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HomeMy WebLinkAboutDrainage StudyDrainage Study ' l FOR F.S. KAPCHINSKI -BLOCK ONE Lot 17Rl-18R2, 24Rl, 24R2, 28R-32R College Station Brazos County, Texas December 3, 2008 Revised: December 23, 2008 Revised: April 20, 2009 Revised: September 14, 2009 Prepared For: FI Partners, Ltd. 5727 Richmond Ave., Apt. 202 Dallas, TX 75206 Prepared By: RME Consulting Engineers Texas Firm Registration No. F-004695 P.O. Box 9253 College Station, TX 77845 RME No. 220-0321 ATTACHMENTS: Section l .O -General Information Rep lat Vicinity Map FIRM Panel Map Section 2.0 -Watersheds & Drainage Areas Wolf Pen Creek Watershed Area Exjsting Conditions Drainage Area Map Proposed Conditions Drainage Area Map Storm System Drainage Area Map Section 3.0 -Hydrologic Modeling Hydrologic Soil Group Data HydroCAD -Existing Conditions Drainage Calculations HydroCAD -Proposed Conditions Drainage Calculations Section 4.0 -Detention Facility & Routing GP-01: Site Grading & Drainage Plan HydroCAD -Proposed Conditions Pond Routing Calculations -Pond 1 Section 5.0 -Storm Drainage System Winstorm -HydrauJic Computations -Storm Drainage System "A" ST-01: Historic Ct. -Plan/Profile 220-0321 Drainage Report-Rev 3.docx Page -iii F.S. Kapchinski -Block One Drainage Study -Rev. No. 3 RME Consulting Engineers September 14, 2009 2. At any developments scenario and analyzed rainfall event, up to the 100-year frequency, the ponding depth at the inlet shall not exceed 24"; METHODOLGY & CONCLUSIONS: The hydraulic analysis, for curb inlet sizing, and corresponding results were determined by using the following equation from the USDG, Table C-8 of Appendix C. Corresponding flows for the studied locations were extracted from the WINSTORM hydraulic program, for stormwater modeling. This TxDOT program's typical use is for modeling gravity stormwater systems. The Winstorm data is summarized, for each system, under the Winstorm -Hydraulic Computations (reference "Attachment-Section 5.0" portion of the report). Required Curb Length (on grade), L =Kc Qo.428°3 (1-;-(nSc))0·6 where, L =calculated curb length requirement (ft); Se= Substitution for Sx which is the cross slope of the road (ft/ft); Kc = 0.6 (coefficient); S =street or gutter slope (ft/ft); a= gutter depression depth (ft); W = width of gutter depression (ft); Eo =ratio of frontal flow to total gutter flow (estimated at 0.50); Required Curb Length (at sag), L =QI (3.0*yl.5) where, L =calculated curb length requirement (ft); Q = gutter discharge (cubic feet per second); y =total depth of water or head on the inlet (ft); Curb inlet sizing, for the both the design storm and 100-year rainfall event, are summarized below in Table #9 -"Curb Inlet Summary". TABLE#9 CURB INLET SUMMARY 10-YR 100-YR 10-YR 100-YR Gutter Required Required Provided Curb Lnlet RunoffQ RunoffQ Slope Length Length Length Location -Curb lnlet 1.0. Tvoe ( cfS) (cfs) (ft/ft) (ft) (ft) (ft) ParkPlace -C.J. "Al" Sag 2.114 2.849 0.0075 1.99 2.69 10 Park Place -C.J. "A2" Sag 23.974 33.380 0.0075 22.60 31.47 IO Historic 0 . -C.l. "A3" Grade 5.213 7.027 0.0445 16.41 18.60 15 Historic Ct. -CI. "A4" Urade 1.782 2.402 0.0445 IU.45 11.85 10 Curb Inlet Notes: l. Design calculations are with a standard gutter depression depth (a) of0.33' and standard depression width (W) of2'; 2. Design calculations are with a n=O.O 18 and a standard cross-sectional slope of 3 .0% (0.03 ft/ft); 3. Curb inlets analyzed at sags will utilize the depth (y) of 6" unless otherwise noted; 4. Curb inlets at grade were allowed to be undersized so long as the downstream gutter section and ultimate receiving sag inlet could accommodate conveyed flows. 220-0321 Drainage Report-Rev 3.docx Page -14 F.S. Kapchinski -Block One Drainage Study -Rev. No. 3 RME Consulting Engineers September 14, 2009 METHODOLGY & CONCLUSIONS: The hydraulic analysis, for street drainage with straight crowns, and corresponding results were determined by using the following equation for triangular channels. Corresponding flows for the studied locations were extracted from the WINSTORM hydraulic program, for stormwater modeling. This TxDOT program's typical use is for modeling gravity stormwater systems. The Winstorm data is summarized, for each system, under the Winstorm -Hydraulic Computations (reference "Attachment -Section 5.0" portion of the report). Flow Depth, Y = {Qn I [(0.56z*S0•5)]}318 where, Y = depth of flow (ft); Q = gutter discharge (cubic feet per second); z =reciprocal of the crown slope (ft/ft); S = street or gutter slope (ft/ft); n =Manning's roughness coefficient (typically 0.018); Flow Velocity, V = [(1.49...;.-n) * (R213 * S112)] where, V =velocity of flow (fps); R = hydraulic radius (cross-sectional area/wetted perimeter); S =street or gutter slope (ft/ft); n =Manning's roughness coefficient (typically 0.014); Street drainage depths, for the both the design storm and 100-year rainfall event, are summarized below in Table #8 -"Street Drainage Summary". TABLE#8 STREET DRAINAGE SUMMARY JO.YR 100-YR 10-YR 100-YR Gutter Flow Flow 10-YR 100-YR RunoffQ RunoffQ Slope Depth Depth Velocity Velocity Location (cfs1 (cfs) (ft/ft) ( ft1 (ft) (fps) rms1 Historic Ct. -C.l. "A3" 5.213 7.027 0.0445 0.21 0.24 4.49 Historic Ct. -C.l. "A4" 1.782 2.402 0.0445 0.14 0.16 3.44 Street Dramage Notes: 1. Design calculations are with a n=0.018 and z=33.3 (cross-slope of3.00%); 2. Runoff rates illustrated are from the Winstorm program. These Q's are the total runoff values being conveyed in the gutter immediately upstream of the identified inlet. For curb inlets at grade, the total runoff is input in I ieu of that inlet's intercept capacity; 3. The maximum allowable depth, during the design storm, for all streets is 0.42'; 5.2 Storm Drain Inlets SYSTEM CRITERIA: 1. All curb inlets within this project are specified as recessed curb inlets with gutter depressions. Curb inlets that are located on streets with less than a 1 % longitudinal slope shall be analyzed as curb inlets at sumps; 220-0321 Drainage Report-Rev 3.docx Page -13 4.84 3.70 F.S. Kapchinski -Block One Drainage Study -Rev. No. 3 5.3 Storm Drain Conduits SYSTEM CRITERIA: RME Consulting Engineers September 14, 2009 1. Storm drainage systems are designed to convey the design storm and analyzed during the 100-year rainfall event. A gravity over-flow route, contained within the right-of- way or public drainage easement, has been provided so that conduits that are unable to convey the 100-year storm can "spill" over into these over-flow systems so that situations that are hazardous to life, property, or public infrastructure is prevented; 2. For the design storm, the minimum flow velocity in a conveyance element shall not be less than 2.5 fps and not greater than 15.0 fps; 3. Roughness coefficients for storm sewer pipes were assigned at 0.012 for smooth-lined High Density Poly-Ethylene (HDPE) pipe and 0.013 for RCP ; 4. Junction boxes were provided at all changes in conduit size and grade or alignment changes. Where junction box spacing exceeded 300 feet for 54" diameter pipe, or smaller, and 500' for pipes exceeding 54" in diameter, additional manhole were provided to maintain the desired spacing; 5. Storm sewer condillts with a diameter of 18" through 24" were hydraulically analyzed with a 25% reduction in cross-sectional area to compensate for potential partial blockage. Therefore 18" sized pipes were input as 1.30' diameter pipe and 24" sized pipes were inputted as a 1. 73 ' diameter pipe; 6. Conveyance elements were sized so that the design storm's hydraulic grade line would be equal to or less than 12" below the respective curb inlet curb elevation; TAIL WATER CONSIDERATIONS: Tailwater for the storm drainage system was calculated by taking a cross-section of the unnamed tributary, immediately downstream of the outlet, and performing a normal depth calculation. The water surface elevation developed from this normal depth calculation was then inputted as the systems tailwater elevation. METHODOLGY & CONCLUSIONS: The hydraulic analysis, for storm drain conduits, and corresponding results, were determined by using the WINSTORM hydraulic program for stonnwater modeling. This TxDOT program's typical use is for modeling gravity stormwater systems. The Winstorm data is summarized, for each system, under the Winstorm -Hydraulic Computations (reference "Attachment -Section 5.0" portion of the report). Also, for graphical illustration purposes the hydraulic grade line (HGL), for the 10-year and 100- year, are identified on ST-01: Historic Ct. Plan/Profile of the construction drawings (see "Attachment -Section 5.0" portion of the report). Storm drain conveyance elements and system, for the design storm, are summarized below in Table #10 -"Storm Drainage Summary". As illustrated in the Winstorm output data the discharge velocities for the 10-year and 100-year rainfall event are respectively 7.63 fps and 9.75 fps for System "A". 220-032 1 Drainage Report-Rev 3.docx Page -15 Drainage Study F.S. KAPCHINSKI -BLOCK ONE Lot 17Rl-18R2, 23, 24Rl, 24R2, 28R-32R College Station Brazos County, Texas TABLE OF CONTENTS: PAGE 1.0 General Information ...................................................................................................................................... 1 1.1 Scope of Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2 Site and General Location ....................................................................................................................... 1 1.3 Description of Existing Conditions and Drainage Patterns ..................................................................... 1 1.4 FEMA Information .................................................................................................................................. 2 2.0 Watersheds & Drainage Areas ...................................................................................................................... 3 2.1 Detention Facility Watersheds (Existing Conditions) ............................................................................. 3 2.2 Detention Facility Watersheds (Proposed Conditions) ............................................................................ 3 2.3 Sub-Drainage Basins for Storm Sewer Collection System ...................................................................... 4 3.0 Hydrologic Modeling ..................................................................................................................................... 4 3.1 SCS -TR20 Formula & Methodology .................................................................................................... 4 3.2 Cumulative Precipitation "P" .................................................................................................................. 5 3.3 SCS Runoff Curve Numbers "CN" ......................................................................................................... 6 3.4 Time of Concentration ............................................................................................................................. 6 3.5 Rational Formula and Methodology ........................................................................................................ 8 3 .6 Storm water Runoff Quantities ................................................................................................................. 8 4.0 Detention Facility & Routing ........................................................................................................................ 9 4.1 Detention Facility Criteria ....................................................................................................................... 9 4.2 Methodology .......................................................................................................................................... 10 4.3 Detention Facility Configuration ........................................................................................................... 11 4.4 Detention Facility Outlet Structures ...................................................................................................... 11 4.5 Routing Results and Conclusions .......................................................................................................... 11 5.0 Storm Drainage System ...........................................................................................................................•... 12 5 .1 Street Drainage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 5.2 Storm Drain Inlets ................................................................................................................................. 13 5.3 Storm Drain Conduits ............................................................................................................................ 15 6.0 Certification .....................................................................................•......................•..................................... 17 220-0321 Drainage Report-Rev 3.docx Page -i LIST OF TABLES: PAGE Section 3.0 -Hydrologic Modeling Table #1: Rainfall Depth ........................................................................................................................................ 6 Table #2: Composite Curve Number ...................................................................................................................... 6 Table #3: T11 -Overland Sheet Flow ..................................................................................................................... 7 Table #4: T 12 -Shallow and/or Concentrated Flow ................................................................................................ 7 Table #5: Tc Summary ........................................................................................................................................... 8 Table #6: Drainage Basin Runoff Quantities ......................................................................................................... 9 Section 4.0 -Detention Facility Routing Table #7: Detention Facility Routing ................................................................................................................... 12 Section 5.0 -Storm Drainage System Table #8: Street Drainage Summary .................................................................................................................... 13 Table #9: Curb Inlet Summary ............................................................................................................................. 14 Table #10: Storm Drainage Summary .................................................................................................................. 16 220-0321 Drainage Report-Rev 3.docx Page -ii ATTACHMENTS: Section 1.0 -General Information Rep lat Vicinity Map FIRM Panel Map Section 2.0 -Watersheds & Drainage Areas Wolf Pen Creek Watershed Area Existing Conditions Drainage Area Map Proposed Conditions Drainage Area Map Storm System Drainage Area Map Section 3.0 -Hydrologic Modeling Hydrologic Soil Group Data HydroCAD -Existing Conditions Drainage Calculations HydroCAD -Proposed Conditions Drainage Calculations Section 4.0 -Detention Facility & Routing GP-01: Site Grading & Drainage Plan HydroCAD -Proposed Conditions Pond Routing Calculations -Pond l Section 5.0 -Storm Drainage System Winstorm -Hydraulic Computations -Storm Drainage System "A" ST-01: Amazing Ct. -Plan/Profile 220-032 1 Drainage Report-Rev 3.docx Page -iii Drainage Study -Revision No. 3 F .S. KAPCHINSKI -BLOCK ONE Lot 17Rl-18R2, 24Rl, 24R2, 28R-32R College Station Brazos County, Texas 1.0 GENERAL INFORMATION 1.1 Scope of Report: This report addresses the existing conditions and proposed drainage improvements for the F.S. Kapchinski subdivision (Block One) replat of Lots l 7Rl-18R2, 23 , 24Rl-25R2, 28R-32R. This drainage study's scope will analyze the proposed detention facility design methods and proposed configurations, and the internal storm drainage system improvements designed for the development. All drainage system improvements (i.e. regional detention facilities, storm sewer, etc ... ) will be designed to accommodate the anticipated proposed/ultimate development conditions. The proposed development and drainage improvements are designed and analyzed in accordance with the criteria outlined in the "Unified Stormwater Design Guidelines" (USDG) manual of the City of College Station (CoCS). 1.2 Site and General Location: The replat development of this portion of F.S. Kapchinski consists of 3.714 acres ofland consisting of sixteen (16) residential lots (6 of which are currently already improved) with the construction of their associated improvements of paving, drainage, and utilities. The existing and proposed developments are depicted on the Replat which is provided in the "Attachment -Section 1.0" portion of this report. F.S. Kapchinski (Block One) has access to Park Place along its northwest and northeast property line. Developments adjacent to these lots are all residential consisting of single- farnily residential to the north and east and the multi-family development of Scandia Apartments to the west and south. A Vicinity Map, for this project site, is provided and is located in the "Attachment - Section 1.0" portion of this manual. This map is being provided as an aid in locating the site. Drawings describing the work and its specific locations are contained in the Construction Drawings prepared by RME Consulting Engineers, College Station, Brazos County, TX. These Construction Drawings are included as part of this Drainage Report by reference. 1.3 Description of Existing Conditions and Drainage Patterns: The 3.198 acres of land, which contains the proposed development, is a moderately well sloping (approximately 4%) substantially undeveloped site with natural overland drainage that conveys runoff to a secondary drainage system of Wolf Pen Creek. This 220-0321 Drainage Report-Rev 3.docx Page -1 F.S. Kapchinski -Block One Drainage Study -Rev. No. 3 RME Consulting Engineers September 14, 2009 secondary system consist of curb inlets that receive runoff from Park Place, conveyed in a 18" diameter storm sewer pipe, and then discharges into an unnamed tributary that is well defined. The headworks/subdivision discharge point of unnamed tributary is approximately 540 linear feet from its confluence with Wolf Pen Creek. A photograph of the existing outfall structure is depicted below. It consists generally of an open- backed curb inlet with an opening of approximately 4' with a grated gutter. Existing Outfall Structure of 18" Storm Sewer The subject development area is primarily an unimproved area with the exception of the construction of five (5) residential development on original lots NE Yz of 18, 23, 24 and 28, and two existing metal structures, to be removed, on lots 31 and 32, and the upland areas of the watershed being a portion of the parking areas of the adjacent apartment developments. Existing land-cover general consists of open grassy areas with some thick brush, weeds, and trees along the fence lines. Elevations range on the site from approximately 301 ' Mean Sea Level (MSL) to approximately 315 ' MSL. The Brazos County soil maps, as reported on the NRCS Web Soil Survey web-based program, indicates that the studied area is primarily comprised of Type C and D soils. These soils generally consist of clays or silty clay/sand mixtures with low absorption rates. Both pre-and post-runoff from the subject development will drain in a northwesterly direction through the proposed drainage structures or detention facility. Runoff is then discharged into the unnamed tributary, via a new storm sewer system crossing under Park Place. Eventually the unnamed tributary discharges into Wolf Pen Creek, thence to Carters Creek, thence to the Navasota River, thence to the Brazos River and ultimately to the Gulf of Mexico. 1.4 FEMA Information: A small portion of the subject development lies within mapped 100-year floodplain as graphically depicted by the Federal Emergency Management Agency (FEMA) -Flood Insurance Rate Map (FIRM) Community/Panel number 480083 0144C, with an 220-0321 Drainage Report-Rev 3.docx Page -2 F.S. Kapchinski -Block One Drainage Study -Rev. No. 3 RME Consulting Engineers September 14, 2009 effective date of July 2, 1992. A portion of this FIRM Panel Map is located in the "Attachment -Section 1.0" section of the Drainage Report. 2.0 WATERSHEDS & DRAINAGE AREAS 2.1 Detention Facility Watersheds (Existing Conditions): As previously discussed, the subject development area within the F.S. Kapchinski subdivision is located in a watershed of an unnamed tributary that drains into the Wolf Pen Creek Watershed Area. An exhibit of this watershed is taken from the USDG manual with the HCC area identified and is entitled as previously mentioned and has been included in the "Attachment -Section 2.0" appendix of the report. Since this drainage study will include the hydrologic/hydraulic modeling of one (1) detention facility, an appropriate drainage area map called the Existing Conditions Drainage Area Map (which is located in the "Attachment-Section 2.0" portion of the Drainage Report), was developed for considerations of runoff patterns and analysis and is described as follows. Drainage Area "X" -This drainage area is approximately 3.45 acres and will consist of the proposed development area and upstream contributing areas, at pre-development or existing conditions. At the downstream limit of this drainage area is the secondary drainage system of the unnamed tributary of Wolf Pen Creek. Analysis of this drainage area will provide runoff characteristics for the appropriate portion of the subject development at its current existing conditions. This runoff data will be the "benchmark" data for the respective post-development area analysis so that increased runoff can be measured and appropriately detained. 2.2 Detention Facility Watersheds (Proposed Conditions): For post-development conditions two (2) individual drainage basins were considered and analyzed and are as follows. The Proposed Conditions Drainage Area Map illustrates these drainage areas and is located in the "Attachment -Section 2.0" section of the Drainage Study. Drainage Area Map "P 1" -This drainage area consists of an area within Drainage Area "X" and comprises 1.25 acres of land. Proposed runoff conditions from this drainage area will be evaluated at the anticipated development conditions. The hydrologic data generated from this drainage area will drain into Pond 1, routed through the detention facility and discharged into the existing unnamed tributary of Wolf Pen Creek via this project's storm sewer system. Ultimately, routed flows, combined with flows from undetained flows from Drainage Area "P2", will be compared to the runoff values generated from Drainage Area "X"; Drainage Area Map "P2" -This drainage area consists of an area within Drainage Area "X" and comprises 2.36 acres of land. Proposed runoff conditions from this drainage area will be evaluated at the anticipated development conditions and released from the site undetained; 220-0321 Drainage Report-Rev 3.docx Page -3 F.S. Kapchinski -Block One Drainage Study -Rev. No. 3 2.3 Subdrainage Basins for Storm Sewer Collection System: RME Consulting Engineers September 14, 2009 For analysis of the internal storm drainage system, the proposed Drainage Areas "Pl" and "P2" were further broken down into smaller sub-drainage areas so that individual curb inlets, grate inlets, and conveyance elements could properly be designed and analyzed. The Storm System Drainage Area Map illustrates these sub-drainage areas and is located in the "Attachment -Section 2.0" portion of this Drainage Study. The sub-drainage areas, per system, are briefly described below. • System A -Replatted portion of F.S. Kapchinski and the upstream contributing drainage areas of the Scandia Apartment complex. Some special considerations were made for sub-drainage areas within this system and are noted as follows: o DA Al -Runoff calculated from this drainage area drains to the curb inlet on the northwest side of Park Place; o DA A2 -Runoff calculated from this drainage area is primarily from the Scandia Apartment Complex which surrounds the subject development and drains to the curb inlet on the southeast side of Park Place; o DA AS -Runoff calculated from this drainage area was inputted into called Junction Box AS and the routed flow from Pond 1; 3.0 HYDROLOGIC MODELING 3.1 SCS -TR 20 Formula and Methodology: The Natural Resources Conservation Service (NRCS), formerly the Soil Conservation Service, developed the runoff curve number method as a means of estimating the amount of rainfall appearing as runoff. The SCS-TR 20 formula calculates the peak discharge and volumes in a reliable fashion for moderate sized (SO to 400 acres) watersheds. This hydrologic method will also be utilized for all detention facility sizing regardless of the size of the contributing drainage area. The SCS unit hydrograph procedure (also known as the TR-20 runoff method) generates a runoff hydrograph by the following basic steps: (For brevity, this is a simplified description.) The SCS-TR20 methodology was employed for hydro logic computations of the Unnamed Tributary's Watershed and Post-Development Watersheds/Drainage Areas. 1. A rainfall distribution is selected which indicates how the storm depth will be distributed over time. This is usually a standardized distribution, such as the SCS Type II storm, and often a standardized duration of 24 hours is selected; 2. The design storm depth is determined from rainfall maps, based on the return period being modeled. Combined with the rainfall distribution, this specifies the cumulative rainfall depth at all times during the storm; 3. Based on the Time-of-Concentration (Tc), the storm is divided into "bursts" of equal duration. For each burst, the SCS runoff equation and the average Curve Number (CN) are used to determine the portion of that burst that will appear as runoff; 220-0321 Drainage Report-Rev 3.docx Page -4 F.S. Kapchinski -Block One Drainage Study -Rev. No. 3 RME Consulting Engineers September 14, 2009 The SCS runoff equation determines the precipitation excess runoff that results from a given cumulative precipitation: (P-Ia)2 Q= ------------(Q=O if P<Ia) (P-Ia)+S 1000 S= ----------10 CN with Ia = 0.2 s (P-.2S)2 Q= ------------ (P+. 8 S) where, Q = Precipitation excess runoff (inches); P = Cumulative precipitation (inches) -Table C-6 of the USDG -further discussion in the next sub-section; Ia = Initial abstraction (inches); S = Potential maximum retention (inches); CN = Curve Number -The Antecendent Mositure Condition (AMC) 1 and 3 are implemented by adjusting the Curve Numbers. The AMC specifies the moisture level in the ground immediately prior to the storm. Four conditions are defined: 1 - I Dry 2-IINormal 3 -III Wet 4 -Frozen or Saturated It is common policy to use AMC 2 for most design work. Other values should be used only under special circumstances. AMC 3 is sometimes used to study wet conditions, such as a spring rainfall event. AMC 3 usually causes a dramatic increase in runoff, and is not normally used for design purposes. Unless otherwise specified AMC 2 will be utilized for all hydrologic computations that employ the SCS-TR 20 method. 4. A Unit Hydrograph, in conjunction with the Tc, is used to determine how the runoff from a single burst is distributed over time. The result is a complete runoff hydrograph for a single burst; 5. Individual hydrographs are added together for all bursts in the storm, yielding the complete runoff hydrograph for the storm. 3.2 Cumulative Precipitation "P": As sited earlier the NRCS SCS-TR20 methodology utilizes rainfall depth "P" at various storm durations for the various storm frequencies that will be analyzed. The information 220-0321 Drainage Report-Rev 3.docx Page -5 F.S. Kapchinski -Block One Drainage Study -Rev. No. 3 RME Consulting Engineers September 14, 2009 reported in the SCS TP40 is provided in Table C-6 of the USDG, for Brazos County, TX, and is summarized below in Table #1 -"Rainfall Depth". TABLE #1 Rainfall Depth Storm Duration 2-YR 5-YR 10-YR 25-YR 50-YR 100-YR 24-hr 4.50 6.20 7.40 8.40 9.80 11.00 3.3 SCS Runoff Curve Numbers "CN": The Soils Conservation Service (SCS) runoff Curve Number, for each sub-drainage basin, was determined by composite method of percentage of land cover to the total sub- drainage basin. These CNs were estimated from the NRCS, Urban Hydrology for Small Watersheds, TR 55 (June 1986) by comparison of runoff surface types. Runoff surface types where determined by field reconnaissance, aerial maps, and utilizing the NRCS Web Soil Survey web-based program. The associated sectional maps and Hydrologic Soil Group Data figures and tables which substantiate the selection of these CN s are contained in the "Attachment -Section 3.0" section of the Drainage Study. Calculations for the composite runoff CNs are illustrated below in Table #2 -"Composite Curve Number". TABLE#2 Composite Curve Number (CNwtd) TypeD Open Space Woods Good Good Residential Drainage Condition Condition ( 1/8 acre) Pavement Composite Area I.D. CN=77 CN=80 CN=92 CN=98 CNwtd x 22.7% 43.8% 13.8% 19.7% 85 Pl 0.0% 9.0% 36.3% 54.7% 94 P2 0.0% 0.0% 81.4% 18.6% 93 3.4 Time of Concentration & Lag: The Time-of-Concentration (Tc), for each watershed, is used to determine the intensity of the rainfall event for the corresponding drainage basin. Time-of-Concentration is defined as the time required for the surface runoff to flow from the most hydraulically remote point in a watershed to the point of analysis. The Tc is the summation of the flow time for overland sheet flow plus shallow overland flow and/or concentrated flow to the lower reach of the watershed. Overland sheet flow is a method developed by Overton and Meadows and is typically used for flow distances of 300 feet or less. Concentrated flows are estimated by velocities determined by use of the Manning's Equation. These two types of flow time calculations are further explained as follows. Overland Sheet Flow, Tt = {0.007 (n L)0·8} I {Pi112 s0A} where, T1 = travel time (hours); 220-0321 Drainage Report-Rev 3.docx Page -6 F.S. Kapchinski -Block One Drainage Study -Rev. No. 3 RME Consulting Engineers September 14, 2009 n =Manning's roughness coefficient -This represents the flow-ability of runoff across a particular surface type and is a dimensionless coefficient. These coefficients are obtained from Table C-5 of the USDG; Pi = ith-year recurrence interval for the 24-hour rainfall depth (inches) -Rainfall depths are obtained from Table C-6 of the USDG; S =land slope (feet/foot) Shallow Concentrated Flow, Tt = D/(60V) where, Tt =Travel time (minutes); D = Flow distance (feet); V = Average velocity of runoff (ft/sec) -These values are determined from interpolation velocities recorded in Table C-4 of the USDG; Table #3 -"Tu-Overland Sheet Flow" and Table #4 -"T t2-Shallow Concentrated Flow" illustrates the flow travel times for each segment of the sub-drainage basin in respect to the condition of the flow. The Tc's for each sub-drainage basin where then computed and are summarized below in Table #5 -"Tc Summary". TABLE#3 Ttl -Overland Sheet Flow Overland Average Flow Land Travel Drainage Manning's Distance Pi Slope Time Area I.D. "n" (L) (100-vear) (S) (Tc) x 0.24 74 11.0 0.0075 0.149 Pl 0.24 74 11.0 0.0075 0.149 P2 0.24 74 11.0 0.0100 0.133 TABLE#4 Tt2 -Shallow and/or Concentrated Flow Shallow (Unpaved) Shallow (Paved) Flow Average Flow Average Drainage Distance Velocity Distance Velocity Time Area I.D. (Dl) (Vl) (D2) (V2) (Tc) x 417 2.7 150 1.7 4.04 Pl 0 2.7 200 l.7 1.96 P2 0 2.7 530 3.0 2.94 1) Unpaved Shallow Flow average velocities were estimated using the following equation V = 16. l 35*S05 where, V =fps S = average slope Assumptions -Manning's N = 0.05 & Hydraulic radius = 0.4 ft 2) Paved Shallow Flow average velocities were estimated using the following equation V = 20.328*S05 where, V =fps S = average slope Assumptions -Manning's N = 0.025 & Hydraulic radius = 0.2 ft 220-0321 Drainage Report-Rev 3.docx Page -7 F.S. Kapchinski -Block One Drainage Study -Rev. No. 3 Drainage Area l.D. x Pl P2 TABLE#S Tc SUMMARY Combined Overland Channel Flow Flow Time Time 0.149 4.04 0.149 1.96 0.133 2.94 3.5 Rational Formula and Methodology: Tc (min) 13.0 10.9 10.9 RME Consulting Engineers September 14, 2009 The Rational Method (Q=CIA) is one of the more frequently used methods to determine the peak runoff from a watershed and is typically reliable for small watersheds ( < 50 acres). The Rational Method generates hydro logic data based on drainage area geometrics, surface conditions, and rainfall intensities. The Rational Method will be employed to determine the sizes of watershed's runoff values for the sub-drainage areas, for the internal storm drain systems, and it is explained further as: Q=CIA where, Q = peak runoff rate (cubic feet per second); C = runoff coefficient -This represents the average runoff characteristics of the land cover within the drainage area and is a dimensionless coefficient. Runoff coefficients are interpolated from either Table C-2 or C-3 of the USDG; I= average rainfall intensity (in/hr); A = area of land that contributes storm water runoff to the area of study (acres); RUNOFF COEFFICIENT CC): The runoff coefficient (C) for various sub-drainage basins was estimated from the USDG, Table C-2 and C-3 by comparison of runoff surface types to percentage of land coverage and total drainage area. TIME OF CONCENTRATION "Tc": Stated previously Tc's for the Rational Method will be ten (10) minutes. RAINFALL INTENSITY (I): Rainfall intensities (I) are the average rate of rainfall in inches per hour for a given rainfall event. The duration of "I" is assumed to occur at the computed Time-of- Concentration for each respective drainage basin. Rainfall intensities can be determined by use of intensity-duration-frequency (IDF) curves or from intensity equations which are provided in the TxDOT Hydraulic Manual. 3.6 Stormwater Runoff Quantities: Stormwater runoff quantities were calculated, using the SCS-TC 20 formula and Rational Method, with the assistance of the Hydrologic/Hydraulic stormwater modeling program HydroCAD. Runoff values for the larger watersheds are summarized below in Table #6 -"Drainage Basin Runoff Quantities". HydroCAD-Existing Conditions Drainage 220-0321 Drainage Report-Rev 3.docx Page -8 F.S. Kapchinski -Block One Drainage Study -Rev. No. 3 RME Consulting Engineers September 14, 2009 Calculations and HydroCAD-Proposed Conditions Drainage Calculations and their supporting data are contained the "Attachment -Section 3.0" appendix of this Drainage Report. These calculated runoff quantities were reviewed and considered reasonable for the studied watershed. TABLE#6 DRAINAGE BASIN RUNOFF QUANTITIES Drainage Drainage Drainage Rainfall Area Area Area Event (X) (Pl) (P2) (yr) (cfs) (cfs) (cfs) 2 14.46 7.52 11.94 5 21 .93 10.59 16.95 10 27.20 12.75 20.45 25 31.58 14.54 23.36 50 37.68 17.04 27.42 100 42.89 19.18 30.88 Runoff values generated from the smaller sub-drainage areas, for purposes of modeling the proposed storm sewer system and street drainage, are not summarized below but are covered in the subsequent Section 5.0 -Storm Drainage System. 4.0 DETENTION FACILITY & ROUTING 4.1 Detention Facility Criteria STORAGE: 1. The storage ability of the detention facility is such that it can adequately detain the receiving stormwater runoff from upstream drainage areas so that runoff from the project site is controlled to pre-development "existing" conditions. The storage requirements are more fully explained in the following section; 2. The maximum storage depths for design and ultimate conditions shall be as follows: Facility Location Parking Areas Rooftops Landscaped Areas Design Hydrograph 0.50 ft 0.50 ft 3.0ft Ultimate Hydrograph 1.5 ft 1.0 ft 4.50 ft 3. All detention facilities located on natural streams or water courses that are designed with a permanent storage component shall meet all criteria, in terms of design and construction, for Dams and Reservoirs as required by the Texas Commission on Environmental Quality (TCEQ); 4. Detention facilities shall have an additional 10% in storage to account for sedimentation, except those located in parking areas or rooftops. 220-0321 Drainage Report-Rev 3.docx Page -9 F.S. Kapchinski -Block One Drainage Study -Rev. No. 3 OUTLET STRUCTURES: RME Consulting Engineers September 14, 2009 The detention facility outlet structures are designed so that the system can be drained by means of gravity. Discharge velocities shall be verified that they are below the minimum velocities receivable by the type and nature of the receiving system or attenuated so that they are below these minimums. PHYSICAL CHARACTERISTICS: 1. Side slopes shall not exceed 4:1 for vegetative cover and 2:1 for non-vegetative cover; 2. Bottom slopes must be 2.00% or steeper to low flow outlet; 3. A low-flow invert shall be provided for all facilities which have a vegetative cover at the facility bottom; EMERGENCY OVERFLOW: 1. The geometry of the emergency overflow shall be that of a rectangular weir; 2. Surface treatment of the overflow weir shall be consistent with the expected velocities at ultimate conditions. Proper treatments shall be provided to accommodate or attenuate the discharge velocities; 3. A minimum of 0.5 feet of freeboard shall be provided around the perimeter of the detention facility as measured between the maximum water surface elevation and the pool elevation and the ultimate conditions. 4.2 Methodology: The purpose of a detention facility is to store the increased runoff created by the impervious and improved areas, and discharge it at a rate so that the immediate downstream structure and/or property experiences decreases or no change as compared to existing conditions. Using the peak runoff rates, generated and illustrated in Section 3.6 of this report, hydrographs for each rainfall event and respective drainage basins were created for existing conditions. These hydrographs were constructed by means of triangular approximation method which is limited to smaller watersheds located within the secondary drainage system of a major watershed. Other assumptions and geometric conditions that are used to build these hydrographs are as listed below. Using this data, and inputting it into HydroCAD, approximate hydrographs were determined for each drainage basin at selected rainfall events. Triangular Approximation: 1. Peak Runoff (Q) occurs at "Tc"; 2. The outflow portion of the triangular hydrograph is Tc x 2; Using this information, the storage volume of the detention facility can be estimated. This storage volume shall be such that the peak discharges of the development hydrograph, or the routed hydrograph, from the detention facilities will be equal to or less than the "Benchmark" discharges. For this project, at proposed development conditions, the discharge values shall be such that the routed flows through Pond 1 (from Drainage Area "P 1 "), plus the undetained runoff values from Drainage Area "P2", are equal to or less than the peak discharge rates of Drainage Area "X". 220-0321 Drainage Report-Rev 3.docx Page -10 F.S. Kapchinski -Block One Drainage Study -Rev. No. 3 4.3 Detention Facility Configuration: RME Consulting Engineers September 14, 2009 The detention facility for the subject development will consist of one pond. With the construction of this detention facility, called Pond 1, an outlet structure will be installed to detain/meter increased runoff from Drainage Area "Pl". The proposed GP-01: Site Grading & Drainage Plan for this project more fully depicts these improvements and is contained under the "Attachment -Section 4.0" portion of this report. The detention facility is briefly summarized below: Pond 1: Runoff from Drainage Area "Pl" is conveyed by means of overland flow. Pond 1 is "dry" pond with a bottom elevation of 306.83' and a maximum berm or ponding elevation of 312.00'. Sideslopes of the detention pond will be primarily vertical with perimeter retaining wall at all sides excluding the northeast for maintenance access. The pond will be constructed with a concrete low-flow pilot channel and all earthen areas will have a bottom slope at a 2.00%. Runoff routed through Pond 1 is metered through an irregular shaped weir and this is discharged into the storm drainage system of the proposed development; 4.4 Detention Facility Outlet Structure: The detention facility outlet structure has been designed to accommodate and route collected stormwater runoff, from Drainage Area "Pl" so that during analyzed/routed rainfall events the post-development discharge rates are near or less than the "benchmark" discharge values generated from Drainage Area "X". These "benchmark" discharge values are illustrated in Table #6 contained in Section 3.6 of this report. The discharge structure of each detention pond will serve as the restricting or metering device, and are summarized below: Pond 1 : Pond 1 discharge structure is an irregular shaped weir cut into a concrete box structure which discharges into the 18" diameter private storm drain. This outlet weir structure will extend to a height of 311.50'. The irregular shaped weir will have the geometric shape as follows. Head = 0.0 ' -V-notch width of O"; Head= 3.17' -V-notch width of 0.35'; Head= 4.67' -Rectangular width of 12"; The maximum berm height will extend also to an elevation of 312.00' which will provide 0.50' of :freeboard above the maximum pool elevation occurring during the 100-year rainfall event. Tailwater considerations for the outlet of Pond 1 were set at a free discharge condition. 4.5 Routing Results and Conclusions: Once the project's detention facility and outlet structure was determined, then the hydro graph for Drainage Basins "P 1" could be routed through the detention system. The routing of this hydro graph, for each analyzed rainfall event, was accomplished by means of the Hydrologic/Hydraulic stormwater modeling program HydroCAD. The program mathematically solves for continuity between the detention facilities storage capabilities, in respect to height versus storage and height versus discharge rate, with the inflow 220-0321 Drainage Report-Rev 3.docx Page -11 F.S. Kapchinski -Block One Drainage Study -Rev. No. 3 RME Consulting Engineers September 14, 2009 hydrograph and inputted tailwater conditions. HydroCAD -Proposed Conditions Pond Calculations -Pond 1 and its supporting data is contained the "Attachment -Section 4.0" section of this Drainage Report. As shown below in Table #7 -"Detention Facility Routing", the designed detention facility system can accommodate inflow runoff and adequately detain this stormwater so that the facility's discharge rates are minimally below the "benchmark" discharges without overtopping the maximum berm elevation. TABLE #7 DETENTION FACILITY ROUTING Routed D.A. "P2" Benchmark Ditt: m Rainfall Storage Max. Discharge Discharge Discharge Discharge Max. Berm Event Volume Pool Elev Rate Rate Rate Rate Elev. Free board (yr) (cu.ft.) (ft) (cfs) (cfs) (cfs) (cfs) (ft) (ft) DETENTION POND 1 -PROPOSED CONDITIONS 2 7,663 309.46 1.62 11.94 13.63 -0.07 312.00 2.54 5 10,389 310.08 2.82 16.95 20.67 -0.90 312.00 1.92 lO 11,983 310.43 4.14 20.45 25.64 -1.05 312.00 1.57 25 13,200 310.69 5.38 23.36 29.77 -1.03 312.00 1.31 50 14,716 311.00 7.09 27.42 35.52 -1.01 312.00 1.00 JOO 15,921 311.23 8.57 30.88 40.43 -0.98 312.00 0.77 5.0 STORM DRAINAGE SYSTEM The "system criteria" listed below in the follow sub-sections are only the main highlights of the CoCS -USDG. The proposed development and drainage improvements are designed and analyzed in full accordance with the criteria outlined in this manual. 5.1 Street Drainage SYSTEM CRITERIA: 1. The maximum velocity of street flow shall not exceed 10 fps. At "T" street intersection the flow velocity will be checked on the stem of the "T". The minimum velocity shall be maintained by keeping a gutter slope of 0.60% or greater; 2. The depth of flow shall be limited to the top of the curb for the design flow (10-year rainfall event) and shall be contained within the right-of-way during the 100-year rainfall event: a. Local Streets -The design storm in local streets shall be limited to the top of crown or the top of curb, whichever is less; b. Collector Streets -Design storm flow in collector streets shall be limited so that one 12-foot wide area at the center of the street will remain clear of water; 3. Curb inlets shall be placed in a manner to ensure that the design storm flows are intercepted along street legs in advance of the curb returns. For intersection types of Collector to Local, the curb inlets shall be placed along the local legs. For intersection types of Local to Local it is preferred that the curb inlets be located along two legs. 220-0321 Drainage Report-Rev 3.docx Page -12 F.S. Kapchinski -Block One Drainage Study -Rev. No. 3 RME Consulting Engineers September 14, 2009 METHODOLGY & CONCLUSIONS: The hydraulic analysis, for street drainage with straight crowns, and corresponding results were determined by using the following equation for triangular channels. Corresponding flows for the studied locations were extracted from the WINSTORM hydraulic program, for stormwater modeling. This TxDOT program's typical use is for modeling gravity stormwater systems. The Winstorm data is summarized, for each system, under the Winstorm -Hydraulic Computations (reference "Attachment -Section 5.0" portion of the report). Flow Depth, Y = {Qn I [(0.56z*S0.s)]}318 where, Y = depth of flow (ft); Q = gutter discharge (cubic feet per second); z =reciprocal of the crown slope (ft/ft); S =street or gutter slope (ft/ft); n =Manning's roughness coefficient (typically 0.018); Flow Velocity, V = [(1.49+n) * (R213 * S112)] where, V =velocity of flow (fps); R =hydraulic radius (cross-sectional area/wetted perimeter); S = street or gutter slope (ft/ft); n =Manning's roughness coefficient (typically 0.014); Street drainage depths, for the both the design storm and 100-year rainfall event, are summarized below in Table #8 -"Street Drainage Summary". TABLE#8 STREET DRAINAGE SUMMARY 10-YR 100-YR 10-YR 100-YR Gutter Flow Flow 10-YR JOO-YR RunoffQ RunoffQ Slope Depth Depth Velocity Velocity Location (cfs) (cfs) (ft/ft) (ft) (ft) (fus) (fus) Amazing Ct. -C.l. "A3" 5.213 7.027 0.0445 0.21 0.24 4.49 Amazing Ct. -C.l. "A4" 1.782 2.402 0.0445 0.14 0.16 3.44 Street Dramage Notes: I. Design calculations are with a n=0.018 and z=33.3 (cross-slope of3.00%); 2. Runoff rates illustrated are from the Winstorm program. These Q's are the total runoff values being conveyed in the gutter immediately upstream of the identified inlet. For curb inlets at grade, the total runoff is input in lieu of that inlet's intercept capacity; 3. The maximum allowable depth, during the design storm, for all streets is 0.42'; 5.2 Storm Drain Inlets SYSTEM CRITERIA: 1. All curb inlets within this project are specified as recessed curb inlets with gutter depressions. Curb inlets that are located on streets with less than a 1 % longitudinal slope shall be analyzed as curb inlets at sumps; 220-0321 Drainage Report-Rev 3.docx Page -13 4.84 3.70 F .S. Kapchinski -Block One Drainage Study -Rev. No. 3 RME Consulting Engineers September 14, 2009 2. At any developments scenario and analyzed rainfall event, up to the 100-year frequency, the ponding depth at the inlet shall not exceed 24"; METHODOLGY & CONCLUSIONS: The hydraulic analysis, for curb inlet sizing, and corresponding results were determined by using the following equation from the USDG, Table C-8 of Appendix C. Corresponding flows for the studied locations were extracted from the WINSTORM hydraulic program, for stormwater modeling. This TxDOT program's typical use is for modeling gravity stormwater systems. The Winstorm data is summarized, for each system, under the Winstorm -Hydraulic Computations (reference "Attachment -Section 5.0" portion of the report). Required Curb Length (on grade), L =Kc Q0.42s0.3(1 + (nSe))0·6 where, L =calculated curb length requirement (ft); Se= Substitution for Sx which is the cross slope of the road (ft/ft); Kc = 0.6 (coefficient); S =street or gutter slope (ft/ft); a= gutter depression depth (ft); W = width of gutter depression (ft); Eo =ratio of frontal flow to total gutter flow (estimated at 0.50); Required Curb Length (at sag), L =QI (3.0*y1·5) where, L =calculated curb length requirement (ft); Q = gutter discharge (cubic feet per second); y =total depth of water or head on the inlet (ft); Curb inlet sizing, for the both the design storm and 100-year rainfall event, are summarized below in Table #9 -"Curb Inlet Summary". TABLE#9 CURB INLET SUMMARY 10-YR 100-YR IO-YR 100-YR Gutter Required Required Provided Cwt Inlet RunoffQ RunotfQ Slope Length Length Length Location -Curb Inlet l.D. Tvne (cfs) (cfs) (ft/ft) (ft) (ft) (ft) Park Place -C.I. "Al" Sag 2.114 2.849 0.0075 1.99 2.69 IO Park Place -C.I. "A2" Sag 23.974 33.380 0.0075 22.60 31.47 10 Amazing Ct. -C.l. "A3" Grade 5.213 7.027 0.0445 16.41 18.60 15 Amazino rr. -r.1. "A4" Grade l.782 2.402 0.0445 10.45 l l.85 10 Curb Inlet Notes: 1. Design calculations are with a standard gutter depression depth (a) of0.33' and standard depression width (W) of2'; 2. Design calculations are with a n=0.018 and a standard cross-sectional slope of3.0% (0.03 ft/ft); 3. Curb inlets analyzed at sags will utilize the depth (y) of6" unless otherwise noted; 4. Curb inlets at grade were allowed to be undersized so long as the downstream gutter section and ultimate receiving sag inlet could accommodate conveyed flows. 220-0321 Drainage Report-Rev 3.docx Page -14 F.S. Kapchinski -Block One Drainage Study -Rev. No. 3 5.3 Storm Drain Conduits SYSTEM CRITERIA: RME Consulting Engineers September 14, 2009 1. Storm drainage systems are designed to convey the design storm and analyzed during the 100-year rainfall event. A gravity over-flow route, contained within the right-of- way or public drainage easement, has been provided so that conduits that are unable to convey the 100-year storm can "spill" over into these over-flow systems so that situations that are hazardous to life, property, or public infrastructure is prevented; 2. For the design storm, the minimum flow velocity in a conveyance element shall not be less than 2.5 fps and not greater than 15.0 fps; 3. Roughness coefficients for storm sewer pipes were assigned at 0.012 for smooth-lined High Density Poly-Ethylene (HDPE) pipe and 0.013 for RCP; 4. Junction boxes were provided at all changes in conduit size and grade or alignment changes. Where junction box spacing exceeded 300 feet for 54" diameter pipe, or smaller, and 500' for pipes exceeding 54" in diameter, additional manhole were provided to maintain the desired spacing; 5. Storm sewer conduits with a diameter of 18" through 24" were hydraulically analyzed with a 25% reduction in cross-sectional area to compensate for potential partial blockage. Therefore 18" sized pipes were input as 1.30' diameter pipe and 24" sized pipes were inputted as a 1. 73 ' diameter pipe; 6. Conveyance elements were sized so that the design storm's hydraulic grade line would be equal to or less than 12" below the respective curb inlet curb elevation; TAIL WATER CONSIDERATIONS: Tail water for the storm drainage system was calculated by taking a cross-section of the unnamed tributary, immediately downstream of the outlet, and performing a normal depth calculation. The water surface elevation developed from this normal depth calculation was then inputted as the systems tailwater elevation. METHODOLGY & CONCLUSIONS: The hydraulic analysis, for storm drain conduits, and corresponding results, were determined by using the WINSTORM hydraulic program for stormwater modeling. This TxDOT program's typical use is for modeling gravity stormwater systems. The Winstorm data is summarized, for each system, under the Winstorm -Hydraulic Computations (reference "Attachment -Section 5.0" portion of the report). Also, for graphical illustration purposes the hydraulic grade line (HGL), for the 10-year and 100- year, are identified on ST-01: Amazing Ct. Plan/Profile of the construction drawings (see "Attachment -Section 5.0" portion of the report). Storm drain conveyance elements and system, for the design storm, are summarized below in Table #10 -"Storm Drainage Summary". As illustrated in the Winstorm output data the discharge velocities for the 10-year and 100-year rainfall event are respectively 7.63 fps and 9.75 fps for System "A". 220-0321 Drainage Report-Rev 3.docx Page -15 F.S. Kapchinski -Block One Drainage Study -Rev. No. 3 US Node DS Node ID ID JBI OUT! Al JBI A2 Al A3 A2 A4 A3 JB2 A3 A5 JB2 JBI OUT! Al JBI A2 Al A3 A2 A4 A3 JB2 A3 A5 JB2 TABLE #10 STORM DRAINAGE SUMMARY Pipe Size Diameter Velocity Capacity RunoffQ USHGL (in) (fus) (cfs) (cfs) (ft) SYSTEM "A" -DESIGN STORM (10-YEAR) 30 7.61 56.29 37.30 295.20 30 8.59 62.93 37.30 296.71 30 12.15 56.08 36.16 297.44 24 12.56 29.05 15.53 299.35 18 4.10 11.97 1.78 300.42 18 11.34 14.44 8.57 305.74 18 8.07 9.46 8.57 308.00 SYSTEM "A" -ANALYZED STORM (100-YEAR) 30 9.75 56.29 47.88 295.73 30 9.75 62.93 47.88 297.52 30 10.23 56.08 46.31 297.89 24 10.97 29.05 17.96 299.48 18 4.02 11 .97 2.40 300.48 18 11.34 14.44 8.57 305.74 18 8.07 9.46 8.57 308.00 Storm Drainage System Notes: RME Consulting Engineers September 14, 2009 US Top of Curb Di ff Elev. (ft) (ft) 298.30 -3.10 300.65 -3.94 301.04 -3.60 303.08 -3.73 304.28 -3.86 311.25 -5.51 312.00 -4.00 298.30 -2.57 300.65 -3.13 301.04 -3.15 303.08 -3.60 304.28 -3.80 311.25 -5.51 312.00 -4.00 1. All proposed storm sewer system outfalls are specified with velocity dissipaters at the headwall; 6.0 CERTIFICATION Rabon Metcalf, P .E. State of Texas P.E. No. 88583 Texas Firm Registration No. F-004695 220-0321 Drainage Report-Rev 3.docx Page -16 Section 1.0 GENERAL INFORMATION F.S. KAPCHINSKI SUBDIVISION: LOTS 17, NE ~ OF 18, 24, 38-32 PARK PLACE, COLLEGE STATION LIMIT OF DETAILED STUDY 500 APPROXIMATE SCALE 0 500FEET E3 E3 E3 NATIONAL FLOOD lllSURANCE PROGRAM FLOOD INSURANCE RATE MAP BRAZOS COUNTY, TEXAS AND INCORPORATED AREAS (IEE MAP INDEX FOR PANELS NOT PRINTED) Mm Wfil .!l!!!!! 4&0012 0144 480083 0144 MAP NUMBER 48041 C0144 C EFFECTIVE DATE: JULY 2, 1992 Federal Emersency Manngement Agency This Is an official copy of a portion of the above referenced flood map. It was extracted using F-MIT Version 1.0. This map does not reflect changes or amendments which may have been made subsequent to the date on the tiUe block. Futher Information about National Flood Insurance Program flood hazard maps Is available at www.fema.gov/mltltsd. PMnt Date: 12/'2/2000 fp<lnted at scale and type "'l Section 2.0 WATERSHEDS & DRAINAGE AREAS 0 ,. ~ \ Tf'I (" .. : \~ 1,650 Feet 6,600 Figur.e.B-21: Wolf Pen Creek Watershed Area ·- / .. · Section 3.0 HYDROLOGIC MODELING ~ b> ill N A Map Scale: 1:1,180 1r printed on A size (8.5" x 11 ') sheel. Hydrologic Soil Group-Brazos County, Texas (Hydrologic Soil Group Data) ----c:====---------=========:::iMeters 0 15 30 60 90 ----c::::==:::::i-------mc=======::::iFeet 0 50 100 200 300 lSDA Natural Resources ~ Conservation Service Web Soil Survey 2.2 National Cooperative Soll Survey ~ ~ ~ ~ "' 4/20/2009 Page 1of4 30' 36'47'' 30' 36' 42" MAP LEGEND Area of Interest (AOI) D Area of Interest (AOI) Solls Soil Map Units Soll Ratings D A D ND DB D B/D D c D C/D DD Hydrologic Soil Group-Brazos County, Texas (Hydrologlc Soil Group Data) MAP INFORMATION Map Scale: 1: 1, 180 if printed on A size (8.5" " 11 ") sheet. The soil surveys that comprise your AOI were mapped at 1 :20,000. Please rely on the bar scale on each map sheet for accurate map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: http://websoilsurvey.nrcs.usda.gov Coordinate System: UTM Zone 14N NAD83 This product Is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Survey Area Data: Brazos County, Texas Version 8, Jun 12, 2008 Date(s) aerial images were photographed: 1995 Not rated or not available The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. Political Features Cities Water Features • Oceans Streams and Canals Transportation +++ Ralls Natural Resources Conservation Service Interstate Highways US Routes Major Roads Local Roads Web Soil Survey 2.2 National Cooperative Soil Survey 4/20/2009 Page 2 of 4 Hydrologic Soil Group-Brazos County, Texas Hydrologic Soil Group Data Hydrologic Soil Group Hydrologic Soil Group-Summary by Map Unit-Brazos County, Texas Map unit symbol Map unit name Rating Acres inAOI Percent of AOI ZcB Zack-Urban land complex, 1 to D 3.0 5 percent slopes ZcD Zack-Urban land complex, 5 to D 0.0 8 percent slopes Totals for Area of Interest 3.0 Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long-duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (AID, BID, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink-swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (AID, B/D, or CID), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Rating Options Aggregation Method: Dominant Condition Natural Resources Conservation Service Web Soil Survey 2.2 National Cooperative Soil Survey 99.6% 0.4% 100.0% 4/20/2009 Page 3 of4 Hydrologic Soil Group-Brazos County, Texas Component Percent Cutoff: None Specified Tie-break Rule: Lower Natural Resources Conservation Service Web Soil Survey 2.2 National Cooperative Soil Survey Hydrologic Soil Group Data 4/20/2009 Page4 of4 Jaffer-TR20 C-042009 HydroCAD-Existing Conditions Drainage Calculations Type II 24-hr 2-Year Rainfal/=4.50" Prepared by {enter your company name here} HydroCAD®7.10 sin 003394 ©2005 HydroCAD Software Solutions LLC Subcatchment DA-X: Pre-Development "X" Runoff = 13.63 cfs@ 12.05 hrs, Volume= 0. 777 af, Depth> 2. 70" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Type 1124-hr 2-Year Rainfall=4.50" Area (ac) CN Description 3.450 85 Pre-Development Conditions Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.0 Direct Entry, Existing Conditions 15 14 13 12 10 9 .!!? ~ 8 ~ 0 7 u: 6 5 4 3- 2- 0 0 Subcatchment DA-X: Pre-Development "X" Hydrograph Type II 24-hr 2-Year Rainfall=4.50" Runoff Area=3.450 ac Runoff Volume=O. 777 af Runoff Depth>2. 70" Tc=13.0 min CN=85 I I I 1 • 13.63 cfs • I' ., 2 3 4 5 6 7 8 9 10 11 12 Time (hours) 14 15 16 17 18 19 20 Page 1 412012009 1-Runottl Jaffer-TR20 C-042009 HydroCAD-Existing Conditions Drainage Calculations Type II 24-hr 5-Year Rainfal/=6.20" Prepared by {enter your company name here} HydroCAD® 7 .10 sin 003394 © 2005 HydroCAD Software Solutions LLC Subcatchment DA-X: Pre-Development "X" Runoff = 20.67 cfs@ 12.04 hrs, Volume= 1.207 af, Depth> 4.20" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Type 1124-hr 5-Year Rainfall=6.20" Area (ac) CN Description 3.450 85 Pre-Development Conditions Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.0 Direct Entry, Existing Conditions Subcatchment DA-X: Pre-Development "X" Hydrograph 23 22 21 . 20 '. 19 Type II 24-hr 5-Year 18 11 _ Rainfall=6.20" en 13' ~ 12~ ~ 11 ~ 0 ii: 10~ 9~ 16 -Runoff Area=3.450 ac Runoff Volume=1.207 af Runoff Depth>4.20" Tc=13.0 min 14 8 7 5 4 : 3~ 2: CN=85 20.67 cfs ~-i_ ______________ ,,,_,.,..""""' ...... ;:;::;:;:;:;::::;:;;::::::.. .......... ~ . ....,.....::::::::;:::;:;:;:;::;:;::;::;;:;:;:;:::;::;:;:;:;;;:;::;;;:j 0 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time {hours) Page2 4/20/2009 I-Runoff. Jaffer-TR20 C-042009 HydroCAD-Existing Conditions Drainage Calculations Type II 24-hr 10-Year Rainfal/=7.40" Prepared by {enter your company name here} HydroCAD® 7.10 s/n 003394 © 2005 HydroCAD Software Solutions LLC Subcatchment DA-X: Pre-Development "X" Runoff = 25.64 cfs@ 12.04 hrs, Volume= 1.518 af, Depth> 5.28" Runoff by SGS TR-20 method, UH=SCS, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=7.40" Area (ac) CN Description 3.450 85 Pre-Development Conditions Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.0 24 22 18 :§" 16 . .£. ~ 14- 0 ii: 12-: 8 6 2 Direct Entry, Existing Conditions Subcatchment DA-X: Pre-Development "X" Hydrograph Type II 24-hr 10-Year Rainfall=7 .40" Runoff Area=3.450 ac Runoff Volume=1.518 af Runoff Depth>5.28" Tc=13.0 min CN=85 25.64 cfs o-l-.,....,.,...,..,..,........,..,..........,....,.,.._~."""""'-~-~ •. • .. ~. ~--~-.~-~-~-.~-~-~-.-· .,....,.,...,..,.....,...;:;::;:;:;:::;::;::;:;:;::;:;:;,;:::;::;:::;,~.~.~.~.~.::;:J. 0 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Page3 412012009 I -Runoff~ Jaffer-TR20 C-042009 HydroCAD-Existing Conditions Drainage Calculations Type II 24-hr 25-Year Rainfal/=8.40" Prepared by {enter your company name here} HydroCAD® 7.10 s/n 003394 © 2005 HydroCAD Software Solutions LLC Subcatchment DA-X: Pre-Development "X" Runoff = 29.77 cfs@ 12.04 hrs, Volume= 1. 780 af, Depth> 6.19" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 25-Year Rainfall=8.40" Area (ac} CN Description 3.450 85 Pre-Development Conditions Tc Length Slope Velocity Capacity Description (min} (feet} (ft/ft) (ft/sec} (cfs) 13.0 Direct Entry, Existing Conditions Subcatchment DA-X: Pre-Development "X" Hydrograph 32~ 30-'. 28 . Type II 24-hr 25-Year ::: Rainfall=S.40" 22 Runoff Area=3.450 ac ., 20 · Runoff Volume=1. 780 af ~ 18 ~ 16 0 . ii: 14 . 12 10 8 6- 4- Runoff Depth>6.19" Tc=13.0 min CN=85 I 29.77 cts I :.t... __ ..................................... ..._...__...~;:;:;:;:;;:;:;:;;:;:;::;:;::;::::.. ................ ......::;:::;;:;:::;:;::;:;:;;:;:;:;:;:;:;;::;::;:;::;:;:;:;:;:;J 0 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Page4 4/20/2009 I-Runoff. Jaffer-TR20 C-042009 HydroCAD-Existing Conditions Drainage Calculations Type II 24-hr 50-Year Rainfaf/=9. BO" Prepared by {enter your company name here} HydroCAD® 7 .10 sin 003394 © 2005 HydroCAD Software Solutions LLC Subcatchment DA-X: Pre-Development "X" Runoff = 35.52 cfs@ 12.04 hrs, Volume= 2.150 af, Depth> 7.48" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 50-Year Rainfall=9.80" Area {ac) CN Description 3.450 85 Pre-Development Conditions Tc Length Slope Velocity Capacity Description {min) {feet) {ft/ft) (ft/sec) {cfs) 13.0 Direct Entry, Existing Conditions Subcatchment DA-X: Pre-Development "X" Hydrograph 38 . 36. ~-Type II 24-hr 50-Year 30 Rainfall=9.80" 28- 14. Runoff Area=3.450 ac Runoff Volume=2.150 af Runoff Depth>7.48" Tc=13.0 min 12~ CN=85 4- 35.52 cfs ~l....-.. ~ ................................. ..-........... --.~.~--~-~. ::;::;::;::;:::;::;::::;:;:......,~ .. ~ ........ ..:::::::::;:::;:;:;;::;:;:::~.;:::~.:::::;:;;::;J 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Page 5 4/20/2009 1-Runoffj Jaffer-TR20 C-042009 HydroCAD-Existing Conditions Drainage Calculations Type 1124-hr 100-Year RainfaJ/=11 .00" Prepared by {enter your company name here} HydroCAD® 7.10 sin 003394 © 2005 HydroCAD Software Solutions LLC Subcatchment DA-X: Pre-Development "X" Runoff = 40.43 cfs@ 12.04 hrs, Volume= 2.470 at, Depth> 8.59" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 100-Year Rainfall=11.00" Area (ac) CN Description 3.450 85 Pre-Development Conditions Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.0 Direct Entry, Existing Conditions Subcatchment DA-X: Pre-Development "X" Hydrograph 44 42 Type II 24-hr 100-Year 34 Rainfall=11.00" 32 28 ~ 26 ~ 24 , 3: 22-£ 20 · 18~ 16- Runoff Area=3.450 ac Runoff Volume=2.470 af Runoff Depth>S.59" Tc=13.0 min 14' CN=85 12-' 10 5· 6 . 4 · 40.43 els 21:~------------~;;;:;:;:;:;::;:;:;:;:;;:;:;:::;:;:;:::::....... .................. ..:;::::;;;;;:;::;;:;:;::;:;:;:;::;::;:;:;::;:;;:;:;;:;::j o· . , . . , -. . . . , . 0 2 3 4 5 6 7 8 9 10 11 ·12 13 14 15 16 17 18 19 20 nme (hours) Page 6 412012009 1-Runoffl Post-Deve pment P1 Post-Development P2 Jaffer-TR20 C-042009 Prepared by {enter your company name here} HydroCAD-Proposed Conditions Drainage Calculations Type II 24-hr 2-Year Rainfal/=4.50" HydroCAD® 7 .1 O sin 003394 © 2005 HydroCAD Software Solutions LLC Page 2 412012009 Time span=0.00-20.00 hrs, dt=0.05 hrs, 401 points Runoff by SGS TR-20 method, UH=SCS Reach routing by Stor-lnd+ Trans method -Pond routing by Stor-lnd method Subcatchment DA-P1: Post-Development P1 Subcatchment DA-P2: Post-Development P2 Runoff Area=1 .250 ac Runoff Depth>3.59" Tc=10.9 min CN=94 Runoff=6.43 cfs 0.374 af Runoff Area=2.360 ac Runoff Depth>3.49" Tc=10.9 min CN=93 Runoff=11 .94 cfs 0.686 af Total Runoff Area= 3.610 ac Runoff Volume= 1.060 af Average Runoff Depth= 3.53" Jaffer-TR20 C-042009 HydroCAD-Proposed Conditions Drainage Calculations Type II 24-hr 2-Year Rainfal/=4.50" Prepared by {enter your company name here} HydroCAD® 7.10 sin 003394 © 2005 HydroCAD Software Solutions LLC Subcatchment DA-P1: Post-Development P1 Runoff = 6.43 cfs @ 12.02 hrs, Volume= 0.374 af, Depth> 3.59" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 2-Year Rainfall=4.50" Area (ac) CN Description 1.250 94 Post-Development Conditions Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.9 Direct Entry, Proposed Conditions 7- Subcatchment DA-P1: Post-Development P1 Hydrograph I 6.43 cfs I 6 Type II 24-hr 2-Year Rainfall=4.50" 5 Runoff Area=1.250 ac Runoff Volume=0.37 4 af ~ Runoff Depth>3.59" u: 3-Tc=10.9 min 2_ CN=94 1- 0 , 0 • •t • y ••• , •• 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Page 3 412012009 I-Runoffj Jaffer-TR20 C-042009 HydroCAD-Proposed Conditions Drainage Calculations Type 1124-hr 2-Year Rainfal/=4.50" Prepared by {enter your company name here} HydroCAD® 7 .10 sin 003394 © 2005 HydroCAD Software Solutions LLC Subcatchment DA-P2: Post-Development P2 Runoff = 11 .94 cfs @ 12.02 hrs, Volume= 0.686 af, Depth> 3.49" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 2-Year Rainfall=4.50" Area (ac) CN Description 2.360 93 Proposed-Development Conditions Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.9 13~ 12 11-: 10 9 8 ~ ~ 1-: ~ 0 6 u: 5 4-: 3- 2-: 1-: 0 0 Direct Entry, Proposed Conditions Subcatchment DA-P2: Post-Development P2 Hydrograph Type II 24-hr 2-Year Rainfall=4.50" Runoff Area=2.360 ac Runoff Volume=0.686 af Runoff Depth>3.49" Tc=10.9 min CN=93 f 11 .94cfs l •"I I • I t •• I • f I I 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) ~age4 412012009 I-Runoff~ Jaffer-TR20 C-042009 Prepared by {enter your company name here} HydroCAD-Proposed Conditions Drainage Calculations Type II 24-hr 5-Year Rainfal/=6.20" HydroCAD® 7 .1 O sin 003394 © 2005 HydroCAD Software Solutions LLC Pages 412012009 Time span=0.00-20.00 hrs, dt=0.05 hrs, 401 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Ster-Ind+ Trans method -Pond routing by Ster-Ind method Subcatchment DA-P1: Post-Development P1 Subcatchment DA-P2: Post-Development P2 Runoff Area=1.250 ac Runoff Depth>S.19" Tc=10.9 min CN=94 Runoff=9.07 cfs 0.540 af Runoff Area=2.360 ac Runoff Depth>S.07" Tc=10.9 min CN=93 Runoff=16.95 cfs 0.998 af Total Runoff Area= 3.610 ac Runoff Volume= 1.538 af Average Runoff Depth= 5.11 " Jaffer-TR20 C-042009 HydroCAD-Proposed Conditions Drainage Calculations Type II 24-hr 5-Year Rainfal/=6.20" Prepared by {enter your company name here} HydroCAD® 7 .10 sin 003394 © 2005 HydroCAD Software Solutions LLC Subcatchment DA-P1: Post-Development P1 Runoff = 9.07 cfs@ 12.02 hrs, Volume= 0.540 af, Depth> 5.19" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 5-Year Rainfall=6.20" Area (ac) CN Description 1.250 94 Post-Development Conditions Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.9 10- 9 8- 7- 6 :? ~ 3: 5- 0 u: 4- 3- 2 1- o- 0 Direct Entry, Proposed Conditions Subcatchment DA-P1: Post-Development P1 Hydrograph Type II 24-hr 5-Year Rainfall=6.20" Runoff Area=1.250 ac Runoff Volume=0.540 af Runoff Depth>5.19" Tc=10.9 min CN=94 I •I \ I I 9.07 cfs I 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Page6 4/20/2009 I-Runoff I Jaffer-TR20 C-042009 HydroCAD-Proposed Conditions Drainage Calculations Type II 24-hr 5-Year Rainfa/1=6.20" Prepared by {enter your company name here} HydroCAD® 7.10 sin 003394 © 2005 HydroCAD Software Solutions LLC Subcatchment DA-P2: Post-Development P2 Runoff = 16.95 cfs@ 12.02 hrs, Volume= 0.998 af, Depth> 5.07" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Type 1124-hr 5-Year Rainfall=6.20" Area (ac) CN Description 2.360 93 Proposed-Development Conditions Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.9 Direct Entry, Proposed Conditions Subcatchment DA -P2: Post-Development P2 Hydrograph 18- 17 ~:, Type II 24-hr 5-Year 14~ Rainfall=6.20" 13 , Runoff Area=2.360 ac 12 ~ ~ 11 ·Runoff Volume=0.998 af ~ 10" ~ 9: Runoff Depth>S.07" ii: 8-: 1_ Tc=10.9 min : 5-: CN=93 5~ 4-: 3- 2.: 1-: I 16.95 cfs I ot....'......,......,.,........,.._,...._,~ .. •.•.--~.~.;:;:;;=.::::::;,;:::::::;::::::::;:;::::,_....,.......,._::;:=.~-:;:;::;:;;:;::;:;::;:::;:::;::;,~.;:::;:;:::;;:::::::;:::;:~ 0 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Page ? 412012009 I -Runoff~ Jaffer-TR20 C-042009 Prepared by {enter your company name here} HydroCAD-Proposed Conditions Drainage Calculations Type 1124-hr 10-Year Rainfal/=7.40" HydroCAD® 7.10 sin 003394 © 2005 HydroCAD Software Solutions LLC Page 8 4/20/2009 Time span=0.00-20.00 hrs, dt=0.05 hrs, 401 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-lnd+ Trans method -Pond routing by Stor-lnd method Subcatchment DA-P1: Post-Development P1 Subcatchment DA-P2: Post-Development P2 Runoff Area=1.250 ac Runoff Depth>6.32" Tc=10.9 min CN=94 Runoff=10.92 cfs 0.658 at Runoff Area=2.360 ac Runoff Depth>6.20" Tc=10.9 min CN=93 Runoff=20.45 cfs 1.220 at Total Runoff Area= 3.610 ac Runoff Volume= 1.878 af Average Runoff Depth= 6.24" Jaffer-TR20 C-042009 HydroCAD-Proposed Conditions Drainage Calculations Type II 24-hr 10-Year Rainfal/=7.40" Prepared by {enter your company name here} HydroCAD® 7.10 sin 003394 © 2005 HydroCAD Software Solutions LLC Subcatchment DA-P1: Post-Development P1 Runoff = 10.92 cfs@ 12.02 hrs, Volume= 0.658 af, Depth> 6.32" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=?.40" Area (ac) CN Description 1.250 94 Post-Development Conditions Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.9 12 11- 10 9 8 Direct Entry, Proposed Conditions Subcatchment DA-P1: Post-Development P1 Hydrograph Typell24-hr10-Year Rai nfall=7 .40" Runoff Area=1-.250 ac Runoff Volume=0.658 af Runoff Depth>6.32" Tc=10.9 min CN=94 Page9 4/20/2009 I -Runoff~ Jaffer-TR20 C-042009 HydroCAD-Proposed Conditions Drainage Calculations Type 1124-hr 10-Year Rainfal/=7.40" Prepared by {enter your company name here} HydroCAD® 7.10 sin 003394 © 2005 HydroCAD Software Solutions LLC Subcatchment DA-P2: Post-Development P2 Runoff = 20.45 cfs @ 12.02 hrs, Volume= 1.220 af, Depth> 6.20" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10-Year Rainfall=?.40" Area (ac) CN Description 2.360 93 Proposed-Development Conditions Tc Length Slope Velocity Capacity Description (min) (feet} (ft/ft) (ft/sec) (cfs) 10.9 22 21 20 19 18 17 16 15 14 ~ 13 ~ 12 ~ 11 u:: 10 9 8 7 6 5 4 3 2 Direct Entry, Proposed Conditions Subcatchment DA-P2: Post-Development P2 Hydrograph Type II 24-hr 10-Year Rainfall=7 .40" Runoff Area=2.360 ac Runoff Volume=1.220 af Runoff Depth>6.20" Tc=10.9 min CN=93 20.45 cfs 1~1~~..,........--"l'!~~;::;:;:::;:;:;::;:;:;.;:;:;::;:;:;:;:;::;::;:.:;::;:::.,.,.......,.........,.....;::;:;::;:;;::;:;;:;:;:;::;:;:;:;:;:;:;:;:;:;::;:;:;:;:;:;::I o"""' , 0 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Page 10 412012009 I -Runoff~ Jaffer-TR20 C-042009 Prepared by {enter your company name here} HydroCAD-Proposed Conditions Drainage Calculations Type II 24-hr 25-Year Rainfall=B.40" HydroCAD® 7 .10 sin 003394 © 2005 HydroCAD Software Solutions LLC Page 11 4/20/2009 Time span=0.00-20.00 hrs, dt=0.05 hrs, 401 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-lnd+ Trans method -Pond routing by Stor-lnd method Subcatchment DA-P1: Post-Development P1 Subcatchment DA-P2: Post-Development P2 Runoff Area=1 .250 ac Runoff Depth>7.26" Tc=10.9 min CN=94 Runoff=12.45 cfs 0.757 at Runoff Area=2.360 ac Runoff Depth>7.14" Tc=10.9 min CN=93 Runoff=23.36 cfs 1.405 af Total Runoff Area= 3.610 ac Runoff Volume= 2.161 af Average Runoff Depth= 7.18" Jaffer-TR20 C-042009 HydroCAD-Proposed Conditions Drainage Calculations Type II 24-hr 25-Year Rainfa/1=8.40" Prepared by {enter your company name here} HydroCAD® 7.10 sin 003394 © 2005 HydroCAD Software Solutions LLC Subcatchment DA-P1: Post-Development P1 Runoff = 12.45 cfs@ 12.02 hrs, Volume= 0.757 af, Depth> 7.26" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 25-Year Rainfall=8.40" Area (ac) CN Description 1.250 94 Post-Development Conditions Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.9 Direct Entry, Proposed Conditions Subcatchment DA-P1: Post-Development P1 Hydrograph 13 12 11 10- Type II 24-hr 25-Year Rainfall=B.40" 9~ Runoff Area=1.250 ac ~ 7 0 ii: 6 5 Runoff Volume=O. 757 af Runoff Depth>7.26" Tc=10.9 min 4_ CN=94 2 1- I 12.45 cfs I 0 •I " "I I •• "I• • • f • "I • I 0 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 nme (hours) Page 12 4/20/2009 I-Runoff~ Jaffer-TR20 C-042009 HydroCAD-Proposed Conditions Drainage Calculations Type II 24-hr 25-Year Rainfal/=8.40" Prepared by {enter your company name here} HydroCAD® 7 .1 O s/n 003394 © 2005 HydroCAD Software Solutions LLC Subcatchment DA-P2: Post-Development P2 Runoff = 23.36 cfs@ 12.02 hrs, Volume= 1.405 af, Depth> 7.14" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 25-Year Rainfall=8.40" Area (ac) CN Description 2.360 93 Proposed-Development Conditions Tc Length Slope Velocity Capacity Description (min) (feet) {ft/ft) (ft/sec) (cfs) 10.9 Direct Entry, Proposed Conditions Subcatchment DA-P2: Post-Development P2 Hydrograph 25...--~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 25~ 24.: 23 22-·Type II 24-hr 25-Year 21~ ~~~ Rainfall=8.40" 18 17 16 ti) 15 ~ 14 ;r; 13 0 12 u: 11 ; 10· Runoff Area=2.360 ac Runoff Volume=1.405 af Runoff Depth>7.14" Tc=10.9 min 9 . 0: CN=93 1 : 6 _ 5{ 4-' 3{ 2- I 23.36 cfs I ~ ~i: ....... .,..........,......_ ..... ~ .. ~--"""""'·~·~--~-~.~.~.;::::~.~.~-~ .. ~.: ....... .....,.. ........ ......::;::;:;:;:;:;:;:;:;;:;:::::;:;==~.::;::;:;::;::;~ 0 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Page 13 412012009 Jaffer-TR20 C-042009 Prepared by {enter your company name here} HydroCAD-Proposed Conditions Drainage Calculations Type II 24-hr 50-Year Rainfa/1=9. 80" HydroCAD® 7 .10 sin 003394 © 2005 HydroCAD Software Solutions LLC Page 14 412012009 Time span=0.00-20.00 hrs, dt=0.05 hrs, 401 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-lnd+ Trans method -Pond routing by Stor-lnd method Subcatchment DA-P1: Post-Development P1 Subcatchment DA-P2: Post-Development P2 Runoff Area=1.250 ac Runoff Depth>B.59" Tc=10.9 min CN=94 Runoff=14.59 cfs 0.894 af Runoff Area=2.360 ac Runoff Depth>8.46" Tc=10.9 min CN=93 Runoff=27.42 cfs 1.665 af Total Runoff Area= 3.610 ac Runoff Volume= 2.559 af Average Runoff Depth= 8.51" Jaffer-TR20 C-042009 HydroCAD-Proposed Conditions Drainage Calculations Type II 24-hr 50-Year Rainfa//=9.80" Prepared by {enter your company name here} HydroCAD® 7 .10 sin 003394 © 2005 HydroCAD Software Solutions LLC Subcatchment DA-P1: Post-Development P1 Runoff = 14.59 cfs@ 12.02 hrs, Volume= 0.894 af, Depth> 8.59" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 50-Year Rainfall=9.80" Area (ac) CN Description 1.250 94 Post-Development Conditions Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.9 Direct Entry, Proposed Conditions 16 15 Subcatchment DA-P1: Post-Development P1 Hydrograph 14.59 cfs ::. Type II 24-hr 50-Year 12 · Rainfall=9.80" 11 10 !!: 8 0 iL 7 Runoff Area=1.250 ac . . Runoff Volume=0.89.4 af Runoff Depth>S.59" Tc=10.9 min CN=94 ol......,., ....... ~ . .__..._~,.,.;;;;;;;;;=;;;;;;;:;,~.;::;:;:;:.~.~.;:::::;::;;::;:;;:;::;::;::;:::::;,...,.....,., ....... ,.:::;;:;:;:;:;::;:;:;:.~,;:;::;::;::;:;:;:;:::;:;:;::::;:.F .. ~ .. ~., 0 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Page 15 412012009 Jaffer-TR20 C-042009 HydroCAD-Proposed Conditions Drainage Calculations Type 1124-hr 50-Year Rainfal/=9.80" Prepared by {enter your company name here} HydroCAD® 7.10 s/n 003394 © 2005 HydroCAD Software Solutions LLC Subcatchment DA-P2: Post-Development P2 Runoff = 27.42 cfs@ 12.02 hrs, Volume= 1.665 af, Depth> 8.46" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 50-Year Rainfall=9.80" Area (ac) CN Description 2.360 93 Proposed-Development Conditions Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.9 Direct Entry, Proposed Conditions Subcatchment DA-P2: Post-Development P2 Hydrograph 30 28 25-Type II 24-hr 50-Year Rainfall=9.80" 24 22 20: Runoff Area=2.360 ac ~ 10-Runoff Volume=1.665 af ~ 16~ ~ : Runoff Depth>S.46" 0 14 u:: : 12: Tc=10.9 min 10: CN=93 8 6~ 4- 2 27.42 cfs ol-.. .......... ....,........,~..._~:;:p;:;:;;:;:;:;::;:;:;;:;::;:;:;::;:;;::::;:::::~~ .......... ~:;::::::;::;;;:;:;;:;:;::;::;:;:;:;:;:;::;:;:;:~ 0 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Page 16 412012009 I -Runoff~ Jaffer-TR20 C-042009 Prepared by {enter your company name here} HydroCAD-Proposed Conditions Drainage Calculations Type 1124-hr 100-Year Rainfa/1=11.00" HydroCAD® 7.10 sin 003394 © 2005 HydroCAD Software Solutions LLC Page 17 4/20/2009 Time span=0.00-20.00 hrs, dt=0.05 hrs, 401 points Runoff by SGS TR-20 method, UH=SCS Reach routing by Ster-Ind+ Trans method -Pond routing by Stor-lnd method Subcatchment DA-P1: Post-Development P1 Subcatchment DA-P2: Post-Development P2 Runoff Area=1.250 ac Runoff Depth>9. 72" Tc=10.9 min CN=94 Runoff=16.42 cfs 1.013 at Runoff Area=2.360 ac Runoff Depth>9.60" Tc=10.9 min CN=93 Runoff=30.88 cfs 1.888 at Total Runoff Area= 3.610 ac Runoff Volume= 2.901 af Average Runoff Depth= 9.64" Jaffer-TR20 C-042009 HydroCAD-Proposed Conditions Drainage Calculations Type 1124-hr 100-Year Rainfal/=11.00" Prepared by {enter your company name here} HydroCAD® 7.10 sin 003394 © 2005 HydroCAD Software Solutions LLC Subcatchment DA-P1: Post-Development P1 Runoff = 16.42 cfs@ 12.02 hrs, Volume= 1.013 af, Depth> 9. 72" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Type 1124-hr 100-Year Rainfall=11.00" Area (ac) CN Description 1.250 94 Post-Development Conditions Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.9 Direct Entry, Proposed Conditions Subcatchment DA-P1: Post-Development P1 Hydrograph 1s- 17c 16 15 14 13 Type II 24-hr 100-Year Rainfall=11.00" 12 Runoff Area=1.250 ac ~ 11 -Runoff Volume=1.013 af ~ 10 . ~ 9 · Runoff Depth>9.72" ii: 8- 7 · Tc=10.9 min 5 · CN=94 5 4 3 2~ 1 I 16.42 cfs I ol· ....... .,......,.._..._,~.""""'!.~:;::;:;:;::;::;::;:::;:;:;::;:;:;:;:~.~.:;::;:;::.,;:::::;.;,:::.~ ........ ~.---,....::;::;::;:;;:;::;:;::;:;:;:;:;::;:;:;:;:;:;:;:;:;:;:;,:;:;:;:J 0 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Page 18 4/20/2009 1-Runottj Jaffer-TR20 C-042009 HydroCAD-Proposed Conditions Drainage Calculations Type 1124-hr 100-Year Rainfal/=1 1.00" Prepared by {enter your company name here} HydroCAD® 7 .1 O sin 003394 © 2005 HydroCAD Software Solutions LLC Subcatchment DA-P2: Post-Development P2 Runoff = 30.88 cfs@ 12.02 hrs, Volume= 1.888 af, Depth> 9.60" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Type 1124-hr 100-Year Rainfall=11 .00" Area (ac) CN Description 2.360 93 Proposed-Development Conditions Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.9 Direct Entry, Proposed Conditions Subcatchment DA-P2: Post-Development P2 Hydrograph I 30.88 cfs I 34 : 32 . 30 28_ Type II 24-hr 100-Year 26-Rainfall=11.00" 24-R u n off Area=2.360 ac 22 c;;-20: Runoff Volume=1.888 af :§. 18 ~ 16 Runoff Depth>9.60" u:: 14-Tc=10.9 min 12 10 8 6 4 2. CN=93 04.-......,..........,.,_.._.~. ~ .. ~.;;:=;:;::;:;.~.~-;:;::;::::;;:::;.~.=::.;:::..,....,. ....... ........,,....::;:;:::;:;:::;:;:;:::;::;::;:;:;:::;::;:;:;:::;::::J 0 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Page 19 4/20/2009 1-Runoffj Section 4.0 DETENTION FACILITY & ROUTING HydroCAD -Proposed Conditions Pond Calculations -Pond 1 Jaffer-TR20 E-091409 Type II 24-hr 2-Year Rainfal/=4.50" Prepared by {enter your company name here} HydroCAD® 7.10 s/n 003394 © 2005 HydroCAD Software Solutions LLC Inflow Area= Inflow = Pond P1: Pond 1 for 2-Year event 0.374 af Page 1 9/14/2009 Outflow = Primary = 1.250 ac, Inflow Depth> 3.59" 6.43 cfs@ 12.02 hrs, Volume= 1.62 cfs @ 12.25 hrs, Volume= 1.62 cfs @ 12.25 hrs, Volume= 0.344 af, Atten= 75%, Lag= 13.8 min 0.344 af Routing by Stor-lnd method, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 309.46'@ 12.25 hrs Surf.Area= 4,203 sf Storage= 7 ,663 cf Plug-Flow detention time= 113.1 min calculated for 0.343 af (92% of inflow) Center-of-Mass det. time=83.6 min ( 827.8 -744.2) Volume Invert Avail.Storage Storage Description #1 306.83' 19,987 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation (feet) Surf.Area (sq-ft) Inc.Store (cubic-feet) Cum.Store (cubic-feet) 306.83 308.00 309.00 310.00 311 .00 312.00 Device Routing #1 Primary #2 Primary 0 3,502 3,975 4,472 4,981 5,519 0 2,049 3,739 4,224 4,727 5,250 Invert Outlet Devices 0 2,049 5,787 10,011 14,737 19,987 306.83' Custom Weir/Orifice, C= 2.62 Head (feet) 0.00 3.17 3.17 4.67 Width (feet) 0.00 0.35 1.00 1.00 311 .50' 2.00' x 2.00' Horiz. Orifice/Grate Limited to weir flow C= 0.600 Primary OutFlow Max=1 .62 cfs@ 12.25 hrs HW=309.46' (Free Discharge) t1=Custom Weir/Orifice (Weir Controls 1.62 cfs@ 4.2 fps) 2=0rifice/Grate (Controls 0.00 cfs) HydroCAD -Proposed Conditions Pond Calculations -Pond 1 Jaffer-TR20 E-091409 Type II 24-hr 2-Year Rainfa//=4. 50" Prepared by {enter your company name here} HydroCAD® 7.10 s/n 003394 © 2005 HydroCAD Software Solutions LLC Page 2 9/14/2009 7 6 5 2 0 311 ~ 310 ~ c 0 ~ 309 iii 0 308 0 Pond P1: Pond 1 Hydrograph 6.43 cfs Inflow Area=1.250 ac Peak Elev~309.46' Storage=7 ,663 cf 2 3 4 5 6 7 8 9 10 11 12 13 Time (hours) Pond P1 : Pond 1 Stage-Area-Storage Surface/Horizontal/Wetted Area (sq-ft) 500 1,000 1,500 2,000 2.500 3,000 3,500 2,000 4,000 6,000 8.000 1 o.ooo 12,000 Storage (cubic-feet) -Inflow -Primary 14 15 16 17 18 19 20 4,000 4,500 5,000 5,500 -Surface -Storage 14.000 16,000 18,000 HydroCAD -Proposed Conditions Pond Calculations -Pond 1 Jaffer-TR20 E-091409 Type II 24-hr 5-Year Rainfal/=6. 20" Prepared by {enter your company name here} HydroCAD® 7.10 s/n 003394 © 2005 HydroCAD Software Solutions LLC Inflow Area= Inflow = Pond P1: Pond 1 for 5-Year event 0.540 af Page 3 9/14/2009 Outflow = Primary = 1.250 ac, Inflow Depth > 5.19" 9.07 cfs @ 12.02 hrs, Volume= 2.82 cfs@ 12.21 hrs, Volume= 2.82 cfs@ 12.21 hrs, Volume= 0.503 af, Atten= 69%, Lag= 11 .8 min 0.503 af Routing by Stor-lnd method, Time Span= 0.00-20.00 hrs, dt= 0.05 .hrs Peak Elev= 310.08'@ 12.21 hrs Surf.Area= 4,515 sf Storage= 10,389 cf Plug-Flow detention time= 101 .2 min calculated for 0.502 af (93% of inflow) Center-of-Mass det. time=74.9 min ( 810.8 -735.9) Volume Invert Avail.Storage Storage Description #1 306.83' 19,987 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation (feet) Surf.Area (sq-ft) Inc.Store (cubic-feet) Cum.Store (cubic-feet) 306.83 308.00 309.00 310.00 311 .00 312.00 Device Routing #1 Primary #2 Primary 0 3,502 3,975 4,472 4,981 5,519 0 2,049 3,739 4,224 4,727 5,250 Invert Outlet Devices 0 2,049 5,787 10,011 14,737 19,987 306.83' Custom Weir/Orifice, C= 2.62 Head (feet) 0.00 3.17 3.17 4.67 Width (feet) 0.00 0.35 1.00 1.00 311 .50' 2.00' x 2.00' Horiz. Orifice/Grate Limited to weir flow C= 0.600 Primary OutFlow Max=2.80 cfs@ 12.21 hrs HW=310.08' (Free Discharge) t1=Custom Weir/Orifice (Weir Controls 2.80 cfs@ 4.4 fps) 2=0rifice/Grate (Controls 0.00 cfs) HydroCAD -Proposed Conditions Pond Calculations -Pond 1 Jaffer-TR20 E-091409 Type II 24-hr 5-Year Rainfal/=6.20" Prepared by {enter your company name here} HydroCAD® 7 .10 sin 003394 © 2005 HydroCAD Software Solutions LLC Page4 9/14/2009 10 9 8 7 6 4 3 2 0 0 311 ::-310 ! c .Q ~ .. 309 iii 308 0 Pond P1: Pond 1 Hydrograph 9.07 cfs Inflow Area=1.250 ac Peak Elev=310.08' Storage=10,389 cf 2.82 cfs 2 3 4 5 6 7 8 9 10 11 12 13 Time (hours) Pond P1: Pond 1 Stage-Area-Storage Surface/Horizontal/Wetted Area (sq-ft) 500 1,000 1,500 2,000 2,500 3,000 3,500 2,000 4,000 6,000 8,000 10,000 12,000 Storage (cubic-feet) -Inflow -Primary 14 15 16 17 18 19 20 4,000 4,500 5,000 5,500 -Surface -Storage 14,000 16,000 18,000 HydroCAD -Proposed Conditions Pond Calculations -Pond 1 Jaffer-TR20 E-091409 Type II 24-hr 10-Year Rainfal/=7.40" Prepared by {enter your company name here} HydroCAD® 7.10 s/n 003394 © 2005 HydroCAD Software Solutions LLC Inflow Area= Inflow = Outflow = Primary = Pond P1: Pond 1 1.250 ac, Inflow Depth > 6.32" for 10.92 cfs@ 12.02 hrs, Volume= 4.14 cfs @ 12.19 hrs, Volume= 4.14 cfs@ 12.19 hrs, Volume= 10-Year event 0.658 af 0.616 af, Atten= 62%, 0.616 af Routing by Stor-lnd method, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 310.43'@ 12.19 hrs Surf.Area= 4,691 sf Storage= 11 ,983 cf Plug-Flow detention time=94.6 min calculated for 0.616 af (94% of inflow) Center-of-Mass det. time= 69.6 min ( 801 .2 -731.6) Volume Invert Avail.Storage Storage Description Page 5 9/14/2009 Lag= 10.2 min #1 306.83' 19,987 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation (feet) 306.83 308.00 309.00 310.00 311.00 312.00 Device Routing #1 Primary #2 Primary Surf.Area (sq-ft) 0 3,502 3,975 4,472 4,981 5,519 Inc.Store (cubic-feet) 0 2,049 3,739 4,224 4,727 5,250 Invert Outlet Devices Cum.Store (cubic-feet) 0 2,049 5,787 10,011 14,737 19,987 306.83' Custom Weir/Orifice, C= 2.62 Head (feet) 0.00 3.17 3.17 4.67 Width (feet) 0.00 0.35 1.00 1.00 311.50' 2.00' x 2.00' Horiz. Orifice/Grate Limited to weir flow C= 0.600 Primary OutFlow Max=4.12 cfs@ 12.19 hrs HW=310.43' (Free Discharge) t1=Custom Weir/Orifice (Weir Controls 4.12 cfs@4.2 fps) 2=0rifice/Grate (Controls 0.00 cfs) HydroCAD -Proposed Conditions Pond Calculations -Pond 1 Jaffer-TR20 E-091409 Type II 24-hr 10-Year Rainfal/=7.40" Prepared by {enter your company name here} HydroCAD® 7.10 s/n 003394 © 2005 HydroCAD Software Solutions LLC Page6 9/14/2009 12 11 10 9 8 3: 6 0 ii: 5 4 3 2 0 0 311 ~ 310 ~ c: .2 ~ GI 309 iii 308 0 Pond P1: Pond 1 Hydrograph Inflow Area=1.250 ac Peak Elev=310.43' Storage=11,983 cf 2 3 4 5 6 7 8 9 10 11 12 13 Time (hours) Pond P1: Pond 1 Stage-Area-Storage Surface/Horizontal/Wetted Area (sq-ft) 500 1,000 1,500 2,000 2,500 3,000 3,500 2,000 4,000 6,000 8,000 10,000 12,000 Storage (cubic-feet) -Inflow -Primary 14 15 16 17 18 19 20 4,500 5,000 5,500 -Surface -Storage 14,000 16,000 18,000 HydroCAD -Proposed Conditions Pond Calculations -Pond 1 Jaffer-TR20 E-091409 Type II 24-hr 25-Year Rainfal/=8.40" Prepared by {enter your company name here} HydroCAD® 7 .1 O s/n 003394 © 2005 HydroCAD Software Solutions LLC Inflow Area= Inflow = Pond P1: Pond 1 for 25-Year event 0.757 af Page 7 9/14/2009 Outflow = Primary = 1.250 ac, Inflow Depth> 7.26" 12.45 cfs @ 12.02 hrs, Volume= 5.38 cfs @ 12.17 hrs, Volume= 5.38 cfs @ 12.17 hrs, Volume= 0.711 af, Atten= 57%, Lag= 9.2 min 0.711 af Routing by Stor-lnd method, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 310.69'@ 12.17 hrs Surf.Area= 4,821 sf Storage= 13,200 cf Plug-Flow detention time=89.5 min calculated for 0.709 af (94% of inflow) Center-of-Mass det. time= 65.8 min ( 794.5 -728.8 ) Volume Invert Avail.Storage Storage Description #1 306 .83' 19,987 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store {feet} {sg-ft} {cubic-feet} {cubic-feet} 306.83 0 0 0 308.00 3,502 2,049 2,049 309.00 3,975 3,739 5,787 310.00 4,472 4,224 10,011 311 .00 4,981 4,727 14,737 312.00 5,519 5,250 19,987 Device Routing Invert Outlet Devices #1 Primary 306.83' Custom Weir/Orifice, C= 2.62 Head (feet) 0.00 3.17 3.17 4.67 Width (feet) 0.00 0.35 1.00 1.00 #2 Primary 311 .50' 2.00' x 2.00' Horiz. Orifice/Grate Limited to weir flow Primary OutFlow Max=5.31 cfs@ 12.17 hrs HW=310.67' (Free Discharge) t1=Custom Weir/Orifice (Weir Controls 5.31 cfs@ 4.3 fps) 2=0rifice/Grate (Controls 0.00 cfs) C= 0.600 HydroCAD -Proposed Conditions Pond Calculations -Pond 1 Jaffer-TR20 E-091409 Type II 24-hr 25-Year Rainfall=B.40" Prepared by {enter your company name here} HydroCAD® 7.10 sin 003394 © 2005 HydroCAD Software Solutions LLC Page8 9/14/2009 312 311 c: ,g .. it 309 jjj 308 0 0 Pond P1: Pond 1 Hydrograph 12.45 cfs Inflow Area=1.250 ac Peak Elev=310.69' Storage=13,200 cf 5.38 cfs 2 3 4 5 6 7 8 9 10 11 12 13 Time (hours) Pond P1 : Pond 1 Stage-Area-Storage Surface/Horizontal/Wetted Area (sq-ft) 500 1,000 1,500 2,000 2,500 3,000 3,500 2,000 4,000 6,000 8,000 10,000 12,000 Storage (cubic-feet) -Inflow -Primary 14 15 16 17 18 19 20 4,000 4,500 5,000 5,500 -Surface -Storage 14,000 16,000 18,000 HydroCAD -Proposed Conditions Pond Calculations -Pond 1 Jaffer-TR20 E-091409 Type II 24-hr 50-Year Rainfal/=9. 80" Prepared by {enter your company name here} HydroCAD® 7 .10 s/n 003394 © 2005 HydroCAD Software Solutions LLC Inflow Area = Inflow = Pond P1: Pond 1 for 50-Year event 0.894 af Page 9 9/14/2009 Outflow = Primary = 1.250 ac, Inflow Depth> 8.59" 14.59 cfs@ 12.02 hrs, Volume= 7.09 cfs@ 12.16 hrs, Volume= 7.09 cfs@ 12.16 hrs, Volume= 0.844 af, Atten= 51 %, Lag= 8.4 min 0.844 af Routing by Stor-lnd method, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 311 .00'@ 12.16 hrs Surf.Area= 4,979 sf Storage= 14,716 cf Plug-Flow detention time=83.8 min calculated for 0.842 af (94% of inflow) Center-of-Mass det. time= 61 .4 min ( 786.8 -725.5 ) Volume Invert Avail.Storage Storage Description #1 306.83' 19,987 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation (feet) Surf.Area (sq-ft) Inc.Store (cubic-feet) Cum.Store (cubic-feet) 306.83 308.00 309.00 310.00 311 .00 312.00 Device Routing #1 Primary #2 Primary 0 3,502 3,975 4,472 4,981 5,519 0 2,049 3,739 4,224 4,727 5,250 Invert Outlet Devices 0 2,049 5,787 10,011 14,737 19,987 306.83' Custom Weir/Orifice, C= 2.62 Head (feet) 0.00 3.17 3.17 4.67 Width (feet) 0.00 0.35 1.00 1.00 311 .50' 2.00' x 2.00' Horiz. Orifice/Grate Limited to weir flow C= 0.600 Primary OutFlow Max=7.05 cfs@ 12.16 hrs HW=310.99' (Free Discharge) t1=Custom Weir/Orifice (Weir Controls 7.05 cfs@ 4.6 fps) 2=0rifice/Grate (Controls 0.00 cfs) HydroCAD -Proposed Conditions Pond Calculations -Pond 1 Jaffer-TR20 E-091409 Type II 24-hr 50-Year Rainfal/=9. 80" Prepared by {enter your company name here} HydroCAD® 7.10 s/n 003394 © 2005 HydroCAD Software Solutions LLC 16 15 14 13 12 11 Pond P1: Pond 1 Hydrograph Inflow Area=1.250 ac Peak Elev=311.00' 10 Storage=14,716 cf ~ 9 3: 8 0 ii: 7 o!...._......,..,.,_~~-.....,.Mllll~~~~:;;=::~.....,.:::::;:::;:;;;:~;;:=;==:;:::;==;=;:;:I 0 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 Time (hours) Pond P1: Pond 1 Stage-Area-Storage Surface/Horizontal/Wetted Area (sq-ft) Page 10 9/14/2009 -Inflow -Primary 500 1,000 1,500 2,000 2,500 3,000 3,500 4,500 5,000 5,500 -Surface c: 0 :;::; .. 311 ~ 309 w 308 _._ .......... _._...._ .......... _._...._ .......... __._...._ ......... __._...._..._.__._...._..._.__._...._..._.__._...._ ......... __._...._.._.__._...._.._.__._ ....... .._."""'"'::~ -Storage 0 2,000 4,000 6,000 8,000 10,000 12,000 14,000 16,000 18,000 Storage (cubic-feet) HydroCAD -Proposed Conditions Pond Calculations -Pond 1 Jaffer-TR20 E-091409 Type II 24-hr 100-Year Rainfa/1=11 .00" Prepared by {enter your company name here} HydroCAD® 7 .10 sin 003394 © 2005 HydroCAD Software Solutions LLC Inflow Area= Inflow = Pond P1: Pond 1 for 100-Year event 1.013af Page 11 9/14/2009 Outflow = Primary = 1.250 ac, Inflow Depth > 9. 72" 16.42 cfs @ 12.02 hrs, Volume= 8.57 cfs @ 12.15 hrs, Volume= 8.57 cfs @ 12.15 hrs, Volume= 0.959 af, Atten= 48%, Lag= 7.9 min 0.959 af Routing by Stor-lnd method, Time Span= 0.00-20.00 hrs, dt= 0.05 hrs Peak Elev= 311.23'@ 12.15 hrs Surf.Area= 5,107 sf Storage= 15,921 cf Plug-Flow detention time=79.9 min calculated for 0.956 af (94% of inflow) Center-of-Mass det. time= 58 .3 min ( 781.4 -723.1 ) Volume Invert Avail.Storage Storage Description #1 306.83' 19,987 cf Custom Stage Data (Prismatic) Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store {feet} {sg-ft} {cubic-feet} {cubic-feet} 306.83 0 0 0 308.00 3,502 2,049 2,049 309.00 3,975 3,739 5,787 310.00 4,472 4,224 10,011 311 .00 4,981 4,727 14,737 312.00 5,519 5,250 19,987 Device Routing Invert Outlet Devices #1 Primary 306.83' Custom Weir/Orifice, C= 2.62 Head (feet) 0.00 3.17 3.17 4.67 Width (feet) 0.00 0.35 1.00 1.00 #2 Primary 311.50' 2.00' x 2.00' Horiz. Orifice/Grate Limited to weir flow Primary OutFlow Max=B.56 cfs@ 12.15 hrs HW=311 .23' (Free Discharge) t1=Custom Weir/Orifice (Weir Controls 8.56 cfs@ 4.8 fps) 2=0rifice/Grate (Controls 0.00 cfs) C= 0.600 HydroCAD -Proposed Conditions Pond Calculations -Pond 1 Jaffer-TR20 E-091409 Type II 24-hr 100-Year Rainfal/=11.00" Prepared by {enter your company name here} HydroCAD® 7 .10 s/n 003394 © 2005 HydroCAD Software Solutions LLC Page 12 9/14/2009 18 17 16 15 14 12 11 i 10 .e :t: 9 0 ii: 8 7 6 5 4 3 2 312 311 :; 310 ~ c .!2 ~ Cl> 309 w 308 0 0 Pond P1: Pond 1 Hydrograph Inflow Area=1.250 ac Pea k Elev=311 .23' Storage=15,921 cf 2 3 4 5 6 7 8 9 10 11 12 13 Time (hours) Pond P1: Pond 1 Stage-Area-Storage Surface/Horizontal/Wetted Area (sq-ft) 500 1,000 1,500 2,000 2,500 3,000 3,500 2,000 4,000 6,000 8,000 10,000 12,000 Storage (cubic-feet) -Inflow -Primary 14 15 16 17 18 19 20 4,000 4,500 5,000 5,500 -Surface -Storage 14,000 16,000 18,000 Section 5.0 STORM DRAINAGE SYSTEM stmOutput.txt WinStorm (STORM DRAIN DESIGN) PROJECT NAME : 220 JOB NUMBER 0321 PROJECT DESCRIPTION : Park Place-System A DESIGN FREQUENCY ANALYSYS FREQUENCY MEASUREMENT UNITS: 10 Years 100 Years ENGLISH OUTPUT FOR DESIGN FREQUENCY of: 10 Years =========================================== Runoff Computation for Design Frequency. Version 3.05, Jan. 25 , 2002 Run @ 9/14/2009 11:14:04 AM ============================================================================= ID C Value A-1 0.96 A-2 0.7 A-3 0.75 A-4 0.96 A-5 0.0 Area (acre) 0.26 7.08 0.81 0.22 0 .00 Tc (min) 10 .00 31.63 10 .00 10.00 10 .00 On Grade Inlet Configuration Data Tc Used (min) 10 .00 31 .63 10 .00 10.00 10.00 Intensity (in/hr) 8 .63 4 .78 8 .63 8 .63 0 .00 Supply Q (cfs) 0 .000 0 .000 0 .000 0 .000 8 .570 Total Q (cfs) 2 .114 23.711 5.213 1 .782 8.570 =============================================================================== Inlet ID A-3 A-4 Inlet Type Curb Curb Inlet Slopes Gutter Length Long Trans n Depr. (ft) ( % ) ( % ) (ft) 15 .00 4.45 3.00 0.014 0 .33 10 .00 4 .45 3 .00 0.014 0.33 On Grade Inlets Conmputation Data. Grate Width Type (ft) n/a n/a n/a n/a Pond Width Allowed (ft) 12.00 12 .00 Critic Elev. (ft) 303 .08 304 .28 ================================================================================= Inlet ID A-3 A-4 Inlet Type Curb Curb Total Q (cfs) 5.213 1.782 Intercept Capacity (cfs) 4 .967 1 .765 Sag Inlets Configuration Data. Q Bypass Allow Actual (cfs) (cfs) 5.000 5 .000 0.246 0 .017 To Inlet Required ID Length A-2 A-2 (ft) 18.36 10 .81 Actual Length (ft) 15 .00 10.00 Ponded Width (ft) 7.47 5.00 ================================================================================== Page 1 stmOutput.txt Inlet Inlet Length/ Grate Left-Slope Right-Slope Gutter Depth Critic ID Type Perim. Area Long Trans Long Trans n DeprW Allowed Elev. (ft) (sf) ( % ) ( % ) ( % ) ( % ) (ft) (ft) (ft) ---------------------------------------------------------------------------------- A-1 Curb 10.00 n/a 0 .7 5 3 .00 0.75 3 .00 0.014 2 .00 0 .50 301.04 A-2 Curb 10.00 n/a 0 .75 3 .00 0.75 3 .00 0.014 0.00 0 .50 300.54 Sag Inlets Computation Data . ================================================================================ Inlet Inlet ID Type A-1 A-2 Curb Curb Length Grate Perim Area (ft) (ft) (sf) 10.00 10 .00 n/a n/a n/a n/a Total Q Inlet Capacity (cfs) (cfs) 2 .114 23.9 74 11 .059 13.436 Cumulative Junction Discharge Computations Total Head (ft) 0 .166 1. 046 Ponded Width Left Right (ft) (ft) 5.73 11 .77 5 .73 16.17 ================================================================================= Node Node Weighted Cumulat . Cumulat . Intens. User Additional Total I. D. Type C-Value Dr.Area Tc Supply Q Q in Node Disch. (acres) (min) (in/hr) cfs) (cfs) (cfs ) --------------------------------------------------------------------------------- OUT l CircMh 0.719 8 .36 31.68 4 .78 8 .570 0.00 37 .301 A-1 Curb 0.719 8 .36 31 .68 4 .7 8 8 .570 0.00 37 .301 A-2 Curb 0.712 8 .10 31 .63 4.78 8 .570 0.00 36.156 A-3 Curb 0.794 1. 02 10 .11 8 .60 8.570 0.00 15 .5 33 A-4 Curb 0.960 0 .22 10.00 8.63 0.000 0.00 1 .782 A-5 CircMh 0.000 0 .00 0 .00 0.00 8.570 0.00 8 .570 Jl JnctBx 0.719 8 .36 31 .68 4 .7 8 8 .570 0 .00 37 .301 J2 JnctBx 0.000 0 .00 10 .00 8.63 8.570 0.00 8 .570 Conveyance Configuration Data ================================================================================== Run# Node I. D. Flowline Elev. US OS US OS (ft) (ft) 1 Jl OUTl 293 .03 292 .47 2 A-1 Jl 295 .25 293.13 3 A-2 A-1 295.98 295 .35 4 A-3 A-2 298.45 296 .75 5 A-4 A-3 300.08 298 .88 6 J2 A-3 305 .02 298 .88 7 A-5 J2 307 .03 305.12 Shape # Circ 1 Circ 1 Circ 1 Circ 1 Circ 1 Circ 1 Circ 1 Page 2 Span (ft) 0 .00 0.00 0 .00 0 .00 0 .00 0 .00 0 .00 Rise (ft) 2 .50 2 .50 2.50 1. 73 1. 30 1. 30 1. 30 Length (ft) 34 .91 105.75 33 .7 2 55.87 43.12 177.84 129.00 Slope ( % ) 1. 60 2 .01 1. 87 3 .04 2 .78 3 .4 5 1. 48 n value 0 .012 0.012 0.013 0 .012 0 .013 0 .012 0.012 stmOutput .txt Conveyance Hydraulic Computations . Tailwater = 294.951 (ft) ================================================================================== Hydraulic Gradeline Depth Velocity June Run# us Elev OS Elev Fr .Slope Unif. Actual Unif . Actual Q Cap Loss (ft) (ft) ( % ) (ft) (ft) (f/s) (f/s) (cfs) (cfs) (ft) ---------------------------------------------------------------------------------- 1* 295 .20 294 .95 0 .704 1. 48 2 .48 12.28 7 .61 37 .30 56.29 0.000 2* 296.71 295 .20 0 .704 1. 39 2.07 13 .34 8.59 37 .30 62 .93 0.000 3* 297 .44 296.81 0.777 1. 46 1. 46 12 .15 12 .15 36.16 56 .08 0.000 4* 299 .35 297 .65 0.870 0 .90 0 .90 12 .56 12.56 15.53 29.05 0.000 5* 300 .42 299 .35 0 .062 0 .34 0 .47 6.47 4 .10 1. 78 11. 97 0 .000 6* 305 .74 299 .60 1 .216 0 .72 0 .72 11. 34 11 .34 8 .57 14 .44 0 .000 7* 308 .00 306 .09 1 .216 0.97 0 .97 8 .07 8 .07 8 .57 9 .46 0 .000 ================================================================================== OUTPUT FOR ANALYSYS FREQUE NCY of : 100 Years Runoff Computation for Analysis Frequency. ============================================================================= ID C Value A-1 0.96 A-2 0 .7 A-3 0.75 A-4 0.96 A-5 0.0 Area (acre) 0 .26 7.08 0.81 0 .22 0 .00 Tc (min) 10.00 31. 63 10 .00 10 .00 10.00 Tc Used (min) 10 .00 31.63 10.00 10.00 10.00 Intensity (in/hr) 11 .64 6.54 11. 64 11 .64 0 .00 Supply Q (cfs) 0 .000 0 .000 0 .000 0.000 8.570 Total Q (cfs) 2.849 32 .436 7 .027 2 .402 8.570 On Grade Inlet Configuration Data =============================================================================== Inlet ID A-3 A-4 Inlet Type Curb Curb Inlet Slopes Gutter Length Long Trans n Depr. (ft) ( % ) ( % ) (ft) 15 .00 4 .45 3.00 0.014 0.33 10 .00 4 .45 3.00 0.014 0 .33 On Grade Inlets Conmputation Da ta. Grate Width Type (ft) n/a n/a n/a n/a Pond Width Allowed (ft) 12.00 12.00 Critic Elev . (ft) 303 .08 304 .28 ================================================================================= Inlet ID A-3 Inlet Type Curb Total Q (cfs) 7 .027 Intercept Capacity (cfs) 6 .213 Q Bypass Allow Actual (cfs) (cfs) 5 .000 0 .814 Page 3 To Inlet Required ID Length (ft) A-2 21 .49 Actual Length (ft) 15.00 Ponded Wi dth (ft) 8 .37 stmOutput .txt A-4 Curb 2 .402 2.272 5 .000 0 .130 A-2 12.47 10 .00 5 .60 Sag Inlets Configuration Data . ================================================================================== Inlet Inlet Length/ Grat e ID Type Perim. Area (ft) (sf) Left-Slope Long Trans ( % ) ( % ) Right-Slope Long Trans ( % ) ( % ) Gutter n DeprW (ft) Depth Allowed (ft) Critic Elev. (ft ) A-1 A-2 Curb 10 .00 Curb 10.00 n/a n/a 0 .7 5 3 .00 0 .7 5 3.00 0.75 3 .00 0 .014 2 .00 0 .75 3 .00 0.014 0 .00 0.50 0 .50 301.04 300 .54 Sag Inlets Computation Data. Inlet Inlet ID Type A-1 A-2 Curb Curb Length Grate Perim Area (ft) (ft) (sf) 10.00 10.00 n/a n/a n /a n/a Total Q Inlet Capacity (cfs) (cfs) 2 .849 33.380 11 .059 13 .436 Cumulative Junction Discharge Computations Total Head (ft) 0 .202 1 .793 Ponded Width Left Right (ft) (ft) 6 .40 13 .33 6 .40 18 .30 ================================================================================= Node Node Weighted Cumulat . Cumulat . Intens . User Additional Total I. D. Type C-Value Dr.Area Tc Supply Q Q in Node Disch. (acres) (min) (in/hr) cfs) (cfs) (cfs) --------------------------------------------------------------------------------- OUTl CircMh 0.719 8 .36 31 .67 6.54 8.570 0 .00 47 .876 A-1 Curb 0 .719 8.36 31 .67 6.54 8 .570 0 .00 47.876 A-2 Curb 0 .712 8.10 31 .63 6 .54 8 .570 0 .00 46.30 6 A-3 Curb 0 .794 1. 02 10.10 11 . 59 8.570 0 .00 17.961 A-4 Curb 0.960 0 .22 10 .00 11 . 64 0 .000 0 .00 2 .402 A-5 CircMh 0.000 0 .00 0 .00 0.00 8.570 0.00 8.570 Jl JnctBx 0 .71 9 8 .36 31 .67 6.54 8 .570 0 .00 47.876 J2 JnctBx 0 .000 0 .00 10 .00 11 .64 8 .570 0.00 8 .570 Conveyance Configuration Data ================================================================================== Run# Node I .D. Flowline Elev. US OS US OS (ft) (ft) 1 Jl OUTl 293 .03 292 .47 2 A-1 Jl 295 .25 293 .13 3 A-2 A-1 295 .98 295 .35 4 A-3 A-2 298 .45 296 .75 5 A-4 A-3 300 .08 298 .88 Shape # Circ 1 Circ 1 Circ 1 Circ 1 Circ 1 Page 4 Span (ft) 0 .00 0.00 0 .00 0.00 0.00 Rise (ft) 2.50 2.50 2 .50 1. 73 1. 30 Length (ft) 34.91 105.75 33 .72 55 .87 43 .12 Slope ( % ) 1. 60 2.01 1. 87 3 .04 2 .78 n value 0.012 0.012 0 .013 0.012 0 . 013 6 7 J2 A-5 A-3 J2 305 .02 307.03 stmOutput .txt 298 .88 305.12 Circ 1 0.00 1.30 Circ 1 0.00 1.30 Conveyance Hydraulic Computations. Tailwater = 295 .327 (ft) 177.84 129.00 3.45 1. 48 0.012 0.012 ================================================================================== Hydraulic Gradeline Depth Run# US Elev OS Elev Fr.Slope Unif . Actual (ft) (ft) ( % ) (ft) (ft) l* 295 .73 295.33 1.161 1. 77 2 .50 2* 297.52 295.73 1.161 1. 63 2 .50 3* 297.89 297.52 1 .274 1. 73 2.17 4* 299 .48 297.89 1.164 0 .98 1.14 5* 300.48 299.48 0.112 0 .39 0.60 6* 305 .74 299.60 1.216 0 .72 0.72 7* 308.00 306.09 1.216 0.97 0.97 Velocity Unif. Actual (f/s) (f/s) 12.90 9.75 14.12 9 .75 12 .79 10.23 13 .02 10.97 7 .05 4 .02 11.34 11 .34 8 .07 8 .07 Q (cfs) 47.88 47.88 46.31 17.96 2.40 8.57 8.57 Cap (cfs) 56 .29 62 .93 56.08 29.05 11 .97 14 .44 9.46 June Loss (ft) 0.000 0.000 0.000 0.000 0.000 0 .000 0.000 ===================================END============================================ * Super critical flow. NORMAL TERMINATION OF WINSTORM. Warning Messages for current project: Runoff Frequency of: 10 Years Capacity of grade inlet exceeded at inlet Id= A-3 Capacity of grade inlet exceeded at inlet Id= A-4 Total flow is <= then allowable carryover flow at inlet Id= A-4 A minimum drain size was assigned to this inlet . Computed right ponded width exceeds allowable width at inlet Id= A-2 Capacity of sag inlet exceeded at inlet Id= A-2 Discharge decreased downstream node Id= Jl Previous intensity used. Runoff Frequency of: 100 Years Capacity of grade inlet exceeded at inlet Id= A-3 Capacity of grade inlet exceeded at inlet Id= A-4 Total flow is <= then allowable carryover flow at inlet Id= A-4 A minimum drain size was assigned to this inlet . Computed right ponded width exceeds allowable width at inlet Id= A-2 Computed left ponded width exceeds allowable width at inlet Id= A-2 Capacity of sag inlet exceeded at inlet Id= A-2 Discharge decreased downstream node Id= Jl Previous intensity used . Page 5 SECTION IX APPENDIX D -TECHNIGAL DESIGN SUMMARY Engineering Firm Name and Address: ~'urisdiction 'f?.fY1£ (Ol-SbJ~ /tr.fC?r ~€:rt N~ City: Bryan ro . ~Yi qzs;;:g, V College Station Cot...r...~ $71r7to,..S, IX. 778'-I Z Date of Submittal: Lead Engineer's Name and Confct lnfo.(phone, e-mail, fax): Other: 1<!AfboN A. N'le-rc.Ac.,F; .£. 97' -6''70-03-z.·7 '1?Af!:::Ja.J rs l!..M~E:E./Z.. c~ Supporting Engineering I Consulting Firm(s): Other contacts: Developer I Owner I Applicant lnfc1rmation Developer I Applicant Name and Address: Phone and e-mail: AL--:r: -:flt FF (2¥_ Av A:rr tn~) 3rv-1g33 S'lZ.. 7 ~r.,eff,..-ZO/'ID l21 Zo'Z. ~ l 7k. 7520 (p Property Owner(s) if not Developer I Applicant (&address): Phone and e-mail: 711/VfP- Project Identification Development Name: r;s. /(.A f'CfflN?/<:.J Is subject property a site project, a single-phase subdivision, or p.art of a multi-phase subdivision? ~(Al GrL-1£'... If multi-phase, subject prc1perty is phase of Legal description of subject property (phase) or Project Area: (see Section II, Paragraph B-3a) J3;>t,,.oC \<:. CN8-lo-r //fl.I -t8fl'2.., zve.1 1 2:aie1 -32.~/ If subject property (phase) is second or later phase of a project, describe general status of all earlier phases. For most recent earlier phase Include submittal and review dates. General Location of Project Area, or subject property (phase): ~ 9'.t:>~ oF f'~~ fMCE 1~11fret.'-I ~op-7tf£ ~Pt A APP.re 7fV!br/!?:> In City Limits? Extraterritorial Jurisdi1;tion (acreage): Bryan: acres. Bryan: College Station: College Station: ;J'.'15~ acres. Acreage Outside ET J: Part 2 -Proiect Administration I Continued (page 2.2) Project Identification (continued) STORMWATER DESIGN GUIDELINES Effective February 2007 Page 3 of26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNIGAL DESIGN SUMMARY Roadways abutting or within Project Area or Abutting tracts, <>latted land, or built subject property: developments: rh-~ p~ ~(Dfi.#{t t.f>r<.. le;-{$ CF-~p C.f;:/tf'IJ.p f:,et+NPt 1t ./JfJ ~mK>rff!:, Named Regulatory Watercourse(s) & Watershed(s): Tributary 13asin(s): Plat Information For Project or Subject Property {or Phase) Preliminary Plat File#: H/.A Final Plat File #: Date: Name: Status and Vol/Pg: If two plats, second name: File#: Status: Date: Zoning Information For Project or Subject Property {or Phase) Zoning Type: '!<-I+~-~ ~g or Proposed? Case Code: Case Date Status: Zoning Type: Existing or Proposed? Case Code: Case Date Status: Stormwater Management Planning For Project or Subject Property {or Phase) Planning Conference(s) & Date(s): Participants: /o/Js-/oie ~Ae=:of'l /l/Je--ic.A<-.F hl-r.. JAFF!U.'.... Preliminary Report Required? Submittal Date Review Date Review Comments Addressed? Yes --No --In Writing? When? Compliance With Preliminary Drainage Report. Briefly describe (or attach documentation explaining) any deviation(s) from provisions of Preliminary Drainc:ge Report, if any. fl/tt Part 2-Project Administration 1 Continued (page 2.3) Coordination For Project or Subject Property {or Phase) STORMWATER DESIGN GUIDELINES Effective February 2007 Page 4 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 .;t:.J SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Note: For any Coordination of stormwater matters indicated belo'N, attach documentation describing and substantiating any agreements, understandings, contracts, or approvals. Coordination With Other Departments of Jurisdiction City (Bryan or Dept. Contact: Date: Subiect: College Station) 1------+------+-----l--------------i Coordination W ith Summarize need(s) & actions taken (include contacts & dates): Non-jurisdiction City Needed? Yes __ No ___.!l: Coordination with Summarize need(s) & actions taken (include contacts & dates): Brazos County Needed? / Yes No v Coordination with TxDOT Needed? Yes __ No /' Coordination with T AMUS Needed? Yes No / Summarize need(s) & actions taken (include contacts & dates): Summarize need(s) & actions taken (include contacts & dates): Permits For Project or Subject Property {or Phase) As to stormwater management, are permits required for the propl)sed work from any of the entities listed below? If so, summarize status of efforts toward that obiective in spaces below. Entity US Army Crops of Engineers No~ Yes_ US Environmental Protection Agency No ___L Yes_ Texas Commission on Environmental Quality No Yes V Brazos River Authority No V' Yes _ Permitted or Aooroved? Part 3 -Property Characteristics Status of Actions (include dates) /,.f;:7"TfU.. OP-£r:.C~C()f.J ~<L ~G,.J ~~ oF Wlr1a 'f ~ lft1f'tZov. l Start (Page 3.1) Nature and Scope of Proposed Work STORMWATER DESIGN GUIDELINES Effective February 2007 Page 5 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Existing: Land proposed for development currently used, including extent of impervious cover? 2-Sml\u.. tv1~"1111.. ~I c...Clt N Ct-Y-rv1 I N"O'it. f!3v11.r~ Site _ .. _Redevelopment of one platted lot, or two or more adjoining platted lots. Development __ 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 seri1e one or more platted lots. Development __ Construction of streets and utilities to seri1e one or more proposed lots on Project lands represented by pending plats. Site projects: building use(s), approximate floor ~:pace, impervious cover ratio. Describe Subdivisions: number of iots by general type of L se, linear feet of streets and Nature and drainage easements or ROW. Size of t..o'1? -=:: /'O Proposed ??t .. Gf:,;"(e, :::: Soo l. 'F. Project Is any work planned on land that is not platted If yes, explain: or on land for which platting is not pending? VNo Yes -- FEMA Floodplains Is any part of subject property abutting a Named Regulatory Watmcourse I No__i_ Yes __ (Section II , Paragraph B1) or a tributary thereof? Is any part of subject property in floodplain I No_ Yes_L Rate Map I c.tL/ C. area of a FEMA-regulated watercourse? Encroachment(s) Encroachment purpose(s): __ Building ste(s) __ Road crossing(s) into Floodplain areas planned? __ Utility crossing(s) __ Other (explain): No _L 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. Part 3 -Prope¢t Characteristics I Continued (Page 3.2) t:tydrologic Attributes of Subject Prope1ty (or Phase) Has an earlier hydrologic analysis been done for larger area including subject property? STORMWATER DESIGN GUIDELINES Effective February 2007 Page 6 of 26 APPi::NDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Yes Reference the study (&date) here, and attach copy if not already in City files. -- Is the stormwater management plan for the property in substantial conformance with the earlier study? Yes No If not, explair how it differs. Nov If subject property is not part of multi-phase project, desc:ribe 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? __IL No --Yes Describe them (include approximate size, volume, outfall, model, etc). /' Any known drainage or flooding problems in areas near subject property? __ No v Yes Identify: ~rUlfeJO 1iooJ:::> lNltr Act...t&:F.:l!3~ ~ Yz. of:.. ltJT I 8 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. __ Detention not required. -- What decision has been reached? By whom? If the need for /<M~ l'CO'f £>u l. -r I >-J C:r 'GJbtr-I~ Type 1 Detention How was determination made? must be evaluated: L..<oc.A-7ro,...J U..,,7(-f J ,.J 7HE ;.../jj~Hrc:o Part 3 -Pro12em Characteristics I Continued (Page 3.3) Hydrologic Attributes of Subject Property (or Phase) (continued) Does subject property straddle a Watershed or Basin divide? _ V No --Yes If yes, describe splits below. In Part 4 describe design concept for handling this. Watershed or Basin STORMWATER DESIGN GUIDELINES Effective February 2007 Page 7 of26 I Larger acreage I Lesser acreage I I APP :::NDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNIGAL DESIGN SUMMARY Above-Project Areas(Section II, Paragraph 83-a) / Does Project Area (project or phase) receive runoff from upl :md areas? 11 No --Yes Size(s) of area(s) in acres: 1) 2) 3) 4) Flow Characteristics (each instance) (overland sheet, shallo'N concentrated, recognizable concentrated section(s), small creek (non-regulatory), regulc:itory Watercourse or tributary); Flow determination: Outline hydrologic methods and assumptions: Does storm runoff drain from public easements or ROW onto or across subject property? --No --Yes If yes, describe facilities in easement or ROW: Are changes in runoff characteristics subject to change in fuf:ure? Explain Conveyance Pathways (Section II , Paragraph C2) Must runoff from study property drain across low~ropertie1;; before reaching a Regulatory Watercourse or tributary? No Yes Describe length and characteristics of each conveyance pathway(s). Include ownership of property(ies). G4o l-F. oF-,4 VJE.l-1-f>e.PtlJfJD --rr.2.1 'fbu7 ~'(bf co JA.}oz...P f~ C£F--raL~ Part 3 -Pro~ertv 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), describEi their provisions. part of STORMWATER DESIGN GUIDELINES Effective February 2007 Page 8 of26 APPl:NDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNIGAL DESIGN SUMMARY path,.ay(s)? _V_ INo __ Yes Pathway Areas Nearby Where runoff must cross lower properties, describe c.haracteristics of abutting lower property(ies). (Existing watercourses? Easement or Consent aquired?) Describe any built or improved drainage facilities exiuting near the property (culverts, bridges, lined channels, buried conduit, swales, dete11tion ponds, etc). f3X10-r1rJGi /elf ~"70~ ~/f!AAJ~ of. Cutek!!:;. '1-SLP't':::> fr1 -nt£ 'Gur"'rP or f1e:J.L~ fi~tCE:. "'f> fl.aJ;'A.Cf!ISI /o 7~ur ~Elf~ Drainage ~--------------------------------i Facilities Do any of these have hy,logic or hydraulic influence on proposed stormwater design? __ No Yes If yes, explain: /Al L. v..J fr!D(l CoNSrft4°rt 1¥!-S oF &X.l~C'f I ~VfZl,o~rneu--1£, ~o"-IYt ~i:n... $--(SrfCt'Yt Part 4 -Drainage Conce~t and Design Parameters I Start (Page 4.1) i Stormwater Management Com;ept Discharge(s) From Upland Area(s) If runoff is to be received from upland areas, what design dra nage features will be used to accommodate it and insure it is not blocked by future develo~ment? Describe for each area, flow section, or discharge point. STORMWATER DESIGN GUIDELINES Effective February 2007 Page 9 of26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Discharge(s) To Lower Property(ies) (Section II, Paragraph E1) Does project i:/1ude drainage features (existing or future) proposed to become public via platting? __ No __ Yes Separate lnstrumert? No Yes Per Guidelines reference above, how will Establishing Easements (Scenario 1) runoff be discharged to neighboring =z Pre-de;velopment Release (Scenario 2) property(ies)? Combination of the two Scenarios -- Scenario 1: If easements are proposed, describe where nee jed, and provide status of actions on each. (Attached Exhibit # ) Scenario 2: Provide general description of how release(s) will be managed to pre-development conditions (detention, sheet flow, partially concentrated, etc.). (Attached Exhibit# ) 6rf-D/ 1/k:.-n=:1-rt<~ ~D/ w rrH IVIDrJ!>ill N"(r Jr:>evt C,£ • 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. If Scenario 2, or Combination are to be u~, has proposed cesign been coordinated with owner(s) of receiving property(ies)? No __ Ye;s Explain and provide documentation. Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.2) Stormwater Management Concept (1:ontinued) Within Project Area Of Multi-Phase Project Will project result Identify gaining Basins or Watersheds and acres shifting: in shifting runoff between Basins or between STORMWATER DESIGN GUIDELINES Effective February 2007 Page 10 of26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Watersheds? V' No __ Yes What design and mitigation is used to compensate for increased runoff from gaining basin or watershed? 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) invo :Ving otht:r 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. C'-· u Q) "' c Q) 5i >-a: "' c Cl "iii Q) 0 Oz "'iii ll Q) .«: Are aquatic echosystems proposed? __ No project(s)? __ Yes In which phase(s) or Are other Best Management Practices for reducing s·:ormwater pollutants proposed? __ No __ Yes Summarize type of BMP and extent of use: 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 elementn __ Channel features __ Swales __ Ditches __ Inlets __ '/alley gutters __ Outfalls __ Culvert features __ Bridges Other Part 4 -Drainage Concel!t and Design Parameters I Continued (Page 4.3) Stormwater Management Concept (1:ontinued) Within Project Area Of Multi-Phase Project (continued) Will Project Area include bridge(s) or culvert(s)? /No --Yes Identify type and general size and In which phase(s). STORMWATER DESIGN GUIDELINES Effective February 2007 Page 11 of26 APP~NDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNIC:AL DESIGN SUMMARY 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): Within Or Serving Subject Property (Phase, or Site) If property part of larger Project Area, is design in substantial confonnance with earlier analysis and report for larger area? __ Yes No, then summarize the difference(s): Identify whether each of the types of drainage features listed Jelow are included, extent of use, and general characteristics. Ul .c di ~~~>-..c di ..... Ul ·~ ~ Ul di ..... :i:: di ::J 0 ~~zl di c: '-l1l <( Typical shape? I Surfac:es? Steepest side slopes: Usual front slopes: Usual back slopes: Flow line slopes: least ___ _ Typical distance from travelway: typical greatest ____ _ (Attached Exhibit# ) Are longitudinal culvert ends in compliance with El-CS Standard Specifications? ___ Yes No, then explain: At intersections oyotherwise, do valley gutters cmss arterial or collector streets? ___ No _I/_ Yes If yes explain: V'A<..~ 6:rv-t'7~ ()..)l..(... i3f;. ~-r(l...:c--r~ kr fl}(l.1t.. fZir£ Are valley gutters proposed to cross any street away from an intersection? ~No __ Yes Explain: (number of locatierns?) Part 4 -Drainage Conceet and Design Parameters I Continued (Page 4.4) Stormwater Management Concept (1:ontinued) Within Or Serving Subject Property (Phase, or Site) (continUE1d) :0 '-Gutter line slopes: Least f).l.o~ Usual Greatest 4'/s/. -'-di ::J :i:: ('· 0 ::J "O Are inlets recessed on arterial and collector streets? VYes No If "no·, 15 Cl di identify where and why. "O Ul -c: ::J ~ l1l STORMWATER DESIGN GUIDELINES Effective February 2007 Page 12 of26 -- APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Will inlets capture 10-year design stormflow to prevent flooding of intersections (arterial with arterial or collector)? __IL. Yes __ No If no, explain where and why not. Will inlet size and placement prevent exceed~allov1able water spread for 10-year design storm throughout site (or phase)? __ YeB __ No If no, explain. Sag curves: Are inlets placed at low points? ___L Yes --No Are inlets and conduit sized to prevent 100-year stormflow from ponding at greater than 24 inches? ~Yes __ No Explain "no" answers. Will 100-yr stormflow be contained in combination of ROW and buried conduit on whole length of all streets? v Yes __ No If no, describe where and why. Do ~igns for curb, gutter, and inlets comply with B-CS Technical Specifications? Yes __ No If not, describe difference(s) and attach justification. ,, Are any 12-inch laterals used? __L No --Y•E!S Identify length(s) and where used. C'-· "'O Pipe runs between system I Typical ~b Z.16 Q) I/) Longest ~ Q) access points (feet): !~ Are junction boxes used at each bend? _L_ Yes --No If not, explain where and why. I/) .!: 0 ~z "'O I E ..... 0 Are downstream so~t or below upstream soffits? Least amount that hydraulic ii) ~ Yes __ No __ If not, explain where and wh·f: grade line is below gutter line ~OF-UtitC..IJ-t. Ar Jii7t (!::>-rt ,.Jc,-(system-wide): I :5 'lo-L«l &wic::L 7ie-11..1 o .. °l Ct.> Part 4 -Drainage Conce(!t and Design Parameters I Continued (Page 4.5) Stonnwater Management Concept (1:ontinued) Within Or Serving Subject Property (Phase, or Site) (continuod) Q) ' Describe watercourse(s), or system(s) receivin;J system discharge(s) below r~ "'O ~ ~ (include design discharge velocity, and angle between converging flow lines). IU ·-..... > ~ 1U 0, a. ..... ~ 1) Watercourse (or system), velocity, and angle? :: Q) a.. -Ul -j ::I ~ c ~ I 0 b f-0°1 fr~ ::,.. 0 .!: 0 --1/) STORMWATER DESIGN GUIDELINES Effective February 2007 Page 13 of26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised Februarv 2008 SECTION IX APPENDIX D -TECHNIGAL DESIGN SUMMARY 2) Watercourse (or system), velocity, and ang e? 3) Watercourse (or system), velocity, and angl1:?? For each outfall above, what measures are taken to prevent erosion or scour of receiving and all facilities at juncture? 1) &:, ~C~r-t171C UJrrt+ ?cc.tc. ~?, p-f?J:+,F 2) 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) ('o· 2 Q) ~"' ..... Q) Flow line slopes (minimum and maximum): "'>-c ! I -g 0 r~1 Outfall characteristics for each (velocity, convergent angle, & end treatment). "' Q) .... Will 100-year design storm runoff be contained within easement(s) or platted drainage ct: ROW in all instances? --Yes --No If "no" explain: Part 4 -Drainage Concef;!t and Design Parameters I Continued (Page 4.6) Stormwater Management Concept (continued) Within Or Serving' Subject Property (Phas~or Site) (continu1~d) 'Q "' Are roadside ditches used? ~No __ Yes If so, provide the following: "' Q) Is 25-year flow contained with 6 inches of freeboard throughout? __ Yes No tg Q) -fi -- 0 :!: Are top of banks separated from road shoulders 2 fe1~t or more? __ Yes --No p;: 0 Are all ditch sections trapezoidal and at least 1.5 feet deep? Yes No ---- STORMWATER DESIGN GUIDELINES Effective February 2007 Page 14 of26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY For any "no" answers provide location(s) and explain: If conduit is beneath a swale, provide the following in·'ormation (each instance). Instance 1 Describe general location, approximate ength: "' Q) >- II Is 100-year design flow contained in conduit/swale cc1mbination? --Yes --No If "no" explain: c: 0 (1J Easement Width z iii Space for 100-year storm flow? ROW 1\1~ Swale Surface type, minimum Conduit Type and size, minimum and maximum and maximum slopes: slopes, design sto1·m: ('--~ rn -c 4i -c (1J c: >-Inlets Describe how conduit is loaded (from streetshtorm drains, inlets by type): c: (1J c: ..c: (1J 0 ._ c: .!?. Q) c: a. 0 0 :;:; Access Describe how maintenance access is provided (to swale, into conduit): -(1J 0 E :J .E -~ .!: .!: Q) -c E Instance 2 Describe general location, approximate length: Q) (1J rn "' :J rn Q) c: -c .Q ·5 Is 100-year design flow contained in conduit/swale combination? Yes No iii 0 ----._ If "no" explain: c: a. :.0 Qi E Q) 0 ..c: Space for 100-year storm flow? ROW Easement Width 0 rn .... .!! Swale Surface type, minimum Conduit Type and size, minimum and maximum :J (1J -c ._ and maximum slopes: slopes, design sto·m: c: (1J 0 a. -.!: Q) Q) rn Inlets Describe how conduit is loaded (from streets/:~torm drains, inlets by type): ~ c: ~ rn Q) ._ <( Access Describe how maintenance access is proviced (to swale, into conduit): Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4. 7) Stormwater Management Concept (1:ontinued) Within Or Serving Subject Property (Phase, or Site) (continuod) -c If "yes" provide the following information for each instance: "' Q) Q) ·-Instance 1 Describe general location, approximate length, surfacing: (ij ::; ~ :;::: ..0 l Ill ::i I -0 c =..c: c ~j STORMWATER DESIGN GUIDELINES Effective February 2007 Page 15 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY 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 provic e: Instance 2 Describe general location, approximate length, surfacing: 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 31 41 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 ---- ~ shaped, see "Swales" in this Part. If creating side banks, provide information below. -0 .£ cu Will design replicate natural channel? Yes No If "no", for each instance Ill "' 0 -----0. 0. describe section shape & area, flow line slope (min. & max.), surfaces, and 100-year 0 x ... w design flow, and amount of freeboard: 0. Ill Ill Instance 1: c cu cu >- E I cu > 0 Instance 2: ... 0. E o F1 Instance 3: () Part 4 -Drainage Conce~t and Design Parameters j Continued (Page 4.8) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continu1!d) Existing channels {small creeks}: Are these used? --No --Yes Ill If "yes" provide the information below. c:: -cu ~ E Will small creeks and their floodplains remain undisturbed? __ Yes No How c cu ' many disturbance instances? Identify ea1;h planned location: "'> . ..c 0 () a. E " STORMWATER DESIGN GUIDELINES Effective February 2007 Page 16 of 26 APF ENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY For each location, describe length and general type of proposed improvement (including floodplain changes): For each location, describe section shape & area, flow line slope (min. & max.), surfaces, and 100-year design flow. Watercourses (and tributaries): Aside from fringe changes, are Regulatory Watercourses proposed to be altered? __ No ---Yes Explain below. Submit full report describing proposed changes to R1~gulatory Watercourses. Address existing and proposed section size and shape, surfaces, alignment, flow line changes, length affected, and capacity, and provide full documentation of analysis procedures and data. Is full report submitted? Yes --No If "no" explain: All Proposed Channel Work: For all proposed cha inel work, provide information 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. Will 100-year flow be contained with one foot of freehoard? --Yes --No If not, identify location and explain: Are ROW I easements sized to contain channel and required maintenance space? --Yes --No If not, identify location(s) and explain: Part 4 -Drainage ConceRt and Design Parameters I Continued (Page 4.9) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continui~d) How many facilities for subject property project?_{_ For each provide info. below. c: For each dry-type facilitiy: Facility 1 Facility 2 0 ;:; f/J ().? { I c.f 'Z<./ I FF c: Cl) Acres served & design volume + 10% Cl) :.:: c G>~ .100-yr volume: free flow & plugged 1'1&>Fi"" 9(Q~~A .~ D cu 4 Cl) 1.1. z .'10 "2J1 ..... Design discharge (10 yr & 25 yr) < ( Spillway crest at 100-yr WSE? ~yes no __ yes no ---- STORMWATER DESIGN GUIDELINES Effective February 2007 Page 17 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY . Berms 6 inches above plugged WSE? I ___;{_ yes --no , __ yes --no Explain any "no· answers: For each facility what is 25-yr design Q, and design cf outlet structure? Facility 1: 2. ./'1 cJ·s -B" r;tl Orl-t PFI Cfi.~ Facility 2: Do outlets and spillways discharge into a public facirn:y in easement or ROW? Facility 1: v Yes No Facility 2: --Yes --No --If "no" explain: For each, what is velocity of 25-yr design discharge ~1t outlet? & at spillway? Facility 1: /. 3Z ~ & -Facility ~~: & Are energy dissipation measures used? ~No __ Yes Describe type and location: For each, is spillway surface treatment other than concrete? Yes or no, and describe: Facility 1: 6;~~~ (.)..11Y1~ w B-1 Facility 2: For each, what measures are taken to prevent erosirn or scour at receiving facility? Facility 1: ~ot:> ppe:;> Facility 2: If berms are used give heights, slopes and surface treatments of sides. Facility 1: Facility 2: Part 4 -Drainage Conceet and Design Parameters I Continued (Page 4.10) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continuod) Do structures comply with 8-CS Specifications? Ye!S or no, and explain if "no": Ill Cl> Facility 1; v~s :;:::; =:o (.) Q) (1J :l LL c C :;:: Facility 2: 0 c :;::: 0 c (.) Q) -Qi 0 For additional facilities provide all same information on a separate sheet. STORMWATER DESIGN GUIDELINES Effective February 2007 Page 18 of26 APFENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY /' Are parking areas to be used for detention? ~ f\ o --Yes What is maximum depth due to required design storm? Roadside Ditches: Will culverts serve access driveways at roadside ditches? 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 comply with 8-CS Technical SpHcifications? __ Yes --No Explain any "no• answers: <'-· Ill Cl c ·;;; Are culverts parallel to public roadway alignment? ___ Yes No Explain: Ill e -- 0 Ill ~~ ro I > ·;::: Creeks at Private Drives: Do private driveways, dri11es, or streets cross drainage a. iii ways that serve Above-Project areas or are in public easements/ ROW? -0 0 No Yes If "yes• provide information below. !\1 ---- How many instances? Describe location and provide information below. Q) Location 1: > 3 0 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 100-year flow? For more instances describe location and same infornation on separate sheet. Part 4 -Drainage ConceRt and Design Parameters I Continued (Page 4.11 ) Stormwater Management Concept (•::ontinued) Within Or Serving Subject Property (Phase, or Site) (continuod) 0 Named Regulalo!:}l Watercourses (& Tributaries}: Are culverts proposed on these 111:= facilities? V No __ Yes, then provide full mport documenting assumptions, t:: ..0 Q) :J criteria, analysis, computer programs, and study findings that support proposed > a. s-design(s). Is report provided? __ Yes No If "no", explain: o ro --Q) -0 .... Q) <( Ill :J STORMWATER DESIGN GUIDELINES Effective February 2007 Page 19 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Arteri~ or Major Collector Streets: Will culverts s :?rve these types of roadways? I/' No __ Yes How many instances? ____ For each identify the location and provide the information below. Instance 1: Instance 2: Instance 3: Yes or No for the 100-year design flow: 1 2 3 Headwater WSE 1 foot below lowest curb top? Spread of headwater within ROW or easement? Is velocity limited per conditions (Table C-11)? Explain any "no· answer(s): Minor !!ollector or Local Streets: Will culverts serve these types of streets? 7No --Yes How many instances? for each identify the location and provide the information below: Instance 1: Instance 2: Instance 3: For each instance enter value, or "yes· /"no" for: 1 2 3 Design yr. headwater WSE 1 ft. below curb top? 100-yr. max. depth at street crown 2 feet or less? Product of velocity (fps) & depth at crown (ft) = ? Is velocity limited per conditions (Table C-11)? Limit of down stream analysis (feet)? Explain any "no" answers: Part 4 -Drainage Conceet and Design Parameters I Continued (Page 4.12) Storrnwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continu1!d) All Proposed Culverts: For all proposed culvert facilities (except driveway/roadside Ul 'C ditch intersects) provide information requested in ne>:t eight boxes. t:: Q) Do culverts and travelways intersect at 90 degrees? Yes No If not, Q) 2 -- -- > ·-identify location(s) and intersect angle(s), and justify the design(s): --:J c: () 0 ~ STORMWATER DESIGN GUIDELINES Effective February 2007 Page 20 of 26 APF'ENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY Does drainage way alignment change within or near limits of culvert and surfaced approaches thereto? __ No --Yes If "yes" id entify 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: Are flumes or conduit to discharge into or near surfac:ed approaches to culvert ends? --No --Yes If "yes" identify location(s), describe outfall design treatment(s): Is scour/erosion protection provided to ensure long te:rm stability of culvert structural components, and surfacing at culvert ends? __ Yes __ No If "no· Identify locations and provide justification(s): 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? Do appreciable hydraulic effects of any culvert extend downstream or upstream to neighboring land(s) not encompassed in subject pro~1erty? --No --Yes If "yes" describe location(s) and mitigation measures: Are all culvert designs and materials in compliance with B-CS Tech. Specifications? --Yes --No If not, explain in Special Desi!1n Section of this Part. Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.13) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continuod) / Is a bridge included in plans for subject property proj1:!ct? ~No --Yes If "yes" provide the following information. Name(s) and functional classification of the roadway(s)? Iii Q) C> "C ·;:: CD What drainage way(s) is to be crossed? STORMINATER DESIGN GUIDELINES Effective February 2007 Page 21 of26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY 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 iii Plan (SW3P) :J a established for ..... project construction? Ql ~ --No --Yes 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 type and location be·low. Provide full 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? --Yes --No If "no" explain: Part 4 -Drainage Conceet and Design Parameters I Continued (Page 4.14) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continu13d) Special Designs -Deviation From B-CS Technical Specifications If any design(s) or material(s) of traditional runoff-handling fa::ilities deviate from provisions of B-CS Technical Specifications, check type facility(ies) and e>:plain 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 STORMWATER DESIGN GUIDELINES Effective February 2007 I Justification for Deviation (attach additional sheets if needed) Page 22 of26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY 1) 2) 3) 4) 5) Have elements been coordinated with the City Engineer or h ar/his designee? For each item above provide "yes• or "no·, action date, and staff name: 1) 2) 3) 4) 5) Design Parameters Hydrology /' Is a map(s) showing all Design Drainage Areas provided? v' Yes No ----- Briefly summarize the range of applications made of the Rational Formula: Sr?o~wt Sp.;..srt-r£ Mao£,£../ tJ Cr What is the size and location of largest Design Drainage Area to which the Rational Formula has been applied? ().~g, acres Location (or identifier): Part 4 -Drainage Conce12t and Design Parameters I Continued (Page 4.15) Design Parameters (continuod) Hydrology (continued) In making determinations for time of concentration, was segrnent analysis used? --1L'"No Yes In approximately what percent of Design Drainage Areas? % As to intensity-duration-frequency and rain depth criteria for de17ining runoff flows, were any criteria other than those provided in these Guidelines used? __ No __ Yes If "yes" identify type of data, source(s), and where applied: STORMWATER DESIGN GUIDELINES Effective February 2007 Page 23 of 26 APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 ' . SECTION IX APPENDIX D -TECHNIC;AL DESIGN SUMMARY 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 /0 /0 0 Open channels Swale/buried conduit combination in lieu of channel Swales Roadside ditches and culverts serving them Detention facilities: spillway crest and its outfall /€> 0 Z.-/ao Detention facilities: outlet and conveyance structure(s) 2-/fD c 2.-/1.:l 'C Detention facilities: volume when outlet plugged 2..-/oc::;;, 2.-/ oC 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) (.,. 4 ct -?. (o '1 Lowest (feet per second) e;_G74' /. ~'2.. Streets and Stonn Drain Systems Provide the summary information outlined below: Roughness coefficients used: For street gutters: t) • l • /IZ- For conduit type(s) A~;-= O· 0 ('2-RcP-:.o. 01g, Coefficients: Part 4 -Drainage Conce~t and Design Parameters I Continued (Page 4.16) Design Parameters (continujtd) Hydraulics (continued) Street and Storm Drain Systems (continued) For the following, are a~mptions other than allowable per Guidelines? V Yes Inlet coefficients? __ No __ Yes Head and frictio ri losses __ No --Explain any "yes" answer: ~ In conduit is velocity generally increased in the downstream .jirection? ~Yes No TNo Are elevation drops provided at inlets, manholes, and junction boxes? --Yes Explain any "no" answers: Al err A7 ~0-SS'"t#F-11"'1 ~ STORMWATER DESIGN GUIDELINES Effective February 2007 Page 24 of26 bv1Z.. -Zb /" Lrf'lcA-L ~.S APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY /' Are hydraulic grade lines calculated and shown for design stcirm? ~Yes --No For 100-year flow conditions? _L.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: J-)ot.-M~l-t=:P~H Cl) <..c.u~ '7IC.IC> ""' C.t} lf-tJNF:l-I mMtta A-rr=t-t./ ~(>J,.S0'1"~rt7 cF ourFITc..<-- 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: Culverts If plan sheets do not provide the following for eac1 culvert, describe it here. For each design dischar~1e, will operation be outlet (barrel) CC1ntrol or inlet control? Entrance, friction and exit losses: Bridges Provide all in bridge report Part 4 -Drainage ConceQt and Design Parameters I Continued (Page 4.17) Design Parameters (continuE1d) 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 ~C/}t) fVf/\J~7oe...wl Part 5 -Plans and SQecifications STORMWATER DESIGN GUIDELINES Effective February 2007 Page 25 of 26 APFENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008 , ' . SECTION IX APPENDIX D -TECHNICAL DESIGN SUMMARY 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: Attestation Provide attestation to the accuracy and completeness of the fore·~oing 6 Parts of this Technical Desi n Summa Draina e Re ort b si nin and sealin below. "This 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 Unified Drainage Design Guidelines for the owners of the proporty. All licenses and permits required by any and all state and federal regulatory agencies for the proposed drainage improvements have been issued or fall under applicable genera' permits." Licensed Professional Engineer State of Texas PE No. Bes 6 ~ STORMWATER DESIGN GUIDELINES Effective February 2007 Page 26 of26 (Affix Seal) APPENDIX. D: TECH. DESIGN SUMMARY As Revised February 2008