bacteria . Bacteria levels are typically measured during stream sampling at trend or sentinel stations within an urban subwatershed. Baseline condition compared to Water contact bacteria standards are exceeded in rural streams no more than 10 to 20% of storm events per year, and are rarely exceeded during dry weather (USGS , 200 l ). References used to derive The basic conceptual model for dry and wet weather bacteria behavior for urban watersheds has been advanced by Schueler (1999 -Figure 1), based on an extensive analysis of storm water and dry weather monitoring data for urban subwatersheds across the country. Other data sources include Mallin et al. (2000, 2001) and Pitt et al. (2003). Utility in restoration planning and design The bacteria indicator can help target discharge prevention and source contro l restoration practices, and can be used to set realistic and achievable goals for water contact recreation during dry and wet weather. Comments Extensive runoff monitoring has estab li shed reliab le estimates of storm water bacteria concentrations over a wide range of IC in many regions of the country (Pitt et al., 2003). Although bacteria levels are highly variable, we are reasonably confident in the broad pattern. A-9 Appendix A: Derivation of Predictions for the Impervious Cover Model A-10 14 . Aquatic Life Toxicity Definition and measurement of indicator This in dicator is defined as the potential for ambient metal , pesticide or chloride concentrations in storm water runoff to cause mortality in exposed aquatic organisms in urban streams. The degree to which ambient concentrations of sto rm water pollutants can cause either chronic or acute toxicity to aquatic life are still wide ly debated (see review in CWP, 2003). Baseline condition compared to Ambient metal , chloride or pesticide le vels measured during storms in a rural stream. In general, acute toxicity is rarely encountered during storms in rural streams, unless adjacent agricultural or orchard spraying is unusuall y high . References used to derive Several researchers have reported either ac ute or chronic toxicity within individual urban subwatersheds with known impervious cover (Crunkilton et al., 1996 ; Field and Pitt, 1990 ; Ellis , 1986 ; Ireland et al. 1996 ; Connor, 1995 ; Environment Canada , 2001 ). Systematic toxicity monitoring across the range ofIC included in the ICM , howe ver, has not been performed. Several researchers do report a strong urban land use effect (Rice, 1999 and Callender and Rice, 2000). Uti lity in restoration planning and design This indicator is important in definin g priorities and specific pollutant reduction targets for hotspot source control, municipal practices , neighborhood stewardship, and storm water retrofitting in the context of a subwatershed restoration plan. Comments While the urban land use effect is quite strong for this indicator, the actual impac t that toxins exert on urban stream li fe is also quite complex, and probably differs for each class of toxins. In particular, the risk of aquatic life toxicity in NS and UD subwatersheds is problematic for several reasons . First, sensitive aquatic organisms may already be absent in NS and UD su bwatersheds as a result of other hydrolo gical, physical , habitat and water quality stressors. Second, evidence exists that p es ticides may actually be generated at higher rates in impacted subwatersheds compared to NS and UD subwatersheds , since they have more pervious area where pesticides could be potentially applied (Hopkins and Hippe , 1999). B y contrast, NS a nd UD subwatersheds usually contain a greater density of storm water hotspots that have a higher potential for leaks, spills or illegal discharges of toxic pollutants. We have therefore elected to use a more narrative rather than quantitati ve prediction to describe this indicator that looks at potential rather than actual frequency of acute or chronic toxicity. 15. Contaminated Sediments/Fish Advisories Definition and measurement of indicator This indicator can be defined in one of two ways. The first way is to measure the extent to which sediments are enriched in metals, organo- chlorine pesticides and/or polycyclic aromatic hydrocarbons (PAH) compared to reference sediments from rural subwatersheds . The second way is to measure whether the same compounds accumulate in fish ti ss ue to levels that prompt an advisory restricting fish consumption. Base line co ndition compared to Both indicators are measured in relation to bottom sediments or fish tissue collected from rura l subwaters heds . Rural bottom se diments can be contaminated by mercury (which is a widespread national problem) and some pesticides (from agric ultu ral and orchards), but they lack the di sti ncti ve "metal/PAH /organo- ch lorine pesticide" fingerprint that is so di agnos tic of urban bottom se diments. References used to derive Abundant evidence exists to show a strong urban land use effect on sediment contamination . This is evident in urban storm water runoff concentrations (Pitt et al., 2003), urban stream bed sediments (Rice , 1999), urban lake and reservoir sediments (Van Metre et al. 2000 and Callender and Rice , 2000) and urban estuarine sediments (Holland et a l. 2003 a nd Velinsky and Cummins, 1994). A strong urban land use effect was also Urban Subwatershed Restoration Manual 1 Appendix A: Derivation of Predictions for the Impervious Cover Model reported in patterns of sediment contamination in a national survey of sediment quality (US EPA , 1997). The same basic sediment contamination fingerprint has also been widely observed in the bottom sediments of many storm water ponds (Schueler, 1996). Much less evidence is available to make the link between subwatershed IC and pollutant accumulation in fish tissues that prompt fish consumption advisories. There does appear to be a strong clustering of fish consumption advisories around highly urban subwatersheds for non-mercury pollutants (EPA , 2003). In addition, the USGS (2001) reports extensive evidence of metal and PAH accumulation in fish tissues in urban streams, but they did not systematically monitor them over the wide range of subwatershed IC encompassed by the ICM. Utility in restoration planning and design This indicator is important to define priorities and specific pollutant reduction targets for hotspot source control, discharge prevention, municipal practices, neighborhood stewardship, and storm water retrofits in a subwatershed plan. Comments While there is strong evidence for the relation of urbanization and sediment contamination/fish advisories, we lack systematic monitoring over the full range of subwatershed IC to make quantitative predictions at this time. We have therefore elected to use a narrative rather than quantitative prediction for this indicator. 16. Trash and Debris Definition and measurement of indicator This indicator is ideally defined as the unit area loading rate of trash and debris, expressed in dry weight measured for an urban subwatershed. At this time, however, there is no universally accepted method to report trash and debris loadings . Researchers have variously measured trash/debris using units of gallons, tons, cubic feet, and number of trash bags filled. There also is no consistency in whether reported loads represent dry mass, wet mass or only floatables . In addition, the actual techniques to measure trash/debris loads are Urban Subwatershed Restoration Manual 1 quite different, with researchers using booms to capture trash during runoff events, sampling catch basins, measuring the total volume collected by volunteers along a given length of stream or shoreline, or weighing trash collected by skimmer boats in a harbor. Baseline condition compared to A rural stream, with minor trash loading. References used to derive Several debris characterization studies were consulted including CRWQCB (2001 ), OCW (2000), and Steinberg et al. (2002). None of these studies samp led small urban subwatersheds, nor did they evalu ate trash /debris loads over the range of subwatershed IC included in the ICM. It shou ld be noted, however, that most trash and debris problems and management efforts do occur in highly urban and ultra-urban subwatersheds (i.e., NS and UD streams). Utility in restoration planning and design This indicator is useful to target stream cleanups, and define residential and business source control practices in contributing subwatersheds. Severe trash and debris problems may call for enhanced municipal practices such as street sweeping, storm drain cleanouts, storm drain stenciling, or illegal dumping controls. Comments This is perhaps the most poorly understood ICM indicator, due to uneven and inconsistent data quality to measure trash/ debris , and the fact that trash loading rates have not been systematically monitored in subwatersheds over the full range of the IC covered by the ICM model. Virtually no trash loading monitoring has been performed within impacted subwatersheds, so this indicator prediction is merely an educated guess. 17. Other Storm Water Pollutants Definition and measurement of indicator This indicator is defined as the annual unit area mass load of a storm water pollutant produced by an urban subwatershed compared to a rural subwatershed . It can be computed for any subwatershed using the Simple Method (Schueler, 1987), given a reliable estimate of A-11 Appendix A: Derivation of Predictions for the Impervious Cover Model A-12 subwatershed IC and median event mean concentrations for the range of land uses present (see Table A-1 ). Reliable data are available for various measures of organic carbon (COD, BODS), metals (Cu, Zn, Pb), and oil and grease. Baseline condition compared to The annual unit area pollutant load produced by a rural subwatershed, which has been defined regionally in the National Water Quality Assessment by the USGS (2001 ). The term "rural" refers to a mix of forest, pastures and crops; subwatersheds with extensive agricultural or livestock operations can produce higher loads of organic carbon and other pollutants. References used to derive Schueler ( 1987) proposed the general relationship between storm water pollutant loading rates and subwatershed IC, which requires a good estimate of the storm water event mean concentration (EMC). Pitt et al. (2003) present EMC data for a range of common land uses , which is shown in Table A-1 . Uti li ty in restoration planning and design This is a useful indicator to measure pollutant load reduction needed to meet subwatershed or watershed water quality, such as the Watershed Treatment Model (see Manual 2). Comments As noted earlier, Pitt et al. (2003) have established reasonably accurate storm event mean concentration data for most conventional pollutants for most regions of the country (with the possible exception of the northern tier of U.S.). It should be noted that much fewer data are avai lab le to characterize PAH compounds and chlorides. F: Derivation of Aquatic Diversity Predictions for the ICM 18 . Aquatic Insect Diversity Definition and measurement of indicator This index is defined as the average subwatershed macro-invertebrate or aquatic insect diversity score, as computed by Benthic Index of Biotic Integrity or B-IBI (Barbour et al., 1999). It is typically measured in multiple stream reaches within a subwatershed. Baseline condition compared to B-IBI scores for rural streams typicall y range from "good" to "very good." References used to derive Our predictions are based on visua l inspection ofB-IBI vs. IC data plots from th e following studies Boward et al. (1999); MNCPPC (2000); Homer et al. (1997); Black and Veatch (1994); Kennen (1999); Yoder (1991) and Fairfax County (2001). In general, B-IBI scores are only reported up to about 40 to 45 % subwatershed IC, so the poor diversity predicted for streams in the upper NS and the entire UD category simply represents an extension of the data trend line . Utility in restoration planning and design This indicator helps assess the general b iological health of an urban stream, and can be used to track improvements in stream health as a result of the imp lementation of subwatershed restoration practices . Comments The relationship between IC and declining B-IBI scores is strongly supported by current research, although aquatic insect diversity data for UD streams is generally lacking. 19. EPT Taxa Definition and measurement of indicator This indicator is defined as the proportion of sensitive stonefly, caddisfly and mayfly species in the stream insect community, expressed as the percent of the total score for a rural "reference" stream. Streams with high EPT scores contain many pollution and/or temperature sensitive species, whereas streams with low sc ores are deemed pollution tolerant. Baseline condition compared to EPT scores for a rura l stream, which are typically 80 to 100% of the reference stream value. References used to derive The primary references used to predict this indicator were Maxted and Shaver ( 1997) and Morse (2001 ), although this metric is also one of the components of the B-IBI scoring (see# 18). Urban Subwatershed Restoration Manual 1 Appendix A: Derivation of Predictions for the Impervious Cover Model Utility in restoration planning and design This measure of the pollution tolerance of the aquatic insect community indicates the degree to which pollution, degraded habitat, or other stressors are influencing lo cal stream ecology. Comments Again, very little research is available to characterize EPT scores for streams with more than 40% subwatershed IC, which makes it somewhat hard to make predictions for NS and UD stream categories. Based on extensions of the trend lines, however, it is doubtful that any highly urban streams contain any pollution or temperature sensitive species. 20. Fish Diversity Definition and measurement of indicator This indicator is defined as the average fish diversity score for an urban subwatershed compared to a rural one. The fish Index of Biotic Integrity or F-IBI is usually sampled in multiple stream reaches to obtain an average score for an urban su bwatershed (Barbour et al., 1999). Baseline condition compared to Rural streams typically have "good" to "very good" fish-IBI scores , unless there has been a major change in land use or riparian management in the subwatershed (Harding et al., 1998). References used to derive These predictions are based on visual inspection ofF-IBI vs. IC data plots from the following studies Wang et al. (2001 ); MNCPPC (2000); MW COG (1992); Meyer and Couch (2000); Boward et al. (1999); Horner et al. (2001) and Couch et al. (1997). As with B-IBI scores, reported F- IBI data extend only from five to about 45 % subwaters hed IC , so the poor diversity predicted for streams in the upper NS and the entire UD category simply represents an extension of the data trend line . Utility in restoration planning and design Fish diversity scores are an excellent indicator of stream health , from the perspective of both stream researchers and the general public, and scores can be tracked over time to measure progress toward fishery restoration goals. Urban Subwatershed Restoration Manual 1 21. Trout or Salmon Definition and measurement of indi cator This indicator is defined as the ability to maintain a self-reproducing population of trout or salmon within a subwatershed. Where this is not possible, the indicator is alternatively defined as the ability to maintain a put-and-take fishery in the stream. This indi cator is easi ly measured through fishery and spawning surveys in an urb an subwatershed. Baseline condition compared to A rural stream w ith habitat conditions that can support trout or salmon populations . References used to d erive A number of researchers have examined the effect ofIC on trout and salmon and have found that these popu lations are often absent or extremely stressed above 10% subwatershed IC (Boward et al., 19 99 ; Horner et al., 1999; May et al., 1997; WDFW, 1997; Kilham and Steffy, 2002; Scott et al., 1986 ; Kemp and Spotila, 1997; Moscript and Mo ntgomery, 1997). It may be possible to support salmon at the lo wer IC range of imp acted subwatersheds , but no records of self-reproducing populations could be found in either NS or UD subwatersheds . Urban fishery biologists have established put- and-take recreational trout fis heries in some larger I and NS streams . In addition, there is some data that hardier c utthroat trout may inhabit I and NS streams for at least part of their life cycles (May et al., 1997). Uti lity in restoration planning and design This indicator helps set expectations for the fishery resource potential of an urban subwatershed. If a stream can potentiall y support a self- reproduci ng or put-and-take fis hery, it greatly affects the selection of which subwatershed restoration practices to apply (e.g., stream repair/restoration techniques , e limi nation of fish barriers , improved riparian management). Comment s This indicator o bvio us ly only applies to eco-regions that can support a cold- water fishery. An alternative "indicator" fish species could be se lected for regions that have a warm-water fishery. A-13 Appendix A : Derivation of Predictions for the Impervious Cover Model A-14 22. Riparian Plant Diversity Definition and measurement of indicator This indicator measures plant diversity and community structure in the remaining flood plain forests and wetland fragments of the stream corridor. The three main elements used to describe this indicator are a) the relati ve dominance of exotic and native plant species within the fragment, b) fragment patch size and structure and c) overall plant divers ity within the fragment compared to a rural stream corridor. Each of these elements can be measured along the stream corridor, but they rarely are. Baseline condition compared to Each of the three riparian elements should be compared against va lues obtained from flood plain forest or wetland reference sites located in the rural stream corridor. References used to derive This narrative prediction is based on research that has shown a strong urban land use effect for each element in urban riparian areas (Brush and Zipperer, 2002· Groffman et al. 2003; Findlay and Houlihan, 1997 ; Taylor et al., 1995), as well as extensive anecdotal evidence from urban stream corridor surveys. Consistent and uniform techniques to measure and compare riparian plant diversity, however, have not systematically been applied over the range of subwatershed IC encompassed by the ICM. Utility in restoration planning and design This indicator could be quite useful in defining the prospects for effective riparian and natural area restoration in the urban stream corridor, but is not fully developed at this time. Comments This indicator is expressed as very general narrative criteria, relating to dominance of exotic plants, average fragment size and structure and overall plant diversity within the fragment. G: Summary The ICM organizes a combination of published and unpublished research, engineering models , field experience, and hypotheses into a stream classification system for three kinds of urban subwatersheds. The strongest evidence for ICM predictions tends to be concentrated in the 10 to 40% subwatershed IC range; much less is known about the behavior of streams in the upper end of the NS category and the entire UD category. We strongly believe additional research on NS and UD streams will further refine and tighten ICM predictions, and invite researchers to test these hypotheses in future monitoring . Tables A-2, A-3 , and A-4 provide a summary of the ICM predictions for impacted, non- supporting and urban drainage stream classifications, respectively. These tables also include a confidence factor, or CF for each indicator, which qualitatively expresses the relative confidence in each indicator prediction on a scale of one to five (with five being the most confident and one being least confident). Urban Subwatershed Restoration Manual 1 Appendix A : Derivation of Predictions for the Impervious Cover Model Table A-2: ICM Predictions for Impacted Streams (11 to 25% IC) Stream Indicator Prediction CF Influence of Storm Water Runoff 10 to 30% of rainfall converted to runoff 5 Flood Plain Expansion Index Peak discharge for 100-yr storm increased by a 4 factor of 1 .1 to 1. 5 Bankfull Flood inq Frequency 1.5 to 3 bankfull flood events per year 4 Stream Enclosure/Modification 60 to 90% of stream network intact 3 Ripar ian Forest Continuity 50 to 70% of riparian forest buffer intact 3 Stream Interruption 1 to 2 crossinqs per stream mile 2 Channel Enlarqement Cross-sectional area 1.5 to 2 .5 times higher 3 Sed iment Suooly to Stream 2 to 5 times more annual yield 3 Typical Stream Habitat Score Fair , but variable 3 Presence of Large Woody Debris 2 to 8 pieces per 100 feet of stream 2 Summer Stream Temperature 2 to 4 degrees F warmer 3 Annual Nutrient Load 1 to 2 times higher than rural background 4 Violations of Bacteria Standards Frequent violations during wet weather 4 Potent ial Aquatic Life Toxicity Acute toxicity rare , chronic possible 2 Contaminated Bottom Sediments Sediments enriched , but not contaminated ; fish 2 advisories uncommon Trash and Debris Load 1 to 2 tons per square mile per year 2 Aquatic Insect Diversity Fair to good B-IBI scores 4 EPT Taxa 40 to 70% of reference 4 Fish Diversity Fair to good F-IBI scores 4 Capacity to Suooort Trout or Salmon Some limited potential 4 Riparian Plant Diversity Stressed and simplified plant communities 2 CF: Confidence factor based on scale of 1 to 5, with 5 representing the highest level of confidence . Table A-3: ICM Predictions for Non-Supporting Streams (26 to 59% IC) Stream Indicator Prediction CF Influence of Storm Water Runoff 25 to 60% of ra infall converted to runoff 5 Flood plain Expansion Peak Discharge for 100-year storm increased 4 by a factor of 1.5 to 2 Bankfull Flood Frequency 3 to 7 bankfull flood events per year 4 Stream Enclosure/Modification 25 to 60% of stream network intact 3 Ripar ian Forest Continuity 30 to 60% of riparian forest buffer intact 3 Stream Interruption 2 to 10 stream crossings per mile 2 Channel Enlargement Cross-sectional area 2 .5 to 6 times larger 3 Sediment Supply to Stream 5 to 10 times more sediment yield 2 Typ ical Stream Habitat Score Consistently poor 3 Presence of Large Woody Debris Scarce 2 Summer Stream Temperatures 4 to 8 degrees F warmer 3 Annual Nutrient Load 2 to 4 times hiqher than rural backqround 4 Violations of Bacteria Standards Continuous violations during wet weather; 4 episodic violations during dry weather Potential Aqua tic Life Toxicity Moderate potential for acute toxicity during 3 some storms and spills Contamination of Bottom Sediments Episodic potential for acute toxicity ; fish 3 advisories likely Trash and Debris Loading 2 to 5 tons per square mile per year 2 Aquatic Insect Diversity Poor B-IBI scores 4 EPT Taxa 20 to 50 of natural reference 3 Fish Diversity Poor F-IBI scores 4 Capacity to Support Trout or Salmon Temporary use only (i.e., put-and-take) 3 Riparian Plant Diversity Simplified and dominated by exotic sp . 2 CF : Confidence factor based on scale of 1 to 5, with 5 representing the highest level of confidence . Urban Subwatershed Restoration Manual 1 A-15 Appendix A : Derivation of Predictions for the Impervious Cover Model Stream Indicator Influence of Storm Water Runoff Flood Plain Expansion Index Stream Enclosure/Modification Annual Nutrient Load Violations of Bacteria Standards Potential Aquatic Life Toxicity Contaminated Bottom Sediments Trash and Debris Loads Aquatic Insect Diversity EPTTaxa rt Trout or Salmon Prediction 60 to 90% of rainfall converted to runoff Peak Discharge for 100-year storm increased b factor of 2 to 3 7 to 1 0 bankfull events er ear 10 to 30% of stream network intact >30% of ri arian forest buffer intact No streams left to cross Cross-sectional area 6 to 12 times lar er Sediment ield lower Poor, often absent Absent Continuous violations during wet weather, fr uent violations durin d weather High potential for acute toxicity episodes durin dr and wet weather Sediment contamination and bio-accumulation should be resumed Very poor B-IBI scores 0 to 20% of reference Ve or F-IBI scores None Ri arian Plant Diversit Isolated remnants; Dom inated b exotics CF 5 4 2 2 2 2 2 2 3 4 4 2 3 2 2 2 2 2 A-1 6 Urban Subwatershed Restoration Manual 1 Appe ndix B: Organization o f Restoration Tech nique Profile Sheets Appendix B: Organization of Restoration Technique Profile Sheets for the Manual Series Manual 3: Storm Water Retrofit Practices Storage Retrofit Techniques Modify Existing Detention Ponds (SR-1) Storage Above Roadway Culverts (SR-2) New Storage Below O utfa ll s (SR-3) Storage in the Conveyance System (SR-4) Storage in Road Right of Ways (SR-5) Large Surface Parlcing Lots (SR-6) On-site Non-Residential Retrofit Techniques Bioretention (OS-7) Swales (OS-8) Infiltration Tench (O S-9) Storm water Filters (O S-1 0) Permeable Pavement (OS-11) Storm Water Planters (OS-12) Cisterns (OS -13) Green Rooftops (OS -14) On-site Residential Retrofit Techniques Rain Barrels (OS-15) Rain Gardens (OS-16) French Drains and Dry We ll s (OS-17) Urban Subwate rs hed Restoration Manual 1 Manual 4: Stream Repair Practices Stream Cleanup Techniques Stream C leanups (C-1) Stream Adoption (C-2) Stream Repair Techniques Bou lder Revetment (R-3) Rootwad Revetment (R-4) Imbricated Rip Rap (R-5) A-Jacks (R-6) Live Cri bwalls (R-7) Streambank Shaping (R-8) Coir Fiber Logs (R-9) Erosion Contro l Fabrics (R-10) Soil L ifts (R-11) Live Stakes (R-12) Live Fascines (R-13) Brush Mattress (R-14) Vegetation Establishment (R-15) Wi ng Deflectors (R-16) Log, Rock and J Vanes (R-17) Rock Vortex Weir (R-18) Rock Cross Vane (R-19) Step Poo ls (R-20) V Log D rops (R-2 1) Lunkers (R-22) Large Woody Debris (R-23) Boul der Clusters (R-24) Baseflow Channe l Creation (R-25) Parall e l P ipes (R-26) Stream D aylighting (R-27) Culvert Modification (R-28) Culvert Replacement and Removal (R-29) Devices to Pass Fis h (R-30) Comprehensive Restoration Techniques Comb ining Stream Repair Practices (S-31) Channel Redesign (S-32) De -channe lization (S -33) B-1 Appendix B: Organization of Restoration Technique Profile Sheets B-2 Manual 5: Riparian Management Practices Site Preparation Techniques Removal/Prevention of Dumping (SP-1) Invasive Species Control (SP-2) Urban Soil Preparation (SP-3) Storm Water Management (SP-4) Revegetation Techniques Active Reforestation (F-5) Park/Greenway Plantings (F -6) Natural Regeneration (F-7) Riparian We tl an d Restoration (F -8) Manual 6: Discharge Prevention Practices Techniques to Find Discharges Outfall Reconnaissance Investigation (D-1) Chemical Outfall Monitoring (D -2) In-stream Dry Weather Sampling (D -3) In-Pipe Investigations (D -4) Hotlines and Citizen Reporting (D-5) Dye, Smoke and TV Testing of Suspect Pipes (D-6) Infrared Aeria l Thermography (D-7) Finding Failing Septic Systems (D -8) Techniques to Fix Discharges Municipal Spill Management (D-9) Structural Repairs (D-10) Techniques to Prevent Discharges Public Education/Employee Training (D-11) Authori ty to Control Discharges (D -12) Manual 7: Pervious Area Management Practices Site Preparation Techniques Removal/Prevention of Dumping (SP -1 ) Invasive Species Control (SP-2) Urban Soil Preparation (SP-3) Storm Water Management (SP-4) Re-vegetation Techniques Active Reforestation (F -5) Park/Greenway Plantings (F-6) Natural Regeneration (F-7) Riparian Wetland Restoration (F-8) Manual 8: Pollution Source Control Practices Neighborhood Stewardship Techniques Low Input Lawn Care (N-1) Reduced Pesticide Use (N-2) Xeriscaping (N-3) Natural Landscaping (N-4) Tree Planting (N-5) Yard Waste Composting (N-6) Soil Reclamation (N-7) Erosion Repair (N-8) Septic System Cleanouts (N-9) Safe Pool Discharges (N-10) Safe Car Washing (N -11) Dri veway Sweeping (N-12) Safe Deicer Use (N-13) Household Hazardous Waste Collection (N-14) Car Fluid Rec ycling (N-15) Downspout Disconnection (N-16) Single Lot Controls (N-1 7) Pet Waste Pick-up (N-18) Storm Water Practice Maintenance (N-19) Bufferscaping (N-20) Storm Drain Stenciling (N-21) Hotspot Pollution Prevention Techniques Vehicle Maintenance and Repair (H-1) Vehicle Fueling (H-2) Vehicle Washing (H -3) Vehicle Storage (H-4) Outdoor Loading and Unloading (H-5) Outdoor Storage (H-6) Spill Prevention and Response (H-7) Dumpster Management (H-8) Building Repair and Remodeling (H-9 ) Building Maintenance (H-10) Parking Lot Maintenance (H-11) Turf Management (H-12) Landscaping/Grounds Care (H -13) Swimming Pool Discharges (H-14) Unique Hotspot Operations (H-15) Urban Subwatershed Restoration Manual 1 Manual 9: Municipal Practices and Programs Techniques for Streets and Storm Drains Street and Parking Lot Sweeping (M-1) Catch Basin Cleaning (M-2) Road Maintenance (M-3) Employee Training (M-4) Best Practices for New Construction Conduct Site ESA (RP-1) Protect and Restore Natural Area (RP-2) Natural Area Maintenance (RP-3) Efficient Use ofIC (RP-4) Employ BSD (RP-5) Maximize Transportation Choices (RP-6) Manage Rooftop Runoff (RP-7) Courtyard Plaza Design (RP-8) Minimize Parking Lot Runoff (RP-9) Design Streetscapes (RP -10 ) Municipal Pollution Prevention (RP-11) Inspection and Enforcement Enforcement (E-1) Urban Subwatershed Restoration Manual 1 Appendix B: Organization of Restoration Technique Profile Sheets B-3 Appendix B: Organization of Restoration Technique Profile Sheets B-4 Urban Subwatershed Restoration Manual 1 References American Forests. 2001. Urban Ecosystem Analysis for the Washington DC Metro Area: An Assessment of Existing Conditions and a Resource for Local Action. Washington, D.C. Barbour, M., J. Gerritsen, B. Snyder and J. Stribling . 1999. Rapid Bioassessment Protocols for Use in Streams and Wadeable Rivers: Periphyton , Benthic Macroinvertebrates and Fish. 2nd Edition. EPA 841-B-99-002. U.S. EPA Office of Water. Washington, D .C . Barton, C . 2003 . "Applications of a Sediment Budget to Assist Urban Stream Restoration ." Watershed Review 1(2): 4. Center for Water and Watershed Studies. University of Washington Black and Veatch. 1994. Longwell Branch Restoration-Feasibility Study Vol. 1. Carroll County, MD Office of Environmental Services. Bledsoe, B. 2001. "Relationships of Stream Response to Hydrologic Changes." Linking Stormwater BMP Designs and Performance to Receiving Water Impacts Mitigation Proceedings. Snowmass, CO. Booth, D . and P. Henshaw. 2001. "Rates of Channel Erosion in Small Urban Streams." Water Science and Application 2: 17-38 . Boward, D., P. Kazyak, S. Stranko, M. Hurd and T. Prochaska. 1999. From the Mountains to the Sea : The State of Maryland s Freshwater Streams . EPA 903- R-99-023. Maryland Department of Natural Resources. Annapolis, MD. Urban Su b watersh e d Res to ration Manual 1 Brown, E. D. Caraco and R. Pitt. 2004. Illicit Discharge Detection and Elimination: A Guidance Manual for Program Development and Technical Assessments. Center for Watershed Protection and University of A labama. Prepared for U.S . EPA Office of Wastewater Management. Brush, G. and W. Zipperer. 2002. "A Comparison of Exotic and Non-exotic P lant Populations in the Gwynns Falls Riparian Corridor." Unpublished Data. Baltimore Ecosystem Study. LTER. California Regional Water Quality Control Board (CRWQCB). 2001. Trash TMDL for the Los Angeles River watershed. Callender, E. and K. Rice. 2000. "The Urban Environmental Gradient: Anthropogenic Influences on the Spatial and Temporal Distributions of Lead and Zinc in Sediments." Environmental Science and Technology 34(2): 232-238. Caraco, D . and E. Brown. 2001. "Managing Phosphorus Inputs Into Lakes II: Crafting an Accurate Phosphorus Budget for Your Lake." Watershed Protection Techniques 3(4): 782-790 Caraco, D. 2000. "The Dynamics of Urban Stream Channel Enlargement." Watershed Protection Techniques 3(3): 729-734 . Caraco, D. 2001. "Managing Phosphorus Inputs Into Lakes III: Evaluating the Impacts of Watershed Treatment." Watershed Protection Techniques 3(4): 791-797. Center for Watershed Protection (CWP). 2002. Unpublished survey of small watershed organizations. References R-1 References R-2 CWP. 2003. Th e Impacts of Imp erviou s Cover on Aquatic Systems : Watershed Protection R esearch Monograph No. 1. Center for Waters hed Protection. Ellicott City, MD. CWP. 2004. Smart Watersheds : Integrating Local Programs to Achieve Measurable Progress in Urban Watershed Restoration. Center for Watershed Protection. Ellicott City, MD . Cheung, I. 2002 . "Extreme Heat, Ground Level Ozone Concentration, and the Urban Heat Island Effect in Washington D.C." Metropolitan Area. North American Urban Heat Island Summit, Toronto, Canada. Connor, V. 1995 . P es ticide To x icity in Storm wa ter Runoff Technical Memorandum. California Regional Water Quality Control Board, Central Valley Region. Sacramento, Ca lifornia . Couch, C. et al. 1997 . "Fish Dynamics in Urban Streams Near Atlanta, Georgia." Technical Note 94. Watershed Protection Techniqu e s . 2( 4): 511-514 . Crunkilton, R ., J. Kleist, J. Ramcheck, W. DeVita and D. Villeneu ve. 1996 . "Assessment of the Response of Aquatic Organisms to Long-term In Situ Exposures of Urban Runoff." Effects of Watershed D evelopm en t and Management on Aquatic Ecosystems. Roesner, L.A., editor. Proceedings of the ASCE Conference. Snowbird, Utah. Dartiguenave, C ., I. ECLille and D. Maidment. 1997. Water Quality Master Planning for Austin, TX. CRWR On line Report 97-6. Dunne, T. and L. Leopold. 1978. Wat er in Environmental Planning . W. Freeman and Company, New York, NY. Ellis, J. 1986. "Pollutional Aspects of Urban Runoff." In Urban Runoff Pollution. H . Torno, J. Marsalek and M . Desbordes , editors. Springer-Verlag, Berlin. Environment Canada. 2001. Priority Substances List Assessme nt Reports . Road Salt. Ministry of Environment. Toronto, Canada. EOA, Inc. 2001 . Stormwater Environm ental Indicators. Pilot Demonstration Project. Final Report. Water Environment Research Foundation. Santa Clara Urban Runoff Pollution Prevention Project. Santa Clara, CA. Fairfax County Department of Public Works and Environmental Services (Fairfax Co). 2001. Fairfax County Stream Protection Strategy Bas e line Study. Stormwater Management Branch, Stormwater Planning Division, Fairfax County, VA. Field , R . and R. Pitt. 1990 . "Urban Storm- induced D ischarge Impacts: US Enviro nm e ntal Protection Agency Research Program Review." Wat er Science Techno logy (22): 10-11. Findlay, C. and J. Houlahan. 1997. "Anthropogenic Correlates of Species Richness in Southeastern Ontario Wet lands." Conservation Biology 11(4): 1000-1009. Finkenbine, J., J. Atwater and D. Mavinic . 2000. "Stream Health After Urbanization." Journal of th e American Water R eso urces Association 36(5): 1149-1160. Fox. M ., S. Bolton and L. Conquest. 2003. Reference conditions for instream wood in Western Washington. In Montgomery, Bolton, B ooth and Wall , eds. Res toration of Puget Sound Rivers . University of Washington Press. Galli, J. 1990. Th ermal Impacts Associated with Urbanization and Stormwater Management B es t Managem ent Practices . Metropol itan Washington Council of Governments. Washington, D .C. Greater Vancouver Sewage and Drainage District. 2002. Effective ness of Stormwater Source Control. Ch2MHill. Vancouver, British Columbia. Urban Subwa tershed Res toration Manual 1 Groffman, P., D. Bain, L. Band, K. Belt, G. Brush, J. Grove , R . Pouyat, I. Yesilonis and W. Zipperer. 2003 . "Down by the Riverside: Urban Riparian Ecology." Frontiers in Ecology and Environment. Ecological Society of America. 1(6) Hammer, T. 1972 . "Stream Channel Enlargement Due to Urbanization." Water Resources R esearch 8(6): 1530-1540. Hardin g, J., E. Benfield, P. Bolstad, G. Helman and E. Jones . 1998. "Stream Biodiversity: the Ghost of Land Use Past." Pro ceedings National Academy of Science. 95: 14843- 14 847 Holland, A., D. Sanger, C. Gawle, S. Lerberg, M. Santiago, G. Riekerk, L. Zimmerman and G. Scott. 2003. "Linkages Between Tidal Creek Ecosystem and the Landscape and Demographic Attributes of Their Watersheds." Journal of Experimental Marine Biology and Ecology. 4243: Hollis, F. 1975 . "The Effects of Urbanization on Floods of Different Recurrence Intervals." Water Resources Research 11 :43 1-435. Hopkins , E. and D . Hippe . 1999. "Can Land Use Patterns Serve as a Predictor of Pesticide Occurrence Within an Urban Landscape?" Proceedings, 1999 Georgia Water Resources Conference. University of Georgia Homer, R., C. May, E. Livingston and J. Maxted. 1999 . "Impervious Cover, Aquatic Community Health, and Stom1water BMPs: Is There a Relationship?" In Proceedings of Th e Sixth Biennial Stormwater Resea rch and Watershed Management Conference. Sept 14-1 7. 1999. Tampa Florida. Southwest Florida Water Management District. Available online: http://www.stormwater- resources.com/ proceedings_of_the_sixth_biennia.htm Urban Subwatershed Restoration Manual 1 Homer, R., C . May, E. Livingston, D. Blaha, M . Scoggins, J. Tims and J. Maxted . 2001. "Structural and Non-structural BMPs for Protecting Streams." in Linking Stormwater BMP D esigns and Performance to R eceiving Water Impact Mitigation. B. Urbonas (editor). Proceedings of an Engineering Research Foundation Conference. Smowmass, CO. American Society of Civil Engineers. pp. 60-77. Homer, R., D. Booth, A . Azous, and C. May. 1997 . "Watershed Determinants of Ecosystem Functioning." In Roesner, L.A . Editor. Effects of Watershed D evelopment and Management on Aquatic Ecosystems. Proceedings of the ASCE Conference. Snowbird, Utah. 1996 . Ireland, D., G. Burton, Jr. and G. Hess. 1996. "In Situ Toxicity Evaluations of Turbidity and Photoinduction of Polycyclic Aromatic Hydrocarbons." En vironmental Toxicology and Chemistry 15(4): 574-581. Jones, K., K. Ritters, J. Wickham, R . Tankersly, R. O'Neill , D. Chaloud, E. Smith and A. Neale . 1997. An Ecological Assessment of the United States Mid- Atlantic R egio n : a Landscape Atlas. U.S. EPA Office of Research and Development. EPN600/R-97 /130 . Kemp, S. and J. Spotila. 1997. "Effects of Urbanization on Brown Trout Salmo trutta , Other Fishes and Macroinvertebrates in Valley Creek, Valley Forge, PA." American Mid!. Nat. 138:55-68 . Kennen, J. 1999 . "Relation of Macroinvertebrate Community Impairment to Catchment Characteristics in New Jersey Streams ." Journal of the American Water Resources Association 35(4):939- 955 . Kilham , S. and L. Steffy. 2002. "Response of Biota to Urbanization in a Watershed in the Philadelphia, PA Area." Presented at the American Society of Limnology and Oceanography Meeting held in Victoria, BC, Canada on June 10-14, 2002. References R-3 References R-4 Konrad, C . 2003. "Opportunities and Constraints for Urban Stream Rehabi litation." In Montgomery, Bo lton , Booth and Wall , eds. R es toration of Pu get Sound Rive rs . University of Wa sh ington Pres s . 505 pp. Konrad , C . and D. Booth. 2002. Hy drolog ic Trends A ssociated w ith Urban D evelopm ent for Se lected Streams in th e P uget Sound Basin -Wes tern Wa shing ton . USGS Water Resource s In vestigation Report 02-4040 . Kwon , H. 200 l . Rede velopm ent Roundtable Consensus Agreem ent: Smart Site Pra cti ces for R ede ve lopm ent and Infill Projects. Center for Watershed Protection . Ell icott City, MD . Leopo ld , L. 1968. Hy drology for Urban L and Us e Planning -A Guidebook on th e Hy drologi c Effe cts of Urban Land Us e. Washington, D .C . Geo logical Survey Circular 554 . Leopo ld, L. 1994. A Vi ew of th e Rive r. Harvard Uni versity Press . Cambridge, MA . MacRae, C . 1996 . "Ex perience From Morphologica l Research on Canadian Streams: Is Control of the Two-ye a r Frequency Runoff Event the Best Basis for Stream Channel Protection?" In Roesner, L.A . Editor. Effects of Wat ersh ed Developm ent and Management on Aquatic Eco systems . Proceedings of the ASCE Conference. Snowbird, Utah. MacRae, C . and M. DeAndrea . 1999 . Assessing th e Impact of Urbanization on Chann el Morph olo gy. Second International Conference on Natural Channe l Systems. N iagra Fa ll s, OT. Ma ll in , M ., K . Will iams , E . Es ham an d R. Lowe . 2000. "Effect of Human Development on Bacterio logica l Water Quality in Coastal Watersheds." Ecolog ical Applications 10(4) 1047-1056 . Mallin , M ., S. Ensign, M. Mciver, G. Swank and P. Fowler. 200 l. "D emographic , Landscape and Metro logic Factors Controllin g the Micro bi al Pollution of Coastal Waters ." Hy drobiologia 460 : 185- 193. Maryla nd-Nati onal Capital Park an d P lanning Commiss ion (MNCPPC). 2000. Stream Condition Cumulative I mpact Models For th e Potoma c Subregion . Silver Spring, MD . Maxted, J. and E . Shaver. 1997 . "The Use of Rete ntio n Basins to Mitigate Stormwater Impacts on Aquatic Life ." In Roesner, L.A . Editor. Effects of Watersh ed D e velopment and Management on Aquatic Ecosystems. Proceedings of the ASCE Conference. Snowbi rd, Utah. May, C ., R . Homer, J. Karr, B . Mar and E. Welch. 1997 . "Effects of Urbanization on Small Streams in the Puget Sound Lowland Ecoregion ." Wat ersh ed Prote ction Techniques 2(4): 483-494. Metropo litan Washington Council of Governments (MWCO G). 1992. Watersh ed R es tora tion Sourcebook. Department of Environmental Programs. Washington, DC . Meyer, J. and C . Cou ch. 2000. Influen ces of Wat e rshed Land Use on Stream Ecosystem Structu re and Functio n . NCER QA Grant Fina l R eport. Morse, C . 200 1. The Response of Firs t and Second Order Streams to Urban Land-use in Maine, USA . Masters Thesis . The University of Maine. Orono, ME . Moscript, A. a nd D . Mo ntgomery. 1997 . "Urbanization, Flood Frequency, and Sa lmo n A bundance in Puget Lowland Streams ." Journal of th e American Wat er R es ources Ass ociation. 33 : 1289-1297 . Urban Subwatershed Restoration Manual 1 Nehrke S. and L. Roesner. 2002. "Effects of Detention and BMPs on Flow Frequency of Runoff." In B. Urbonas, ed. Linking Stormwater BMP Designs and Performance to R ece iving Water Impact Mitigation . American Society of Civi l Engineers. Northern Virginia Regional Commission (NVRC). 2001. The Effect of Urbanization on the Natural Drainage Network in th e Four Mi le Run Watershed. Orange County Watersheds (OCW). 2000. Debris Characterization study. AN0-8-023- 258-0 Watershed and Coastal Resources Division. Orange County, CA. Palmer, M., G. Moglen, N. Bockstael, J . Pizzuto, C. Wiegand, And K . Van Ness. 2003. "The Ecological Consequences of Changing Land Use for Running Waters, with a Case Study of Urbanizing Watersheds in Maryland." Yale Forestry and Environmental Science Bulletin. 107:85-113 Paul, M. and J. Meyer. 2001. "Streams in the Urban Landscape." Annual Review of Ecology and Systematics: 32: 33-65. Pitt, R., A. Maestre, and R. Morquecho. 2003. The National Stormwater Quality Database (NSQD, version 1.0). University of Alabama and the Center for Watershed Protection. Rice, K . 1999 . "Trace Element Concentration in Streambed Sediment Across the Coterminous United States." Environmental Science and Technology. 33( 15): 2499-2504. Sauer, V., T. Stricker and K. Wilson. 1983 . Flood Characteristics of Urban Watersheds in th e Unit ed States. U.S. Geological Survey Water Supply Paper 2207. Urban Su bwatershe d Res to ration Manual 1 Schueler, T. 1987. Controlling Urban Runoff: A Practical Manual for Planning and Designing Urban Best Management Practices . Metropolitan Washington Council of Governments . Washington, D.C. Schueler, T. 1994. "Poll utant Dynamics of Pond Muck." Watershed Protection Techniques 1(2). Schueler, T. 1999. "Microbes and Urban Watersheds." Watershed Protection Techniques 3(1 ): 551-596. Schueler, T. and D. Caraco. 2001. "The Prospects for Low Impact Land Deve lopment at th e Watershed Level." In Linking Stormwater BMP Designs and Performance to Receiving Water Impacts Mitigation. United Engineering Foundation. Snowmass, CO. Scott, J., C. Steward and Q . Stober. 1986. "Effects of Urban Development on Fish Population Dynamics in Kelsey Creek, Washington." Transactions of the American Fisheries Society. 115:555 -567. Steinb erg, , N., J. Way, and D. S u szkowski. 2002. An Analysis of Environmental Indicators for the NY/NJ Harbor Estuary. New York/New Jersey Harbor Estuary Program. Hudson River Foundation for Science and Environmental Research. Swann, C. 2000 . "Understanding Watershed Behavior." Watershed Protection Techniques. 3(3):671-679 Taylor, B., K. Ludwa and R . Homer. 1995. Third Puget Sound Research Meeting Urbanization Effects on Wetland Hydrology and Water Quality. Proceedings of the Puget Sound Water Quality Authority Meetin g. Olympia, WA. Trimble, S . 1997 . "Contribution of Stream Channel Erosion to Sediment Yield from an Urbanizing Watershed." Science 278 : 1442-1444. References R-5 References R-6 U.S. EPA. 2003. Update : National Listing of Fish and }Vildlife Advisories. Office of Water, EPA-823-F-03-003. U.S. EPA. 1997. National Sediment Quality Survey. EPA-823-R-97-006 Office of Water, Washington, D.C USGS. 1996. Effects of Increased Urbanizaton from 19 70s to 1990s on Storm Runoff Characteristics in P erris Valley, California. USGS Water Resources Investigations Report 95-4273. USGS . 2001. The Quality of Our Nations Waters: Nutrients and Pesticides. USGS. FS-047-01. Van Metre , P., B. Mahler and E. Furlong. 2000. "Urban Sprawl Leaves its PAH Signature." Environmental Science and Technology. 34(19): 4064-4070. Velinsky, D. and I.Cummins. 1994 . Distribution of Chemical Contaminants in Wild Fish Species in the Washington, D. C. Area. Interstate Commission on the Potomac River Basin, ICPRB ., Rockville, MD. Report No. 94-1. Wang, L., J. Lyons , P. Kanehl and R. Bannerman. 2001. "Impacts of Urbanization on Stream Habitat and Fish Across Multiple Spatial Scales." Environmental Management. 28(2):255- 266. Washington Department of Fish and Wildlife (WDFW). 1997 . Final Environmental Impact Statem e nt for the Wild Salmonid Policy. Olympia, Washington. Yoder, C. 1991. "The Integrated Biosurvey As a Tool for Evaluation of Aquatic Life Use Attainment and Impairment in Ohio Surface Waters." In Biological Criteria : Research and Regulation, Proceedings of a Symposium, 12-13 December 1990, Arlington, VA. U.S. EPA, Office of Water, Washington, D.C. EPA-440/5-91-005:110. Urban Subwatershed Restoration Manual 1