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HomeMy WebLinkAboutFolder - CopyFOR OFFICE USE ON'iYA Case No. Q-\-(._l-\ Date Submitted CITY OF C OLLEGE STATION Planning & Development Services DEVELOPMENT PERMIT MINIMUM SUBMITTAL REQUIREMENTS 200 development permit fee. $600 Public Infrastructure Inspection Fee if applicable. (This fee is payable if construction of a public waterline, sewerline, sidewalk, street or drainage facilities is involved.) ~ Drainage and erosion control plan, with supporting Drainage Report two (2) copies each ONA Notice of Intent (N .0 .1.) if disturbed area is greater than 5 acres Date of *Required Pre application Confere nee : ____ __;;3'=-::u;.;..:111~e_"2._9-_,_.,.,.__...2-=o""""""o"-x~------ *(Req uired for areas of special flood hazard) LEGAL DESCRIPTION Lot 15 R-1, Block B, Eastmark Phase Ill Resubdivision . . APPLICANT'S INFORMATION (Primary Contact for the Project): Name Municipal Development Group/Lenwood Adams E-Mail __ ___,:,m,,..:.,d=g:i..:c=s=tx=@=-i..va=h""'o::..;:o::..:... c=o::..:.m"-'------ Street Address 2551 Texas Ave South Ste.A ---------------~~~~-~~~~~------- City ___ C_o_l_le_g~e_S_t_a_tio_n ____ State Texas Zip Code 77840 Phone Number ---~(_97_9~)6_9_3_-5_3_5_9 ___ _ Fax Number (979)693-4343 PROPERTY OWNER'S INFORMATION: Name ___ ---"-C~h=ar~le=s'-=La=n~g~in~g~h~a~m'-'--"-c/~o~J~M~C"'----E-Mail ----"-c=la"""n""'"in.,,g~h=a~m"""@_,_j"-'m"""c'---~m ... g-'-"m""'t'""'. c-""o~m __ Street Address 13140 Coit Rd. Ste. 220-LB22 ------------------'-"""-'-~~"-'--'-~-"'-'~==-"'-==-==------- City Dallas State Texas Zip Code 75240 Phone Number ____ ~(9~7_2~)2_3_4_-1_5~5~0____ Fax Number (972)234-1580 ARCHITECT OR ENGINEER'S INFORMATION: Name ____ M~u~ni~c~ip~a~l~D~ev~e~lo~p~m~en~t'--G~ro~u~p ___ _ E-Mail ------'-m""'"d=g"""'c::..;:s=tx""""@~va=h"'"'o::....:o::..:...c""'o::..:.m~--- Street Address 2551 Texas Ave South Ste.A --------------~~~~~~~~~~'--'-'--'------- City Bryan State Texas Zip Code 77840 Phone Number (979) 693-5359 Fax Number (979) 693-4243 Application is hereby made for the following development specific site/waterway alterations: ACKNOWLEDGMENTS: I, ~'7/f-, design engin~/owner, hereby acknowledge or affirm that: The information and conclusions contained in the above plans and supporting documents comply with the current requirements of the City of College Station, Texas City Code, Chapter 13 and its associated Drainage Policy and Design Standards. ~~~-- Property Owner(s) Page 1 of 2 As a condition of approval of this permit application, I agree to construct the improvements proposed in this application according to these documents and the requirements of Chapter 13 of the College Station City Code Contractor CERTIFICATIONS: A. I, ~ certify that any nonresidential structure on or proposed to be on this site as part of this application is designated to prevent damage to the structure or its contents as a result of flooding from the 100-year storm. Engineer Date B. I, L-5 A, certify that the finished floor elevation of the lowest floor, including any basement, of any residential structure, proposed as part of this application is at or above the base flood elevation established in the latest Federal Insurance Administration Flood Hazard Study and maps, as amended. Engineer Date C. I, ~J fr:' certify that the alterations or development covered by this permit shall not diminish the flood- carrying capacity of the waterway adjoining or crossing this permitted site and that such alterations or development are consistent with requirements of the City. of College Station City Code, Chapter 13 concerning encroachments of floodways and of floodways fringes. Engineer Date D. I, ~o certify that the proposed alterations do not raise the level of the 100 year flood above elevation established in the latest Federal Insurance Administration Flood Hazard Study. Date Conditions or comments as part of approval: ----------------------- In accordance with Chapter 13 of the Code of Ordinances of the City of College Station, measures shall be taken to insure that debris from construction, erosion, and sedimentation shall not be deposited in city streets, or existing drainage facilities. All development shall be in accordance with the plans and specifications submitted to and approved by the City Engineer for the above named project. All of the applicable codes and ordinances of the City of College Station shall apply. Page 2 of 2 CITY OF COLLEGE STATION Planning & Devdopmml Servicn SITE LEGAL DESCRIPTION: Eastmark Phase 111 Subdivision Lot 15 R-1, Block B University Commons Phase Ill DATE OF ISSUE: 02/11/08 OWNER: TYPE OF DEVELOPMENT: SPECIAL CONDITIONS: DEVELOPMENT PERMIT PERMIT NO. 07-79A FOR AREAS INSIDE THE SPECIAL FLOOD HAZARD AREA RE: CHAPTER 13 OF THE COLLEGE STATION CITY CODE SITE ADDRESS: 950 Colgate Drive DRAINAGE BASIN: Wolf Pen Creek VALID FOR 3 MONTHS CONTRACTOR: Full Development Permit All construction must be in compliance with the approved construction plans All trees required to be protected as part of the landscape plan must be completely barricaded in accordance with Section 7.5.E., Landscape/Streetscape Plan Requirements of the City's Unified Development Ordinance, prior to any operations of this permit. The cleaning of equipment or materials within the drip line of any tree or group of trees that are protected and required to remain is strictly prohibited. The disposal of any waste material such as, but not limited to, paint, oil, solvents, asphalt, concrete, mortar, or other harmful liquids or materials within the drip line of any tree required to remain is also prohibited. ***UTILITY AND GRADING ONLY***NO RETAINING WALL UNTIL ORB APPROVAL**** The Contractor shall take all necessary precautions to prevent silt and debris from leaving the immediate construction site in accordance with the approved erosion control plan as well as the City of College Station Drainage Policy and Design Criteria. If it is determined the prescribed erosion control measures are ineffective to retain all sediment onsite, it is the contractors responsibility to implement measures that will meet City, State and Federal requirements. The Owner and/or Contractor shall assure that all disturbed areas are sodden and establishment of vegetation occurs prior to removal of any silt fencing or hay bales used for temporary erosion control. The Owner and/or Contractor shall also insure that any disturbed vegetation be returned to its original condition, placement and state. The Owner and/or Contractor shall be responsible for any damage to adjacent properties, city streets or infrastructure due to heavy machinery and/or equipment as well as erosion, siltation or sedimentation resulting from the permitted work. In accordance with Chapter 13 of the Code of Ordinances of the City of College Station, measures shall be taken to insure that debris from construction, erosion, and sedimentation shall not be deposited in city streets, or existing drainage facilities. I hereby grant this permit for development of an area inside the special flood hazard area. All development shall be in accordance with the plans and specifications submitted to and approved by the City Engineer in the development permit application for the above named project and all of the codes and ordinances of the City of College Station that apply. A(4rlj(Jr: Date ~===-=-0 2-1/-08 Owner/ Agent/Contractor Date 7 ·I ... . . ;;. .. ~ SANITARY SEWER REPORT FOR UNIVERSITY COMMONS PHASE III MDG JOB NO. 000076-3957 COLLEGE STATION, BRAZOS COUNTY, TEXAS OCTOBER 2007 Ofc: 979.693.5359 Fax: 979.693.4243 Email: mdgcstx@yahoo.com Project Scope and Description: The purpose of this analysis is to determine whether there is adequate capacity in the proposed sewer' line to provide service for The University Commons Phase III of College Station Development. The project site is located near the intersection of Southwest Parkway and State Highway 6. lt lies just east of the existing University Commons Apartments and just northwest of the existing Wolf Pen Creek Bowling Center. Analysis of Proposed Sewer Flow: The University Commons Phase III of College Station is classified for residential land use. There are 48 units in Phase III. Using the 2007 Bryan/College Station Uniform Design Guidelines, the flow for the proposed site was estimated. The peak flow was calculated by multiplying the Average Daily Flow by 4.0. The estimated total peak flow with infiltration for the University Commons Phase III of College Station Development is 15,270 total gpd. Results: The 6" line has an overall capacity of 0.252 ft 3/s and 0.201 ft3/s at 80% capacity, and the total peak with infiltration is 0.024 ft3 !.s. Therefore the proposed 6" sanitary sewer line is more than adequate. Attachments: • Flow calculations Sewer Size Calculations Daily Wastewater Flow per lot Total Number of Units Average Daily Wastewater Flow Peaking Factor Peak Daily Wastewater Flow lnflitration Total Wastewater Flow Total Wastewater Flow Total Wastewater Flow Slope at Collection Point Diameter Manning's n Capacity Capacity (80% Full) Total Wastewater Flow Capacity> Total Flow References: OK 60 gal/day/lot 48 units 2880 gal/day 4 11520 gal/day 3750 gal/day 15270 gal/day 10.60 gal/min 0.024 ft3/s 0.008 ft/ft 6 in 0.013 0.252 ft3/s 0.201 ft3/s 0.024 ft3/s 1. Unified Design Guidelines, City of Bryan/College Station (2007) Infiltration 750 gal/acre 5 acres 3750 gal/day FLOODPLAIN EVALUATION REPORT FOR UNIVERSITY COMMONS APARTMENTS 1.52 ACRE TRACT MDG JOB NO. 000076-3957 COLLEGE STATION, BRAZOS COUNTY, TEXAS JUNE 2007 2551 Texas Ave. South, Ste. A, College Station, TX 77840 Ofc: 979.693 .5359 Fax: 979.693.4243 Email: mdgcstx@yahoo.com Project Scope: This report outlines the floodplain evaluation that was conducted for Jamespoint Management Company in conjunction with a site plan for the possible development of a 1.52 acre tract. The floodplain evaluation began by review of the existing Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map (FIRM). Then, the existing FEMA hydraulic model of Wolf Pen Creek was obtained from the City of College Station as well as the topographic map from which the model was constructed. Next, using current topography from the MDG surveying crew, the hydraulic model was updated and the current floodplain was determined. Even with the most updated to ographic information, the current floodplain/floodway boundaries have not chan ed from the FIRM. Fma y, the mo e was up a e to e ermme w at impact p acmg fill on the site would have on the base flood elevation of Wolf Pen Creek. General Location and Description: The project site is located near the intersection of Southwest Parkway and State Highway 6. It is comprised of a 1.52 acre tract that lies just east of the existing University Commons Apartments and just northwest of the existing Wolf Pen Creek Bowling Center. The site is separated by Wolf Pen Creek by a strip of land that varies from 100 feet to 300 feet wide that was previously dedicated to the City of College Station Parks Department. Approximately half of the site is wooded with dense underbrush characteristic of backwater floodplain. The remainder of the site is an open, grassy area that appears to be regularly maintained. The site generally slopes from southwest to northeast (towards Wolf Pen Creek) with elevations ranging from 263.0 ft to 257.0 ft. Existing FEMA Hydraulic Model: The existing hydraulic model for Wolf Pen Creek was obtained from Mr. Donnie Willis, Drainage Inspector for the City of College Station. The model was originally constructed in the Army Corps of Engineers' HEC-2 modeling software. For review, the HEC-2 input files were exported to HEC- RAS (Hydrologic Engineering Center -River Analysis System). HEC-RAS is the Army Corps of Engineers successor to HEC-2 and is considered the standard modeling software for floodplain applications. After review, the floodplain model is consistent with the physical characteristics of Wolf Pen Creek near the site; no major deficiencies were found. Two of the cross sections in the model cross the site. The topographic map that was used to construct this model was also obtained from the City of College Station. The topographic map and the results of the FEMA hydraulic model are shown in Exhibit 1. As shown in Exhibit 1, the entire site is located within the 100-yr floodplain which has an elevation of approximately 263.3 ft. Additionally, approximately half of the site lies within the regulatory floodway. The floodway is the land most severely affected by flooding and must be able to carry and discharge floodwaters. No development is allowed in this area. Updated Hydraulic Model: The FEMA hydraulic model was updated to include the current topography. A recent field survey conducted by the MDG surveying crew produced more detailed topographic data near cross sections 77.70, 80.80, and 83 .60. These cross sections were updated using the current topographic data. The model was run again, and the base flood elevation remained the same. The base flood elevation did not change because the site is located within a backwater floodplain that is created when water backs up at the box culverts that cross Highway 6. The current topographic data and the results from the updated hydraulic model are shown in Exhibit 2. Impact of Fill on the Base Flood Elevation: The City of College Station has a policy in place that only allows filling in the floodplain if it produces a 0.0 ft rise in the base flood elevation. Thus, the model was adjusted to reflect the placement of fill on the site under proposed development conditions and analyzed to determine the effect of fill on the base flood elevation. For the analysis, it was assumed that the portion of the site not located within the floodway would be filled to elevation 264.0 ft. The base flood elevation in this area is roughly 263.3 ft. Cross sections 80.80 and 83.60 were revised to reflect the placement of fill. The placement of fill as described would result in 0.0 ft rise in the base flood elevation, so the criterion set forth by the City of College Station is satisfied. Conclusions: After a thorough analysis, it was determined that only 0.84 acres of the 1.52 acres may be filled for development. This would require roughly 4,000 cubic yards of fill to be placed to elevate this portion of the site out of the 100-yr floodplain. The remaining 0.68 acres of the site is located within the regulatory floodway and may not be developed. The included exhibits depict the area of the site that may be developed. The entire HEC-RAS project files (Existing, Updated, and Fill) are attached on CD for review. References: 1. HEC-RAS 3.1.3 http://www.hec.usace.army.mil/software/hec-ras/hecras-download.html 2. HEC-RAS Users Manual. USACE, November 2002. http://www.hec.usace.army.mil/software/hec-ras/hecras-document.html 3. HEC-RAS Hydraulic Reference Manual. USACE, November 2002. http://www.hec.usace.army.mil/software/hec-ras/hecras-document.html \ ~ ~:~(}JN~~ ~ ~ ~ Page I of! Carol Cotter -Temporary Certificate of Occupancy University~~ \ V1;, o'B From: To: Date: Subject: CC: Carol, "Charles Laningham" <claningham@jmc-mgmt.com> <c.cotter@cstx.gov>, <ccotter@cstx.gov> 10/10/2008 3:39 PM Temporary Certificate of Occupancy University Commons "Dawn Michalewicz" <dmichalewicz@jamespoint.com>, "Erica Freeman" <ericaf@jamespoint.com>, "Ron Laningham" <rlaningham@jmc-mgmt.com>, "Gregory K. Taggart" <mdgcstx@yahoo.com> This memo is provided to confirm our earlier phone conversation regarding issuance of a temporary CO for the new building at University Commons. I am President of Charlan Commons, Inc., the corporate general partner of College Station Commons Ltd, the owner of University Commons Apartments and in that capacity am authorized to execute documents and make binding agreements on behalf of the property. Your legal department has copies of the partnership documents, which were provided for the water easement completed earlier this year. We will promptly execute and deliver to your office such documents, as your legal department requires and prepares to grant a blanket easement for electrical service by the City of College Station to the new building at University Commons. 30 days should be sufficient time to prepare the documents, update the title policy, secure the needed signatures and return the documents to your office. I request that you contact Lee Adams of Adams & Taggart, Engineers to coordinate getting any questions answered or assistance as needed. We ask that the City issue a temporary certificate of occupancy today, subject to getting the easement documentation prepared by the city legal department, delivered to me and returned to your office within 30 days. We need the certificate today please, as we have a number of residents in temporary quarters, including A&M Galveston transferees, who need to move this weekend. Thanks for your assistance. Please call should any additional language be needed in this memo. I will fax you a signed copy of this memo. Charles Laningham President Charlan Commons, Inc. General Partner College Station Commons, Ltd. 972/234-1551 I am using the Free version of SP AMfighter for Personal use. SP AMfighter has removed 207 of my spam emails to date. Try SP AMfi hter for free now! The Trial and Professional version does not have this message in the email file://C:\Documents and Settings\ccotter\Local Settings\Temp\XPgrpwise\48EF771FCity ... 11111 /2008 Carol Cotter -University Commons Phase III From: To: Date: Subject: Lee- carol Cotter Adams and Taggart Assoc 10/15/2008 3:03 PM University Commons Phase III Page 1 of 1 Electrical has informed me that the drawing submitted for the PUE dedication is correct. You can submit the Easement Dedication Sheet and supporting documents when you are ready. carol file://C:\Documents and Settings\ccotter\Local Settings\Temp\XPgrpwise\48F6064ACity ... 11/11/2008 CollegeStation Commons, Ltd. October 10, 2008 Ms. Carol Cotter PE Development Engineer City of College Station, Public Works College Station, Texas 77840 13140 Coit Rd. Suite 220 Dallas, TX 75240 Ph<>~e: 972/234-1551 Fax: 9721234-1 580 E-mail: claningham@jmc-mgmlcom Re : Utility Easement, University Commons Apartments Dear Ms. Cotter, This letter is provided to confirm our earlier phone conversation regarding issuance of a temporary certificate of occupancy for the new building at University Commons Apartments. I am the President of Charlan Commons, Inc., the corporate general partner of College Station Commons, Ltd, the owner of University Commons Apartments and in that capacity I am authorized to execute documents and make binding agreements on behalf of the property. Your legal department has copies of the partnership documents, which were provided for the water easement completed earlier this year. We will execute and deliver to your office such documents prepared by your legal department as needed to grant a blanket easement for elecirical service to the new building at University Commons by the City of College Station . Thirty days should be sufficient time to prepare the documents , update the title policy, secure the needed signatures and return the documents to your office. I request that you contact Lee Adams of Adams & Taggart, Engineers for any assistance needed in getting the easement documentation prepared. We ask that the City issue a temporary certificate of occupancy today, subject to having the city legal department prepare the easement documentation, forward to me for execution and returned to your office within 30 days. We need the certificate today please, as we have a number of residents in temporary quarters, including A&M Galveston transferees, who need to move this weekend. Thanks for your assistance. Please call should any further information be needed. Charles Laningham President Charlan-Commons, Inc. General Partner luewefleuew lU!odsewer NO: 1 2 3 4 , 5 6 7 8 9 10. 11 12 13 .. .I Engineer's Cost Estimate for ' Public lnfras,ructure University Commons, Phase Ill Public Water and Sanitary DESCRIPTION QTY. UNIT UNIT PRICE MOBILIZATION 1 LS ' $1,500.00 6" SDR26 D3034 (STRUCTURAL) 126 LF •· $62.00 8" RESTRAINED JOINT DIP 190 LF $73.00 16" STEEL CASIN~ ' 150 LF $95.00 4' DIAMETER MANHOLE (0-8') DEEP 2 EA $2 ,500.00 REMOVE EX SANITARY SEWER LINE 190 LF $11.50 REMOVE EX SAN SWR MANHOLE 2 EA $400.00 CONNECT EX SERVIE TO PROP MH 1 EA $500.00 STD CLEAN OUT ASSEMBLY 1 EA $350.00 TOTAL SANITARY SEWER 8" C909 CL200 (STRUCTURAL) 240 LF $72 .00 8" MJ GATE VALVE 3 EA $800.00 8" MJ 45 BEND 13 EA $240.00 FIRE HYDRANT ASSEMBLY (0-6')BURY 1 ' EA $2,550.00 TOTAL WATER TOTAL COST AMOUNT $1,500.00 $7,812.00 $13,870.00 $14,250.00 < $5,000.00 $2,185.00 $800.00 $500.00 $350.00 $46,267.00 $17,280.00 $2,400.00 $3,1°20.00 $2,550 .00 $25,350.00 $71,617.00 .,· NO: 1 2 3 4 , 5 6 7 8 9 10 11 12 13 Engineer's Cost Estimate for , Public Infrastructure University Commons, Phase Ill Public Water and Sanitary •• .I DESCRIPTION QTY. UNIT UNIT PRICE MOBILIZATION 1 LS ' $1,500.00 6" SDR26 D3034 (STRUCTURAL) 126 LF l $62.00 8" RESTRAINED JOINT DIP 190 LF $73.00 16" STEEL CASING ' ' 150 LF $95.00 4' DIAMETER MANHOLE (0-8') DEEP 2 EA $2,500.00 REMOVE EX SANITARY SEWER LINE 190 LF $11 .50 REMOVE EX SAN SWR MANHOLE 2 EA $400.00 CONNECT EX SERVIE TO PROP MH 1 EA $500.00 STD CLEANOUT ASSEMBLY 1 EA $350.00 TOTAL SANITARY SEWER 8" C909 CL200 (STRUCTURAL) 240 LF $72.00 8" MJ GATE VALVE 3 EA $800.00 8" MJ 45 BEND 13 EA $240.00 FIRE HYDRANT ASSEMBLY (0-6')BURY 1 EA $2,550.00 TOTAL WATER TOTAL COST AMOUNT $1 ,500.00 $7,812.00 $13,870.00 $14 ,250.00 $5 ,000.00 $2 ,185.00 $800.00 $500.00 $350.00 $46,267.00 $17,280.00 $2,400.00 $3,f20.00 $2 ,550.00 $25,350.00 $71,617.00 ., ·. ,.("\ .. d-& \f\ J ~ 'V. (\' ~{)~ .' . · .. r ~ ___ _:__ ____ __;,,t_a_0_<J_~ a---=--~~~; ..:"\\;;] 2551 Texas Ave. South, Ste. A, College Station, TX 77840 \ ,\ (A\ "'~~~<,, Ofc: 979.693.5359 ~ax: 979 .693.4243 Email: mdgcstxd@y{lhoo.com ~R"~ ~~~· ~. January 21, 2008 Development Services City of College Station . 1101 Texas Ave. College Station, Texas 77842 Subject:. . University Commons Phase III Dear Development Staff: The purpose of this letter is to acknowledge that the construction plans for the public water, · sanitary sewer, paved areas and streets for the subject project, to the best of my knowledge, do not deviate from the B/CS Design Guideline Manual. Any alternate design or construction methodology that was used is listed below: . ·1. Retaining walls are a proprietary design by Reinforce Earth Company. J , , I also acknowledge, to the best of my knowledge, that the details provided in the construction plans are in accordance with the Bryan/ College Station Standard Details. Sincerely, Municipal Development Group ~~--:- . ' n wood S. Adams, P.E. Managing Principal· 'f ENGINEERING COMMENTS NO. 3 1. Provide written response to staff comments, addressing all comments. 2. Submit revised metes and bounds for PUE dedication. 3. You should be connecting water line on other side of existing valve Sta 2+57.46, otherwise you will have top be shutting down additional water lines in the complex which may be needed for fire protection. 4. You need to revise your tap off the public main. The required isolation valve makes the fire suppression line private. Your meters need to be off a public line with the meters located in a PUE. 5. Note the required isolation valve. 6. Each tee requires two valves. 7. Regarding previous comment, all the proposed valves have to be on horizontal pipe for valve stems to be plumb and usable. 8. Show limits of structural fill. 9. Clearly indicate the proposed sanitary sewer line serving the building is private and remove from PUE. As a private line you do not need a manhole, but can end in cleanout. TCEQ crossing separation requirements also don't apply. Ensure that it meets plumbing code. 10. Remove invert information from water line profile. It is not applicable. 11. Show existing sewer line conflict near Sta 0+15. Indicate TCEQ crossing requirements. 12. Show storm sewer conflict with water line (Sta 0+50). 13. Provide "Letter Acknowledging City Standards". 14. The manhole at Sta 1+08.92 is not needed. 15. Bolted and gasketed manhole lids are required. Reviewed by: Carol Cotter Date: December 20 , 2007 FIRE FLOW AND WATER REPORT FOR UNIVERSITY COMMONS PHASE III MDG JOB NO. 000076-3957 COLLEGE STATION, BRAZOS COUNTY, TEXAS DECEMBER 2007 -*:~o~~F~'\ .i-:~E-,~ ' ~~ .... ·····~:+ '• ':7* '~:,, , ................ -...... -1.!\, · I-l EH\i'OOD S. ADM~S 1"' -.l ...... ~.,,., \ ................. 1 ... 1! \~ •• ~~ 63357 L .. ~··"' . . . 2551 Texas Ave. South, Ste. A, College Station, TX 77840 Ofc: 979.693.5359 Fax: 979.693.4243 Email: mdgcstx@yahoo.com The project site is located near the intersection of Southwest Parkway and State Highway 6. lt lies just east of the existin g University Commons Apartments and just northwest of the existing Wolf Pen Creek Bowling Center. The site will be service by one existing 8" water ma ms. A fire flow analysis was conducted in conjunction with EPANet for the proposed fire hydrant at University commons apartment. The domestic water section of the Bryan/College Station Unified Design Guideline Manual was used to determine the required flow rates and pressures for the proposed hydrant. T his manual states that fire hydrants must provide a minimum of 1,000 gallons per minute in residential areas while holding a minimum pressure of 20 psi. Additionally, the TCEQ guidelines dictate that systems provide minimum system pressures of 35 psi during normal operation as well as residual pressures of 20 psi during fire flow scenarios. Flow data for the existing hydrants in the Col lege Station Water system was obtained from College Station Utilities-Water Services Department. The fire flow tests repo1t the static, residual, and pitot pressures. The elevation was estimated from topographic maps, and the total head was calculated using the energy equation. Flow data for the existing fire hydrant located at 230 l EastMark hydrant was used. Flow data for the existing hydrant (E-125) located on the eastern side of the development at University Commons apartment was obtained from the City of College Station Uti lities. The information is as fo llows: Static Pressure: 112 psi Residual Pressure: 108 psi Flow Rate: 1500 gpm From the gathered data on the two existing hydrants, the Hydraulic Grade Line (HGL) for the hydrant was determined using the equation: HGL =z + P/d Where HGL =>Hydraulic Grade Line (ft) z => Elevation (ft) P => Pressure (psi) d => Density (62.4 lbs/ct) Knowing the HGL for the hydrants, the HGL for every node in the network was obtained using the calculation: HGL2 = HGL1 -KQ2 Where K => Head loss coefficient Q => Flow rate (cfs) HGL2 =>Downstream HGL (ft) HGL1 =>Upstream HGL (ft) For this calculation, it is important to start at a known HGL, and move down the network computing the HGL in order from upstream to downstream. However, if the known HGL is located downstream and upstream 1-IGLs need to be determined, the calculation can be reversed to accommodate the situation. The equation for this instance is as follows: HGL1 = HGL2 + KQ2 The head loss coefficient (K) for each pipe section is calculated using: K = (fL)/(2*DA2g) Where f => Friction factor L => Length of pipe (ft) D => Diameter of pipe (ft) A => Area of pipe (ft) g => Grav ity (32.2 ft/s2) The HGL for the proposed fire l~ydrant was determined using this method. The pressure at the hydrant was determined by rearranging the above equation that solved for the HGL. Knowing the pressure, the flow rate of the hydrant can be determined using the following equation: Q = 29.83cD112*sqrt(P) Where Q => Flow Rate (gpm) c => Friction Coefficient (0.7-0.9) D => Diameter of Outlet (in) P => Pressure (psi) A model was built in the hydraulic simulation software EPANet 2.0. The model consists of links and nodes that represent the physical arrangement of the pipe network as well as hydraulic characteristics like pipe diameter, roughness, and nodal elevations. The connections to existing water mains were modeled as reservoirs with constant heads as previously calculated. The Hazen-Williams equation is used to model friction losses within the pipe network. In EPA.Net, the model was simulated using the initial base demands, and all resulting pressures are hi gher than the required 35 psi. Then a fire demand of I 024 gpm including domestic water and fire flow was assigned to each node sequentially in different scenarios. During each scenario, the model was queried to determine if any nodes had pressures below the required 20 psi; none were found. The water distribution line meets the fire flow criteria outlined in the Unified Design Guideline Manual. Several reports are attached showing the results from the static system response and response from each hydrant in operation. After completion of the analysis, it was determined that the proposed fire hydrants for The University Commons will supply flow rates ranging from 1372.7 to 1500 gpm. The hydrants can provide a total of 2872. 7 gpm while staying above the minimum pressure requirement of 20 psi. Because this water distribution line meets the fire flow criteria outl ined in the Unified Design Guideline Manual, it will sufficiently suppl y The University Commons Apartment Development with domestic water. An attached table indicates the total fire flow requirements for each building, and the coverage by the fire hydrants. The required flow for each building was compared to the supplied flow, as indicated on the table. Also, tables are included that indicate fire flow req uirements in accordance with Appendix C of the 2003 In ternational Fire Code (tables B105.1 and Cl05.1). The building type fo r a minimum required fire flow and flow duration for buildings is Type V-A. Hydrant Report University Commons.-3957 Hydrant Static Flow Node Elevation Pressure lllmnl EX-E-125 268.5 108.9 1500.0 FH-1 264.0 110.6 1372.7 Fire Flow Requirements and Supply Area Since Spinklered Hydrant Building Height* (sq. ft.) NFF1 reduce 50% Supply Spacing3 Dist3 (a om) (gpm) AE 33' 22q83 27 50 1375 2872.7 500 250 *NFF' : The Needed Fire Flow (gpm) according of to Table 8105.1 of the International Fire Code (at 2 hr. duration) *Spacing': Average spacing (feet) between hydrants according to table C105.1 of the International Fire Code *Dist' : Maximum Distance (feet) from any point on street or road frontage to a hydrant according to table C105.1 *Num : Minimum number of Hydrants of Table C105.1 of the International Fire Code Height* : Maximum building height for construction type IV is 65 feet according to the 2006 IBC (table 503) References: 1. City of Bryan/College Station Unified Design (2007). 2. EPANet 2 .0 Users Manual. Environmental Protection Agency (2002). 3. TCEQ, Water Utilities Division "Rules and Regulations for Public Water System." Junction E125 J1 FH1 J2 J3 f => L => D => A => Q => Elevation (ft) HGL(ft) 268.50 519.73 266.70 519.73 264.00 519.29 264.20 519.29 266.30 519.29 Friction factor Length of pipe (ft) Diameter of pipe (ft) Area of pipe (ft) Gravity (32.2 tus ') HGL2 = HGL1 -KQ ' K => Headless coefficient Q => Flowrate (els) HGL2 => Downstream HGL (ft) HGL, => Upstream HGL (ft) University Commons. Job # 000076-3957 P (psi) Q(gpm) 108.87 1500.0 109.65 110.63 1372.7 110.54 109.63 Pipe Dia. (ft) Length (ft) A 0.67 53 B 0.67 49 c 0.67 43 D 0.67 76 E 0.67 29 HGL = z + P/d HGL => Hydraulic Grade Line (ft) z => Elevatio~ (ft) P => Pressure (psi) d => Densitv (lbs/cf) Q = 29.83cD•2•sqrt(P) Q => -Flow Rate (gpm) c => Friction Coefficient (.7-.9) D => Diameter of Outlet (in) P => Pressure (psi) K 0.091 0.084 0.074 0.131 0.050 Fire Flow Analysis Q(gpm) V(ft/s) 0 0.00 1000 6.38 0 0.00 0 0.00 0 0.00 Fire Hydrant Number: E-125 Static Pressure: 112 psi Residual Pressure: 108 psi Flowrate: 1500 gpm 3.342 els HGL: 517.73 ft " ( , ~ D __ J2 c • B FH-1 J1 E-125 EPANET2 Page 1 ·~ ( ' " BASE' Page 1 12/10/2007 11:47:17 AM ********************************************************************** .,, ~·· E P A N E T Hydraulic and Water Quality Analysis for Pipe Networks version 2.0 ********************************************************************** Input File: FIREFLOW.NET Link -Node Table: Link ID A B c D E Node Node ID Jl FHl J2 J3 E-125 Results: Link Results: Link ID A B c D E Start Node E-125 Jl FHl J2 J3 Demand GPM 24.00 24.00 24.00 24.00 -96. 00 End Node Jl FHl J2 J3 E-125 Head Pres$ure ft psi 519.72 109.64 519.72 110.81 519.72 110.72 519.73 109.81 519.73 0.00 Flow velocityunit Headloss GPM fps ft/Kft 45. 21 21.21 -2.79 -26.79 -50.79 0.29 0.14 0.02 0.17 0.32 0.10 0.02 0.00 0.04 0.12 Page 1 Length Diameter ft in 53 8 49 8 43 8 76 8 29 8 Quality 0.00 0.00 0.00 0.00 0.00 Reservoir Status Open open open open open .. t DlOOO Page 1 12/10/2007 11:46:35 AM ********************************************************************** .... ·: E P A N E T Hydraulic and Water Quality Analysis for Pipe Networks version 2.0 ;': ********************************************************************** Input File: FIREFLOW.NET Link -Node Table: Link ID A B c D E Node Node ID J1 FHl J2 J3 E-125 Results: Link Results: Start Node E-125 Jl FHl J2 J3 Demand GPM 24.00 1024.00 24.00 24.00 -1096.00 End Node J1 FHl J2 J3 E-125 Head Pressure ft psi 519.13 109.38 518. 62 110.33 518.91 : 110.37 519.49 109. 71 519.73 0.00 Link ID Flow velocityunit Headloss A B c D E GPM fps ft/Kft 593. 71 569.71 -454.29 -478.29 -502.29 3.79 3.64 2.90 3.05 3.21 11. 31 10.47 6.89 7.58 8.29 Page 1 Length Diameter ft in 53 8 49 8 43 8 76 8 29 8 Quality 0.00 0.00 0.00 0.00 0.00 Reservoir Status open open Open open Open From: To: Date: Subject: Attachments: CC: Lee, Alan Gibbs Municipal Development Group 7/3/2007 7:17 PM Fwd: University Commons Ph 3 -Water Fire Line_ 4a.doc Cotter, Carol Also, in order to accommodate future looping, extend a PUE from the eastern end of the proposed waterline to the eastern boundary of the plat. Alan Gibbs, P.E. City of College Station Sr. Asst. City Engineer, Public Works >>>Alan Gibbs 7/3/2007 7:15 PM >>> Lee, See the attached general guidance for fire lines for sprinkled projects. We will need a fire flow report looking at the building size and construction type to determine the flow and number of hydrants. Sprinkling will reduce the flow requirement by 50%. General suggestions: Fire Department would like to see the FDC on West end of the building. Hopefully an 8inch dead end is adequate -your report should look at pressures and velocities as well as flows. If the 8 is adequate, you may simply replace the bend (by the closest existing hydrant) with an 8x8x8 tee, reconnect the FH, subout for the fire line (PUE ending at a valve), and a master meter on the east end of the building. If only a single additional FH is needed and spacing is adequate, it could be located near the middle of the building. Alan Gibbs, P.E. City of College Station Sr. Asst. City Engineer, Public Works .. I , . ~· ·" • . . ' . '·. ' . ~ . . Appendix D Technical Des·ign Summary Unified Stormwater Design Guidelines City of College Station City of Bryan February 2007 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY The Cities of Bryan and College Station both require storm drainage design to follow these Unified Stormwater Design Guidelines. Paragraph C2 of Section Ill (Administration) requires submittal of a drainage report in support of the drainage plan (stormwater management plan) proposed in connection with land development projects, both site projects and subdivisions. That report may be submitted as a traditional prose report, complete with applicable maps, graphs, tables and drawings, or it may take the form of a "Technical Design Summary". The format and content for such a summary report shall be in substantial conformance with the description in this Appendix to those Guidelines. In either format the report must answer the questions (affirmative or negative) and provide, at minimum, the information prescribed in the "Technical Design Summary" in this Appendix. The Stormwater Management Technical Design Summary Report shall include several parts as listed below. The information called for in each part must be provided as applicable. In addition to the requirements ·for the Executive Summary, this Appendix includes several pages detailing the requirements for a Technical Design Summary Report as forms to be completed. These are provided so that they may be copied and completed or scanned and digitized. In addition, electronic versions of the report forms may be obtained from the City. Requirements for the means (medium) of submittal are the same as for a conventional report as detailed in Section Ill of these Guidelines. Note: Part 1 -Executive Summary must accompany any drainage report required to be provided in connection with any land development project, regardless of the format chosen for said report. Note: Parts 2 through 6 are to be provided via the forms provided in this Appendix. Brief statements should be included in the forms as requested, but additional information should be attached as necessary. Part 1 -Executive Summary Report Part 2 -Project Administration Part 3 -Project Characteristics Part 4 -Drainage Concept and Design Parameters Part 5 -Plans and Specifications Part 6 -Conclusions and Attestation STORMWATER MANAGEMENT TECHNICAL DESIGN SUMMARY REPORT Part 1 -Executive Summary This is to be a brief prose report that must address each of the seven areas listed below. Ideally it will include one or more paragraphs about each item. 1. Name, address, and contact information of the engineer submitting the report, and of the land owner and developer (or applicant if not the owner or developer). The date of submittal should also be included. STORMWATER DESIGN GUIDELINES Effective February 2007 Page 1 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised ___ _ SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY 2. Identification of the size and general nature of the proposed project, including any proposed project phases. This paragraph should also include reference to applications that are in process with either City: plat(s), site plans, zoning requests, or clearing/grading permits, as well as reference to any application numbers or codes assigned by the City to such request. 3. The location of the project should be described. This should identify the Named Regulatory Watershed(s) in which it is located, how the entire project area is situated therein, whether the property straddles a watershed or basin divide, the approximate acreage in each basin, and whether its position in the Watershed dictates use of detention design. The approximate proportion of the property in the city limits and within the ET J is to be identified, including whether the property straddles city jurisdictional lines. If any portion of the property is in floodplains as described in Flood Insurance Rate Maps published by FEMA that should be disclosed. 4. The hydrologic characteristics of the property are to be described in broad terms: existing land cover; how and where stormwater drains to and from neighboring properties; ponds or wetland areas that tend to detain or store stormwater; existing creeks, channels, and swales crossing or serving the property; all existing drainage easements (or ROW) on the property, or on neighboring properties if they service runoff to or from the property. 5. The general plan for managing stormwater in the entire project area must be outlined to include the approximate size, and extent of use, of any of the following features: storm drains coupled with streets; detention I retention facilities; buried conveyance conduit independent of streets; swales or channels; bridges or culverts; outfalls to principal watercourses or their tributaries; and treatment(s) of existing watercourses. Also, any plans for reclaiming land within floodplain areas must be outlined. 6. Coordination and permitting of stormwater matters must be addressed. This is to include any specialized coordination that has occurred or is planned with other entities (local, state, or federal). This may include agencies such as Brazos County government, the Brazos River Authority, the Texas A&M University System, the Texas Department of Transportation, the Texas Commission for Environmental Quality, the US Army Corps of Engineers, the US Environmental Protection Agency, et al. Mention must be made of any permits, agreements, or understandings that pertain to the project. 7. Reference is to be made to the full drainage report (or the Technical Design Summary Report) which the executive summary represents. The principal elements of the main report (and its length), including any maps, drawings or construction documents, should be itemized. An example statement might be: "One __ -page drainage report dated one set of construction drawings ( __ sheets) dated ____ , and a ___ -page specifications document dated ____ comprise the drainage report for this project." STORMWATER DESIGN GUIDELINES Effective February 2007 Page 2 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised ___ _ SECTIO N IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 2 -Project Administration I Start (Page 2.1) Engineering and Design Professionals Information Engineering Firm Name and Address: Jurisdiction MiAvi;lipttl beveAop~t11l-bro~f City: Bryan 2-GS-I Ttxa) A\Jl, SotA-fh Sfe..A '/.. College Station C 6 /I e1t 9-Kfi avi Ti. 7 7 t 40 Date of Submittal: Lead Engineer's Name and Contact lnfo.(phone, e-mail, fax): Other: Un tf 5 ft P, t/I~ -'53?1 woo · AaMS, .e. to1~-4i.43t::~ Supporting Engineering I Consulting Firm(s): Other contacts: Developer I Owner I Applicant Information Developer I Applicant Name and Address: Phone and e-mail: Lhttrll5 LAviJ~~ttlV1 e-;o JM~ Jne-. i ~J4P cw-R. s +-t-220 -Ll5 il atlas '75'24-o 1.7 t) 234--15'70 . cltt111'Y11flt1m Djn-ic..,-~1rnf-. ne Property Owner(s) if not Developer I Applicant (&·address): Phone and e-mail: Project Identification Development Name: Unlve,v>;~ Co>'Vl mo11s PhttsL-11f Is subject property a site project, a single-phase subdivision, or part of a multi-phase subdivision? ~ 11lfi -e nase-If multi-phase, subject property is phase 3 of 3 Legal description of subject property (phase) or Project Area: (see Section II , Paragraph B-3a) __ B J . ~ ~ ,t v (< b\1 N Jltd_er o P Loi-10 -R 11 f6 Li= 8 SttstvtAtu1'!::. R_e,~tA!?tli111~/4YJ P~)e.Jr If subject property (phase) is second or later phase of a project, describe general status of all earlier phases. For most recent earlier phase Include submittal and review dates. ErAdiv p~ttSlS-1 q "le !fl/ co t11plef-(., ait i. ivi scv-v /ce ltpr-; l 14q ~ S:t\bt'\11 :ll J ~ff rovttl General Location of Project Area, or subject property (phase): Pht11sl1[ In City Limits? Extra~erritorial Jurisdiction (acreage): Bryan: ['J /Ir acres. Bryan: tJ/k College Station: ~JA-I I College Station: I ·uK acres. Acreage Outside ET J: NLA- STORMWATER DESIGN GUIDELINES Effective February 2007 Page 3 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised ___ _ t SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 2 -Project Administration I Continued (page 2.2) Project Identification (continued) Roadways abutting or within Project Area or Abutting tracts, platted land, or built subject property: w;lr~~~s:& uJ= 8t0hMV'~J)V'\ V'L Uvllveirs,~ Co1tt1wt5rzs frpAr/-rntnb Named Regulatory Watercourse(s) & Watershed(s): Tributary Basin(s): WolP Pevi Cre6=- Plat Information For Project or Subject Property (or Phase) Preliminary Plat File#: Final Plat File#: 1'?7 /53 ~ Date: j Name: Status and Vol/Pg: If two plats, second name: File#: Status: Date: Zoning Information For Project or Subject Property (or Phase) Zoning Type: \NP(,, ~or Proposed? Case Code: Case Date Status: Zoning Type: Existing or Proposed? Case Code: Case Date Status: rJAc- Stormwater Management Planning For Project or Subject Property (or Phase) Planning Conference(s) & Date(s): Participants: Chtlv ! C> La Yi; Ill J lti.t\ Vii 2.,7 TtAVlL 1-0Ul Co.vo \ CJJ ~eVl Wvt lj\)()6 "r)__ /t-Jtf. Vl15 G v~ T tt 9.~ a. Y't f\)D "' Preliminary Report Required? Submittal Date Review Date Review Comments Addressed? Yes --No ('10 In Writing? When? Compliance With Preliminary Drainage Report. Briefly describe (or attach documentation explaining) any deviation(s) from provisions of Preliminary Drainage Report, if any. N/A: STORMWATER DESIGN GUIDELINES Effective February 2007 Page 4 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised ___ _ SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 2 -Project Administration I Continued (page 2.3) Coordination For Project or Subject Property (or Phase) Note: For any Coordination of stormwater matters indicated below, attach documentation describing and substantiating any agreements, understandings, contracts, or approvals. Coordination Dept. Contact: Date: Subject: With Other IS-i .. :titio"' RaJ,,,, .. H7H'(;S 1/ n /07 I Nai10111 o~ Dutv-OS~T Departments of Slu:\-..-10 I ~r1d11.vtJOPMW ~fJnterma-Jurisdiction City (Bryan or r1rt-\><lAUUoPYl'IW Co11-Pr.r1•.,1,1a-College Station) D"''tlq On1a1.+ (' ,V'; ~ U-(,\ ('tl D(t.vttwJ, PMll+ Ch~CL- Coordination With Summarize need(s) & actions taken (include contacts & dates): Non-jurisdiction City Needed? V Yes __ No __ Coordination with Summarize need(s) & actions taken (include contacts & dates): Brazos County Needed? No V Yes -- Coordination with Summarize need(s) & actions taken (include contacts & dates): TxDOT Needed? Yes No V -- Coordination with Summarize need(s) & actions taken (include contacts & dates): T AMUS Needed? Yes No v -- -- Permits For Project or Subject Property (or Phase) As to stormwater management, are permits required for the proposed work from any of the entities listed below? If so, summarize status of efforts toward that objective in spaces below. Entity Permitted or Approved? US Army Crops of Engineers No V Yes - US Environmental Protection Agency No V Yes - Texas Commission on Environmental Quality No V Yes -- Brazos River Authoy Yes No __ - STORMWATER DESIGN GUIDELINES Effective February 2007 Status of Actions (include dates) .. Page 5 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised ___ _ SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 3 -Pro~ert:x: Characteristics I Start (Page 3.1) Nature and Scope of Proposed Work Existing: Land proposed for development currently used, including extent of impervious cover? \. tpg at:1e> 0 ~ 4. t:;t;; Ctt.xes . o . tl r dMJ tJ prnevi r V'~ihw fi~tt~ Site __ Redevelopment of one platted lot, or two or more adjoining platted lots. Development _L Building on a single platted lot of undeveloped land . Project __ Building on two or more platted adjoining lots of undeveloped land. (select all __ Building on a single lot, or adjoining lots, where proposed plat will not form applicable) a new street (but may include ROW dedication to existing streets). __ Other (explain): Subdivision __ Construction of streets and utilities to serve one or more platted lots. Development __ Construction of streets and utilities to serve one or more proposed lots on Project lands represented by pending plats. Site projects: building use(s), approximate floor space, impervious cover ratio. Describe Subdivisions: number of lots by general type of use, linear feet of streets and drainage easements or ROW. , Nature and J!-Jd;.,_1 " ?-s/JJr'!t24~fnunf bwfi/,,'J />IL f'Momfj Size of Pro~osed fAJ.1.devdrJd tJ!tt Id f3u.//dJ11p ~lzt!-15 42-~nL halrom1 Project un/ts 1 '3 s ftJiJ.it.S Is any work planned on land that is not platted If yes, explain: or on land for which platting is not pending? i__No --Yes FEMA Floodplains Is any part of subject property abutting a Named Regulatory Watercourse I N y .:j.__ (Section II, Paragraph B1) or a tributary thereof? 0 --es Is any part of subject property in floodplain !No_ Yes_lL_ Rate Map area of a FEMA-regulated watercourse? Encroachment(s) Encroachment purpose(s): ~ Building site(s) __ Road crossing(s) into Floodplain areas planned? __ Utility crossing(s) __ Other (explain): No -- Yes /,. If floodplain areas not shown on Rate Maps, has work been done toward amending the FEMA- approved Flood Study to define allowable encroachments in proposed areas? Explain. Flo Pel phi11 E t11Jlu11fi11J1 t:t!lzulJ d_ mod() !U .ffdud C4J~ No. oo-o~-l'i'p3f dAfol MAP-ch /J.1 i.00 /. £~tfl/Utth~n 5"}/Pv0 o. o If Y'JSe, ;.,_ f;{l~ wift. Hood f'l?!Jrl hi/. STORMWATER DESIGN GUIDELINES Effective February 2007 Page 6 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised ___ _ SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 3 -Pro~erty Characteristics I Continued (Page 3.2) Hydrologic Attributes of Subject Property (or Phase) Has an earlier hydrologic analysis been done for larger area including subject property? Y{f Reference the study (&date) here, and attach copy if not already in City files. lt~acYie.l LoM~ Mavd-i 131 lOOI Is the stormwater maJement plan for the property in substantial conformance with the earlier study? Yes No If not, explain how it differs. No If subject property is not part of multi-phase project, describe stormwater management plan for the property in Part 4. --If property is part of multi-phase project, provide overview of stormwater management plan for Project Area here. In Part 4 describe how plan for subject property will comply therewith. , Do existing topographic features on subject property store or detain runoff? ~No --Yes Describe them (include approximate size, volume, outfall, model, etc). Any ~nown draina~e or foding problems in areas .near subject property? __ No ~Yes l de~tify:fl-fovhaYi ~. fht-fYiu-1-..1 w;J/ b6 'hllut ~,bov& ~ w1 lhou e levt:di~ fh L (~. ThL vewv./nde.,v-,~ pa~!-tJ ltze ttcJ~d@'f a.11.d LA.JJ ~/ b!-a111t./stu""6d. Based on location of study property in a watershed, is Type 1 Detention (flood control) needed? (see Table B-1 in Appendix B) __ Detention is required. Need must be evaluated. 2\.__ Detention not required. -- What decision has been reached? By whom? If the need for ~ ttl,V'tl1.nA-<1j~ /tt11uu_d Type 1 Detention How was determi nation made? must be evaluated: !Ht1J1 61bbS-PY&iew:lo1 111.ai 1-fJ)/)rey~//J~ STORMWATER DESIGN GUIDELINES Effective February 2007 Page 7 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised ___ _ SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 3 -Pro12ert~ Characteristics I Continued (Page 3.3) Hydrologic Attributes of Subject Property (or Phase) (continued) Does subject property straddle a Watershed or Basin divide? ~No --Yes If yes, describe splits below. In Part 4 describe desiqn concept for handling this. Watershed or Basin Larqer acreaqe Lesser acreaqe Wol FP~ {Y'eek \J~vf ttlou~ fb Cavfev CtuJ--ft-// Above-Project Areas(Section II, Paragraph 83-a) Does Project Area (project or phase) receive runoff from upland areas? __ No ~ Yes Size(s) of area(s) in acres: 1) l. & 2) 3) 4) Flow Characteristics (each instance) (overland sheet, shallow concentrated, recognizable concentrated section(s), small hek (non-regulatory), regulatory Watercourse or tributary); OVt-f/'wJ.. <;hel--f fto~ Cu lvtrl-UYld(!Y' (Jt?Jja.f fD Oi<..fhtll a.f /oodWAy. DtAV'Jvt1 PiooL ovev-.ft ow w l 11 fy-Ave,l dow1-i reJtV-'1.-tl ~ wA11/rwn.tou1:lvds oe~~luvt~ w~ll i11 Al1 e.tisf1Vll eA~t.JWMt ~ t'.N'J> • Flow determination: Outline hydrologic methods and assumptions: ~ -A MfloV\£\1 Mdtiotl w/Tj.b6T G;uff:. o.v-J., lfytif(Ot:tt/c.. pipe o0 Does storm runoff drain from public easements or ROW onto or across subject property? --:f..-No --Yes If yes, describe facilities in easement or ROW: Are changes in runoff characteristics subject to change in future? Explain f']Cl Conveyance Pathways (Section II , Paragraph C2) Must runoff from study property drain across lower properties before reaching a Regulatory Watercourse or tributary? ~ No Yes Describe length and characteristics of each conveyance pathwa~s). Include ownership of property(ie~OY\ s:+-e. f'IAY'I dff lt> '1V\~tu( LrowV) ~.or.~V\iV1ilf ft.NL ~d~ r"lfl.~I'\ ;~o w~ II . S<'!~ plttt-1.S fov-V'de>d:h-J iss.4y;A.to . oft-~Jte,, dV'tl;M.dt.-CclV..lS fr. Y"e,f-tJ.JVtl~o IA){/} aM. f\o~ "ll-\.dtvft..e. ~ If& ~ Ao o#c t)JA~ tlMJl c~l:- STORMWATER DESIGN GU IDELINES Effective February 2007 Page 8 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised ___ _ SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 3 -Pro~ert~ Characteristics I Continued (Page 3.4) Hydrologic Attributes of Subject Property (or Phase) (continued) Conveyance Pathways (continued) Do drainage If yes, for what part of length? % Created by? __ plat, or easements exist for any __ instrument. If instrument(s), describe their provisions. part of pathway(s)? Nk No -- Yes -- Where runoff must cross lower properties, describe characteristics of abutting lower property(ies). (Existing y;atercourses? Easement or Consent aquired?) Pathway Areas Nk Describe any built or improved drainage facilities existing near the property (culverts, bridges, lined channels, buried conduit, swales, detention ponds, etc). No V\l- Nearby Drainage Do any of these have hydrologic or hydraulic influence on proposed stormwater Facilities design? --No --Yes If yes , explain: tJ /rt STORMWATER DESIGN GUIDELINES Effective February 2007 Page 9 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised ___ _ SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Start (Page 4.1) Stormwater Management Concept Discharge(s) From Upland Area(s) If runoff is to be received from upland areas, what design drainage features will be used to accommodate it and insure it is not blocked by future development? Describe for each area, flow section, or discharge point. \. ~ Prv Fvu~ Vtl~ tA-plA~) c;U~~{H"g~ ~vu 24-'' sfvv-'1A I ;hl- o . 8 K II & fmvi d (Jfe,lo P /l1f,11t -;; it.t-I d ~ Jv.r ' "' fJ fAtter k ttll dva 1MJ0 h ftootfiPa11 tH~ (~ Discharge(s) To Lower Property(ies) (Section II , Paragraph E1) Does project include drainage features (existing or future) proposed to become public via platting? .J:,._ No --Yes Separate Instrument? No Yes Per Guidelines reference above, how will __ Establishing Easements (Scenario 1) runoff be discharged to neighboring property(ies )? __ Pre-development Release (Scenario 2) Combination of the two Scenarios -- Scenario 1: If easements are proposed, describe where needed, and provide status of actions on each. (Attached Exhibit# ) t'1k Scenario 2: Provide general description of how release(s) will be managed to pre-development conditions (detention, sheet flow, partially concentrated, etc.). (Attached Exhibit# ) (',0'1C~cdio11 f/OvV ./,, d iss; p ttfvy-. ~/Aw -w crt-el:- alV'OS> aoJ vJ'Ar · Combination: If combination is proposed, explain how discharge will differ from pre- development conditions at the property line for each area (or point) of release. NoV\i If Scenario 2, or Combination are to be used, has proposed design been coordinated with owner(s) of receiving property(ies)? documentation. NA- STORMWATER DESIGN GUIDELINES Effective February 2007 No Page 10 of 26 --Yes Explain and provide APPENDIX. D: TECH. DESIGN SUMMARY As Revised ___ _ SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Concept and Design Parameters I Continued (Page 4.2) Stormwater Management Concept (continued) Within Project Area Of Multi-Phase Project Will project result in shifting runoff between Basins or Identify gaining Basins or Watersheds and acres shifting: NA between 1--W-h_a_t_d-es-i-gn~a-nd~m-it-ig-a-ti_o_n-is_u_s_e_d_t_o_c_o_m_p_e_n_sa_t_e_fo_r_i_n-cr_e_a-se-d~ru_n_o_ff~---1 wzsheds? from gaining basin or watershed? --~:s NA How will runoff from Project Area be mitigated to pre- development conditions? Select any or all of 1, 2, and/or 3, and explain below. 1. ~With facility(ies) involving other development projects. 2. ~ Establishing features to serve overall Project Area. 3. ~On phase (or site) project basis within Project Area. 1. Shared facility (type & location of facility; design drainage area served; relationship to size of Project Area): (Attached Exhibit# ) 2. For Overall Project Area (type & location of facilities): (Attached Exhibit# ) 3. By phase (or site) project: Describe planned mitigation measures for phases (or sites) in subsequent questions of this Part. N k <'-· -c Q) VJ c Q) fii >- 0:: VJ c .Ql VJ Q) 0 Oz Jxl Q) ~ Are aquatic echosystems proposed? __ No __ Yes In which phase(s) or project(s)? Nk Are other Best Management Practices for reducing stormwater pollutants proposed? L_;i l f f:u (J, Aw~~·~ s;~~};::Jfi,~01 ~~zo;~'k_ f f~f tc/lon If design of any runoff-handling facilities deviate from provisions of B-CS Technical Specifications, check type facility(ies) and explain in later questions. Detention elements Conduit elements Channel features =Swales __ Ditches_ Inlets __ Valley gutters L Outfalls __ Culvert features __ Bridges Other STORMWATER DESIGN GUIDELINES Effective February 2007 Page 11 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised ___ _ SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Concegt and Design Parameters I Continued (Page 4.3) Stormwater Management Concept (continued) Within Project Area Of Multi-Phase Project (continued) Will Project Area include bridge(s) or culvert(s)? __ No ..lL_ Yes Identify type and general size and In which phase(s). f(p -2-4'1 I Y1 0 V1 lL-t Pha~ If detention/retention serves (will serve) overall Project Area, describe how it relates to subject phase or site project (physical location, conveyance pathway(s), construction sequence): ' NA- Within Or Serving Subject Property (Phase, or Site) If property part of larger Project Area, is design in substantial conformance with earlier analysis and report for larger area? __ Yes No, then summarize the difference(s): . NA:- Identify whether each of the types of drainage features listed below are included, extent of use, and general characteristics. Typical shape? I Surfaces? C'-· "'O <ll CJ) Steepest side slopes: Usual front slopes: Usual back slopes: CJ) :::J <ll CJ) >- <ll I ..i:::: Flow line slopes: least Typical distance from travelway: ~ "'O typical (Attached Exhibit # ) <ll 0 greatest "'O 'iii z ]1'1 Are longitudinal culvert ends in compliance with B-CS Standard Specifications? Yes No, then explain: <( CJ) At intersections or otherwise, do valley gutters cross arterial or collector streets? .n <ll No Yes If yes explain: ::; C'-· >---U"'O I ..i:::: <ll -CJ) ·-:::J 5: ..... Are valley gutters proposed to cross any street away from an intersection? CJ) <ll -::::: <ll :::J 0 No Yes Explain: (number of locations?) ~ oiz -- -- ]~01 STORMWATER DESIGN GUIDELINES Effective February 2007 Page 12 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised ___ _ SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage ConceQt and Design Parameters I Continued (Page 4.4) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Gutter line slopes: Least 0.. (pt;'/, Usual 0 .(p:;'L· Greatest I .t;<;"'{ Are inlets recessed on arterial and collector streets? --Yes --No If "no", identify where and why. Nk Will inlets capture 10-year design stormflow to prevent flooding of intersections (arterial with arterial or collector)? --Yes --No _If no, explain where and why not. C'· N~ "O Q) ; VI Will inlet size and placement prevent exceeding allowable water spread for 10-year :J .__ Q) design storm throughout site (or phase)? Yes No If no, explain. :::::: -- --:J Nk Cl "O ~ c "O ro w Sag curves: Are inlets placed at low points? Yes No Are inlets and .c ~ -- --.__ ·-conduit sized to prevent 100-year stormflow from ponding at greater than 24 inches? :J ...... u c Yes No Explain "no" answers. 0 ..c u ----~-~ VI \'\A: Qi Q) .__ v; Q) Will 100-yr stormflow be contained in combination of ROW and buried conduit on .__ <{ whole length of all streets? Yes No If no, describe where and why. ---- NI\- Do designs for curb, gutter, and inlets comply with B-CS Technical Specifications? Yes --No If not, describe difference(s) and attach justification. t'1 A. ! Are any 12-inch laterals used? _!::,__No --Yes Identify length(s) and where used. C'· "O Pipe runs between system j Typical QJ VI Longest VI QJ access points (feet): :J >- !1 Are junction boxes used at each bend? --Yes --No If not, explain where and why. VI c NP< ·-0 ~z "O I E .__ Least amount that hydraulic 0 Are downstream soffits at or below upstream soffits? v; ..!!! Yes No __ If not, explain where and why: grade line is below gutter line --(system-wide): Nk Nk STORMWATER DESIGN GUIDELINES Effective February 2007 Page 13 of 26 . APPENDIX. D: TECH. DESIGN SUMMARY As Revised ___ _ SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Concept and Design Parameters I Continued (Page 4.5) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Ul Q) u c C1l Vi c Q) ..... ~a "fil E :J ..... . !: .2 c . 0 .2 ~.!: ~ ~ ....... C1l ~VI VI Q) c :g '[ij Ei .a Ci §w 0 Q) ....... .c Cf) VI Q) ~ C1l 0.. Q) VI c ~ i I VI Q) ~ Describe watercourse(s), or system(s) receiving system discharge(s) below (include design discharge velocity, and angle between converging flow lines). 1) Watercourse (or system), velocity, and angle? 2) Watercourse (or system), velocity, and angle? 3) Watercourse (or system), velocity, and angle? For each outfall above, what measures are taken to prevent erosion or scour of receiving and all facilities at juncture? 1) 2) N k 3) Are swale(s) situated along property lines between properties? ..:::£.____No __ Yes Number of instances: For each instance answer the following questions. Surface treatments (including low-flow flumes if any): l ~ v lYiul Cro vJ Y1 o ·lfc:J/. -I.~/. Flow line slopes (minimum and maximum): Outfall characteristics for each (velocity, convergent angle, & end treatment). Will 100-year design storm runoff be contained within easement(s) or platted drainage ROW in all instances? __ Yes __ No If "no" explain: STORMWATER DESIGN GUIDj::LINES Effective February 2007 Page 14 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised ___ _ SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage ConceQt and Design Parameters j Continued (Page 4.6) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) rn Are roadside ditches used? k, No __ Yes If so , provide the following: a.> Is 25-year flow contained with inches of freeboard throughout? __ Yes __ No .c .B Are top of banks separated from road shoulders 2 feet or more? __ Yes No 0 -- a.> Are all ditch sections trapezoidal and at least 1.5 feet deep? --Yes --No 32 For any "no" answers provide location(s) and explain: rn -0 Cll 0k 0 0::: If conduit is beneath a swale, provide the following information (each instance). Instance 1 Describe general location, approximate length: rn a.> >-I~ Is 100-year design flow contained in conduiUswale combination? ..2!:::,._ Yes --No If "no" explain: c 0 Cll z v; Space for 1 OD-year storm flow? ROW Easement Width I~ Swale Surface type, minimum Conduit Type and size, minimum and maximum 0 and maximum slopes: slopes, design storm: ·.;:::; tJk 24'1 RCP.:> £18L t:: C'-· 'O .!!2 -0 a.> Cll c >. Inlets Describe how conduit is loaded (from streets/storm drains, inlets by type): c Cll c .c Cll I I (.) '-r::~V\ll open ptairit-c .2 a.> c D.. 0 0 ; Access Describe how maintenance access is provided (to swale, into conduit): -Cll 0 E :::i NA .!!! .2 c c a.> -0 E Instance 2 Describe general location, approximate length: a.> Cll rn rn N~ :::i rn a.> c -0 0 ·5 Is 1 OD-year design flow co ntained in conduiUswale combination? Yes No ~ 0 -- --'-If "no" explain: c D.. :.0 Qi E a.> 0 .c Space for 100-year storm flow? ROW Easement Width (.) rn ..... a.> Swale Surface type, minimum Conduit Type and size, minimum and maximum :::i ~ -0 and maximum slopes: slopes, design storm: c Cll 0 D.. ~ a.> rn ~ c Inlets Describe how conduit is loaded (from streets/storm drains, inlets by type): Cll .s. 5: rn a.> -< Access Describe how maintenance access is provided (to swale, into conduit): STORMWATER DESIGN GUIDELINES Effective February 2007 Page 15 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised ____ _ SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Concept and Design Parameters I Continued (Page 4. 7) Stormwater Management Concept (col)tinued) Within Or Serving Subject Property (Phase, or Site) (continued) .!'.; ro a. E x ow ..:= If "yes" provide the f.ollowing information for each instance: Instance 1 Describe general location, approximate length, surfacing: 15 VI Is 100-year design flow contained in swale? __ Yes __ No Is swale wholly c a> within drainage ROW? __ Yes __ No Explain "no" answers: .; ~I !---------------------------------~ u Access Describe how maintenance access is provide: ~ 0 ;z 1><1 >-------------------------------< ~ Instance 2 Describe general location, approximate length, su rfacing: Q) ·;::: C'-· :l VI .0 c ::; Q) o E £ ~ .3: ro Q) VI '-Q) 0 ~s VI Q ~~ .0 :l c. Is 100-year design flow contained in swale? __ Yes __ No Is swale wholly within drainage ROW? __ Yes __ No Explain "no" answers: Access Describe how maintenance access is provided: Instance 3. 4. etc. If swales are used in more than two instances, attach sheet providing all above information for each instance. "New" channels: Will any area(s) of concentrated flow be channelized (deepened, widened, or straightened) or otherwise altered? __ No __ Yes If only slightly c---shaped, see "Swales" in this Part. If creating side banks, provide information below. "O c ~ ro Will design replicate natural channel? __ Yes __ No If "no", for each instance g_ ~ describe section shape & area, flow line slope (min. & max.), surfaces , and 100-year [ w design flow, and amount of freeboard : VI VI c Q) Q) >-l I .s ~ 1~1 0 Instance 1: Instance 2: Instance 3: STORMWATER DESIGN GUIDELINES Effective February 2007 Page 16 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised ____ _ SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.8) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Existing channels {small creeks}: Are these used? ~ No --Yes If "yes" provide the information below. Will small creeks and their floodplains remain undisturbed? __ Yes l_No How many disturbancp instances? Identify each planned location: f="looclplo.i11 ;lld per ttthd\eL f:"/OJt stud~ I-tho F1llel f6 2/A-. o (?v" 0.i~ltv Bt=b 2.U~ .3 For each location, describe length and general.type of proposed improvement (including floodplain changes): p,·u; WO -floodplttiVl ptodJA(L~ o.o ('l~C. 11-\. gr&: For each location, describe section shape & area, flow line slope (min . & max.), surfaces, and 100-year design flow. 'O CIJ ::J c ~ Watercourses {and tributaries): Aside~om fringe changes, are Regulatory 0 Watercourses proposed to be altered? __ No __ Yes Explain below. ~ en c Submit full report describing proposed changes to Regu latory Watercourses. Address CIJ existing and proposed section size and shape, surfaces, alignment, flow line changes, E CIJ length affected, and capacity, and provide full documentation of analysis procedures > e and data. Is full report submitted? Yes --No If "no" explain: 0.. E a:; Nit c c ro All Pro12osed Channel Work: For all proposed channel work, provide information ..c 0 requested in next three boxes. If design is to replicate natural channel, identify location and length here, and describe design in Special Design section of this Part of Report. N/-i Will 100-year flow be contained with one foot of free board? --Yes --No If not, identify location and explain: NA Are ROW I easements sized to contain channel and required maintenance space? --Yes --No If not, identify location(s) and explain: tJA:- STORMWATER DESIGN GUIDELINES Effective February 2007 Page 17 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised ___ _ SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.10) Stormwater Management Concept (continued)· Within Or Serving Subject Property (Phase, or Site) (continued) Do structures comply with B-CS Specifications? Yes or no, and explain if "no": rn Facility 1; Q) Nf>c :;::: =::o (.) Q) ro :::i Facility 2: LL c c +::; 0 c '.+= 0 c (.) Q) ~ a; For additional facilities provide all same information on a separate sheet. 0 Are parking areas to be used for detention? __ No --Yes What is maximum depth due to required design storm? Roadside Ditches: Will culverts serve access driveways at roadside ditches? -.:z!::,._ No --Yes If "yes", provide information in next two boxes. Will 25-yr. flow pass without flowing over driveway in all cases? --Yes --No Without causing flowing or standing water on public roadway? --Yes --No Designs & materials co mply with B-CS Technical Specifications? __ Yes --No Explain any "no" answers: C'· rn Ol .~ rn Are culverts parallel to public roadway alignment? __ Yes No Explain: rn 0 --t; rn Q) Q) NA-{ii >- > I ·;:: Creeks at Private Drives: Do private driveways, drives, or streets cross drainage 0.. {ii ways that serve Above-Project areas or are in public easements/ ROW? "O 0 No Yes If "yes" provide information below. Q) z ----~Al How many instances? Describe location and provide information below. Q) Location 1: -2! :::i (.) Q) Location 2: ~ Location 3: For each location enter value for: 1 2 3 Design year passing without toping travelway? Water depth on travelway at 25-year flow? Water depth on travelway at 1 OD-year flow? ' For more instances describe location and same information on separate sheet. STORMWATER DESIGN GUIDELINES Effective February 2007 Page 19 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised ____ _ SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce12t and Design Parameters I Continued (Page 4.11) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Named Regulator~ Watercourses {&Tributaries}: Are culverts proposed on these facilities? _:f:::__ No __ Yes, then provide full report documenting assumptions, criteria, analysis, computer programs, and study findings that support proposed design(s). Is report provided? __ Yes --No If "no", explain: ~ Arterial or Major Collector Streets: Will culverts serve these types of roadways? Q) <J.l No Yes How many instances? For each identify the ..c (/) ---- <J.l location and provide the information below. (/) ro Instance 1: <J.l .... >-~ I~ Instance 2: Instance 3: c 0 o~ Yes or No for the 100-year design flow: 1 2 3 z E ~1~ Headwater WSE 1 foot below lowest curb top? Spread of headwater within ROW or easement? E ~-C1l Is velocity limited per conditions (Table C-11)? (/) (/) gi-o Explain any "no" answer(s): ·-c ~ C1l 0 c ..... 0 u ·->-ro C1l u ~ ..Q -0 <J.l C1l .0 Minor Collector or Local Streets: W ill culverts serve these types of streets? 0 ·-.......... u u No Yes How many instances? for each identify the ·-(/) -<J.l ----.g -0 location and provide the information below: Cl. <J.l -Cl. Instance 1: rn~ -0 >-Instance 2: <J.l c (/) C1l :J '+-Instance 3: (/) 0 t (/) <J.l <J.l ..::: u For each instance enter value, or "yes" /"no" for: 1 2 3 :J c u C1l Design yr. headwater WSE 1 ft. below curb top? <J.l u; ..... c <( ·-100-yr. max. depth at street crown 2 feet or less? ~ 0 Product of velocity (fps) & depth at crown (ft) = ? E ..... 0 Is velocity limited per conditions (Table C-11)? :t:.. Limit of down stream analysis (feet)? Explain any "no" answers: STORMWATER DESIGN GUIDELINES Effective February 2007 Page 20 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised ___ _ SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.1 2) Stormwater Management Concept (continued) ., Within Or Serving Subject Property (Phase, or Site) (continued) All Proposed Culverts: For all proposed culvert facil ities (except driveway/roadside ditch intersects) provide information requested in next eight boxes . Do culverts and travelways intersect at 90 degrees? --Yes --No If not, identify location(s) and intersect angle(s), and justify the design(s): NI\- Does drainage way alignment change within or near limits of culvert and surfaced approaches thereto? __ No --Yes If "yes" identify location(s), describe change(s), and justification: ~~ Are flumes or conduit to discharge into culvert barrel(s)? __ No __ Yes If yes, identify location(s) and provide justification: 'O Are flumes or conduit to discharge into or near surfaced approaches to culvert ends? Q) ~No __ Yes If "yes" identify location(s), describe outfall design treatment(s): ::::i c ~ 0 ~ rn t Q) > :5 Is scour/erosion protection provided to ensure long term stability of culvert structural u components, and surfacing at culvert ends? __:i:,,__ Yes __ No If "no" Identify locations and provide justification(s): \) ;S$l ptt-\tiY' ~())( I Will 100-yr flow and spread of backwater be fully contained in street ROW, and/or drainage easements/ ROW? __ Yes --No if not, why not? NA: Do appreciable hydraulic effects of any culvert extend downstream or upstream to neighboring land(s) not encompassed in subject property? .J__ No __ Yes If "yes" describe location(s) and mitigation measures: Are all culvert designs and materials in compliance with 8-CS Tech. Specifications? ~Yes __ No If not, explain in Special Design Section of this Part. STORMWATER DESIGN GUIDELINES Effective February 2007 Page 21 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised ___ _ SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce12t and Design Parameters I Continued (Page 4.13) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Is a bridge included in plans for subject property project? ::;,..__No --Yes If "yes" provide the following information . Name(s) and functional classification of the roadway(s)? What drainage way(s) is to be crossed? ~ Q) CJ) -0 ·;:: ro A full report supporting all aspects of the proposed bridge(s) (structural, geotechnical, hydrologic, and hydraulic factors) must accompany this summary report. Is the report provided? --Yes --No If "no" explain: Is a Stormwater Provide a general description of planned techniques: ~ Pollution Prevention No !'101 " LU£ thtWL t:i ft&-. ro Plan (SW3P) :J w i'!l p 10 vlk {.{ lr~, tl~tl /vi ler a established for .... project construction? Q) ro s LNo --Yes pmt-u t \m · Special Designs -Non-Traditional Methods Are any non-traditional methods (aquatic echosystems, wetland-type detention, natural stream replication, BMPs for water quality, etc.) proposed for any aspect of subject property project? ~No --Yes If "yes" list general ~ype and location below. Provide fu ll report about the proposed special design(s) including rationale for use and expected benefits. Report must substantiate that stormwater management objectives will not be compromised, and that maintenance cost will not exceed those of traditional design solution(s). Is report provided? STORMWATER DESIGN GUIDELINES Effective February 2007 Yes -- -- NA Page 22 of 26 No If "no" explain: APPENDIX. D: TECH. DESIGN SUMMARY As Revised ___ _ SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage ConceQt and Design Parameters I Continued (Page 4.1 4) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Special Designs -Deviation From 8-CS Technical Specifications If any design(s) or material(s) of traditional runoff-handling facilities deviate from provisions of B-CS Technical Specifications, check type facility(ies) and explain by specific detail element. Detention elements __ Drain system elements Channel features ---- Culvert features Swales Ditches Inlets Outfalls ---------- __ Valley gutters __ Bridges (explain in bridge report) In table below briefly identify specific element, justification for deviation(s). Specific Detail Element Justification for Deviation (attach additional sheets if needed) 1) 2) r.\ 3) N 'K 4) \ 5) Have elements been coordinated with the City Engineer or her/his designee? For each item above provide "yes" or "no", action date, and staff name: 1) 2) 3) 4) 5) Design Parameters Hydrology No Is a map(s) showing all Design Drainage Areas provided? ~Yes --Briefly summarize the range of applications made of the Rational Formula: Prd~opm°'t tttAtt peb-t JeveJ~t~u-ct -Row What is the size and location of largest Design Drainage Area to which the Rational Formula has been applied? l, ·fa acres Location (or identifier): off'--sjfe, STORMWATER DESIGN GUIDELINES Effective February 2007 Page 23 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised ___ _ SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters j Continued (Page 4.1 5) Design Parameters (continued) Hydrology (continued) In making determinations for time of concentration, was segment analysis used? L No Yes In approximately what percent of Design Drainage Areas? % As to intensity-duration-frequency and rain depth criteria for determining runoff flows, were any criteria other than those provided in these Guidelines used? ..:i:__ No __ Yes If "yes " identify type of data, source(s), and where applied: For each of the stormwater management features listed below identify the storm return frequencies (year) analyzed (or checked), and that used as the basis for design. Feature Analysis Year(s) Design Year Storm drain system for arterial and collector streets Storm drain system for local streets Open channels Swale/buried conduit combination in lieu of channel Swales Roadside ditches and culverts serving them Detention facilities: spillway crest and its outfall Detention facilities: outlet and conveyance structure(s) Detention facilities: volume when outlet plugged Culverts serving private drives or streets Culverts serving public roadways Bridges: provide in bridge report. Hydraulics What is the range of design flow velocities as outlined below? Design flow velocities; Gutters Conduit Culverts Swales Channels Highest (feet per second) Lowest (feet per second) Streets and Storm Drain Systems Provide the summary information outlined below: Roughness coefficients used: For conduit type(s) R. c_,() STORMWATER DESIGN GUIDELINES Effective February 2007 For street gutters: C.0:2-I Coefficients: .g I . Page 24 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised ___ _ SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Part 4 -Drainage Conce~t and Design Parameters j Continued (Page 4.16) Design Parameters (continued) Hydraulics (continued) Street and Storm Drain Systems (continued) For the following, are assumptions other than allowable per Gu idelines? Inlet coefficients? No Yes Head and friction losses No Yes -- -- ---- Explain any "yes" answer: NA- In conduit is velocity generally increased in the downstream direction? --Yes --No Are elevation drops provided at inlets, manholes, and junction boxes? --Yes --No Explain any "no" answers: •' Are hydraulic grade lines calculated and shown for design storm? --Yes --No For 100-year flow conditions? --Yes --No Explain any "no" answers: What tailwater conditions were assumed at outfall point(s) of the storm drain system? Identify each location and explain: Open Channels If a HEC analysis is utilized, does it follow Sec Vl.F.5.a? __ Yes __ No Outside of straight sections, is flow regime within. limits of sub-critical flow? __ Yes __ No If "no" list locations and explain: NA Culverts If plan sheets do not provide the following for each culvert, describe it here. For each design discharge, will operation be outlet (barrel) control or inlet control? Entrance, friction and exit losses: Bridges Provide all in bridge report STORMWATER DES IGN GUIDELINES Effective February 2007 Page 25 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised ___ _ SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Pa.rt 4 -Drainage ConceQt and Design Parameters I Continued (Page 4.17) Design Parameters (continued) Computer Software What computer software has been used in the analysis and assessment of stormwater management needs and/or the development of facility designs proposed for subject property project? List them below, being sure to identify the software name and version, the date of the version, any applicable patches and the publisher \tyJv&lc ~ydwuli~ -aMa_lyz.itAj chttvi~Js avv\_ Odvwts · bodso.i,,, 3/Jr:sSocJt:<.fC-> jv,.c,,. ' ) Part 5 -Plans and SQecifications Requirements for submittal of construction drawings and specifications do not differ due to use of a Technical Design Summary Report. See Section Ill , Paragraph C3. Part 6 -Conclusions and Attestation Conclusions Add any concluding information here: Nw.l Ar).P.vtC£ Attestation Provide attestation to the accuracy and completeness of the foregoing 6 Parts of this Technical Desiqn Summary Drainage Report by signing and sealing below. "T/1is report (plan) for the drainage design of the development named in Part B was prepared by me (or under my supervision) in accordance with provisions of the Bryan/College Station Unffied Drainage Design Guidelines for the owners ~y All licenses and permits required by any and all state and federal regulatory ~ proposed drainage improvements have been issued or fall under app/i~:lx * ~di' ~ r·-~MM_\il LENWOOD S. ADAMS ~ Licensed Professional Engineer :;\-··-··•········ .. ;-··f ~~\?~ 63357 <.v¢.···~J State of Te xas PE No. 62~5~ STORMWATER DESIGN GUIDELINES Effective February 2007 . ~~;'t/STfffi.··~~ \~~V,tj~·· 't~-o;,, _, ~ Page 26 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised ___ _ 1. Select your county. 2. Enter the time of concentration , ) :"~ebt'inty '§l;\~'Coefficient~ '' 2-yearii : ''5-year"' r'lO~year Brazos "};fr.''. e.(in) ,., ,.. 0.806 ' 0.785 0.763 ..... .~ b ~ '.1'~ ' 65 76 80 '·' ~ d (mins) ;.l!ltJ. 8:0 8.5 ' 8.5 Intensity (in/hr)* 6.3 7.7 8.6 Coefficient 2-year-;,'· 5-year 1 " 10-year ... '!;~'!: e (mm) .• ~· --,:i4!f1,~" b lJ, ; ~·i,l ' d (mins)':'~.· .. Intensity (mm/hr)* * for time of Concentration = Q=CIA DA1 DA2 (1 .6 AC) (0.88 AC) 10.21 cfs 5.61 cfs 0.806 0.785 0.763 1651 ' 1930 ' 2032 8.0 8.5 8.5 160.7 195.4 219.3 10 mins "•45fyear '50\i'( ' . ;;year 100" ·""' i'X , -... Y.e~r 0.754 0.745 0.730 89 98 96 8.5 8.5 8.0 9.9 11 .1 11 .6 25-year SO~)rear 100-y,,ear 0.754 '' .. 0.745 0.730 ; ~: ''[ 2261 , .2489 2438 8.5 .... ,8.5 8~0 250.5 283.2 295.6 .. DRAINAGE AREA MAP 0 JOO 200 --------SCALE; J" =JOO' ~ ~--------~ -w -w -w - w _J D.A. 1 Q =C I A (lOOyr) = 0.55 * 11.6 * 1.6 = 10.208 (cfs) E.lle 2,tructures YJew Qptions t!elp Culvert Diameter: ft :2 __ Pipe Culv_'.'.'.' ::._C'._ulvert Performance Curv~. Starting Flow Rate: §0.21 .... cfs :J Chatt Number: , Scale Number: 3 Manning's N Value: 0.021 Entrance Loss Coef: 0.1 Culvert Length: 98 Downstream Elev: 259 Upstream Elev: 261.85 Flow Rate I Tail water ! (ch) 1 Depth (ft) : 1 io.21 -·r -o--· Select Select Select ft ft ft l.ncremental Flow Rate: 0 cfs Number of Increments: 0 : Stmting T ailwater: Incremental T ailwale1: 1-l~-----11 :: I H\tl Outlet I Normal •1' Critical Depth at Outlet Vet , Ctrl (It) Depth (ft) , Depth (It) Outlet (It) (fps) 1.14 0.91 .. . ' Gutter Flow Calculations Q=(0.56/n) (Sx"(5/3)) (S"0.5) (T"(8/3)) Q= n= Sx= S= T= Gutter flow rate ( cfs) Manning's N Pavement cross slope (tuft) Longitudinal slope (tuft) width of flow or spread (ft) Q= CIA Flow Depth D= 0.55*11 .6*0.88 5.61 cfs 0.27 ft Ref. City of Bryan Drainage Design Guidelines Result 5.61 0.014 0.03 0.0065 8.86 - . -. ";.' -, .- " . -, 1 ' ., ' ~~ !~ ~.fJ . ' l ' FIRE FLOW AND WATER REPORT FOR UNIVERSITY COMMONS PHASE III MDG JOB NO. 000076-3957 COLLEGE STATION, BRAZOS COUNTY, TEXAS OCTOBER 2007 2551 Texas Ave. South, Ste. A, College Station, TX 77840 Ofc: 979.693.5359 Fax: 979.693.4243 Email: mdgcstx@yahoo.com The project site is located near the intersection of Southwest Parkway and State Highway 6. It lies just east of the existing University Commons Apartments and just northwest of the existing Wolf Pen Creek Bowling Center. The site will be service by one existing 8" water mams. A fire flow analysis was conducted in conjunction with EPANet for the proposed fire hydrant at University commons apa11ment. The domestic water section of the Bryan/College Station Unified Design Guideline Manual was used to determine the required flow rates and pressures for the proposed hydrant. This manual states that fire hydrants must provide a minimum of 1,000 gallons per minute in residential areas while holding a minimum pressure of 20 psi. Additionally, the TCEQ guidelines dictate that systems provide min imum system pressures of 35 psi during normal operation as well as residual pressures of 20 psi during fire flow scenarios. Flow data for the existing hydrants in the College Station Water system was obtained from College Station Utili ties-Water Services Department. The fire flow tests report the static, residual, and pitot pressures. The elevation was estimated from topographic maps, and the total head was calculated using the energy equation. Flow data for the existing fire hydrant located at 2301 EastMark hydrant was used. Flow data for the existing hydrant (E-125) located on the eastern side of the development at University Commons apartment was obtained from the City of College Station Utilities. The information is as follows: Static Pressure: l 12 psi Residual Pressure: l 08 psi Flow Rate: 1500 gpm From the gathered data on the two existing hydrants, the Hydraulic Grade Line (HGL) for the hydrant was determined using the equation: HGL = z + P/d Where HGL =>Hydraulic Grade Line (ft) z => Elevation (ft) P => Pressure (psi) d => Density (62.4 lbs/cf) Knowing the HGL for the hydrants, the HGL for every node in the network was obtained using the calculation: Where K=> Q => Head loss coefficient Flow rate ( cfs) HGL2 =>Downstream HGL (ft) HGL1 =>Upstream HGL (ft) For this calculation, it is important to start at a known HGL, and move down the network computing the HGL in order from upstream to downstream. However, if the known HGL is located downstream and upstream HGLs need to be determined, the calculation can be reversed to accommodate the situation. The equation for this instance is as follows: HGL1 = HGL2 + KQ2 The head loss coefficient (K) for each pipe section is calculated usin g: K = (tL)/(2*DA2g) Where f => Friction factor L => Length of pipe (ft) D => Diameter of pipe (ft) A => Area of pipe (ft) g => Gravity (32.2 ft/s2) The HGL for the proposed fire hydrant was determined using this method. The pressure at the hydrant was determined by rearranging the above equation that solved for the HGL. Knowing the pressure, the flow rate of the hydrant can be determined using the following equation: Q = 29.83c0"2*sqrt(P) Where Q => Flow Rate (gpm) c => Friction Coefficient (0 .7-0.9) D => Diameter of Outlet (in) P => Pressure (psi) A model was built in the hydrauli c s imulation software EPANet 2 .0. The mode l consists of links and nodes that represent the physical arrangement of the pipe network as well as hydraulic characteristics like pipe diameter, roughness, and nodal elevations. The connections to existing water mains were modeled as reservoirs with constant heads as previously cakulated. The Hazen-Williams equation is used to model friction losses within the pipe network. In EPANet, the model was simulated using the initial base demands, and all resulting pressures are higher than the required 35 psi. Then a fire demand of 1024 gpm including domestic water and fire flow was assigned to each node sequentially in different scenarios. During each scenario, the model was queried to determine if any nodes had pressures below the required 20 psi; none were found. The water distribution line meets the fire flow criteria outlined in the Unified Design Guideline Manual. Several reports are attached showing the results from the static system response and response from each hydrant in operation. After completion of the analysis, it was determined that the proposed fire hydrants for The University Commons wi ll supply flow rates ranging from 1365 to 1500 gpm. The hydrants can provide a total of 423 1.5 gpm whil e staying above the minimum pressure requirement of 20 psi. Because this water distri bution line meets th e fire flow criteria outlined in the Unified Design Guideline Manual, it wi ll sufficiently supply The University Commons Apartment Development w ith domestic water. An attached table indicates th e total fire fl ow requirements fo r each buildin g, and the coverage by the fi re hydrants. The req uired flow for each building was compared to the supplied flow, as indicated on the table. Also, tables are includ ed that indicate fire flow requirements in accordance with Appendix C of th e 2003 International Fire Code (tables B 105 .1 and C 105 .1 ). The building type for a mi nimum req ui red fire flow and fl ow du ration fo r buildi ngs is Type V-A. Hydrant Report University Commons.-3957 H~drant Static Flow Node Elevation Pressure i9.illnl EX-E-125 270.5 108.0 1500.0 FH-1 266.5 109.41 1365 .1 FH-2 264.0 109.62 1366.4 Fire Flow Requirements and Supply Buildin Area s . ft.) NFF1 H 3 Dist3 Num AE 22683 2750 225 3 *NFF' : The Needed Fire Flow (gpm) according of to Table 8105.1 of the International Fire Code (at 2 hr. duration) *Spacing•: Average spacing (feet) between hydrants according to table C105.1 of the International Fire Code *Dist' : Maxi mum Distance (feet) from any point on street or road frontage to a hydrant according to table C105.1 *Num : Minimum number of Hydrants of Table C105.1 of the International Fire Code Height* : Maximum building height for construction type IV is 65 feet according to the 2006 IBC (table 503) References: 1. City of Bryan/College Station Unified Design (200 7). 2. EPANet 2.0 Users Manual. Environmental Protection Agency (2002). 3. TCEQ, Water Ut ilities Division "Rul es and Regul ations fo r Publi c Water System." Junction Elevation (ft) HGL(ft) E1 25 270.50 519.73 FH1 266.50 518.99 FH2 264.00 516.98 J1 263.20 516.98 J2 262.30 516.98 K = (fl)/(2.DA2 g) f => L => D => A=> a=> Friction factor Length of pipe (ft) Diameter of pipe (ft) Area of pipe (ft) Gravity (32.2 ft/s 2) HGL2 = HGL, -KQ K => Headless coefficient Q => HGL2 => HGL, => Flowrate (ds) Downstream HGL (fl) Upstream HGL (ft) < University Commons. Job # 000076-3957 P (psi) Q(gpm) 108.00 1500.0 109.41 1365.1 109.62 1366.4 109.97 110.36 Pipe Dia. (ft) Length (ft) A 0.67 82.45 B 0.67 225.09 c 0.67 59.32 D 0.67 87.69 HGL = z + P/d HGL => Hydraulic Grade Line (ft) z => Elevation (ft) P => Pressure (psi) d => Density Obs/cf) Q = 29.83cD•2•sqrt(P) Q => c => D => p => Flow Rate (gpm) Friction Coefficient (.7-.9) Diameter of Outlet (in) Pressure (psi) Fire Flow Analysis K Q(gpm) V(ft/s) 0.142 1000 6.38 0.387 1000 6.38 0.102 0 0.00 0.1 51 0 0.00 Fire Hydrant Number: E-125 Static Pressure: 112 psi Residual Pressure: 108 psi Flowrate: 1500 gpm 3.342 ds HGL: 519.73 ft Day 1, 12:00' EPANET2 Page 1 FIREFLOW_base Page 1 8/13/2007 2:24:10 PM ********************************************************************** E P A N E T Hydraulic and water Quality Analysis for Pipe Networks version 2.0 i< ********************************************************************** Input File: FIREFLOW.NET Link -Node Table: Link ID A B c D Node Results: Node ID FH-1 FH -2 Jl J2 E-125 Link Results: Link ID A B c D start Node E-125 FH -1 FH -2 Jl Demand GPM 24.00 24.00 24.00 24.00 -96.00 End Node FH -1 FH -2 Jl J2 Head Pressure ft psi 535.80 116.69 535.78 117.76 535.78 118.11 535.77 118.50 535.82 0.00 Flow velocityUnit Headloss GPM fps ft/Kft 96.00 72.00 48.00 24.00 0.61 0.46 0.31 0.15 0.19 0.11 0.05 0.02 Page 1 Length Diameter ft in 82.45 225. 09 59.32 87 .69 Quality 0 .00 0.00 0.00 0.00 0.00 8 8 8 8 Reservoir status Open open open Open ( FH -1 Page 1 8/13/2007 2:25:02 PM ********************************************************************** J. E p A N E T .... , -:: Hydraulic and water Quality ir ·!: Analysis for Pipe Networks "/: -:: version 2.0 i< ********************************************************************** Input File: FIREFLOW.NET Link -Node Table: Link ID A B c D Node Results: Node ID FH-1 FH-2 Jl J2 E-125 Link Results: Link ID A B c D start Node E-125 FH-1 FH-2 Jl Demand GPM 1024.00 24.00 24.00 24.00 -1096.00 Flow GPM 1096. 00 72.00 48.00 24.00 End Node FH-1 FH-2 Jl J2 Length Diameter ft in 82.45 225. 09 59.32 87.69 8 8 8 8 Head Pressure .Quality ft psi 534.36 116.06 534.34 117.14 534.33 117.48 534.33 117.87 . 535.82 0.00 velocityUnit Headloss fps ft/Kft 7.00 0.46 0.31 0.15 17.68 0 .11 0.05 0.02 Page 1 0.00 0.00 0.00 0.00 0.00 Reservoir Status open Open open open FH-2 Page 1 8/13/2007 2:25:26 PM ********************************************************************** E P A N E T Hydraulic and water Quality Analysis for Pipe Networks version 2.0 "'.': ********************************************************************** Input File: FIREFLOW.NET Link -Node Table: Link ID A B c D Node Node ID FH-1 FH -2 Jl J2 E-125 Results: Link Results: ' start Node E-125 FH -1 FH-2 Jl Demand GPM 24.00 1024.00 24.00 24.00 -1096.00 End Node FH-1 FH-2 Jl J2 Head Pressure ft psi 534.36 116.06 530.54 115.49 530.54 115.84 530.54 116.23 535.82 0.00 Link ID Flow velocityUnit Headloss A B c D GPM fps ft/Kft 1096.00 1072.00 48.00 24.00 7.00 6.84 0.31 0.15 17.68 16.97 0.05 0.01 Page 1 Length Diameter ft in 82.45 8 225. 09 8 59.32 8 87.69 8 Quality 0.00 0.00 0.00 0.00 0.00 Reservoir Status open open open open (c FIRE HYO RAN T-300' ;.- '--•' < / ~--:: /: -___ ~ ---/ RADIUS 0 IOO 200 -----SCALE.: I "= IOO' ; ,t ~: . ) , . .,, ~­ . ,! , ;. • " .. . .I . , . :, i .• ., ;~ l .... ', · . .; . ~ ,. i '.!. ~ .... ·' ~ FLOODPLAIN EVALUATION REPORT FOR UNIVERSITY COMMONS APARTMENTS 1.52 ACRE TRACT MDG JOB NO. 000076-3957 COLLEGE STATION, BRAZOS COUNTY, TEXAS JUNE 2007 2551 Texas Ave. South, Ste. A, College S~ation, TX 77840 Ofc: 979.693.5359 Fax: 979.693.4243 Email: rndgcstx@yahoo.com Project Scope: This report outlines the floodplain evaluation that was conducted for Jamespoint Management Company in conjunction with a site plan for the possible development of a 1.52 acre tract. The floodplain evaluation began by review of the existing Federal Emergency Management Agency (FEMA) Flood Insurance Rate Map (FIRM). Then, the existing FEMA hydraulic model of Wolf Pen Creek was obtained from the City of College Station as well as the topographic map from which the model was constructed. Next, using current topography from the MDG surveying crew, the hydraulic model was updated and the current floodplain was determined. Even with the most updated topographic information, the current floodplain/floodway boundaries have not changed from the FIRM. Finally, the model was updated to determine what impact placing fill on the site would have on the base flood elevation of Wolf Pen Creek. General Location and Description: The project site is located near the intersection of Southwest Parkway and State Highway 6. It is comprised of a 1.52 acre tract that lies just east of the existing University Commons Apartments and just northwest of the existing Wolf Pen Creek Bowling Center. The site is separated by Wolf Pen Creek by a strip of land that varies from I 00 feet to 300 feet wide that was previously dedicated to the City of College Station Parks Department. Approximately half of the site is wooded with dense underbrush characteristic of backwater floodplain. The remainder of the site is an open, grassy area that appears to be regularly maintained. The site generally slopes from southwest to northeast (towards Wolf Pen Creek) with elevations ranging from 263.0 ft to 257.0 ft. Existing FEMA Hydraulic Model: The existing hydraulic model for Wolf Pen Creek was obtained from Mr. Donnie Willis, Drainage Inspector for the City of College Station. The model was originally constructed in the Army Corps of Engineers' HEC-2 modeling software. For review, the HEC-2 input files were exported to HEC- RAS (Hydrologic Engineering Center-River Analysis System). HEC-RAS is the Army Corps of Engineers successor to HEC-2 and is considered the standard modeling software for floodplain applications. After review, the floodplain model is consistent with the physical characteristics of Wolf Pen Creek near the site; no major deficiencies were found. Two of the cross sections in the model cross the site. The topographic map that was used to construct this model was also obtained from the City of College Station. The topographic map and the results of the FEMA hydraulic model are shown in Exhibit 1. As shown in Exhibit I, the entire site is located within the 100-yr floodplain which has an elevation of approximately 263.3 ft. Additionally, approximately half of the site lies within the regulatory floodway. The floodway is the land most severely affected by flooding and must be able to carry and discharge floodwaters. No development is allowed in this area. Updated Hydraulic Model: The FEMA hydraulic model was updated to include the current topography. A recent field survey conducted by the MDG surveying crew produced more detailed topographic data'near cross sections 77 .70, 80.80, and 83.60. These cross sections were updated using the current topographic data. The· model was run again, and the base flood elevation remained the same. The base flood elevation did not change because the site is located within a backwater floodplain that is created when water backs up at the box culverts that cross Highway 6. The current topographic data and the results from the updated hydraulic model are shown in Exhibit 2. Impact of Fill on the Base Flood Elevation: The City of College Station has a policy in place that only allows filling in the floodplain if it produces a 0.0 ft rise in the base flood elevation. Thus, the model was adjusted to reflect the placement of fill on the site under proposed development conditions and analyzed to determine the effect of fill on the base flood elevation. For the analysis, it was assumed that the portion of the site not located within the floodway would be filled to elevation 264.0 ft. The base flood elevation in this area is roughly 263.3 ft. Cross sections 80.80 and 83.60 were revised to reflect the placement of fill. The placement of fill as described would result in 0.0 ft rise in the base flood elevation, so the criterion set forth by the City of College Station is satisfied. Conclusions: After a thorough analysis, it was determined that only 0.84 acres of the 1.52 acres may be filled for development. This would require roughly 4,000 cubic yards of fill to be placed to elevate this portion of the site out of the I 00-yr floodplain. The remaining 0.68 acres of the site is located within the regulatory floodway and may not be developed. The included exhibits depict the area of the site that may be developed. The entire HEC-RAS project files (Existing, Updated, and Fill) are attached on CD for review. References: I. HEC-RAS 3.1.3 http://www.hec.usace.army .mi I/so ftware/hec-ras/hecras-down load .htm I 2. HEC-RAS Users Manual. USACE, November 2002. http://www.hec.usace.army.111 i I/so ftware/hec-ras/hecras-document.htm 1 3. HEC-RAS Hydraulic Reference Manual. USACE, November 2002. http://www. hec. us ace .army.mi II software/hec-ras/hecras-docu men t .html Federal Emergency Management Agency Washington, D.C. 20472 CERTIFIED MAIL RETURN RECEIPT REQUESTED The Honorable Lynn Mcllhaney Mayor, City of College Station P.O. Box 9960 College Station, TX 77842-0960 Dear Mayor Mcllhaney: MAR 132001 IN REPLY REFER TO: Case Number: Community Name: Community Number: Map Panel Number: Effective Date of this Revision: 102-D 00-06-l 803P City of College Station, Brazos County, Texas 480083 48041C0144C MAR 132001 The Flood Insurance Study (FIS) and Flood Insurance Rate Map (FIRM) for the City of College Station, Texas, is revised by this Letter of Map Revision (LOMR) to reflect data submitted in protest of the floodway delineated in a LOMi.. (case number 00-06-l 75P) issued July 10, 2000. This LOMR revises the floodway boundary delineation along Wolf Pen Creek from just upstream of Highway 6 to approximately 1,300 feet upstream of West Frontage Road and revises the base flood elevation (BFE) for Wolf Pen Creek Tributary A immediately upstream of Harvey Road to be consistent with the flood profile, as shown on the enclosed annotated FIRM panel and Floodway Data Tables. This revision was initiated b. j ] , Assistant City Engineer, City of College Station, in a letter dated August 22, 2000. We received a revised hydraulic model to reflect revisions of floodway encroachment of Wolf Pen Creek, a revised hydraulic model to reflect revisions of cross-sectional data of Wolf Pen Creek Tributary A,' and an annotated FIRM showing the revised floodway boundary delineation of the flood having a 1 % annual chance of being equaled or exceeded in any given year (base flood) of Wolf Peri Creek, prepared by Nathan D. Maier Consulting Engineers, Inc., in support of this revision. All data necessary to complete this LOMR were received by December 12, 2000. Based on our review of the submitted data, we are issuing this LOMR to reflect modifications to the hydraulic model data and floodway boundary. This LOMR revises the floodway boundary delineation along Wolf Pen Creek from just upstream of Highway 6 to approximately 1,300 feet upstream of West Frontage Road and r~vises the BFE for Wolf Pen Creek Tributary A immediately upstream of Harvey Road to be consistent with the flood profile, as shown on the enclosed annotated FIRM panel <µld Floodway Data Tables. As a result of the modifications, the BFE along Wolf Pen Creek will not change .and the change in BFE along Wolf Pen Creek Tributary A are not significant enough to cause a change to the nearest whole foot, therefore, no changed BFEs will be published. · · 2 This revision is effective as of the date ofthis letter. Any requests to review or alter this determination should be made within 30 days and must be based on scientific or technical data. We based this determination on the 1 % annual chance discharges published in the FIS for your community. We have not considered changes in watershed conditions that may have occurred since the publication of the FIS and that may have increased discharges. Additionally, future development of projects upstream of the subject area could change watershed conditions and increase discharges. A comprehensive restudy of your community's flood hazards would consider any changes to flood hazard conditions subsequent to the publication of the FIS for your community, and the flood hazards shown in the FIS and FIRM could be increased. This LOMR is based on minimum floodplain management criteria established under the National Flood Insurance Program (NFIP). Your community is responsible for approving all floodplain development and for ensuring all necessary permits required by Federal or State law have been received. State, county, and community officials, based on knowledge of local conditions and in the interest of safety, may set higher standards for construction in the Special Flood Hazard Area (SFHA). If the State, county, or community has adopted more restrictive or comprehensive floodplain management criteria, these criteria take precedence over the minimum NFIP criteria. We provide the floodway designation to your community as a tool to regulate floodplain development. Therefore, the floodway revision we have described in this letter, while acceptable to us, must also be acceptable to your community and adopted by appropriate community action, as specified in Paragraph 60.3(d) of the NFIP regulations. We will not print and distribute this LOMR to primary users, such as local insurance agents or mortgage lenders; instead, the community will serve as a repository for the new data. We encourage you to disseminate the information in this LOMR by preparing, for publication in your community's newspaper, a news release that describes the revision and explains how your community will provide the data and help interpret the NFIP maps. In that way, interested persons, such as property owners, insurance agents, and mortgage lenders, can benefit from the information. ' Use the map panel listed above and revised by this letter for flood insurance policies and renewals issued in your community. We have enclosed an updated version of a document titled List of Current Flood Insurance Stu(iy Data, which includes this letter, to help your community maintain all information for floodplain management and flood insurance. If any of the items in that document are not filed in your community's map repository, please contact the Fed((ral Emergency Management Agency (FEMA) Map Assistance Center at the number listed below for information on how to obtain those items. We have made this determination pursuant to Section 206 of the Flood Disaster Protection Act of 1973 (P.L. 93-234) and in accordance with the National Flood Insurance Act of 1968, as amended (Title Xill of the Housing and Urban Development Act of 1968, P.L. 90-448), 42 U.S.C. 4001-4128, and 44 CFR Part 65. Pursuant to Section 1361 of the National Flood Insurance Act of 1968, as amended, communities participating in the NFIP are required to adopt 3 and enforce floodplain management ordinances that meet or exceed minimum NFIP criteria. These criteria, including adoption of the FIS, FIRM and the modifications made by this LOMR, are the minimum requirements for continued NFIP participation and do not supersede more stringent State or local requirements to which the regulations apply. If you have questions regarding this LOMR, please contact the FEMA Map Assistance Center, toll free, at 1-877-FEMA MAP (1-877-336-2627). Sincerely, Katie Paulson, Program Specialist Hazards Study Branch Mitigation Directorate Enclosures For: Matthew B. Miller, P.E., Chief Hazards Study Branch · Mitigation Directorate cc: Ms. Veronica Morgan, Floodplain Administrator, City of College Station Mr. Teddy D. Mayo, P .E., Assistant City Engineer, City of College Station Mr. Mark Roberts, P.E., Nathan D. Maier Consulting Engineers, Inc. LIST OF CURRENT FLOOD INSURANCE STUDY DATA This list is provided to document all information currently effective for your conununity for insurance and floodplain management. ' Date: MAR 1 3 2001 Conununity: City of College Station, Brazos County, Texas Conununity Number: 480083 Page Number: 1 of2 CURRENT EFFECTIVE FLOOD INSURANCE STUDY DATE: February 9, 2000 FLOOD INSURANCE RATE MAP Map Index 48041CINDO Panel Numbers 0141C,0142C,0143C,0144C 0161C,0181C,0182C,0200C 0163D, 0201D, 0205D LETTERS OF MAP REVISION Panel Numbers 0142C 0143C 0144C 0163D 0181C Effective Date February 9, 2000 Effective Date . July 2, 1992 February 9, 2000 Effective Date September 19, 2000 I March 21, 2000 May 31, 1999 October 14, 1999 July 10, 2000 MAR 132001 July 10, 2000 July 21, 2000 LETTERS OF MAP AMENDMENT AND MAP REVISION BASED ON FILL Panel Numbers 0142C 0144C 0161C BEST AVAILABLE DATA LETTERS None Effective Date January 30, 1995 August 15, 1995 January 9, 1997 January 16, 1998 February 26, 1999 May 25, 1995 October 20, 1995 July 29, 1996 December 2, 1996 May 27, 1999 February 23, 1995 2 ZONE X APPAOXIMA TE SCALE IN FEET iOO 0 ~00 1+3 = E3 ====-==i NATIONAi IUJOO INSURANCE PROIWI . l IW' MUMl!R .\ID41C014'4 C EFIICTM DArr: JULY 2, 1992 ZONE X City of College Station 480083 REVISED AREA ZONE X AREA REVISED BY LOMR DATED JULY 10, 2000 ·--------------·------·-------------------------' BASE FLOOD FLOODING SOURCE FLOODWAY WATER SURFACE ELEVATION (FEET NGVD) SECTION MEAN CROSS SECTION DISTANCE WIDTH AREA VELOCITY REGULATORY WITHOUT WITH INCREASE (FEET) (SQUARE (FEET PER FLOODWAY FLOODWAY FEET\ SECOND\ Wolf Pen Creek Tributary A THESE DATA WERE REVISED BY LOMR ......... D~TED JULY 10, 2000 A 5701 I 205 987 1.4 275.7 276.0 276.0 0.3 B 7751 163 717 1.9 275.8 276.1 276.1 0.3 -c 1,0751 386 1,251 n 279.4 279.4 279.4 0.0 D 1,2601 314 1,047 1.3 279.4 279.4 279.4 0.0 E 1,6501 198 488 2.8 279.7 279.7 279.7 0.0 F 1,790 186 479 2.8 279.9 279.9 279.9 0.0 G 1 Cl1~ ,j ')(IQ ·?1':0 ~ () ?AA Cl ?MJl ?A~.1 . (I ? H 2,400 100 678 2.0 285.7 285.7 286.3 0.6 I 2,730 17 99 13.7 285.8 285.8 285.8 0.0 J 2,90 104 698 1.9 289.7 289.7 289.7 0.0 I Wolf Pen Creek I I I ·I I l I I I Tributary B THESE DA~ WERE _REVISED BY LOMR ·THESE DATA WERE REVISED BY LOMR DATED . AR 3 2001 . T 11.'T'ED Mll,Y ~l A 230 70 331 .9 2.4 284.0 ..--284.02 284.0 0.0 B 730 155 484.2 2.1 289.2 289.2 289.2 00 c 1,055 89 250.3 3.9 289.6 289.6 289.6 0.0 D 1,355 51 180.3 4.4 290.5 290.5 290.5 0.0 E 1,605 46 161.5 5.0 291 .4 291.4 291.4 0.0 1Feet above confluence with Wolf Pen Creek 2Elevation computed without con-sideration of backwater effects from Wolf Pen Creek -t FEDERAL EMERGENCY MANAGEMENT AGENCY )> FLOODWAY DATA OJ BRAZOS COUNTY, TX r-AND INCORPORATED AREAS m WOLF PEN CREEK TRI BUT ARY A -WOLF PEN CREEK TRIBUTARY B ~ BASE FLOOD FLOODING SOURCE -FLOODWAY WATER SURFACE ELEVATION (FEET NGVD) SECTION MEAN CROSS SECTION DISTANCE WIDTH AREA VELOCITY REGULATORY WITHOUT WITH INCREASE (FEET) (SQUARE (FEET PER FLQODWAY FLOODWAY FEET) SECOND) Wolf Pen Creek Tributary C A 60 92 669.0 3.9 292.1 292.8 0.7 0.7 B 170 75 560.0 4.7 292.2 292.8 0.6 0.6 c 320 131 448.0 5.9 292.4 293.1 0.7 0.7 D 485 200 ... 698.0 3.8 293.6 293.9 0.3 0.3 E 660 90 444.0 5.9 293.9 294.1 0.2 0.2 F 1,270 140 617.0 4.3 296.3 296.3 0.0 0.0 G 1,530 483 2,521 .0 1.0 297.4 297.4 0.0 0.0 -'""':\ ~r··.1·"· rr.fn:--1y'i) ir·Jr! () ,-~uc., '\'-) u ,..C.·\] ii'.~ .:. 'l l ' . 'fl ae.·,_.·~~ •. _. ~1.-_.jJ . -c; ·lcnqT T-l ir1•ir' l . · U~-.~.t.l ..:..:_.Jl\-..i ·:._.../ ~ 10]~fit . --JAJ'ED MA~ 13 2001 . -I FEDERAL EMERGENCY MANAGEMENT AGENCY )> FLOODWAY DATA OJ BRAZOS COUNTY,TX r m AND INCORPORATED AREAS .s::i.. Wolf Pen Creek Tributary C -i )> CJ r m .i::i. , . ..FLOODHJG SOURCE CROSS SECTION Wolf Pen Creek (continued) D c· ~E _ F G H I J K L M uISTANCE REVISED DATA 6I1001 8,0801 . 8,8151 9 1901 10, 6101 ll, 5531 16 I 5431 17,8601 18 t 2701 18,8801 FLOODWAY BASE FLOOD WATER SURFACE ELEVATION MEAN WIDTH (FEET) SECTION AREA (SQUARE FEET) VELOCITY REGULATORY WITHOUT WITH FLOODWAY FLOODWAY (FEET PER SECOND) 403 l,8·-19 3.0 349 3,553 1.6 250 2,125 2.6 233 1,974 2.8 243 2,170 2.6 1~2 l,302 235 1,59.S 223 1,448 177 1,145 65 530 THESE DATA WERE REVISED BY LOMR DATED MAY 31, 11199 ( (FEET NGVD) 252.0 252.0 252.8 263 .3 ' ---263.3 264.i 263.7 263.7 264.4 264.0 264.0 264.7 264.9 264.9 265.7 269.4 269.4 270.1 280.7 280.7 281.5 286. 3" 286.3 287.2 287.2 287.2 287.9 288.9 289.6 INCREASE 0.8 0.8 0.7 0.7 0.8 0.7 0.8 0.9 jid6' )tfJO ~ .. 1Feet above confluence with Carters Creek 2Feet above confluence with Wolf Pen Creek REVISED TO FEDERAL EMERGENCY MANAGEMENT AGENCY BRAZOS COUNTY, TX AND INCORPORATED AREAS . t:)~ £_ -t::>CJ -CJ -I 7 !) ,P REFLECT FLOODWAY DATA DATEDJUL 1 0 2000 WOLF PEN CREEK -WOLF PEN CREEK TRIBUTARY A