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HomeMy WebLinkAboutStormwater Drainage StudyStorm Water Drainage Study Brazos Fellowship Addition College Station, Texas December 22, 2011 Mr. Alan Gibbs, P.E., City Engineer City of College Station Planning Services 1101 Texas Avenue College Station, TX 77842 Re: Storm Water Drainage Study Brazos Fellowship Addition College Station, Texas Gessner Engineering Job No.: 11-0361 Dear Mr. Gibbs: This report conveys the results of the storm water drainage study conducted by Gessner Engineering for the proposed Brazos Fellowship addition in College Station, Texas. Gessner Engineering believes that all information contained in this report is valid. Please contact us if you have any questions or if we can be of further assistance. Sincerely, GESSNER ENG4ERING, F-7451 1� Jer n�'y ,t�P.E., C.F.M. G ✓f"'V � �°�--�-�-�- Kyle M. Zapalac, M.E., E.I.T. Executive Summary This storm water drainage report is submitted to the City of College Station, Texas for review on December 22, 2011 by Jeremy N. Peters, P.E., C.F.M. of Gessner Engineering, located at 2501 Ashford Drive, Suite 102, College Station, Texas 77840. This report is submitted on behalf of the owner, Mr. Shawn Parish with Brazos Fellowship at 226 Southwest Parkway East. The proposed project consists of an addition and site improvements of an existing 3.43 acre church property. Proposed improvements include approximately 16,968 square foot building addition and associated parking and site improvements. The site is located at the 226 Southwest Parkway East in College Station, Texas. It is located in the Bee Creek watershed. The site is not located in the FEMA 100 year flood plain, as shown by FIRM number 48041CO205D. Currently, the property is fully developed and mostly impervious. The existing building is approximately 12,562 square feet, and the remaining property is covered by pavement for drives and 249 parking spaces. Adjacent lots to the west, along the southern boundary drain across the southern -most parking area. The proposed site improvements will maintain all existing flow patterns. Most of the existing site drains through two (2) metering structures. The proposed improvements will maintain these flow routes, with the exception of the east half of the building addition. This area will flow to an adjacent drainage area that drains the street to the east of the site. While some of the runoff from the improvements drains to a different drainage area, the overall total runoff from the property is not increased by the proposed conditions. The overall effected area is less than one (1) acre. Due to the size of development at this site, a Notice of Intent is not required to be submitted to the Texas Commission on Environmental Quality. This drainage report includes a report detailing the methods of calculations and results summary, with appendices including drainage area maps and calculations, Autodesk Storm and Sanitary Analysis 2012 reports, and the Technical Design Summary. Introduction This storm water drainage report is intended to determine the change in runoff under post - developed conditions for the proposed addition for Brazos Fellowship. Under existing conditions, adjacent properties drain through the subject tract. However, since no changes will be occurring to adjacent properties, the flows from those properties will not be included in the calculations. The existing site has two (2) weirs that meter runoff and store water in the parking lot. One storage area is the east side of the parking lot, and the other storage area is the west side of the parking lot. Drainage Calculations for this site were prepared according to the National Resource Conservation Method as detailed in Technical Release 55 (TR-55) published in June of 1986. Proposed improvements include approximately 15,000 square foot building addition with associated parking and drive aisle improvements. Curve numbers from TR-55 were used based on developed uses as described above. Pre -developed flows were calculated based on the existing conditions land on the subject tract. The calculated pre -developed and developed flows include the two (2), five (5), ten (10), twenty-five (25), fifty (50) and one -hundred (100) year storms in accordance with the Bryan College Station Unified Stormwater Design Guidelines. Calculations Calculations were performed according to the USDA TR-55 and with the aid of Autodesk Storm and Sanitary Analysis 2012. The output data from the analysis software has been provided as Appendix C. Time of Concentration The time of concentration (travel time) for each drainage area was estimated by summing the flow time for each segment of travel. For sheet flow, travel time was estimated by Manning's Kinematic equation: 0.007 x (nL)0 8 tt — So.4 z Where tt = travel time (hours) n = manning's roughness coefficient L = flow length (feet) S = slope (ft/ft) P2 = 2-year, 24 hour rainfall (inches) For shallow concentrated flow, the travel time was calculated from the flow velocity based on the slope in the direction of flow. These velocities were taken from Table C-4 of the Bryan College Station Unified Stormwater Design Guidelines. The computed times of concentration for each drainage area are included on sheets C-05a and C-05b. Computed values were increased to a minimum time of ten (10) minutes as required. Unit Hyftgmph A generic unit hydrograph was computed by distributing the rainfall depths (Table One) according to the distribution factors for the NCRS Type III 24 hour storm. This hydrograph was then applied to each subarea based on the curve number and time of concentration of that area. Reach Routing Hydrographs were routed from subareas to the outflow through the kinematic wave method. This method allows for hydrographs to be translated with time but not attenuated. The effects of backwater flow and pressure flow in channels were neglected. Peak Runoff Flow Peak Runoff Flow from the site was determined based on the Type III 24 hour storm applied to each drainage area. The depth -duration -intervals for each frequency are included in Table One below, and were obtained from Table C-6 in the Unified Stormwater Design Guidelines. Curve Number values (CN) were determined from Table C-7, Appendix C of the Unified Stormwater Design Guidelines. Runoff from the subject site drains to three (3) separate outfall points. The peak pre - developed flows at each point is shown in Table One. The peak flow at Outfall includes the flows routed through the two existing detention facilities. Drainage areas and calculations are included on sheets C-05a and C-05b, which is attached as Appendix A. Frequency Rainfall Depth (in), 24-hr duration Pre -Developed Peak Flow at Outfall (cfs) Pre -Developed Peak Flow at Outfall-2 cfs Pre -Developed Peak Flow at Off -Site 2 years 4.50 7.24 2.12 0.56 5 years 6.20 9.72 2.90 0.77 10 years 7.40 11.44 3.47 0.92 25 years 8.40 13.58 4.17 1.11 50 ears 9.80 15.37 4.66 1.24 100 ears 11.00 1 19.26 5.26 1 1.39 Table One: Rainfall Depths and Resulting Flows Existing Detention Facilities The existing conditions of the site include detention in the east and west sides of the parking lot. A weir in each parking lot meters runoff to provide detention. The east parking lot is designated as PL-EAST and west parking lot is designated as PL-WEST. No modifications will be made to the detention facilities as part of the proposed addition. The storage volume for PL-EAST is shown in Table Two, and depth vs. volume curve is shown in Figure One. The storage volume for PL-WEST is shown in Table Three, and the depth vs. volume curve is shown in Figure Two. The storage volumes are computed based on a trapezoidal estimate from the areas given at each elevation. Elevation (ft) Area sf Storage (cf) 274.42 0 0 274.6 346.66 31.2 274.8 3335.26 399.39 275.0 5696.62 1302.58 275.2 8230.50 2695.29 Table Two: Stage Storage Data, PL-EAST Elevation (ft) Area sf Storage (d) 274.87 0 0 275.0 383.78 24.95 275.2 2408.55 304.18 275.4 5337.89 1078.82 275.6 8930.09 2505.62 275.8 12692.39 4667.87 276.0 17426.16 7679.73 Table Three: Stage Storage Data, PL-WESI- —ppNrs. VOlm. Cun asuesr _psn n. VOLm Me aF�s Figure One: Stage Storage Curve, PL-EAST Figure Two: Stage Storage Curve, PL-WEST Existing Outlet Structures Two weirs, one for each area, serve as outlet structures. The flowline for the Weir 1 is elevation 274.42 and is 0.48 ft. high by 1.08 ft. wide. Weir 1 is the outlet for PL-EAST. Additionally, the weir overflow is at elevation 274.90. The overflow is included in the overall model. Weir 2 is the outlet for PL-WEST. The flowline for Weir 2 is at elevation 274.87 and is 1.0 ft. high by 1.17 ft. wide. The overflow for this area is at elevation 275.87, and is also included in the model. Table Four shows the outflows from the two detention areas and water surfaces for each storm event. Storm Event PL-EAST Discharge (cfs) PL-EAST Water Surface Elevation ft PL-WEST Discharge (cfs) PL-WEST Water Surface Elevation (ft) 2 years 4.04 274.97 2.42 275.60 5 years 5.55 274.99 3.09 275.73 10 years 6.65 275.00 3.55 275.81 25 years 8.02 275.01 4.65 275.89 50 ears 8.94 275.02 6.11 275.92 100 ears 10.08 275.03 7.92 275.95 Table Four. Pre -Developed Detention Outflows and W.S.E.Ls The The peak post -developed flows at the three outfall locations are shown in Table Five. Hydrographs for each storm event are included as Appendix B. Frequency Rainfall Depth (in), 24-hr duration Post -Developed Peak Flow at Outfall cfs Post -Developed Peak Flow at Outfall-2 (cfs) Post -Developed Peak Flow at Off -Site 2 years 4.50 6.61 2.12 0.56 5 years 6.20 9.74 2.90 0.77 10 years 7.40 11.48 3.47 0.92 25 years 8.40 13.59 4.17 1.11 50 ears 9.80 15.48 4.66 1.24 100 ears 11.00 19.34 5.26 1.39 Table Five: Post -Developed Site Outflows In the storm events where the post -developed flows are greater than pre -developed flows, the increases will not have an adverse effect of downstream properties. Conclusion Based on visual evidence, engineering drainage calculations and sound engineering judgment, Gessner Engineering believes that the post -developed flows for the two (2), five (5), ten (10), twenty-five (25), fifty (50) and one hundred (100) year design storms for this site will not increase enough to adversely affect adjacent properties. Additional detention for this site is not required. "This report for the drainage design of the Brazos Fellowship Addition was prepared by me in accordance with provisions of the Bryan/College Station Unified Drainage Design Guidelines for the owners of the property. All licenses and permits required by any and all state and federal regulatory agencies for the proposed drainage improvements have been issued." I , P.E., C.F.M. State of Texas No. 100217 APPENDIX A: Drainage Area Map and Calculations (Sheets C-05a and C-05b) L.l i I ; ii Ij AZ I I I ' 1\\ A3 ----- --- ' I IXISTNGA ORRIS A4 COMPOSITION A TICWPTION COMPOSTION FAflFA IBpFiI CGRVENGM BER'CN' CESCNIPTION gflEglso" CUHVENUMBST-CN' PgVEMEM 11,538 BB PAWN 5,41E 98 IANPSGPING 1,d00 B9 "NoSCAPING 1.11R Be CplP.BTAAuSvm NUM m 8F COMPO.SD£CURVENUMBEA: 9SB EXISTING BITEA2 COMPOSITION DESCRIPTION pNPp jSpFTI CURVENUMBEEMN° PAVEI.fEM 89,394 90 ROOF B., 9B LANDSCAPING B,142 09 M` N 1) IXISIiNO FLOW] TIMEOFYFASATURN AREA IX OWVNAGEAflFA COMPOSITE CURVE IBBYFARSTORN BeNLENiMTOX MAXIMUM FLOW OE810NATON AC NUMB Cu' 0@M N U U COMP091TECURVENUMBER: Se9 i ( I MI1N U) pT.HT. CFB AI ob. 95B 10 11 1.45 EXISTING AS CUMP091110N MAXROUTESUFLOWFROMAREA: 1.]9 DESCRIPTION AREA(SOFT) CURVE NUMBFA'CN' PAVEMENT 39.RI3 SO ROOF Q283 OB EXISTING FLOWS 'NO5CAP11M ANN BH —_ TIMEOF •—•— PREP OMIMGEpREA COMPOSITE CURVE CONCENi�T10N IOO YFARSIN MAXI MAXIMUM COMPOSITE CURVE NUMBER: 9)� OE41GW190N (AC) NUMDFA'CN' DEPTH IN CFSPURM OUTFALL-2 � I \ I \ I \ I \ I 1 1 \ I \ I \ \ I \ \ 1 \ \ J I \ I I A5 1 \\ 1 `\ 1 1 i \ L \ fj c �✓ _ ___ I 1 I oRUNAGE AREA MAP NOTES: 1) THIS SHEET IS FOR SITE PVJJNINO PURPOSES 01 -- ITISNOTTOBE USED AS A DOCUMENT FOR CONSTRUCTION. OFF -SITE 2) DRNNAGECALCULAMINE WERE PREFORMED WILDING THE NRCS ME MOD. LEGEND: DMINAGEARE4000NDARY A.� ORAINAGEAREA—ELAN.—IN DIRECTION -----341----- EXISTING CONTOURS 40— PROPOSEOCOMOURS — — PROPERTY LINE PROJECT BENCHMARK: Y INCH IRON IRON BOO ABM WITH CAP ELEV.2B2.,V G Gessner Engineering Nor mveor od,, NeM 102 :Maoa Slellm, Tau¢ Ilmo z�,ry�(.e�..\1\� �4 �[��yoo2V :' �gPoxl'n:ca Q PRELIMINARY NOTFOR CONSTRUCTION LL Q � X O U ~ J w O J U) � O W CO J m N LU Issue orrox 11,16/11 Project Number: 11-0361 Drawn By: LHC Checked By: MPT ReVW.w A Al Al )RAINAGE ARE MAPS PLAN Al �..� -- - - -- ` r' 4- o i / ^ ]r1- , `I 1\I NET, IA2 r upx 3F 9r Fji�r/i;T �� II /7/%/ y/y_ n, ri/il�it%vlrrleit4 �rl / ❑ A2 1 I t III I 1 -. Al \ air Ell A3 I I I I - / Po 6EDgDDIUGN �/ ❑ / ❑)I I F t 1 I_ /\ A3 III 13 POST-DWELOPEOAICOMPOSRION POSTAEYFLOPEO Ad COMPP41➢ON POST-0EVROPEp FLOW. EESCIMPTOM (AUTO CURVENUMBER'CN• OFSCPoPTON pPFA I60FT CURVE NUMBER'CH' TIMBRE 100 YFAq STORM OUifALLOF OETFN]I ON PAVEMEM 'N,g28 98 PAVEMENT 5.q 19 gS AREA BMINAOEARFA COMPOSITE CURVE CONSORTIA, ON 100 KAR 8TORM MAMMON FLOW FAgL1TIE3 AT 100YFAR ROOF IB,M6 9S LAMUSCAPVIG i,]22 S9 AT pE316WT➢0N Ipc) NUMBER'CN• IMIHI DEPOIIN) (CF.) ST_ORM ICF.1 LANOGPMG I Z. I Al 0.M STS 10 11 9A3 Wq COMPOSIIECURVE NUMOEP 9S0 A2: O6] 9].1 10 11 (M q.q6 COMPOSITECURVENUMBER: M,; AS L18 9].6 10 11 IO,p e.W POSTIIEVELOPFDA6 COMPOSITION POST-0EVFLOPEDAISOMP0.ITI0N OEBCNPPON ALMA SOF CURVEMWBER"CN' MAX 0.0UTEST FLOW FROM ARLA: PAVEMEM 21MS AS OE8CPoPTION PRFA (SpF]) CURVENUMBER "CN• IANOSCAPPIG A. 80 POSTDSHOLOPE➢FLOWS PAVEM1IENT A,9]0 96 IANp6CHPIAVi 2,iM 69 COMPOSITECURVE NUMBER: 96.1 APFA ___ pWVNAOEARFA __ COMPOSITECVRVE TIMEOF _ NDMANRTONM IMYFHR.TORM OESIGWITON Ig.I NUMBER"CM CDNCEN]PAi10N TERMINI MA%IMUM FLOW COMPOSITE CURVE NUMBER: 97.1 Mlp (US) -„_ AI 0.16 93.8 10 - 11 t.q5 POST-0fVF10PEDA]COMPOSITON MA%.1. FLOW FROM AN. IA9 pEACP..BF A_RFA (SOFTI CARVE NVIABER"CN' _ _ -_ PAVEMENT POS1OEVELOPEPiLOW3 UNPSCAPING 2.]IB 89 AgFA pRpINAOEARFA COMP031TECUNVE ONE ROMARSTORM COMPOSRECURVENUMBMT: 9],S pFS10NpTION (pC) CONCENTPADON NUMBER,MII MAXIMUM FLOW pEPTH(IN) ( _ A6 11.83 M.1 Hu 11 6.49 MAX ROUTED FLOW FROM AREA: I.I. OUTFALL-2 DRAINAGE AREA MPP NOTES: OFF -SITE 1) THIS SHEET IS FOR SIZE PLANNING PURPOSES ONLY. R 15 NOT TO DE USED AS A DOCUMENT FOR CONSTRUCTION. 2) DRAINAGE CALCULATIONS WERE PREFORMED UTILIZING THENRCSMEIHOO. LEGEND: cp Gessner Engineering NOTFOR O 0 Q \/ Ta_ ry y< U) '^ vJ 11- Q O U) F- J > O J LL � (W D m N 00 Issue Date: 11/16/11 Project Number: 11=0361 Drawn By: LHC Che&ed By. MET Revision MMMM� DRAINAGEAREABOUNDARY Al -PALAR LAND FLOWEASTINGCONTOURS40— ORAIICTIO rp"' PRDPOSEO CONTOURS PROPERTY LINE $INCH IRON IRON ROD BM IC CAP ELEV.2R2.4' APPENDIX B: Hydrographs (Sjo) mouui leislal (SID) MoUul leielel E s 0 e (eJ3) MOIJel IWelel A N E H W 0 Y O W b a N (Sp) MoUul leie{el mGG I LF K Y b I:] b NO) Mogul leielel I b' mi I C1, N I g, J I F F b b b a N O (BJo) MoUuI leJelel yF� ('Jo) Mopul lejelelm (813) mollul j218j2j APPENDIX C: Autodesk Calculations Autodesk® Storm and Sanitary Analysis 2012 - Version 6.4.29 (Build 6198) Project Description File Name ................. 100 YR PRE.SPF ##*****#******** Analysis Options #*****########## Flow Units ................ cfs Subbasin Hydrograph Method. SCS TR-55 Time of Concentration...... SCS TR-55 Link Routing Method ....... Kinematic Wave . Storage Node Exfiitration.. None Starting Date ............. SEP-28-2011 00:00:00 Ending Date ............... SEP-29-2011 01:00:00 Report Time Step .......... 00:05:00 *#*********** Element Count ******#****** Number of rain gages ...... 6 Number of subbasins ....... 5 Number of nodes ........... 5 Number of links ........... 5 Raingage Summary **************** Gage Data Data Recording ID Source Type Interval min ------------------------------------------------------------ 10 YR 10 YR CUMULATIVE 6.00 100 YR 100 YR INTENSITY 6.00 2 YR 2 YR INTENSITY 6.00 25 YR 25 YR CUMULATIVE 6.00 5 YR 5 YR CUMULATIVE 6.00 50 YR 50 YR INTENSITY 6.00 Subbasin Summary #*************** Subbasin Total Area ID acres ------------------------------ DA-I 0.30 DA-2 1.19 DA-3 1.16 DA-9 0.16 DA-5 0.63 ***##*#***** Node Summary **########## Node Element ID Type Autodesk Storm and Sanitary Analysis Invert Maximum Ponded External Elevation Elev. Area Inflow ft ft ft° OFF -SITE OUTFALL 0.00 0.00 0.00 OUTFALL OUTFALL 0.00 1.13 0.00 OUTFALL-2 OUTFALL 0.00 0.00 0.00 PL-EAST STORAGE 274.42 275.20 0.00 PL-WEST STORAGE 274.87 276.00 0.00 x xxx xxxxxxxx Link Summary +xxxxxxxxxxx Link From Node To Node Element Length Slope Manning's ID Type ft % Roughness ____________________________________________________________________________________________ WEIR IA PL-EAST OUTFALL WEIR WEIR lB PL-EAST OUTFALL WEIR WEIR 1C PL-EAST OUTFALL WEIR WEIR-2A PL-WEST OUTFALL WEIR WEIR-2B PL-WEST OUTFALL {WEIR ************************** Volume Depth Runoff Quantity Continuity acre-ft inches xxxxxxxxxxxxxxxxxxxxxxxxxx _ Total Precipitation ...... 3.203 11.178 Surface Runoff ........... 0.304 1.062 Continuity Error (&) ..... -0.000 xxxxxxxxxxxxxxxxxxxxxxxx+x Volume volume Flow Routing Continuity acre-ft Mgallons +x+xxx+++++xxxxx+xxxxxxxxx __- External Inflow .......... 0.000 0.000 External Outflow ......... 3.099 0.992 Initial Stored Volume .... 0.000 0.000 Final Stored Volume ...... 0.000 0.000 Continuity Error (S) ..... 0.000 x*xxxxx*x**xx*x*x+xxx+++x++*+xx+x+xx****+* Composite Curve Number Computations Report xxxxxxxxxx+x++xxxxxxxxxxxxxxxxxxxxxxxxxxx+ Subbasin DA-1 Area Soil Soil/Surface Description ---------------- __________-___ (acres) ________-___-_ Group CN __ - 0.30 - 97.00 Composite Area & Weighted CN 0.30 97.00 ---------------- Subbasin DA-2 ---------------- . Area Soil Soil/Surface Description ------------------------------------------------ (acres) ________________--_-_--_-__- Group CN - 1.19 - 96.90 Composite Area & Weighted CN 1.19 96.90 ---------------- Subbasin DA-3 ---------------- Area Soil Soil/Surface Description ________________________________________________________________________________________ (acres) Group CN Autodesk Storm and Sanitary Analysis 1.16 - 97.10 Composite Area 4 Weighted CN 1.16 97.10 ---------------- Subbasin DA-4 --------'------- Area Soil Soil/Surface Description (acres) Group CN -------------------------------------------------------------------------- 0.16 - 95.80 Composite Area 6 Weighted CN 0.16 95.80 Subbasin DA-5 Area Soil Soil/Surface Description (acres) Group CN -----------------------------------------------------------""------------------------- - 0.63 - 96.10 Composite Area 6 Weighted CN 0.63 96.10 x******x*>**xxxx*xxxxxxxxxx**.«xx***x*xx***xxxx xxxx SCS TR-55 Time of Concentration Computations Report x xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Sheet Flow Equation TC = (0.007 * ((n * Lf)^0. B)) / ((P^0.5) * (Sf^0. 4)j Where: To- = Time of Concentration (bra) n = manning's Roughness Lf - Flow Length (ft) P = 2 yr, 24 hr Rainfall (inches) Sf = Slope (ft/ft) Shallow Concentrated Flow Equation V = 16.1345 * (Sf^0.5) (unpaved surface) V = 20.3282 * (Sf^0.5) (paved surface) V = 15.0 * (Sf^0.5) (grassed waterway surface) V = 10.0 * (Sf^0.5) (nearly bare 5 untilled surface) V = 9.0 * (Sf^0.5) (cultivated straight rows surface) V = 7.0 * (Sf^0.5) (short grass pasture surface) V = 5.0 * (Sf^0.5) (woodland surface) V = 2.5 * (Sf^0.5) (forest w/heavy litter surface) Tc = (Lf / V) / (3600 sec/hr) Where: Tc = Time of Concentration (bra) If = Flow Length (ft) V = Velocity (ft/sec) Sf = Slope (ft/ft) Channel Flow Equation V = (1.49 * (R^(2/3)) * (Sf^0.5)) / n R = Aq / Wp To - (Lf / V) / (3600 sec/hr) Where: Autodesk Storm and Sanitary Analysis Autodesk© Storm and Sanitary Analysis 2012 - version 6.4.29 (Build 6198) *******xx********** Project Description ************x*x*x** Pile Name ................. 50 YR PRE.SPP **************** Analysis Options - *****xx***x**xx* Plow Units ................ c£a Subbasin Hydrograph Method. SCS TR-55 Time of Concentration...... SCS TR-55 Link Routing Method ....... Kinematic Wave Storage Node Exfiltration.. None Starting Date ............. SEP-26-2011 00:00:00 Ending Date ............... SEP-29-2011 01:00:00 Report Time Step .......... 00:05:00 ************* Element Count ************* Number of rain gages ...... 6 Number of subbasins ....... 5 Number of nodes ........... 5 Number of links ........... 5 **************** Raingage Summary Gage Data Data Recording ID Source Type Interval min ------------------------------------------------------------ 10 YR 10 YR CUMULATIVE 6.00 100 YR 100 YR INTENSITY 6.00 2 YR 2 YR INTENSITY 6.00 25 YR 25 YR CUMULATIVE 6.00 5 YR 5 YR CUMULATIVE 6.00 50 YR 50 YR INTENSITY 6.00 *********x*****x Subbasin Summary **************** Subbasin Total Area ID acres DA-1 0.30 ➢A-2 1.19 DA-3 1.16 DA-4 0.16 DA-5 0.63 ************ Node Summary ********xx*x Node Element Invert Maximum Ponded External ID Type Elevation Elev. Area Inflow ft ft ft' Autodesk Storm and Sanitary Analysis OFF -SITE 0.00 0.00 0.00 0.00 1.13 0.00 0.00 0.00 0.00 274.42 275.20 0.00 274.87 276.00 0.00 OUTFALL OUTFALL OUTFALL OUTFALL-2 OUTFALL PL-EAST STORAGE PL-WEST STORAGE x**x*x****x* Link Summary ************ Link From Node To Node ID --------------------------------------- WEIR IA PL-EAST OUTFALL WEIR 1B PL-EAST OUTFALL WEIR 1C PL-EAST OUTFALL WEIR-2A PL-WEST OUTFALL WEIR-2B PL-WEST OUTFALL #x*x*x******************** Volume Runoff Quantity Continuity acre-ft Total Precipitation ...... 2.839 Surface Runoff ........... 0.269 Continuity Error (%) ..... -0.000 *******xx*xx*xxx*xxxxxxxxx Volume Flow Routing Continuity acre-ft ******x*x##***x******x**** External Inflow .......... 0.000 External Outflow ......... 2.685 Initial Stored Volume .... 0.000 Final Stored Volume ...... 0.000 Continuity Error (8) ..... 0.000 ******************************xxxxxxxxxxxx Composite Curve Number Computations Report Subbasin DA-I ________________ Soil/Surface Description ---------------------------- Composite Area & Weighted CN ---------------- Subbasin DA-2 ---------------- Soil/surface Description ---------------------------- Composite Area & Weighted CN ---------------- Subbasin DA-3 ________________ Soil/Surface Description Autodesk Storm and Sanitary Analysis Element Type WEIR WEIR WEIR WEIR WEIR Depth inches 9.908 0.937 Volume Mgallons 0.000 0.875 0.000 0.000 Length Slope Manning's ft 8 Roughness Area Soil (acres) _________________________________ Group CN 0.30 - 97.00 0.30 97.00 Area Soil (acres) Group CN _________________________________ 1.19 - 96.90 1.19 96.90 Area Soil (acres) Group CN 1.16 - 97.10 Composite Area & Weighted CN 1.16 97.10 Subbasin DA-4 Area Soil Soil/Surface Description (acres) Group CN ----------------------- ---------------------------------------------------------------- 0.16 - 95.80 Composite Area & Weighted CN 0.16 95.60 Subbas.i.n DA-5 Area Soil Soil/Surface Description (acres) Group CN ---------------------------------------------------------------------------------------- - 0.63 - 96.10 Composite Area & Weighted CN 0.63 96.10 SCS TR-55 Time of Concentration Computations Report Sheet Flow Equation Tc = (0.007 * ((n * Lf)^0.8)) / ((P^0.5) * (Sf^0.4)) Where: Tc - Time of Concentration (bra) n = Manning's Roughness If = Flow Length (ft) P = 2 yr, 24 hr Rainfall (inches) Sf = Slope (ft/ft) Shallow Concentrated Flow Equation V = 16.1345 * (Sf-0.5) (unpaved surface) V = 20.3282 * (Sf^0.5) (paved surface) V = 15.0 * (SfA0.5) (grassed waterway surface) V 10.0 * (Sf^0.5) (nearly bare & untilled surface) V = 9.0 * (SfA0.5) (cultivated straight rows surface) V - 7.0 * (Sf^0.5) (short grass pasture surface) V = 5.0 * (Sf^0.5) (woodland surface) V = 2.5 * (SfA0.5) (forest w/heavy litter surface) Tc = (Lf / V) / (3600 sec/hr) Where: Tc = Time of Concentration (bra) Lf = Flow Length (ft) V = Velocity (ft/sec) Sf = Slope (ft/ft) Channel Flow Equation V = (1.49 * (R^(2/3)) * (Sf^0.5)) / n R = Aq / Wp Te - (Lf / V) / (3600 sec/hr) Where; Autodesk Storm and Sanitary Analysis Autodesk® Storm and Sanitary Analysis 2012 - Version 6.4.29 (Build 6198) x zxxzxxxxxxxxxxzxxx Project Description x xxxzxzzxxzzzxxxzxz Pile Name ................. 25 YR PRE.SPF x xxxxzxzzzzzxzzx Analysis Options x xxxxxxxzxxxxxxx Flow Units ................ cfs Subbasin Hydrograph Method. SCS TR-55 Time of Concentration...... SCS TR-55 Link Routing Method ....... Kinematic Nave Storage Node Exfiltration.. None Starting Date ............. SEP-28-2011 00:00:00 Ending Date ............... SEP-29-2011 01:00:00 Report Time Step .......... 00:05:00 zzzxzzzzxxxxx Element Count z zxzzxzxxxxxx Number of rain gages ...... 6 Number of subbasins ....... 5 Number of nodes ........... 5 Number of links ........... 5 xxxxxzxzxzxzxzxz Raingage Summary xzzzzzzxxxxxxxxx Gage Data Data Recording ID Source Type Interval min ------------------------------------------------------------ 10 YR 10 YR INTENSITY 6.00 100 YR 100 YR INTENSITY 6.00 2 YR 2 YR INTENSITY 6.00 25 YR 25 YR INTENSITY 6.00 5 YR 5 YR INTENSITY 6.00 50 YR 50 YR INTENSITY 6.00 xxxxxxxxxzxxzxxx Subbasin Summary x xxxzxxzzxzzzzxx Subbasin Total Area ID acres -----------------------`------ DA-1 0.30 DA-2 1.19 DA-3 1.16 DA-9 0.16 DA-5 0.63 xxxxxxxxxxxz Node Summary z xxzxxxxxxxx Node Element Invert Maximum Ponded External ID Type Elevation Elev. Area Inflow ft ft ft' Autodesk Storm and Sanitary Analysis OFF -SITE OUTFALL 0.00 0.00 0.00 OUTFALL OUTFALL 0.00 1.13 0.00 OUTFALL-2 OUTFALL 0.00 0.00 0.00 PL-EAST STORAGE 274.42 275.20 0.00 PL-WEST STORAGE 274.87 276.00 0.00 ************ Link Summary **x********* Link From Node To Node Element Length Slope Manning's in ______-_-----_-----------__________---------_---_--_____------_ Type ft % Roughness ------------------ WEIR IA PL-EAST OUTFALL WEIR WEIR 1B PL-EAST OUTFALL WEIR WEIR 1C PL-EAST OUTFALL WEIR WEIR-2A PL-WEST OUTFALL WEIR WEIR-2B PL-WEST OUTFALL WEIR ***x***************x*x**** Volume Depth Runoff Quantity Continuity acre-ft inches xx************************ --------- -_-___- Total Precipitation ...... 2.548 8.892 Surface Runoff ........... 0.240 0.838 Continuity Error (R) ..... -0.000 ************************** Volume Volume Flow Routing Continuity acre-ft Mgallons *************************x --------- ""----- External Inflow .......... 0.000 0.000 External Outflow ......... 2.400 0.782 Initial Stored Volume .... 0.000 0.000 Final Stored Volume ...... 0.000 0.000 Continuity Error (&) ..... 0.000 *****x*x***********x**********xxxx******** Composite Curve Number Computations Report ***************************xx*********xx** ---------------- Subbasin DA-1 --__ --_ Area Soil Soil/Surface Description (acres) Group ___ CN --------------------------------------------------- 0.30 - 97.00 Composite Area & Weighted CN 0.30 97.00 ---------------- Subbasin DA-2 ---------------- Area Soil Soil/Surface Description (acres) Group CN ---------------------------------------------------------------------------------------- _ 1.19 - 96.90 Composite Area & Weighted CN 1.19 96.90 ---------------- Subbasin DA-3 ---------------- Area Soil Soil/Surface Description (acres) Group CN Autodesk Storm and Sanitary Analysis - 1.16 - 97.10 Composite Area & Weighted CN 1.16 97.10 ---------------- Subbasin DA-9 ---------------- Area Soil Soil/Surface Description -----------------------------------------------------------------"'-------------------- (acres) Group CN - 0.16 - 95.80 Composite Area & Weighted CN 0.16 95.80 ---------------- Subbasi.n DA-5 ---------------- Area Soil Soil/Surface Description ---------------------------------------------------- (acres) Group CN ------------ - 0.63 - 96.10 Composite Area & Weighted CN 0.63 96.10 *xxx*xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx*xx**>*****xxxx SCS TR-55 Time of Concentration Computations Report xxxxxxxxxxxxxxxxxxxxxxxx**.xxxxxxxxxxxxxxxxx*xxx xxx Sheet Flow Equation Tc = (0. 007 * ((n * Lf)A0. 8)) / ((P^O. 5) * (SfAO.4)) Where: Tc = Time of Concentration (hrs) n = Manning's Roughness Lf = Flow Length (ft) P = 2 yr, 29 hr Rainfall (inches) Sf = Slope (ft/ft) Shallow Concentrated Flow Equation V = 16.1345 * (SfA0.5) (unpaved surface) V = 20.3282 * (SfAO.5) (paved surface) V = 15.0 * (SfAO.5) (grassed waterway surface) V - 10.0 * (SfA0.5) (nearly bare & untilled surface) V = 9.0 * (SfAO.5) (cultivated straight rows surface) V = 7.0 * (SfAO.5) (short grass pasture surface) V = 5.0 * (SfAC.5) (woodland surface) V = 2.5 * (SfAO.5) (forest w/heavy litter surface) Tc = (Lf / V) / (3600 sec/hr) Where: Tc = Time of Concentration (hrs) Lf = Flow Length (ft) V = Velocity (ft/sec) Sf = Slope (ft/ft) Channel Flow Equation V = (1.99 * (RA(2/3)) * (SfAO.5)) / n A = Aq / Wp Tc - (Lf / V) / (3600 sec/hr) Where: Autodesk Storm and SanitaryAnalysis Autodesk® Storm and Sanitary Analysis 2012 - Version 6.4.29 (Build 6198) Project Description File Name ................. 10 YR PRE.SPF e xeaxxxxx��sxs« Analysis Options Flow Units ................ cfs Subbasin Hydrograph Method. SCS TR-55 Time of Concentration...... SCS TR-55 Link Routing Method ....... Kinematic Wave Storage Node Exfiltration.. None Starting Date ............. SEP-28-2011 00:00:00 Ending Date ............... SEP-29-2011 01:00:00 Report Time Step .......... 00:05:00 •�>xsx>xx>xx: Element Count �s�•rr:�aix»e Number of rain gages ...... 6 Number of subbasins ....... 5 Number of nodes ........... 5 Number of links ........... 5 Raingage Summary s.ta�xxx>xaxxxxxx Gage Data Data Recording I➢ Source Type Interval ------------------------------------------------------------ min 10 YR 10 YR INTENSITY 6.00 100 YR 100 YR INTENSITY 6.00 2 YR 2 YR INTENSITY 6.00 25 YR 25 YR INTENSITY 6.00 5 YR 5 YR INTENSITY 6.00 50 YR 50 YR INTENSITY 6.00 Subbasin Summary Subbasin Total Area ID acres ------------------------------ DA-1 0.30 DA-2 1.19 DA-3 1.16 DA-A 0.16 DA-5 0.63 x♦>x•s+�xxxx Node Summary Node Element ID Type Autodesk Storm and SanitaryAnalysis Invert Maximum Podded External Elevation Elev. Area Inflow ft it ft' OFF -SITE OUTFALL 0.00 0.00 OUTFALL OUTFALL 0.00 1.13 OUTFALL-2 OUTFALL 0.00 0.00 PL-EAST STORAGE 274.42 2.75.20 PL-WEST STORAGE 274.87 276.00 xxxxxxxxxxxx Link Summary xxxxxxxxxxxx Link From Node To Node ID ------------------------------------------ WEIR IA PL-EAST OUTFALL WEIR 1B PL-EAST OUTFALL WEIR 1C PL-EAST OUTFALL WEIR-2A PL-WEST OUTFALL WEIR-2B PL-WEST OUTFALL xxxxxxxxx xxxxxxxxxxxxxxxxx Volume Runoff Quantity Continuity acre-ft xx xxxxxxxxxxxxxxxxxxxxxxxx _________ Total Precipitation ...... 2.126 Surface Runoff ........... 0.198 Continuity Error (&) ..... -0.000 xxxxxxxxxxxxxxxxxxxxxxxxxx Volume Flow Routing Continuity acre-ft xxx:xxxxxxxxxxxxxxxxxxxxxx External Inflow .......... 0.000 External Outflow ......... 1.984 Initial Stored Volume .... 0.000 Final Stored Volume ...... 0.000 Continuity Error (8) ..... 0.000 xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Composite Curve Number Computations Report xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx Subbasin DA-1 ---------------- Soil/Surface Description ---------------------------- Composite Area & Weighted CN ---------------- Subbasin DA-2 ---------------- Soil/Surface Description ---------------------------- Composite Area & Weighted CN ---------------- Subbasin DA-3 ---------------- Soil/Surface Description Autodesk Storm and Sanitary Analysis Element Type WEIR WEIR WEIR WEIR WEIR Depth inches 7.418 0.692 Volume Mgallons 0.000 0.647 0.000 0.000 0.00 0.00 0.00 0.00 0.00 Length Slope Manning's ft % Roughness Area Soil (acres) _________________________________ Group CN 0.30 - 97.00 0.30 97.00 Area Soil (acres) Group CN _________________________________ 1.19 - 96.90 1.19 96.90 Area Soil (acres) Group CN 1.16 - 97.10 Composite Area & Weighted CN 1.16 97.10 ---------------- Subbasin DA-4 ---------------- Area Soil Soil/Surface Description (acres) Group CN -------------------------------------------- ---------------- 0.16 - 95.80 Composite Area & Weighted CN 0.16 95.80 Subbasin DA-5 Area Soil Soil/Surface Description (acres) Group CN ---------------------------------------------------------------------------------------- 0.63 - 96.10 Composite Area & Weighted CN 0.63 96.10 x xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxx SCS TR-55 Time of Concentration Computations Report xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx**xxx*xxxxxxxx Sheet Flow Equation Tc - (0. 007 * ((n * if)^0. 8)) / ((P^0. 5) * (Sf^0.4)) Where: Tc = Time of Concentration (hrs) n = Manning's Roughness Lf = Flow Length (ft) P = 2 yr, 24 hr Rainfall (inches) Sf = Slope (ft/ft) Shallow Concentrated Flow Equation V = 16.1345 * (Sf^0.5) (unpaved surface) V = 20.3282 * (SfA0.5) (paved surface) V = 15.0 * (Sf^0.5) (grassed waterway surface) V = 10.0 * (Sf^D.5) (nearly bare & untitled surface) V = 9.0 * (Sf^0.5) (cultivated straight rows surface) V = 7.0 * (Sf^0.5) (short grass pasture surface) V = 5.0 * (Sf^0.5) (woodland surface) V - 2.5 * (Sf^0.5) (forest w/heavy litter surface) To = (if / V) / (3600 sec/hr) Where; Tc = Time of Concentration (hrs) Lf = Flow Length (ft) V = Velocity (ft/sec) Sf = Slope (ft/ft) Channel Flow Equation V = (1.49 * (R^(2/3)) * (Sf^0.5)) / n R = Aq / Wp Tc = (Lf / V) / (3600 sec/hr) Where: Autodesk Storm and Sanitary Analysts Autodesk@ Storm and Sanitary Analysis 2012 - Version 6.4.29 (Build 6198) x+x+xx+++++x+x+xxxx Project Description ++++xxxxxxxxxxxx+xx File Name ................. 2 YR PRE.SPF xx+xxxxxx+++++++ Analysis Options Flow Units ................ cfs Subbasin Rydrograph Method. SCS TR-55 Time of Concentration...... SCS TR-55 Link Routing Method ....... Kinematic Wave Storage Node Exfiltration.. None Starting Date ............. SEP-28-2011 00:00:00 Ending Date ............... SEP-29-2011 01:00:00 Report Time Step .......... 00:05:00 x xxx+xxxxx+xx Element Count +x+x+++x+xxx+ Number of rain gages ...... 6 Number of subbasins ....... 5 Number of nodes ........... 5 Number of links ........... 5 •++++xxxxxx+xx++ Raingage Summary +x++x++x+x++xx+x Gage Data Data Recording ID Source Type Interval min ------------------------------------------------------------ 10 YR 10 YR INTENSITY 6.00 100 YR 100 YR INTENSITY 6.00 2 YR 2 YR INTENSITY 6.00 25 YR 25 YR INTENSITY 6.00 5 YR 5 YR INTENSITY 6.00 50 YR 50 YR INTENSITY 6.00 xx++++++++++++++ Subbasin Summary x xxxxxxxxxxxxxxx Subbasin Total Area ID acres DA-1 0.30 DA-2 1.19 DA-3 1.16 DA-9 0.16 DA-5 0.63 +++++++++xxx Node Summary +x+x+++xx+++ Node Element ID Type Autodesk Storm and Sanitary Analysis Invert Maximum Ponded External Elevation Elev. Area Inflow ft ft ft' OFF -SITE OUTFALL 0.00 0.00 0.00 OU'1'FALL OUTFALL 0.00 1.13 0.00 OUTFALL-2 OUTFALL 0.00 0.00 0.00 PL-EAST STORAGE 274.42 275.20 0.00 PL-WEST STORAGE 274.87 276.00 0.00 x**xx**x*xxx Link Summary #*#*#*####*# Link From Node To Node Element Length Slope Manning's ID ----------------------------- Type --___ ft 8 Roughness WEIR IA PL-EAST OUTFALL WEIR _____ WEIR 1B PL-EAST OUTFALL WEIR WEIR 1C PL-EAST OUTFALL WEIR WEIR-2A PL-WEST OUTFALL WEIR WEIR-2B PL-WEST OUTFALL WEIR *#*********xx**xxxxxxx##x* Volume Depth Runoff Quantity Continuity acre-ft inches xxx****xx#*#xx##**x#***x** --------- ------- Total Precipitation ...... 1.311 4.573 Surface Runoff ........... 0.118 0.413 Continuity Error (&) ..... -0.000 ************************** Volume Volume Flow Routing Continuity acre-ft Mgallons *xxx****x**#x#*#####*#*##* --------- -____-_-- External Inflow .......... 0.000 0.000 External Outflow ......... 1.183 0.386 Initial Stored Volume .... 0.000 0.000 Final Stored Volume ...... 0.000 0.000 Continuity Error (%) ..... 0.000 #*x**x#*#***x*xxxxxxxxx*x#######x***x*xx** Composite Curve Number Computations Report ---------------- Subbasin DA-1 ---------------- Area Soil Soil/Surface Description ---------------------------------- ---__ (acres) Group CN - 0.30 --------__-_ - _-__ 97.00 Composite Area & Weighted CN 0.30 97.00 ---------------- Subbasin DA-2 ---------------- Area Soil Soil/Surface Description ------------------------------- (acres) _-------_----------____-_-------------__ Group CN - 1.19 - 96.90 Composite Area & Weighted CN 1.19 96.90 ---------------- Subbasin DA-3 ---------------- Area Soil Soil/Surface Description (acres) Group CN Autodesk Storm and Sanitary Analysis Composite Area & Weighted CN 1.16 ________________ Subbasin DA-4 ---------------- Area Soil/Surface ➢escription (acres) -------------------------------------------------------------- - 0.16 Composite Area & Weighted CN 0.16 ---------------- Subbasin DA-5 ---------------- Area Soil/Surface Description (acres) --------------------------------------------------------------. 0.63 Composite Area & Weighted CN 0.63 :*+**xxxxxxxxxxxxxx*xxxxxxxxx*xxxx xxxxxxxxxxxxxxxxx SCS TR-55 Time of Concentration Computations Report **xxxxxxxxxxxxxxx****xxx>xxx********x*x************ Sheet Flow Equation ------------------- Tc = (0.007 * ((n * Lf)AO.S)) / ((PAO.5) * (SfAO.4)) Where: To = Time of Concentration (bra) n = Manning's Roughness Lf = Flow Length (ft) P = 2 yr, 24 hr Rainfall (inches) Sf = Slope (ft/ft) Shallow Concentrated Flow Equation ---------------------------------- V = 16.1345 * (SfAO.S) (unpaved surface) V = 20.3282 * (SfAO.5) (paved surface) V = 15.0 * (SfAO.5) (grassed waterway surface) V = 10.0 * (SfAO.5) (nearly bare & untilled surface) V = 9.0 * (SfA0.5) (cultivated straight rows surface) V = 7.0 * (SfAO.5) (short grass pasture surface) V = 5.0 * (SfAO.5) (woodland surface) V = 2.5 * (SfAO.5) (forest w/heavy litter surface) To = (Lf / V) / (3600 sec/hr) Where: To - Time of Concentration (hrs) Lf = Flow Length (ft) V = Velocity (ft/sec) Sf = Slope (ft/ft) Channel Flow Equation --------------------- V = (1.49 * (RA(2/3)) * (SfAO.5)) / n R = Aq / Wp Tc = (Lf / V) / (3600 sec/hr) Where: Autodesk Storm and Sanitary Analysis 97.10 97.10 Soil Group CN ----------------- 95.80 95.80 Soil Group CN ----------------- 96.10 96.10 Autodesk0 Storm and Sanitary Analysis 2012 - Version 6.4.29 (Build 6198) Project Description File Name ................. 100 YR POST.SPF Analysis Options **************** Flow Units ................ CIS Subbasin Hydrograph Method. SCS TR-55 Time of Concentration...... SCS TR-55 Link Routing Method ....... Kinematic Wave Storage Node Ex filtration.. None Starting Date ............. SEP-28-2011 00:00:00 Ending Date ............... SEP-29-2011 01:00:00 Report Time Step .......... 00:05:00 kkk********** Element Count **k********** Number of rain gages ...... 6 Number of subbasins ....... 5 Number of nodes ........... 5 Number of links ........... 5 **************** Raingage Summary Gage Data Data Recording ID Source Type Interval min ------------------------------------------------------------ 10 YR 10 YR CUMULATIVE 6.00 100 YR 100 YR INTENSITY 6.00 2 YR 2 YR CUMULATIVE 6.00 25 YR 25 YR CUMULATIVE 6.00 5 YR 5 YR CUMULATIVE 6.00 50 YR 50 YR CUMULATIVE 6.00 ****k****k****** Subbasin Summary Subbasin Total Area ID acres ------------------------------ DA-1 0.96 DA-2 0.53 DA-3 1.16 DA-9 0.16 DA-5 0.63 **k**kkk**** Node Summary ********kk** Node Element ID Type Autodesk Storm and Sanitary Analysis Invert Maximum Ponded External Elevation Elev. Area Inflow ft it ft' OFF -SITE OUTFALL 0.00 0.00 OUTFALL OUTFALL 0.00 1.13 OUTFALL-2 OUTFALL 0.00 0.00 PL-EAST STORAGE 274.42 275.20 PL-WEST STORAGE 274.87 276.00 *+*++******* Link Summary Link From Node To Node ID ------------------------------------------ WEIR 1A PL-EAST OUTFALL WEIR 113 PL-EAST OUTFALL WEIR 1C PL-EAST OUTFALL WEIR-2A PL-WEST OUTFALL WEIR-2B PL-WEST OUTFALL ******************+******* Volume Runoff Quantity Continuity acre-ft Total Precipitation ...... 3.204 Surface Runoff ........... 0.306 Continuity Error (8) ..... -0.000 *+*+++**************+***** Volume Flow Routing Continuity acre-ft ************************** External Inflow .......... 0.000 External Outflow ......... 3.055 Initial Stored Volume .... 0.000 Final Stored Volume ...... 0.000 Continuity Error (%) ..... 0.000 Composite Curve Number Computations Report *************************************++*+* Subbasin DA-1 ________________ Soil/Surface Description ---------------------------- Composite Area & Weighted CN ---------------- Subbasin DA-2 ________________ Soil/Surface Description ---------------------------- Composite Area & Weighted CN ---------------- Subbasin DA-3 ---------------- Soil/Surface Description Autodesk Storm and Sanitary Analysis Element Type WEIR WEIR WEIR WEIR WEIR Depth inches 11.178 1.066 Volume Mgallons 0.000 0.995 0.000 0.000 0.00 0.00 0.00 0.00 0.00 Length Slope Manning's ft % Roughness Area Soil (acres) _________________________________ Group CN 0.96 - 97.50 0.96 97.50 Area Soil (acres) --------------------------------- Group CN 0.53 - 97.10 0.53 97.10 Area Soil (acres) Group CN - 1.16 - 97.50 Composite Area & weighted CN 1.16 97.50 ________________ Subbasin DA-9 ---------------- Area Soil Soil/Surface Description (acres) Group CN ---------------------------------------------------------------------------------------- - 0.16 - 95.80 Composite Area & Weighted CN 0.16 95.80 Subbasin DA-5 ---------------- Area Soil Soil/Surface Description (acres) Group CN ---------------------------------------------------------------------------------------- 0.63 - 96.10 Composite Area & Weighted CN 0.63 96.10 SCS TR-55 Time of Concentration Computations Report *********kx**xxxxkx**k**k*x*k*xxxxxx*x**********k*x Sheet Flow Equation To = (0.007 * ((n * Lf)A0.8)) / ((PA0.5) * (SfA0.9)) Where: Tc = Time of Concentration (bra) n - Manning's Roughness Lf = Flow Length (ft) P = 2 yr, 29 hr Rainfall (inches) Sf = Slope (ft/ft) Shallow Concentrated Flow Equation V - 16.1345 * (SfA0,5) (unpaved surface) V = 20.3282 * (SfA0.5) (paved surface) V = 15.0 * (SfA0.5) (grassed waterway surface) V = 10.0 * (SfA0.5) (nearly bare & untilled surface) V = 9.0 * (SfA0.5) (cultivated straight rows surface) V = 7.0 * (SfA0.5) (short grass pasture surface) V = 5.0 * (SfA0.5) (woodland surface) V = 2.5 * (SfA0.5) (forest w/heavy litter surface) Tc - (Lf / V) / (3600 sec/hr) Where: Te = Time of Concentration (bra) Lf = Flow Length (ft) V = Velocity (ft/sec) Sf = Slope (ft/ft) Channel Flow Equation V = (1.99 * (RA(2/3)) * (SfAo.5)) / n R - Aq / Wp To = (Lf / V) / (3600 sec/hr) Where: Autodesk Storm and Sanitary Analysis Autodesk® Storm and Sanitary Analysis 2012 - Version 6.4.29 (Build 6198) x xx xxxxxxxxxxxxxxxx Project Description +xxxxxxxxxxxxxxxxxx File Name ................. 50 YR POST.SPF x xxxxxxxxxxxxxxx Analysis Options x xxxxxxxxxxxxxxx Flow Units cfs Subbasin Hydrograph Method. SCS TR-55 Time of Concentration...... SCS TR-55 Link Routing Method ....... Kinematic Wave Storage Node Exfiltration.. None Starting Date ............. SEP-28-2011 00:00:00 Ending Date ............... SEP-29-2011 01:00:00 Report Time Step .......... 00:05:00 xxxxxxxxxxxxx Element Count x xxx xxxxxxxxx Number of rain gages ...... 6 Number of subbasins ....... 5 Number of nodes ........... 5 Number of links ........... 5 x xxxxxxxxxxxxxxx Raingage Summary x xxxxx.xxxxxxxxx Gage Data Data Recording ID Source Type Interval min ------------------------------------------------------------ 10 YR 10 YR CUMULATIVE 6.00 100 YR 100 YR INTENSITY 6.00 2 YR 2 YR CUMULATIVE 6.00 25 YR 25 YR CUMULATIVE 6.00 5 YR 5 YR CUMULATIVE 6.00 50 YR 50 YR INTENSITY 6.00 x xxxxxxxxxxxxxxx Subbasin Summary xxxxxxxxxxxxxxxx Subbasin Total Area ID acres ------------------------------ DA-1 0.96 DA-2 0.53 DA-3 1.16 ➢A-9 0.16 DA-5 0.63 xxxxxxxxxxxx Node Summary xxxxxxxxxxxx Node Element ID Type Autodesk Storm and Sanitary Analysis Invert Maximum Ponded External Elevation Elev. Area Inflow It £t ft' OFF -SITE 0.00 0.00 0.00 0.00 1.13 0.00 0.00 0.00 0.00 274.42 275.20 0.00 274.87 276.00 0.00 OUTFALL OUTFALL OUTFALL OUTFALL-2 OUTFALL PL-EAST STORAGE PL-WEST STORAGE *****#*#**** Link Summary ************ Link From Node To Node ID ------------------------------ _________ WEIR lA PL-EAST OUTFAI.L WEIR 15 PL-EAST OUTFALL WEIR 1C PL-EAST OUTFALL WEIR-2A PL-WEST OUTFALL WEIR-2R PL-WEST OUTFALL ************************** Volume Runoff Quantity Continuity acre-ft Total Precipitation ...... 2.840 Surface Runoff ........... 0.270 Continuity Error (a) ..... -0.000 ***xx****x**************** Volume Flow Routing Continuity acre-ft External Inflow .......... 0.000 External Outflow ......... 2,697 Initial Stored Volume .... 0.000 Final Stored Volume ...... 0.000 Continuity Error (%) ..... 0.000 *******************#*****#*************x** Composite Curve Number Computations Report Subbasin DA-1 ---------------- Soil/Surface Description ---------------------------- Composite Area a Weighted ON ---------------- Subbasin DA-2 ---------------- Soil/Surface Description ---------------------------- Composite Area 6 Weighted ON ---------------- Subbasin DA-3 ________________ Soil/Surface Description Autodesk Storm and Sanitary Analysis Element Type WEIR WEIR WEIR WEIR WEIR Depth inches 9,906 0.941 Volume Mgallons 0.000 0.879 0.000 0.000 Length Slope Manning's ft % Roughness Area Soil (acres) ------- ------------------------- Group CN 0.96 - 97.50 0.96 97.50 Area Soil (acres) --------------------------------- Group CN 0.53 - 97.10 0.53 97.10 Area Soil (acres) Group CN 1.16 - 97.50 Composite Area & Weighted CN 1.16 97.50 ________________ Subbasin DA-4 ---------------- Area Soil Soil/Surface Description (acres) Group CN ----------------------------------------------------------0.16 ---__ - 95.80 Composite Area & Weighted CN 0.16 95.80 Subbasin DA-5 ---------------- Area Soil Soil/Surface Description (acres) Group CN _______________________________________________________________________--___-_ 0.63 - 96.10 Composite Area & Weighted CN 0.63 96.10 k kkk*#k*****k*********k*#********###**kkk**#***kk** SCS TR-55 Time of Concentration Computations Report Sheet Flow Equation To = (0.007 * ((n * Lf) ^0.8)) / ((P^0.5) * (Sf^0.4)) Where: To - Time of Concentration (bra) n = Manning's Roughness Lf = Flow Length (ft) P = 2 yr, 24 hr Rainfall (inches) Sf = Slope (ft/ft) Shallow Concentrated Flow Equation V = 16.1345 * (Sf^0.5) (unpaved surface) V - 20.3282 * (Sf^0.5) (paved surface) V = 15.0 * (Sf^0.5) (grassed waterway surface) V = 10.0 * (Sf^0.5) (nearly bare & untilled surface) V = 9.0 * (Sf^0.5) (cultivated straight rows surface) V - 7.0 * (Sf^0.5) (short grass pasture surface) V = 5.0 * (Sf^0.5) (woodland surface) V = 2.5 * (Sf^0.5) (forest w/heavy litter surface) To = (Lf / V) / (3600 sec/hr) Where: To = Time of Concentration (bra) Lf = Flow Length (ft) V = Velocity (ft/sec) Sf = Slope (ft/ft) Channel Flow Equation V = (1.49 * (R^(2/3)) * (Sf^0.5)) / n R = Aq / Wp To = (Lf / V) / (3600 sec/hr) Where: Autodesk Storm and Sanitary Analysis Autodesk® Storm and Sanitary Analysis 2012 - Version 6.4.29 (Build 6198) Project Description File Name ................. 25 YR POST.SPF **************** Analysis Options Flow Units ................ cfs Subbasin Hydrograph Method. SCS TR-55 Time of Concentration...... SCS TR-55 Link Routing Method ....... Kinematic wave Storage Node Exfiltration.. None Starting Date ............. SEP-28-2011 00:00:00 Ending Date ............... SEP-29-2011 01:00:00 Report Time Step .......... 00:05:00 Element Count ************* Number of rain gages ...... 6 Number of subbasins ....... 5 Number of nodes ........... 5 Number of links ........... 5 *#************** Raingage Summary ***********xxxx* Gage Data ID Source Data Recording Type Interval min 10 YR 10 YR CUMULATIVE 6.00 100 YR 100 YR INTENSITY 6.00 2 YR 2 YR CUMULATIVE 6.00 25 YR 25 YR INTENSITY 6.00 5 YR 5 YR CUMULATIVE 6.00 50 YR 50 YR CUMULATIVE 6.00 Subbasin Summary **************** Subbasin Total Area ID acres ------------------------------ DA-1 0.96 DA-2 0.53 DA-3 1.16 DA-9 0.16 DA-5 0.63 *****+****** Node Summary Node Element ID Type Autodesk Storm and Sanitary Analysis Invert Maximum Ponded External Elevation Elev. Area Inflow it it ft. OFF -SITE OUTFALL 0.00 0.00 0.00 OUTFALL OUTFALL 0.00 1.13 0.00 OUTFALL-2 OUTFALL 0.00 0.00 0.00 PL-EAST STORAGE 274.42 275.20 0.00 PL-WEST STORAGE 274.87 276.00 0.00 x xxxxxxxxxxx Link Summary x xxxxxxxxxxx Link From Node To Node Element Length Slope Manning's ID Type ft % Roughness ---------------------------------------------------------------------------------- WEIR IA PL-CAST OUTFALL WEIR WEIR 1R PL-EAST OUTFALL WEIR WEIR 1C PL-EAST OUTFALL WEIR WEIR-2A PL-WEST OUTFALL WEIR WEIR-2B PL-WEST OUTFALL WEIR ************************** Volume Depth Runoff Quantity Continuity acre-ft inches x xxxxxxxxxxxxxxxxxxxxxxxxx --------- ------- Total Precipitation ...... 2.549 8.892 Surface Runoff ........... 0.241 0.841 Continuity Error (%) ..... -0.000 ************************** Volume Volume Flow Routing Continuity acre-ft Mgallons x xxxxxxxxxxx*xxxx++**xxxxx --------- ----_-___ External Inflow .......... 0.000 0.000 External Outflow ......... 2.411 0.786 Initial Stored Volume .... 0.000 0.000 Final Stored Volume ...... 0.000 0.000 Continuity Error (8) ..... 0.000 x xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx**xxx Composite Curve Number Computations Report xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx ________________ Subbasin DA-1 ---------------- Area Soil Soil/Surface Description ____________________________________________________________________________ (acres) Group ON - 0.96 - 97.50 Composite Area & Weighted CN 0.96 97.50 ________________ Subbasin DA-2 ---------------- Area Soil Soil/Surface Description ___________________________________________________ (acres) Group ON ___________ - 0.53 - 97.10 Composite Area & Weighted ON 0.53 97.10 ________________ Subbasin DA-3 ---------------- Area Soil Soil/Surface Description (acres) Group CN Autodesk Storm and Sanitary Analysis 1.16 - 97.50 Composite Area S Weighted CN 1.16 97.50 Subbasin DA-4 Area Soil Soil/Surface Description (acres) Group CN ---------------------------------------------------------------------------------------- 0.16 - 95.80 Composite Area & Weighted CN 0.16 95.80 Subbasin DA-5 ---------------- Area Soil Soil/Surface Description (acres) Group CN ---------------------------------------------------------------------------------------- 0.63 - 96.10 Composite Area 6 Weighted CN 0.63 96.10 SCS TR-55 Time of Concentration Computations Report Sheet Flow Equation To = (0. 007 * ((n * Lf) ^0.8)) / ((P^0. 5) * (Sf^0.4)) Where: To = Time of Concentration (hrs) n = Manning's Roughness Lf = Flow Length (it) P = 2 yr, 24 hr Rainfall (inches) Sf = Slope (ft/ft) Shallow Concentrated Flow Equation V = 16.1345 * (Sf^0.5) (unpaved surface) V = 20.3282 * (Sf^0.5) (paved surface) V = 15.0 * (SfA0.5) (grassed waterway surface) V = 10.0 * (Sf^0.5) (nearly bare & untilled surface) V = 9.0 * (Sf^0.5) (cultivated straight rows surface) V = 7.0 * (Sf^0.5) (short grass pasture surface) V = 5.0 * (Sf^0.5) (woodland surface) V = 2.5 * (Sf^0.5) (forest w/heavy litter surface) Tc = (Lf / V) / (3600 sec/hr) Where: Tc = Time of Concentration (hrs) Lf = Flow Length (ft) V - Velocity (ft/sec) Sf = Slope (ft/ft) Channel Flow Equation V = (1.49 * (RA(2/3)) * (Sf^0.5)) / n R = Aq / tip To = (Lf / V) / (3600 sec/hr) Where: Autodesk Storm and Sanitary Analysts Autodesk® Storm and Sanitary Analysis 2012 - Version 6.4.29 (Build 6198) Project Description ******************* File Name ................. 10 YR POST.SPF Analysis Options **************** Flow Units ................ cfs Subbasin Hydrograph Method. SCS TR-55 Time of Concentration...... SCS TR-55 Link Routing Method ....... Kinematic Wave Storage Node Exfiltration.. None Starting Date ............. SEP-28-2011 00:00:00 Ending Date ............... SEP-29-2011 01:00:00 Report Time Step .......... 00:05:00 ************* Element Count ************* Number of rain gages ...... 6 Number of subbasins ....... 5 Number of nodes ........... 5 Number of links ........... 5 Raingage summary Gage Data Data Recording ID Source Type Interval min ------------------------------------------------------------ 10 YR 10 YR INTENSITY 6.00 100 YR 100 YR INTENSITY 6.00 2 YR 2 YR CUMULATIVE 6.00 25 YR 25 YR CUMULATIVE 6.00 5 YR 5 YR CUMULATIVE 6.00 50 YR 50 YR CUMULATIVE 6.00 **************** Subbasin Summary **************** Subbasin Total Area ID acres DA-1 0.96 DA-2 0.53 DA-3 1.16 DA-4 0.16 DA-5 0.63 ************ Node Summary ************ Node Element ID Type Autodesk Storm and Sanitary Analysis Invert Maximum Ponded External Elevation Elev. Area Inflow ft ft ft' OFF -SITE OUTFALL 0.00 0.00 OUTFALL OUTFALL 0.00 1.13 OUTFALL-2 OUTFALL 0.00 0.00 PL-EAST STORAGE 274.42 275.20 PL-WEST STORAGE 274.87 276.00 #####*#***** Link Summary ****######## Link From Node To Node ID ------------------------------------------ WEIR lA PL-EAST OUTFALL WEIR 1B PL-EAST OUTFALI. WEIR 1C PL-EAST OUTFALL WEIR-2A PL-WEST OUTFALL WEIR-2B PL-WEST OUTFALL ####**************x*#***#* Volume Runoff Quantity Continuity acre-ft Total Precipitation ...... 2.127 Surface Runoff ........... 0.200 Continuity Error (%) ..... -0.000 **#######*#########*##*#** Volume Flow Routing Continuity acre-ft External Inflow .......... 0.000 External Outflow ......... 1.995 Initial Stored Volume .... 0.000 Final Stored Volume ...... 0.000 Continuity Error (%) ..... 0.000 Composite Curve Number Computations Report ######xxx**xx#xxxx*x****x****#**##**##*### Subbasin DA-1 Soil/Surface Description ---------------------------- composite Area & Weighted CN ________________ Subbasin DA-2 ________________ Soil/Surface Description ---------------------------- Composite Area & Weighted CN ________________ Subbasin DA-3 ---------------- Soil/Surface Description Autodesk Storm and Sanitary Analysis Element Type WEIR WEIR WEIR WEIR WEIR Depth inches 7.418 0.696 Volume Mgallons 0.000 0.650 0.000 0.000 0.00 0.00 0.00 0.00 0.00 Length Slope Manning's ft % Roughness Area Soil (acres) _________________________________ Group CN 0.96 - 97.50 0.96 97.50 Area Soil (acres) Group CN --------------------------------- 0.53 - 97.10 0.53 97.10 Area Soil (acres) Group CN Composite Area & Weighted CN 1.16 ________________ Subbasin DA-9 ---------------- Area Soil/Surface Description (acres) ________________ _______________------------- 0.16 Composite Area & Weighted CN 0.16 ________________ Subbasin DA-5 --------'------- Area Soil/Surface Description (acres) _______________________ _-___________--- 0.63 Composite Area & Weighted CN 0.63 SCS TR-55 Time of Concentration Computations Report Sheet Flow Equation ___________________ Tc = (0.007 * ((n * Lf)^0.8)) / ((P^0.5) * (Sf^0.9)) Where: Tc = Time of Concentration (hrs) n = Manning's Roughness Lf = Flow Length (ft) P = 2 yr, 24 hr Rainfall (inches) Sf = Slope (ft/ft) Shallow Concentrated Flow Equation ---------------------------------- V = 16.1345 * (Sf^0,5) (unpaved surface) V = 20.3282 * (Sf^0.5) (paved surface) V = 15.0 * (Sf^0.5) (grassed waterway surface) V = 10.0 * (Sf^0.5) (nearly bare & untilled surface) V = 9.0 * (Sf^0,5) (cultivated straight rows surface) V = 7.0 * (Sf^0.5) (short grass pasture surface) V = 5.0 * (Sf^0.5) (woodland surface) V = 2.5 * (Sf^0.5) (forest w/heavy litter surface) To = (Lf / V) / (3600 sec/hr) Where: To = Time of Concentration (hrs) Lf = Flow Length (ft) V = Velocity (ft/sec) Sf = Slope (ft/ft) Channel Flow Equation --------------------- V = (1.99 * (R^(2/3)) * (Sf^0.5)) / n R = Aq / Wp Tc = (Lf / V) / (3600 sec/hr) Where: Autodesk Storm and Sanitary Analysis 97.50 97.50 Soil Group CN ----------------- 95.80 95.80 Soil Group CN ----------------- 96.10 96.10 Autodesk© Storm and Sanitary Analysis 2012 - Version 6.4.29 (Build 6198) x xxxxxxxxxxxxxxxxxx Project Description xxxxxxxxxxxxxxxxxxx File Name ................. 2 YR POST.SPF x xxxxxxxxxxxxxxx Analysis Options xxxxxxxxx xxxxxxx Flow Units ................ cis Subbasin Hydrograph Method. SCS TR-55 Time of Concentration...... SOS TR-55 Link Routing Method ....... Kinematic Wave Storage Node Exfiltration.. None Starting Date ............. SEP-28-2011 00:00:00 Ending Date ............... SEP-29-2011 01:00:00 Report Time Step .......... 00:05:00 xxxxxxxxxxxxx Element Count x xxxxxxxxxxxx Number of rain gages ...... 6 Number of subbasins ....... 5 Number of nodes ........... 5 Number of links ........... 5 x xxxx xxxxxxxxxxx Raingage Summary x xxxxxxxxxxxxxxx Gage Data Data Recording ID Source Type Interval ,in ------------------------------------------------------------ 10 YR 10 YR CUMULATIVE 6.00 100 YR 100 YR INTENSITY 6.00 2 YR 2 YR INTENSITY 6.00 25 YR 25 YR CUMULATIVE 6.00 5 YR 5 YR CUMULATIVE 6.00 50 YR 50 YR CUMULATIVE 6.00 x xxxxxxxxxxxxxxx Subbasin Summary :xxxxxxxxxxx>xxx Subbasin Total Area ID acres ------------------------------ DA-1 0.96 DA-2 0.53 DA-3 1.16 DA-9 0.16 DA-5 0.63 xxxxxxxxxxxx Node Summary xxxxxxxxxxxx Node Element Invert Maximum Bonded External ID Type Elevation Elev. Area Inflow ft ft ft' Autodesk Storm and Sanitary Analysis OFF -SITE OUTFALL 0.00 0.00 0.00 OUTFALL OUTFALL 0.00 1.13 0.00 OUTFALL-2 OUTFALL 0.00 0.00 0.00 PL-EAST STORAGE 274.42 275.20 0.00 PL-WEST STORAGE 274.87 276.00 0.00 Link Summary x***x******* Link From Node To Node Element Length Slope Manning's ID Type £t % Roughness -------------------------------------------------------------------------------------------- WEIR lA PL-EAST OUTFALL WEIR WEIR 1B PL-EAST OUTFALL WEIR WEIR 1C PL-EAST OUTFALL WEIR WEIR-2A PL-WEST OUTFALL WEIR WEIR-2B PL-WEST OUTFALL WEIR ************************** Volume Depth Runoff Quantity Continuity acre-ft inches ******************k******* Total Precipitation ...... 1.311 4.573 Surface Runoff ........... 0.119 0.416 Continuity Error (%) ..... -0.000 ************************** Volume Volume Flow Routing Continuity acre-ft Mgallons **x**x***********x*x*xx*xx --------- ___------ External Inflow .......... 0.000 0.000 External Outflow ......... 1.193 0.389 Initial Stored Volume .... 0.000 0.000 Final Stored Volume ...... 0.000 0.000 Continuity Error (8) ..... 0.000 xxx***************************x*********** Composite Curve Number Computations Report Subbasin DA-1 Area Soil Soil/Surface Description (acres) Group CN ---------------------------------------------------------------------------------------- - 0.96 - 97.50 Composite Area & Weighted CN 0.96 97.50 ________________ Subbasin DA-2 --_-`----------- Area Soil Soil/Surface Description (acres) Group CN --_-__-___ - ----------------------------------------------- 0.53 - 97.10 Composite Area & Weighted CN 0.53 97.10 ---------------- Subbasin DA-3 ---------------- Area Soil Soil/Surface Description (acres) Group CN Autodesk Storm and Sanitary Analysis 1.16 - 97.50 Composite Area & Weighted CN 1.16 97.50 Subbasin DA-4 Area Soil Soil/Surface Description (acres) Group CN ---------------------------------------------------------------------------------------- - 0.16 - 95.90 Composite Area & Weighted CN 0.16 95.80 Subbasin DA-5 Area Soil Soil/Surface Description (acres) Group CN -------------------------------- _------------------------------- 0.63 - 96.10 Composite Area & Weighted CN 0.63 96.10 SCS TR-55 Time of Concentration Computations Report **********************kkk************************** Sheet Flow Equation Tc = (0. 007 * ((n * Lf)^0. 8)) / ((P^0. 5) * (Sf^0.4)) Where: Te = Time of Concentration (bra) n = Manning's Roughness Lf = Flow Length (ft) P = 2 yr, 24 hr Rainfall (inches) Sf = Slope (ft/ft) Shallow Concentrated Flow Equation V = 16.1345 * (SfA0.5) (unpaved surface) V - 20.3262 * (SfA0.5) (paved surface) V = 15.0 * (Sf^0.5) (grassed waterway surface) V = ].0.0 * (Sf^0.5) (nearly bare & untilled surface) V = 9.0 * (SfA0.5) (cultivated straight rows surface) V = 7.0 * (SfA0.5) (short grass pasture surface) V = 5.0 * (Sf^0.5) (woodland surface) V = 2.5 * (SfA0.5) (forest w/heavy litter surface) Tc = (Lf / V) / (3600 sec/hr) where: To = Time of Concentration (hrs) Lf - Flow Length (ft) V = Velocity (ft/sec) Sf = Slope (ft/ft) Channel Flow Equation V = (1.49 * (RA(2/3)) * (SfA0.5)) / n R = Aq I Wp Tc = (Lf / V) / (3600 sec/hr) Where: Autodesk Storm and SanitaryAnalysls APPENDIX D: Technical Design Summary SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 2 — Project Administration Start (Page 2.1) Engineering and Design Professionals Information Engineering Firm Name and Address: Jurisdiction Gessner Engineering City: Bryan 2501 Ashford Drive, Suite 102 College Station, Texas 77840 X College Station Date of Submittal: Lead Engineer's Name and Contact Info.(phone, e-mail, fax): Other: Kyle zapalac, Jeremy Peters, jpeters@gessnerengineering.com kzapalac@gessner (979) 680-8840, (979) 680-8841 en ineerin .com Supporting Engineering / Consulting Firm(s): Other contacts: Developer / Owner / Applicant Information Developer / Applicant Name and Address: Phone and e-mail: Brazos Fellowship -Shawn Parish (979) 68o-8888 226 Southwest Parkway East shawn@brazosfellowship.com College Station, Texas 77840 Property Owner(s) if not Developer / Applicant (& address): Phone and e-mail: Brazos Fellowship Project Identification Development Name: Brazos Fellowship Is subject property a site project, a single-phase subdivision, or part of a multi -phase subdivision? Site Project If multi -phase, subject property Is phase of Legal description of subject property (phase) or Project Area: (see Section II, Paragraph B-3a) Lots 2,3,5,6, Block'B' and Lot 7, Block'D', Ashford Square 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): South of Southwest Parkway East In City Limits? Extraterritorial Jurisdiction (acreage): Bryan: acres. Bryan: College Station: College Station: 3.43 acres. Acreage Outside ETJ: i STORMWATER DESIGN GUIDELINES Page 3 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 2 — Proiect Administration Continued (page 2.2) Project Identification (continued) Roadways abutting or within Project Area or Abutting tracts, platted land, or built subject property: developments: Land -locked, South of Southwest Parkway East Named Regulatory Watercourse(s) & Watershed(s): Tributary Basin(s): Bee Creek Plat Information For Project or Subject Property (or Phase) Preliminary Plat File #: Final Plat File #: 17439 Date: Name: Status and Vol/Pg: 590/269 If two plats, second name: File #: Status: Date: Zoning Information For Project or Subject Property (or Phase) Zoning Type: C-1 Existing or Proposed? Existing 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: PAC- 7/27/11 Gessner Engineering BBA Architects Brazos Fellowship Preliminary Report Required? NO 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 Drainage Report, if any. N/A STORMWATER DESIGN GUIDELINES Page 4 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 2 — Project Administration Continued (page 2.3) Coordination For Project or Subject Property (or Phase) Note: For any Coordination of stormwater matters indicated below, attach documentation describing and substantiating any agreements, understandings, contracts, or approvals. Dept. Contact: Date: Subject: Coordination With Other Departments of Jurisdiction City (Bryan or College Station) Coordination With Summarize need(s) & actions taken (include contacts & dates): Non -jurisdiction City Needed? Yes No X Coordination with Summarize need(s) & actions taken (include contacts & dates):. Brazos County Needed? Yes No X Coordination with Summarize need(s) & actions taken (include contacts & dates): TxDOT Needed? Yes No x Coordination with Summarize need(s) & actions taken (include contacts & dates): TAMUS Needed? Yes _ No X Permits For Project or Subject Property (or Phase) As to stormwater management, are permits required for the proposed work from any of the entities listed below? If so, summarize status of efforts toward that objective ins aces below. Entity Permitted or Status of Actions (include dates) A ' Approved . US Army Crops of Engineers No X Yes _ US Environmental Protection Agency No X Yes Texas Commission on Environmental Quality No X Yes _ Brazos River Authority No x Yes STORMWATER DESIGN GUIDELINES Page 5 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 3 — Property Characteristics Start (Page 3.1) Nature and Scope of Proposed Work Existing: Land proposed for development currently used, including extent of impervious cover? Church Site, 87% Impervious 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 applicable) — Building on a single lot, or adjoining lots, where proposed plat will not form a new street (but may include ROW dedication to existing streets). X Other (explain): Addition Subdivision Construction of streets and utilities to serve one or more lap tted lots. Development _ Construction of streets and utilities to serve one or more proposed lots on Project lands represented by pending plats. Site projects: building use(s), approximate floor space, impervious cover ratio. Describe Subdivisions: number of lots by general type of use, linear feet of streets and Nature and drainage easements or ROW. Size of 16,968 SF Building addition, parking modification Proposed 90%Impervious Project Is any work planned on land that is not platted If yes, explain: or on land for which platting is not pending? x No —Yes FEMA Floodplains Is any part of subject property abutting a Named Regulatory Watercourse No X Yes (Section 11, Paragraph B1) or a tributary thereof? Is any part of subject property in floodplain No X Yes Rate Map area of a FEMA-regulated watercourse? — Encroachment(s) into Floodplain Encroachment purpose(s): — Building site(s) — Road crossing(s) areas planned? Utility crossing(s) Other (explain): No X 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. N/A STORMWATER DESIGN GUIDELINES Page 6 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D — TECHNICAL DESIGN SUMMARY Part 3 — Property Characteristics Continued (Page 3.2) Hydrologic Attributes of Subject Property (or Phase) Has an earlier hydrologic analysis been done for larger area including subject property? 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, explain how it differs. No If subject property is not part of multi -phase project, describe stormwater management X plan for the property in Part 4. If property is part of multi -phase project, provide overview of stormwater management plan for Project Area here. In Part 4 describe how plan for subject property will comply therewith. Do existing topographic features on subject property store or detain runoff? No X Yes Describe them (include approximate size, volume, outfall, model, etc). PL- East-4428.46 CF, Rect., Weir (1.08'x0.48') PL-West-16261.17 CF, Rect., Weir (1.17'x1.0') Any known drainage or flooding problems in areas near subject property? X No _ Yes Identify: 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. X Detention not required. What decision has been reached? By whom? If the need for How was determination made? Type 1 Detention must be evaluated: STORMWATER DESIGN GUIDELINES Page 7 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 3 — Property Characteristics Continued (Page 3.3) Hydrologic Attributes of Subject Property (or Phase) (continued) Does subject property straddle a Watershed or Basin divide? X No Yes If yes, describesplits below. In Part 4 describe design concept for handling this. Watershed or Basin Larger acreage Lesser acreage Above -Project Areas(Section II, Paragraph B3-a) Does Project Area (project or phase) receive runoff from upland areas? x No _ Yes Size(s) of area(s) in acres: 1) 2) 3) 4) Flow Characteristics (each instance) (overland sheet, shallow concentrated, recognizable concentrated section(s), small creek (non -regulatory), regulatory 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 future? Explain Conveyance Pathways (Section II, Paragraph C2) Must runoff from study property drain across lower properties before reaching a Regulatory Watercourse or tributary? No X Yes Describe length and characteristics of each conveyance pathway(s). Include ownership of property(ies). 280 LF, Shallow Concentrated Flow R102653, Park Mance Michael and Carol R102326, Park Mance Michael and Carol R302325, Park Mance Michael and Carol R102323, Park Mance Michael and Carol STORMWATER DESIGN GUIDELINES Page 8 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D — TECHNICAL DESIGN SUMMARY Part 3 — Property 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? 100 % Created by? X plat, or easements instrument. If instrument(s), describe their provisions. exist for any part of pathway(s)? —No X Yes Where runoff must cross lower properties, describe characteristics of abutting lower property(ies). (Existing watercourses? Easement or Consent squired?) Existing Swale Pathway Areas Describe any built or Improved drainage facilities existing near the property (culverts, bridges, lined channels, buried conduit, swales, detention ponds, etc). Detention pond downstream of site Nearby Drainage Facilities Do any of these have hydrologic or hydraulic influence on proposed stormwater design? X No Yes If yes, explain: i 1 1 STORMWATER DESIGN GUIDELINES Page 9 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Start (Page 4.1) Stormwater Management Concept Discharge(s) From Upland Area(s) If runoff is to be received from upland areas, what design drainage features will be used to accommodate it and insure it is not blocked by future development? Describe for each area, flow section, or discharge point. N/A Discharge(s) To Lower Property(ies) (Section II, Paragraph E1) Does project include drainage features (existing or future) proposed to become public via platting? x No _Yes Separate Instrument? No Yes Per Guidelines reference above, how will Establishing Easements (Scenario 1) runoff be discharged to neighboring Pre -development Release (Scenario 2) property(ies)? X Combination of the two Scenarios Scenario 1: If easements are proposed, describe where needed, and provide status of actions on each. (Attached Exhibit #---) Easements Exist Scenario 2: Provide general description of how release(s) will be managed to pre -development conditions (detention, sheet flow, partially concentrated, etc.). (Attached Exhibit #---) Existing detention facilities will be used and post -developed flow will Is released with the same flow characteristics 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 used, has proposed design been coordinated with owner(s) of receiving property(ies)? x No Yes Explain and provide documentation. STORMWATER DESIGN GUIDELINES Page 10 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Continued (Page 4.2) Stormwater Management Concept (continued) Within Project Area Of Multi -Phase Project Identify gaining Basins or Watersheds and acres shifting: Will project result in shifting runoff between Basins or What design and mitigation is used to compensate for increased runoff between Watersheds? from gaining basin or watershed? X No Yes How will runoff from Project With facility(ies) involving other development projects. Area be mitigated to pre- Establishing features to serve overall Project Area. development conditions? F3::::� Select any or all of 1, 2, On phase (or site) project basis within Project Area. and/or 3, and explain below. 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 Existing detention fa ilities 3. By phase (or site) project: Describe planned mitigation measures for phases (or sites) in subsequent questions of this Part. Are aquatic echosystems proposed? No —Yes In which phase(s) or project(s)? a >- Are other Best Management Practices for reducing stormwater pollutants proposed? a- No Yes Summarize type of BMP and extent of use: w — rn N o Z If design of any runoff -handling facilities deviate from provisions of B-CS Technical Specifications, check type facility(ies) and explain in later questions. d _ Detention elements Conduit elements — Channel features Q Swales — Ditches Inlets Valley gutters _ Outfalls Culvert features Bridges Other STORMWATER DESIGN GUIDELINES Page 11 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Desion Parameters I Continued (Page 4.3) Stormwater Management Concept (continued) Within Project Area Of Multi -Phase Project (continued) Will Project Area include bridge(s) or culvert(s)? X No _Yes Identify type and general size and In which phase(s). 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): Existing facilities utilize the east and west sides of the parking lot Within Or Serving Subject Property (Phase, or Site) If property part of larger Project Area, is design in substantial conformance with earlier analysis and report for larger area? X Yes No, then summarize the difference(s): Identify whether each of the types of drainage features listed below are included, extent of use, and general characteristics. Typical shape? Surfaces? �• a Steepest side slopes: Usual front slopes: Usual back slopes: } N W yLU, Flow line slopes: least Typical distance from travelway: typical greatest (Attached Exhibit #) o y z a 0 X Are longitudinal culvert ends in compliance with B-CS Standard Specifications? Yes No, then explain: At intersections or otherwise, do valley gutters cross arterial or collector streets? a C', } No Yes If yes explain: c� a r � N y Are valley gutters proposed to cross any street away from an intersection? v o mz _ No _ Yes Explain: (number of locations?) N a v X Q STORMWATER DESIGN GUIDELINES Page 12 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Continued (Page 4.4) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Gutter line slopes: Least Usual Greatest Are inlets recessed on arterial and collector streets? _ Yes _ No If "no", identify where and why. Will inlets capture 10-year design stormflow, to prevent flooding of intersections (arterial with arterial or collector)? Yes No If no, explain where and why not. a v Will inlet size and placement prevent exceeding allowable water spread for 10-year design storm throughout site (or phase)? Yes No If no, explain. rn c a Sag curves: Are inlets placed at low points? Yes No Are inlets and g w conduit sized to prevent 100-year stormflow from ponding at greater than 24 inches? _ Yes No Explain "no" answers. _ u, w 2 Will 100-yr stormflow be contained in combination of ROW and buried conduit on Q whole length of all streets? _ Yes No If no, describe where and why. Do designs 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? No Yes Identify length(s) and where used. r NN Pipe runs between system Typical Longest } access points (feet): Are junction boxes used at each bend? Yes No If not, explain where and why. a c m o Z 'o E X I o Are downstream soffits at or below upstream soffits? Least amount that hydraulic N Yes No If not, explain where and why: grade line is below gutter line _ (system -wide): STORMWATER DESIGN GUIDELINES Page 13 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Continued (Page 4.5) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Describe watercourse(s), or system(s) receiving system discharge(s) below (include design discharge velocity, and angle between converging flow lines). U 1) Watercourse (or system), velocity, and angle? N C N -0 E 2) Watercourse (or system), velocity, and angle? o 1O c E 0 ESQ 3) Watercourse (or system), velocity, and angle? T N �a 0 O 0 a o. E a� For each outfall above, what measures are taken to prevent erosion or scour of Nreceiving and all facilities at juncture? ro 1) In m a a� 2) N 0 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): 42 m c } Flow line slopes (minimum and maximum): a` 0 NZ Outfall characteristics for each (velocity, convergent angle, & end treatment). m 3x N W < Will 100-year design storm runoff be contained within easement(s) or platted drainage ROW in all instances? Yes No If "no" explain: STORMWATER DESIGN GUIDELINES Page 14 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D — TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Continued (Page 4.6) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Are roadside ditches used? No Yes If so, provide the following: Is 25-year flow contained with 6 inches of freeboard throughout ? Yes No w _ _ Are top of banks separated from road shoulders 2 feet or more? Yes No m _ _ Are all ditch sections trapezoidal and at least 1.6 feet deep? _ Yes No p m For any "no" answers provide location(s) and explain: a (0 0 If conduit is beneath a swale, provide the following information (each instance). Instance 1 Describe general location, approximate length: a Y Is 100-year design flow contained in conduit/swale combination? —Yes —No "no" explain: UIf o m Space for 100-year storm flow? ROW Easement Width Z E Swale Surface type, minimum Conduit Type and size, minimum and maximum X =and maximum slopes: slopes, design storm: 0 w m Inlets Describe how conduit is loaded (from streets/storm drains, inlets by type): c T � C S � U c w oo Access Describe how maintenance access is provided (to swale, into conduit): m o E 0 a E Instance 2 Describe general location, approximate length: a m � v Is 100-year design flow contained in conduit/swale combination? —Yes —No 'o If "no" explain: m `o. c E Space for 100-year storm flow? ROW Easement Width J Swale Surface type, minimum Conduit Type and size, minimum and maximum v and maximum slopes: slopes, design storm: vInlets —Describe how conduit is loaded (from streets/storm drains, inlets by type): m � c 3 0 N v a Access Describe how maintenance access is provided (to swale, into conduit): STORMWATER DESIGN GUIDELINES Page 15 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D — TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Continued (Page 4.7) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) If "yes" provide the following information for each instance: Instance 1 Describe general location, approximate length, surfacing: c a o w 4-- 6 Is 100-year design flow contained in swale? _ Yes _ No Is swale wholly r within drainage ROW? Yes No Explain "no" answers: vAccess Describe how maintenance access is provide: 0 Z a o X Instance 2 Describe general location, approximate length, surfacing: v ar c n a c o E s v 3 Is 100-year design flow contained in swale? _ Yes _ No Is swale wholly °1 `o within drainage ROW? Yes No Explain "no" answers: _ w p M Access Describe how maintenance access is provided: U n 3 n Instance 3.4. etc. If swales are used in more than two instances, attach sheet providing all above information for each instance. "New" channels: Will any area(s) of concentrated flow be channelized (deepened, widened, or straightened) or otherwise altered? _ No Yes If only slightly shaped, see "Swales" in this Part. If creating side banks, provide information below. v -c Will design replicate natural channel? Yes No If "no", for each instance 0 0. describe section shape & area, flow line slope (min. & max.), surfaces, and 100-year o Wu design flow, and amount of freeboard: o N U) Instance 1: C } N E N 'o `o Instance 2: E _ z x I Instance 3: t v STORMWATER DESIGN GUIDELINES Page 16 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Continued (Page 4.8) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Existing channels (small creeks): Are these used? No Yes If" es" provide the information below. Will small creeks and their floodplains remain undisturbed? —Yes —No How many disturbance instances? Identify each planned location: 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. v w c c Watercourses (and tributaries): Aside from fringe changes, are Regulatory u Watercourses proposed to be altered? No Yes Explain below. _ Submit full report describing proposed changes to Regulatory Watercourses. Address E 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: n E c c All Proposed Channel Work: For all proposed channel 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 freeboard? _ Yes _ No If not, identify location and explain: Are ROW / easements sized to contain channel and required maintenance space? Yes _ No If not, identify location(s) and explain: STORMWATER DESIGN GUIDELINES Page 17 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Continued (Page 4.9) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) How many facilities for subject property project? 2 For each provide info. below. For each dry -type facilitiy: Facility 1 Facility 2 Acres served & design volume + 10% 0.532 0.102 Ac Ft 1.157 0.370 Ac Ft 100-yr volume: free flow & plugged 4.46 4.46 8.08 8.08 Design discharge(10 yr & 25 yr) 2.97 3.55 3.56 4.75 Spillway crest at 100-yr WSE? X yes _ no X yes no Berms 6 inches above plugged WSE? _ yes X no yes X no Explain any "no" answers: Berms are part of existing grades. No modification proposed N Ul } x I For each facility what Is 25-yr design Q, and design of outlet structure? Facility 1: 3.55 CTs, 1.07'x0.48' Weir 0 ZI Facility 2: 7.73 CTs, 1.18'xi.0'Weir Do outlets and spillways discharge into a public facility in easement or ROW? Facility 1: —Yes X No Facility 2: —Yes X No v If "no" explain: m N O D_ O LL For each, what is velocity of 25-yr design discharge at outlet? & at spillway? Facility 1: 1.33 & 2.22 Facility 2: 4.00 & 0.75 .5 Are energy dissipation measures used? X No Yes Describe type and ca LL _ location: c 0 c w m For each, is spillway surface treatment other than concrete? Yes or no, and describe: Facility 1: Grass Facility 2: Grass For each, what measures are taken to prevent erosion or scour at receiving facility? Facility 1: Concrete Drive Facility 2: Concrete Drive If berms are used give heights, slopes and surface treatments of sides. Facility 1: N/A Facility 2: N/A STORMWATER DESIGN GUIDELINES Page 18 of26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters I Continued (Page 4.10) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Do structures comply with B-CS Specifications? Yes or no, and explain if "no": Facility 1; No, Existing LL Facility 2: No, Existing C O C w O C O ro 0 For additional facilities provide all same information on a separate sheet. Are parking areas to be used for detention? No x Yes What is maximum depth due to required design storm? 0.55' x 1.08' 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 B-CS Technical Specifications? Yes _ No Explain any "no" answers: N O) C o Are culverts parallel to public roadway alignment? No Explain: _Yes U � U1 �. f0 Q Creeks at Private Drives: Do private driveways, drives, or streets cross drainage m ways that serve Above -Project areas or are in public easements/ ROW? w z No _ Yes If "yes" provide information below. X I How many instances? Describe location and provide information below. Location 1: O 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 information on separate sheet. STORMWATER DESIGN GUIDELINES Page 19 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Continued (Page 4.11) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Named Reaulatory Watercourses (& Tributaries): Are culverts proposed on these facilities? _ No Yes, then provide full report documenting assumptions, criteria, analysis, computer programs, and study findings that support proposed design(s). Is report provided? Yes _ No If "no", explain: Arterial or Maior Collector Streets: Will culverts serve these types of roadways? wNo Yes How many instances? For each identify the _ Iocation and provide the information below. m Instance 1: � a N Instance 2: c 0 Instance 3: c 0 o m Yes or No for the 100-year design flow: 1 2 3 z E `o Headwater WSE 1 foot below lowest curb top? X E Spread of headwater within ROW or easement? Is velocity limited per conditions (Table C-11)? N Explain any "no" answer(s): m 0 0 US T (6 O a o a Minor Collector or Local Streets: Will culverts serve these types of streets? No Yes How many instances? for each identify the v location and --Provide the information below: n a� a Instance 1: Nc Instance 2: a o Instance 3: r � For each instance enter value, or "yes" / "no" for: 1 2 3 U 6 Design yr. headwater WSE 1 ft. below curb top? c 100-yr. max. depth at street crown 2 feet or less? E Product of velocity (fps) & depth at crown (ft) = ? O Is velocity limited per conditions (Table C-11)? Limit of down stream analysis (feet)? Explain any "no" answers: STORMWATER DESIGN GUIDELINES Page 20 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Continued (Page 4.12) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) All Proposed Culverts: For all proposed culvert facilities (except driveway/roadside ditch intersects) provide information requested in next eight boxes. Do culverts and travelways intersect at 90 degrees? _ Yes No If not, identify location(s) and intersect angle(s), and justify the design(s): Does drainage way alignment change within or near limits of culvert and surfaced approaches thereto? _ No _ Yes If "yes" identify location(s), describe change(s), and justification: Are flumes or conduit to discharge into culvert barrel(s)? No _ Yes If yes, identify location(s) and provide justification: Are flumes or conduit to discharge into or near surfaced approaches to culvert ends? No _ Yes If "yes" identify location(s), describe outfall design treatment(s): c .c 0 U U1 'C Is scour/erosion protection provided to ensure long term stability of culvert structural <j 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 property? 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 Design Section of this Part. STORMWATER DESIGN GUIDELINES Page 21 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Continued (Page 4.13) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Is a bridge included in plans for subject property project? X No _ Yes If "yes" provide the following information. Name(s) and functional classification of the roadway(s)? What drainage way(s) is to be crossed? v rn a ro A full report supporting all aspects of the proposed bridge(s) (structural, geotechnical, hydrologic, and hydraulic factors) must accompany this summary report. Is the report provided? —Yes _ No If "no" explain: Is a Stormwater Provide a general description of planned techniques: Z, Pollution Prevention Silt fence, sand bags W Plan (SW3P) d established for `m project construction? m X 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? X No —Yes If "yes" list general type and location below. 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: STORMWATER DESIGN GUIDELINES Page 22 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Continued (Page 4.14) Stormwater Management Concept (continued) Within Or Serving Subject Property (Phase, or Site) (continued) Special Designs — Deviation From B-CS Technical Specifications If any design(s) or material(s) of traditional runoff -handling facilities deviate from provisions of B-CS Technical Specifications, check type facility(ies) and explain by specific detail element. Detention elements _ Drain system elements Channel features Culvert features Swales _ Ditches _ Inlets _Outfalls Valley gutters Bridges (explain in bridge report) In table below briefly identify specific element, justification for deviation(s). Specific Detail Element Justification for Deviation (attach additional sheets if needed) 1) 2) 3) 4) 5) Have elements been coordinated with the City Engineer or her/his designee? For each item above provide "yes" or "no", action date, and staff name: 1) 2) 3) 4) 5) Design Parameters Hydrology Is a map(s) showing all Design Drainage Areas provided? X Yes No Briefly summarize the range of applications made of the Rational Formula: Rational method not used What is the size and location of largest Design Drainage Area to which the Rational Formula has been applied? acres Location (or identifier): STORMWATER DESIGN GUIDELINES Page 23 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 1 T SECTION IX APPENDIX D - TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Continued (Page 4.15) Design Parameters (continued) Hydrology (continued) In making determinations for time of concentration, was segment analysis used? x No —Yes In approximately what percent of Design Drainage Areas? % As to intensity -duration -frequency and rain depth criteria for determining runoff flows, were any criteria other than those provided in these Guidelines used? No _Yes If "yes" identify type of data, source(s), and where applied: IDF not used For each of the stormwater management features listed below identify the storm return frequencies (year) analyzed (or checked), and that used as the basis for design. Feature Analysis Year(s) Design Year Storm drain system for arterial and collector streets Storm drain system for local streets Open channels Swale/buried conduit combination in lieu of channel Swales Roadside ditches and culverts serving them Detention facilities: spillway crest and its outfall 100 yr 100 yr Detention facilities: outlet and conveyance structure(s) 100 yr 100 yr Detention facilities: volume when outlet plugged 100 yr 100 yr Culverts serving private drives or streets Culverts serving public roadways Bridges: provide in bridge report. Hydraulics What is the range of design flow velocities as outlined below? Design flow velocities; Gutters Conduit Culverts Swales Channels Highest (feet per second) Lowest (feet per second) Streets and Storm Drain Systems Provide the summary information outlined below: Roughness coefficients used: For street gutters: For conduit type(s) Coefficients: p I STORMWATER DESIGN GUIDELINES Page 24 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 i SECTION IX APPENDIX D — TECHNICAL DESIGN SUMMARY Part 4 — Drainage Concept and Design Parameters Continued (Page 4.16) Design Parameters (continued) Hydraulics (continued) Street and Storm Drain Systems (continued) For the following, are assumptions other than allowable per Guidelines? Inlet coefficients? —No —Yes Head and friction losses —No —Yes Explain any "yes" answer: In conduit is velocity generally increased in the downstream direction? —Yes —No Are elevation drops provided at inlets, manholes, and junction boxes? —Yes —No Explain any "no" answers: Are hydraulic grade lines calculated and shown for design storm? —Yes —No For 100-year flow conditions? _Yes _No Explain any "no" answers: What tailwater conditions were assumed at outfall point(s) of the storm drain system? Identify each location and explain: Open Channels If a HEC analysis is utilized, does it follow Sec VI.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 each culvert, describe it here. For each design discharge, will operation be outlet (barrel) control or inlet control? Entrance, friction and exit losses: Bridges Provide all in bridge report STORMWATER DESIGN GUIDELINES Page 25 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009 APPENDIX D — TECHNICAL DESIGN SUMMARY Part 4 - Drainage Concept and Design Parameters Continued (Page 4.17) Design Parameters (continued) Computer Software What computer software has been used in the analysis and assessment of stormwater management needs and/or the development of facility designs proposed for subject property project? List them below, being sure to identify the software name and version, the date of the version, any applicable patches and the publisher Autodesk Storm and Sanitary Analysis 2012 Part 5 - Plans and Specifications Requirements for submittal of construction drawings and specifications do not differ due to use of a Technical Design Summary Report. See Section III, Paragraph C3. Part 6 - Conclusions and Attestation Conclusions Add any concluding information here: Attestation Provide attestation to the accuracy and completeness of the foregoing 6 Parts of this Technical Design Summary Drainage Report by signing and sealing 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 uidellnes for the owners of the property. All licenses and permits required by and state and federal regulatory agencies for th���sed drainage improvement have en issued or fall under applicable general peow?t E Of j� 11 (Affix Sea �.•............. a f 1/ AA. / G / Lic se P es sional Engineer �. .... y • �.......... K ET ��i 10 021 j"'RS i State of Texas PE No. 2 r✓ % f tEi�i�ENEEg -W�CMALEIK+ -r STORMWATER DESIGN GUIDELINES Page 26 of 26 APPENDIX. D: TECH. DESIGN SUMMARY Effective February 2007 As Revised February 2009