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Drainage Report
. I DRAINAGE REPORT SEVENTH DAY ADVENTIST CHURCH LOT 1, BLOCK 4 CAT HOLLOW -PHASE III COLLEGE STATION, BRAZOS COUNTY, TEXAS AUGUST, 2001 SUBMITTED BY: MICHAEL G. HESTER, P.E. HESTER ENGINEERING COMPANY 7607 EASTMARK DRIVE, SUITE 253-B COLLEGE STATION, TX 77840 (979) 693-1100 FX:(979) 693-1075 SEVENTii DAY ADVENTIST CHURCH -PAGE 1 o.i, Table Of Contents REPORT COVER TABLE OF CONTENTS CERTIFICATION REPORT Introduction Existing Drainage Basin Description Proposed Drainage Conclusion COMPUTATIONS Pre-Development Peak Discharge Rates Post-Development Peak Discharge Rates Post-Development ''Free-Flow" Peak Discharge Rates Post-Development Peak Discharge Rates Into Proposed Detention Pond Facility ("In-Flow") Pre-Development Hydrograph Tabulations Post-Development Hydrograph Tabulations Post-Development "Free-Flow" Hydrograph Tabulations Post-Development "In-Flow'' To Detention Pond Facility Hydrograph Tabulations COMPARISON OF PRE & POST-DEVELOPMENT HYDROGRAPHS 2-Year Stonn Events 5-Y ear Storm Events 10-Y ear Storm Events 25-Y ear Storm Events Page 1-1 Page 1 Pages 1-1 To 1-4 Page 1-5 Page 1-6 Page 1-7 Page 1-7 Page 1-7 Page2 Page3 Page4 Page 5 Pages 6 & 7 Page 8 & 9 Page 10 & 11 Pages 12 & 13 Page 14 Page 14 Page 15 Page 15 Table Of Contents (Continued) COMPARISON OF PRE & POST-DEVELOPMENT HYDROGRAPHS 100-Year Storm Events DETENTION POND & OUTLET CONTROL COMPONENTS Tabulation & Graph Displaying Depth Vs. Volume For Detention Pond Tabulation & Graph Displaying Depth Vs. Discharge For Outlet Control Structure Tabulation & Graph Displaying The Storage Indication Ratio For The Detention Pond Facility SIMULATIONS FOR THE 2,5,10,25,50 & JOO-YEAR STORM EVENTS 2-YEAR STORM EVENT Tabulation Hydrograph (In-Flow I Out-Flow) 5-YEAR STORM EVENT Tabulation Hydrograph (In-Flow I Out-Flow) IO-YEAR STORM EVENT Tabulation Hydrograph (In-Flow I Out-Flow) 25-YEAR STORM EVENT Tabulation Hydrograph (In-Flow I Out-Flow) Page 1-2 Page 16 Page 17 Page 18 Page 19 Pages20 &21 Page 22 Pages 23 &24 Page 25 Pages 26 &27 Page 28 Pages 29 &30 Page 31 Table Of Contents (Continued) SIMULATIONS FOR THE 2,5,10,25,50 & JOO-YEAR STORM EVENTS 50-YEAR STORM EVENT Tabulation Hydrograph (In-Flow I Out-Flow) 100-YEAR STORM EVENT Tabulation Hydrograph (In-Flow I Out-Flow) TOTAL IN-FLOW I OUT-FLOW HYDROGRAPHS FOR THE 2,5,10,25,50 & 100-YEAR STORM EVENTS Pages 32 &33 Page 34 Pages 35 &36 Page 37 2-Year Storm Event Hydrograph (In-Flow I Out-Flow) Page 38 5-Year Storm Event Hydrograph (In-Flow I Out-Flow) Page 39 10-Year Storm Event Hydrograph (In-Flow I Out-Flow) Page 40 25-Year Storm Event Hydrograph (In-Flow I Out-Flow) Page 41 50-Y ear Storm Event Hydrograph (In-Flow I Out-Flow) Page 42 100-Year Storm Event Hydrograph (In-Flow I Out-Flow) Page 43 SYNOPSIS OF COMPUTATIONS & REPORT Page 44 Page 1-3 Table Of Contents (Continued) APPENDIX PIPE COMPUTATIONS Determine Capacity Of Outlet Pipe Page 1of1 METHODOLOGY Computational Methodology Pages Ml-M3 GRAPHICS Vicinity Map Page VICINITY Drainage Plan (Pre-Development) Page Dl Drainage plan (Post-Development) Page D2 Site Plan Page Cl Grading Plan PagesC2 &C3 Storm Sewer Plan Page CS Storm Water Pollution Prevention Plan Last Page * * * END * * * Page 1-4 CERTI Fl CATI ON I HEREBY CERTIFY THAT THIS REPORT AND ACCOMPANYING DRAINAGE PLAN FOR THE DRAINAGE DESIGN WAS PREPARED BY ME IN ACCORDANCE WITH THE PROVISIONS OF THE CITIES DRAINAGE POLICY AND DESIGN STANDARDS FOR THE OWNER THEREOF. •.,'· Page 1-5 DRAINAGE REPORT SEVENTH DAY ADVENTIST CHURCH LOT 1, BLOCK 4 CAT HOLLOW -PHASE ill COLLEGE STATION, BRAZOS COUNTY, TEXAS AUGUST, 2001 INTRODUCTION: The proposed development is located on the southwest side of the southwest frontage road of Earl Rudder Freeway approximately 2,500 feet from the intersection of Harvey Road (Texas State Highway No.30) and Earl Rudder Freeway (Texas State Highway No.6 East By-Pass). The proposed development is to be located on a 5.00 acre tract or parcel ofland designated as Lot 1, Block 4 of Cat Hollow -Phase III (Final Plat recorded in Volume 2926, Page 47 of the Official Records Of Brazos County, Texas). The project is bounded on the northeast by Earl Rudder Freeway as mentioned above, by a single family development (Cat Hollow-Phase II, Block 2 to the southeast, by Cat Hollow - Phase II , Block 3 to the southwest and by Richard Carter Park to the northwest. The proposed development consists of the construction of a church facility which includes three (3) new buildings, a Fellowship Building, a Sanctuary Building, and a School/Gymnasium Building with 4,351 square feet, 4,000 square feet and 10,225 square feet areas respectively. Concrete drives and parking areas as well as sidewalks will also be constructed as part of the completed project. The subject 5.00 acre tract is currently covered by tall weeds and grasses with sparse trees being comprised mostly of mosquite, elm and post oaks. The natural gradient of the property is approximately 2.00% grade which slopes from a high elevation of approximately 302 msl at the northwest comer of the site to a low elevation of approximately 288 msl at the southwest comer of the said site. The subject property does not lie within a designated 100-year flood plain or special flood hazard area as depicted on FIRM Community Panel No. 48041C0142 C, effective date July 2, 1992 Page 1-6 The site at present comprised of two separately zoned areas, an R-1 area and an R-3 area (See Site Plan-Sheet "Cl" enclosed herewith for clarification). The project is being developed by the Seventh Day Adventist Church which is being represented by Mr. David Claridge, 1500 Lynx Cove, College Station, Texas 77840, Telephone: (979) 260-3447. EXISTING DRAINAGE BASIN DESCRIPTION: The watershed tributary to the subject tract is approximately 5.19 acres, with 5.00 acres on-site and with 0.19 acres draining into the subject tract from Richard Carter Park lying immediately adjacent to northwest of the project. The aforesaid 0.19 acre tributary drainage area will be considered in all subsequent drainage computations regarding total pre and post development storm water run-offhydrographs. PROPOSED DRAINAGE: The proposed grading of the site will route the majority of the anticipated storm water run-off via the proposed drives and parking areas to a storm water detention facility which is proposed to be located in the lower southwest corner of the subject site. The detention pond will contain the run-off produced by the 2, 5, 10, 25, 50 and 100-year storm events. Metering of the storm water will be accomplished by utilization of a inlet box structure with a rectangular weir construct in one of the box faces. The top of the inlet box will incorporate an inlet grate for added outflow capacity during storms that might exceed the 100-year storm event. An emergency spillway is provided for directing excess storm water out of the detention facility to the ditch running parallel and adjacent to the southwest frontage road of Earl Rudder Freeway. The metered stormwater will exit the subject site via a 15" diameter storm sewer line which will connect with existing City of College Station storm drainage infrastructure located at the northeast corner of the intersection of Dominik and Glen Haven Drives (See Sheet "C5" enclosed herewith). A Storm Water Pollution Control Plan was prepared and is included herewith. The Notice of Intent (NOI Form) will be submitted to the EPA for a permit prior to construction activities beginning. CONCLUSION: This project is in compliance with the City of College Station's Stormwater Design Standards. Page 1-7 Btlli!lll'liiti!:'-l lll!l!lliinl::,:::_:::::-'''': :rrr :1111:::11mm:w1tgr::1t1i.11t1i 1at11: :::::::::' :: :::::::::' Tributary Area ("A"): S.19 Acres Pervious Area: S.19 Acres Impervious Area: o.oo Acres Run-Off Coefficient ("Cwt"): 0.30 Time Of Concentration ("T/c"): Woodlands: Low Elevation: High Elevation: Distance (Feet): Slope(% Grade): Velocity ("Vw"): Time : Pastures: Low Elevation: High Elevation: Distance (Feet): Slope (% Grade): Velocity ("Vp"): Time: Pavements: Low Elevation: High Elevation: Distance (Feet): Slope(% Grade): Velocity ("Vpave"): Time : Total Travel Time: Rounded Travel Time: Hourly Intensity Rates ("I"): 2-Year: 4.S3 S-Year: S.S9 10-Year: 6.33 2S-Year: 7.26 SO-Year: 8.24 100-Year: 8.S9 Peak Discharge Rate ("O'l 2-Year: 7.0S S-Year: 8.71 10-Year: 9.86 2S-Year: 11 .30 SO-Year: 12.82 100-Year: 13.38 c = 0.30 c = 0.90 288.7S 30S.70 990.00 1.71 0.86 Feet I Second 19.27 Minutes 0.00 0.00 0.00 0.00 0.00 Feet I Second 0.00 Minutes 0.00 0.00 0.00 0.00 0.00 Feet I Second 0.00 Minutes 19.27 Minutes 19 Minutes Inches I Hour Inches I Hour Inches I Hour Inches I Hour Inches I Hour Inches I Hour Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second SEVENTH DAY ADVENTIST CHURCH -PAGE 2 Tributary Area ("A''): 5.19 Acres Pervious Area: 3.22 Acres Impervious Area: 1.97 Acres Run-Off Coefficient ("Cwt"): 0.53 Time Of Concentration ("T/c"): 1 O Minutes Hourly Intensity Rates ("I"): 2-Year: 6.33 5-Year: 7.69 10-Year: 8.63 25-Year: 9.86 50-Year: 11 .15 100-Year: 11.64 Peak Discharge Rate ("Q"): 2-Year: 17.33 5-Year: 21 .07 10-Year: 23.65 25-Year: 27.01 50-Year: 30.53 100-Year: 31.88 c = 0.30 c = 0.90 Inches I Hour Inches I Hour Inches I Hour Inches I Hour Inches I Hour Inches I Hour Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Predevelopment Post-Development Increase In Peak % Increase 2-Year: 7. 05 Ft3/sec 17.33 Ft3/sec 5-Year: 8. 71 Ft3/sec 21 .07 Ft3/sec 10-Year: 9.86 Ft3/sec 23.65 Ft3/sec 25-Year: 11.30 Ft3/sec 27.01 Ft3/sec 50-Year: 12.82 Ft3/sec 30.53 Ft3/sec 100-Year: 13.38 Ft3/sec 31 .88 Ft3/sec 2-Year Storm Event Requires Approximately: 5-Year Storm Event Requires Approximately: 10-Year Storm Event Requires Approximately: 25-Year Storm Event Requires Approximately: 50-Year Storm Event Requires Approximately: 100-Year Storm Event Requires Approximately: 10.28 Ft3/sec 12.36 Ft3/sec 13. 79 Ft3/sec 15. 71 Ft3/sec 17.71 Ft3/sec 18.50 Ft3/sec 6,942 Cubic Feet 8,536 Cubic Feet 9,641 Cubic Feet 11 ,039 Cubic Feet 12,511 Cubic Feet 13,057 Cubic Feet Time Base (Tb)= 3.00 x Tic And Time Of Concentration (Tic) Of 10 Minutes. SEVENTH DAY ADVENTIST CHURCH · PAGE 3 146 142 140 139 138 138 Tributary Area ("A"): 1.71 Acres Pervious Area: 1.71 Acres c = 0.30 Impervious Area: 0.00 Acres c = 0.90 Run-Off Coefficient ("Cwt"): 0.30 Time Of Concentration ("T/c'l 10 Minutes (Min.) Hourly Intensity Rates ("I"): 2-Year: 6.33 Inches I Hour 5-Year: 7.69 Inches I Hour 10-Year: 8.63 Inches I Hour 25-Year: 9.86 Inches I Hour 50-Year: 11.15 Inches I Hour 100-Year: 11 .64 Inches I Hour Peak Discharge Rate ("Q"): 2-Year: 3.25 Cubic Feet I Second 5-Year: 3.95 Cubic Feet I Second 10-Year: 4.43 Cubic Feet I Second 25-Year: 5.06 Cubic Feet I Second 50-Year: 5.72 Cubic Feet I Second 100-Year: 5.97 Cubic Feet I Second Note: This Sheet Is Used Only If There Is An Area That Discharges From The Subject Site Without Being Directed Thru The Detention Pond. If There Is No "Free-Flow" From The Subject Site The Output Values Presented On This Sheet Will Be Set To Zero (Default) And This Sheet Will Not Be Included In Subsequent Calculations, However, This Sheet Will Remain Within The Printed Report . SEVENTI-l DAY ADVENTIST CHURCH -PAGE 4 .•.e6_··.·.: .••.••.••. -•. · •. ·._:~.: •. ·_··.••.1_··.•··.n.r_:.• •. :.~_rm.·._ •.•.•.••.••. :,·.· .. ·._·n:._··.•·_:._:_~t •• _.:·_e ... ·.·••.··.·.:.· .. :_ ... :.:e:._:_•!_'._e_·:_•_n_:_•_·•.o.·~.:_._·:._ ••..•.• ~.·:._:_·~.·;._:_._::_*.::_:_: •. ·~ •. :_ .. •.•~.i.•_••.•.··.•·n·.··.;•_·:.••.;_: •. ::.ie..•~.·•·.·· .•. : •. ·.;_1.·""".·.•.·.i·.•·.··.··.·.·n:._· •. ·._•·.·.·a·.m_·._;._·• .. · .. · •. : •.••. :.:e.••.: .••.••. : •. : •. :~.: •. :.: •. : •. • •. ~. ::::-••••.••• ...:. . .:.::.:!i ·:! ! ·:::·• F::f:Y.~: v. Q'11.Jf..tt y. £::¥. :;:::::;:::;:::::::::=:::=::::::::::::::::::::::::=::::::::::::::::::::::::::::::::::: Tributary Area ("A"): 3.48 Acres Pervious Area: 1.48 Acres Impervious Area: 2.00 Acres Run-Off Coefficient ("Cwt"): 0.64 Time Of Concentration ("T/c'): 10 Minutes Hourly Intensity Rates ("I"): 2-Year: 6.33 5-Year: 7.69 10-Year: 8.63 25-Year: 9.86 50-Year: 11 .15 100-Year: 11.64 Peak Discharge Rate ("Q"): 2-Year: 14.20 5-Year: 17.26 10-Year: 19.38 25-Year: 22.13 50-Year: 25.02 100-Year: 26.12 c = 0.30 c = 0.90 Inches I Hour Inches I Hour Inches I Hour Inches I Hour Inches I Hour Inches I Hour Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second Cubic Feet I Second SEVENTH DAY ADVENTIST CHURCH • PAGE 5 Pre-Development Inflow Hydrograph Ordinates (Cubic Feet per Second) Time 2-Year 5-Year 10-Year 25-Year SO-Year 100-Year ~Minutes~ Storm Storm Storm Storm Storm Storm 0 0.00 0.00 0.00 0.00 0.00 0.00 1 0.37 0.46 0.52 0.59 0.67 0.70 2 0.74 0.92 1.04 1.19 1.35 1.41 3 1.11 1.37 1.56 1.78 2.02 2.11 4 1.48 1.83 2.08 2.38 2.70 2.82 5 1.85 2.29 2.59 2.97 3.37 3.52 6 2.23 2.75 3.11 3.57 4.05 4.23 7 2.60 3.21 3.63 4.16 4.72 4.93 8 2.97 3.67 4.15 4.76 5.40 5.63 9 3.34 4.12 4.67 5.35 6.07 6.34 10 3.71 4.58 5.19 5.95 6.75 7.04 11 4.08 5.04 5.71 6.54 7.42 7.75 12 4.45 5.50 6.23 7.14 8.10 8.45 13 4.82 5.96 6.75 7.73 8.77 9.15 14 5.19 6.42 7.27 8.33 9.45 9.86 15 5.56 6.87 7.78 8.92 10.12 10.56 16 5.93 7.33 8.30 9.52 10.80 11.27 17 6.30 7.79 8.82 10.11 11.47 11.97 18 6.68 8.25 9.34 10.71 12.15 12.68 19 7.05 8.71 9.86 11.30 12.82 13.38 <=PEAKS 20 6.86 8.48 9.60 11.00 12.49 13.03 21 6.68 8.25 9.34 10.71 12.15 12.68 22 6.49 8.02 9.08 10.41 11.81 12.32 23 6.30 7.79 8.82 10.11 11.47 11.97 24 6.12 7.56 8.56 9.82 11.14 11.62 25 5.93 7.33 8.30 9.52 10.80 11.27 26 5.75 7.10 8.04 9.22 10.46 10.92 27 5.56 6.87 7.78 8.92 10.12 10.56 28 5.38 6.64 7.52 8.63 9.79 10.21 29 5.19 6.42 7.27 8.33 9.45 9.86 30 5.01 6.19 7.01 8.03 9.11 9.51 31 4.82 5.96 6.75 7.73 8.77 9.15 32 4.64 5.73 6.49 7.44 8.44 8.80 33 4.45 5.50 6.23 7.14 8.10 8.45 34 4.27 5.27 5.97 6.84 7.76 8.10 35 4.08 5.04 5.71 6.54 7.42 7.75 36 3.89 4.81 5.45 6.25 7.09 7.39 37 3.71 4.58 5.19 5.95 6.75 7.04 38 3.52 4.35 4.93 5.65 6.41 6.69 39 3.34 4.12 4.67 5.35 6.07 6.34 40 3.15 3.89 4.41 5.06 5.74 5.99 41 2.97 3.67 4.15 4.76 5.40 5.63 42 2.78 3.44 3.89 4.46 5.06 5.28 43 2.60 3.21 3.63 4.16 4.72 4.93 44 2.41 2.98 3.37 3.87 4.39 4.58 45 2.23 2.75 3.11 3.57 4.05 4.23 SEVENTH DAY ADVENTIST CHURCH· PAGE 6 46 2.04 2.52 2.85 3.27 3.71 3.87 47 1.85 2.29 2.59 2.97 3.37 3.52 48 1.67 2.06 2.34 2.68 3.04 3.17 49 1.48 1.83 2.08 2.38 2.70 2.82 50 1.30 1.60 1.82 2.08 2.36 2.46 51 1.11 1.37 1.56 1.78 2.02 2.11 52 0.93 1.15 1.30 1.49 1.69 1.76 53 0.74 0.92 1.04 1.19 1.35 1.41 54 0.56 0.69 0.78 0.89 1.01 1.06 55 0.37 0.46 0.52 0.59 0.67 0.70 56 0.19 0.23 0.26 0.30 0.34 0.35 57 0.00 0.00 0.00 0.00 0.00 0.00 58 0.00 0.00 0.00 0.00 0.00 0.00 59 0.00 0.00 0.00 0.00 0.00 0.00 60 0.00 0.00 0.00 0.00 0.00 0.00 SEVENTH DAY ADVENTIST CHURCH -PAGE 7 Post-Development Inflow Hydrograph Ordinates (Cubic Feet per Second) Time 2-Year 5-Year 10-Year 25-Year 50-Year 100-Year (Minutes) Storm Storm Storm Storm Storm Storm 0 0.00 0.00 0.00 0.00 0.00 0.00 1 1.73 2.11 2.36 2.70 3.05 3.19 2 3.47 4.21 4.73 5.40 6.11 6.38 3 5.20 6.32 7.09 8.10 9.16 9.56 4 6.93 8.43 9.46 10.80 12.21 12.75 5 8.66 10.54 11.82 13.51 15.27 15.94 6 10.40 12.64 14.19 16.21 18.32 19.13 7 12.13 14.75 16.55 18.91 21.37 22.32 8 13.86 16.86 18.92 21.61 24.43 25.50 9 15.60 18.96 21.28 24.31 27.48 28.69 10 17.33 21.07 23.65 27.01 30.53 31.88 <=PEAKS 11 16.46 20.02 22.47 25.66 29.01 30.29 12 15.60 18.96 21.28 24.31 27.48 28.69 13 14.73 17.91 20.10 22.96 25.95 27.10 14 13.86 16.86 18.92 21.61 24.43 25.50 15 13.00 15.80 17.74 20.26 22.90 23.91 16 12.13 14.75 16.55 18.91 21.37 22.32 17 11.26 13.70 15.37 17.56 19.85 20.72 18 10.40 12.64 14.19 16.21 18.32 19.13 19 9.53 11.59 13.01 14.86 16.79 17.53 20 8.66 10.54 11.82 13.51 15.27 15.94 21 7.80 9.48 10.64 12.15 13.74 14.35 22 6.93 8.43 9.46 10.80 12.21 12.75 23 6.06 7.37 8.28 9.45 10.69 11.16 24 5.20 6.32 7.09 8.10 9.16 9.56 25 4.33 5.27 5.91 6.75 7.63 7.97 26 3.47 4.21 4.73 5.40 6.11 6.38 27 2.60 3.16 3.55 4.05 4.58 4.78 28 1.73 2.11 2.36 2.70 3.05 3.19 29 0.87 1.05 1.18 1.35 1.53 1.59 30 0.00 0.00 0.00 0.00 0.00 0.00 31 0.00 0.00 0.00 0.00 0.00 0.00 32 0.00 0.00 0.00 0.00 0.00 0.00 33 0.00 0.00 0.00 0.00 0.00 0.00 34 0.00 0.00 0.00 0.00 0.00 0.00 35 0.00 0.00 0.00 0.00 0.00 0.00 36 0.00 0.00 0.00 0.00 0.00 0.00 37 0.00 0.00 0.00 0.00 0.00 0.00 38 0.00 0.00 0.00 0.00 0.00 0.00 39 0.00 0.00 0.00 0.00 0.00 0.00 40 0.00 0.00 0.00 0.00 0.00 0.00 41 0.00 0.00 0.00 0.00 0.00 0.00 42 0.00 0.00 0.00 0.00 0.00 0.00 43 0.00 0.00 0.00 0.00 0.00 0.00 44 0.00 0.00 0.00 0.00 0.00 0.00 45 0.00 0.00 0.00 0.00 0.00 0.00 SEVENTH DAY ADVENTIST CHURCH -PAGE 8 (/) m < m z ~ ~ -< )> 0 < m z ::J (/) ~ (") :I: c: " (") :I: -0 )> G'l m <O O> c.n c.n c.n c.n c.n 0(00>-...JO>CJ'I 00 9 9 000 9 0 99 66 000000 6 00 00 000000 0 0 0 00 999 9 9 9 00 9 66 000 0 0 0 66 0 00 000 0 0 0 00 0 99 9 9 9 9 000 9 9 00 00 0 0000 0 0 00 00 0 0000 0 0 99 00 9 9 00 000 66 000 666 00 0 00 00 0 000 000 00 99 9999 99 9 66 00 000000 0 00 00 000000 0 00 0 9 66 6 0 00 0 0 9 999 0 00 0 0 00 0 9 99 9 0 00 0 0 00 0 999 9 000 0 000 0 9 0 9 9 0 6 0 0 0 0 0 0 099999000099999 000000000000000 000000000000000 Post-Development "Free-Flow" Inflow Hydrograph Ordinates (Cubic Feet per Second) Time 2-Year 5-Year 10-Year 25-Year 50-Year 100-Year (Minutes) Storm Storm Storm Storm Storm Storm 0 0.00 0.00 0.00 0.00 0.00 0.00 1 0.32 0.39 0.44 0.51 0.57 0.60 2 0.65 0.79 0.89 1.01 1.14 1.19 3 0.97 1.18 1.33 1.52 1.72 1.79 4 1.30 1.58 1.77 2.02 2.29 2.39 5 1.62 1.97 2.21 2.53 2.86 2.99 6 1.95 2.37 2.66 3.04 3.43 3.58 7 2.27 2.76 3.10 3.54 4.00 4.18 8 2.60 3.16 3.54 4.05 4.57 4.78 9 2.92 3.55 3.99 4.55 5.15 5.37 10 3.25 3.95 4.43 5.06 5.72 5.97 <=PEAKS 11 3.08 3.75 4.21 4.81 5.43 5.67 12 2.92 3.55 3.99 4.55 5.15 5.37 13 2.76 3.35 3.77 4.30 4.86 5.08 14 2.60 3.16 3.54 4.05 4.57 4.78 15 2.43 2.96 3.32 3.79 4.29 4.48 16 2.27 2.76 3.10 3.54 4.00 4.18 17 2.11 2.57 2.88 3.29 3.72 3.88 18 1.95 2.37 2.66 3.04 3.43 3.58 19 1.79 2.17 2.44 2.78 3.15 3.28 20 1.62 1.97 2.21 2.53 2.86 2.99 21 1.46 1.78 1.99 2.28 2.57 2.69 22 1.30 1.58 1.77 2.02 2.29 2.39 23 1.14 1.38 1.55 1.77 2.00 2.09 24 0.97 1.18 1.33 1.52 1.72 1.79 25 0.81 0.99 1.11 1.26 1.43 1.49 26 0.65 0.79 0.89 1.01 1.14 1.19 27 0.49 0.59 0.66 0.76 0.86 0.90 28 0.32 0.39 0.44 0.51 0.57 0.60 29 0.16 0.20 0.22 0.25 0.29 0.30 30 0.00 0.00 0.00 0.00 0.00 0.00 31 0.00 0.00 0.00 0.00 0.00 0.00 32 0.00 0.00 0.00 0.00 0.00 0.00 33 0.00 0.00 0.00 0.00 0.00 0.00 34 0.00 0.00 0.00 0.00 0.00 0.00 35 0.00 0.00 0.00 0.00 0.00 0.00 36 0.00 0.00 0.00 0.00 0.00 0.00 37 0.00 0.00 0.00 0.00 0.00 0.00 38 0.00 0.00 0.00 0.00 0.00 0.00 39 0.00 0.00 0.00 0.00 0.00 0.00 40 0.00 0.00 0.00 0.00 0.00 0.00 41 0.00 0.00 0.00 0.00 0.00 0.00 42 0.00 0.00 0.00 0.00 0.00 0.00 43 0.00 0.00 0.00 0.00 0.00 0.00 44 0.00 0.00 0.00 0.00 0.00 0.00 45 0.00 0.00 0.00 0.00 0.00 0.00 SEVENTH DAY ADVENTIST CHURCH -PAGE 10 (/) m < m z :t ~ -< > c < m z ::j (/) -l (") :I: c " (") :I: "Cl > G> m ::: 9 0 00 9 9P 999 9 9 9 9 9 0 0 00 0 00 000 0 0 0 0 0 0 0 00 0 00 000 0 0 0 0 0 00 99 9 00 9 99 9 9 99 9 00 00 00 0 0 00 0 0 00 0 00 00 0 00 0 00 0 0 00 0 99 9 9 9 99 9 99 9 99 9P 00 0 0 0 00 0 00 0 00 00 00 0 0 0 00 0 00 0 00 00 9 9 9 0 9 99 9 99 9 99 9 9 0 0 0 0 0 00 0 00 0 00 0 0 0 0 0 0 0 00 0 00 0 00 0 0 9 0 000 99 00 9 9 9 00 9 0 0 000 00 00 0 0 000 0 0 0 000 00 00 0 0 000 0 999999999999999 000000000000000 000000000000000 Post-Development Flow Routed Through Detention Pond Inflow Hydrograph Ordinates (Cubic Feet per Second) Time 2-Year 5-Year 10-Year 25-Year SO-Year 100-Year (Minutes) Storm Storm Storm Storm Storm Storm 0 0.00 0.00 0.00 0.00 0.00 0.00 1 1.42 1.73 1.94 2.21 2.50 2.61 2 2.84 3.45 3.88 4.43 5.00 5.22 3 4.26 5.18 5.81 6.64 7.50 7.84 4 5.68 6.91 7.75 8.85 10.01 10.45 5 7.10 8.63 9.69 11.06 12.51 13.06 6 8.52 10.36 11.63 13.28 15.01 15.67 7 9.94 12.08 13.56 15.49 17.51 18.28 8 11.36 13.81 15.50 17.70 20.01 20.89 9 12.78 15.54 17.44 19.92 22.51 23.51 10 14.20 17.26 19.38 22.13 25.02 26.12 <=PEAKS 11 13.49 16.40 18.41 21.02 23.76 24.81 12 12.78 15.54 17.44 19.92 22.51 23.51 13 12.07 14.67 16.47 18.81 21.26 22.20 14 11.36 13.81 15.50 17.70 20.01 20.89 15 10.65 12.95 14.53 16.60 18.76 19.59 16 9.94 12.08 13.56 15.49 17.51 18.28 17 9.23 11.22 12.59 14.38 16.26 16.98 18 8.52 10.36 11.63 13.28 15.01 15.67 19 7.81 9.49 10.66 12.17 13.76 14.37 20 7.10 8.63 9.69 11.06 12.51 13.06 21 6.39 7.77 8.72 9.96 11.26 11.75 22 5.68 6.91 7.75 8.85 10.01 10.45 23 4.97 6.04 6.78 7.75 8.76 9.14 24 4.26 5.18 5.81 6.64 7.50 7.84 25 3.55 4.32 4.84 5.53 6.25 6.53 26 2.84 3.45 3.88 4.43 5.00 5.22 27 2.13 2.59 2.91 3.32 3.75 3.92 28 1.42 1.73 1.94 2.21 2.50 2.61 29 0.71 0.86 0.97 1.11 1.25 1.31 30 0.00 0.00 0.00 0.00 0.00 0.00 31 0.00 0.00 0.00 0.00 0.00 0.00 32 0.00 0.00 0.00 0.00 0.00 0.00 33 0.00 0.00 0.00 0.00 0.00 0.00 34 0.00 0.00 0.00 0.00 0.00 0.00 35 0.00 0.00 0.00 0.00 0.00 0.00 36 0.00 0.00 0.00 0.00 0.00 0.00 37 0.00 0.00 0.00 0.00 0.00 0.00 38 0.00 0.00 0.00 0.00 0.00 0.00 39 0.00 0.00 0.00 0.00 0.00 0.00 40 0.00 0.00 0.00 0.00 0.00 0.00 41 0.00 0.00 0.00 0.00 0.00 0.00 42 0.00 0.00 0.00 0.00 0.00 0.00 43 0.00 0.00 0.00 0.00 0.00 0.00 44 0.00 0.00 0.00 0.00 0.00 0.00 45 0.00 0.00 0.00 0.00 0.00 0.00 SEVENTH DAY ADVENTIST CHURCH -PAGE 12 Cf) m < m z ~ 0 )> -< )> ~ m z ::! Cf) -t 0 J: c ;lJ 0 J: .., )> G) m ;;; 0 0 00 9 9 9 9 00 0 9 9 9 9 0 0 00 0 0 0 0 00 0 00 0 0 0 0 00 0 0 0 0 00 0 00 0 0 9 0 00 9 9 00 00 9 9 9 0 9 0 00 000 00 0 0 0 0 0 0 0 0 0 00 0 000 00 0 0 0 0 0 99 99 9 9 99 99 0 99 9 0 00 00 0 0 00 00 0 00 0 0 00 00 0 0 00 00 0 00 0 0 0 0 99 9999 99 999 9 0 0 0 00 0000 00 000 0 0 0 0 00 0000 00 000 0 0 0 000 0 9 0000 9 00 9 9 0 000 0 00000 0 00 0 0 0 000 0 00000 0 00 0 0 990009909999990 000000000000000 000000000000000 Total Pre-Development Vs. Total Post-Development (No Detention) Peak Discharge Rates 2-Year Storm Event 20.00 18.00 16.00 -14.00 J!? ~ 12.00 Q) ei 10.00 IG .t::. 8.00 c.J Cl) Ci 6.00 4.00 2.00 0.00 0 10 20 30 40 50 Time (Minutes) --Pre-Development Hydrograph -Total Post-Development Hydrograph Total Pre-Development Vs. Total Post-Development (No Detention) Peak Discharge Rates 5-Year Storm Event i 60 ~ 15.00 ----#---+--------+-----t-----t-----t----4 Q) ei IG -5 10.00 ----#----+------1'.-----+------+------+------i Cl) Ci 0.00 ~---.a.---............ --~i----....... ----+-..;;;;i,--t 0 10 20 30 40 50 60 Time (Minutes) --Pre-Development Hydrograph -Post-Development Outflow Hydrograph Without Detention SEVENTH DAY ADVENTIST CHURCH -PAGE 14 Total Pre-Development Vs. Total Post-Development (No Detention) Peak Discharge Rates 10-Year Storm Event 25.00 20.00 -J!? ~ 15.00 41 e cu .s::. 10.00 u Cl) c 5.00 0.00 0 10 20 30 40 50 Time (Minutes) --Pre-Development Hydrograph -Post-Development Outflow Hydrograph Without Detention Total Pre-Development Vs. Total Post-Development (No Detention) Peak Discharge Rates 25-Year Storm Event 60 'iii' 20.00 ----#---+------+-----+-----+-----+-----t ~ 41 e 15.oo ----#---1----.+-----+-----+-----+-----l cu .s::. u .!!! c 10.00 +--#---t--~;C---+-~-=----+-----+-----t------; 0 10 20 30 40 50 60 Time (Minutes) --Pre-Development Hydrograph -Post-Development Outflow Hydrograph Without Detention SEVENTH DAY ADVENTIST CHURCH -PAGE 15 Total Pre-Development Vs. Total Post-Development (No Detention) Peak Discharge Rates 50-Year Storm Event 25.00 .----+-+--~--t--------11------+----+----l ~ -; 20.00 .-----l~-+----'~-+-----1-----1-----1-----1 e ca '5 15.00 ----+---+-----------1-----1-----1----~ en i5 10.00.--1---+--~.,C--t--~-=--~-----+----+----l 0 10 20 30 40 50 Time (Minutes) --Pre-Development Hydrograph -Post-Development Outflow Hydrograph Without Detention Total Pre-Development Vs. Total Post-Development (No Detention) Peak Discharge Rates 100-Year Storm Event l u 60 -; 20.00 ------+-------+-----1-----+-----+------! ~ ca '5 15.00 ---+----+----~----1-----t-----+-----t en i5 0 10 20 30 40 50 60 Time (Minutes) --Pre-Development Hydrograph -Post-Development Outflow Hydrograph Without Detention SEVENTH DAY ADVENTIST CHURCH -PAGE 16 Elevation 289.15 290.00 290.50 291 .00 292.00 292.50 Contour Area (Ft2) 0 1,776 4,054 6,687 10,550 12,280 i Q) u. Depth (Ft.) 0.00 0.85 1.35 1.85 2.85 3.35 Volume (Ft3) 0 503 1,922 4,580 13,125 18,827 Detention Pond Depth Vs. Discharge :;;-2.00 ._-----+---..~-----1------t--------j -Q. Q) c 0.00 +-~~~~~+-~~~~----11--~~~~-+~~~~~-1 0 5,000 10,000 15,000 20,000 Detention Pond Volume (Cubic Feet) SEVENTH DAY ADVENTIST CHURCH -PAGE 17 Elevation Depth (Feet) 289.15 0.00 290.00 0.85 290.50 1.35 291 .00 1.85 292.00 2.85 292.50 3.35 Weir: 6 Weir Length "L" (In Inches) 0.50 Weir Length "L" (In Feet) Discharge Ft3/Sec 0.00 1.21 2.42 3.88 7.43 9.46 Rating Curve For Outlet Control Structure Depth Vs. Volume 0.00 .... ___ ...... ____ +------11------+------t 0.00 2.00 4.00 6.00 8.00 10.00 Discharge (Cubic Feet Per Second) SEVENTH DAY ADVENTIST CHURCH · PAGE 18 Depth Storage Discharge 2s/t 2s/t+O (Feet) (Ft3) (Ft3/Sec) (Ft3/Sec) (Ft3/Sec) 0.00 0 0.00 0.00 0.00 0.85 503 1.21 16.77 17.98 1.35 1,922 2.42 64.07 66.49 1.85 4,580 3.88 152.67 156.55 2.85 13,125 7.43 437.50 444.93 3.35 18,827 9.46 627.57 637.03 Storage Indication Curve 10.00 1.00 / v / /~ / v / / I I I 9.00 8.00 7.00 6.00 i ~ Q) E' 5.00 ca .r= u Ill c 4.00 3.00 2.00 0.00 0.00 100.00 200.00 300.00 400.00 500.00 600.00 700.00 2s/t+O (Cubic Feet Per Second) SEVENTH DAY ADVENTIST CHURCH -PAGE 19 Inflow I Outflow Simulation 2-Year Storm Event Time Inflow 11+ 12 2s/t-O 2s/t+O Outflow Depth Elevation (Minutes) (Ft3/Sec) (Ft3/Sec) (Feet) 0 0.00 0.00 0.00 0.00 0.00 0.00 289.15 1 1.42 1.42 1.23 1.42 0.10 0.07 289.22 2 2.84 4.26 4.75 5.49 0.37 0.26 289.41 3 4.26 7.10 10.25 11 .85 0.80 0.56 289.71 4 5.68 9.94 17.66 20.19 1.26 0.87 290.02 5 7.10 12.78 27.40 30.44 1.52 0.98 290.13 6 8.52 15.62 39.34 43.01 1.83 1.11 290.26 7 9.94 18.46 53.39 57.80 2.20 1.26 290.41 8 11 .36 21 .30 69.58 74.69 2.55 1.40 290.55 9 12.78 24.13 87.99 93.71 2.86 1.50 290.65 10 14.20 26.97 108.54 114.96 3.21 1.62 290.77 11 13.49 27.68 129.12 136.23 3.55 1.74 290.89 12 12.78 26.26 147.65 155.38 3.86 1.84 290.99 13 12.07 24.84 164.34 172.50 4.08 1.91 291 .06 14 11.36 23.42 179.23 187.76 4.27 1.96 291 .11 15 10.65 22.00 192.37 201 .23 4.43 2.00 291 .15 16 9.94 20.59 203.80 212.95 4.58 2.05 291 .20 17 9.23 19.17 213.56 222.96 4.70 2.08 291 .23 18 8.52 17.75 221 .71 231 .31 4.80 2.11 291 .26 19 7.81 16.33 228.26 238.03 4.88 2.13 291 .28 20 7.10 14.91 233.27 243.17 4.95 2.15 291.30 21 6.39 13.49 236.78 246.76 4.99 2.16 291.31 22 5.68 12.07 238.81 248.84 5.02 2.17 291 .32 23 4.97 10.65 239.40 249.46 5.03 2.17 291 .32 <=PEAK 24 4.26 9.23 238.60 248.63 5.02 2.17 291 .32 25 3.55 7.81 236.44 246.41 4.99 2.16 291.31 26 2.84 6.39 232.94 242.82 4.94 2.15 291.30 27 2.13 4.97 228.14 237.91 4.88 2.13 291 .28 28 1.42 3.55 222.07 231 .69 4.81 2.11 291 .26 29 0.71 2.13 214.77 224.20 4.71 2.08 291 .23 30 0.00 0.71 206.27 215.48 4.61 2.05 291 .20 31 0.00 0.00 197.28 206.27 4.49 2.02 291 .17 32 0.00 0.00 188.51 197.28 4.38 1.99 291 .14 33 0.00 0.00 179.96 188.51 4.28 1.96 291.11 34 0.00 0.00 171 .61 179.96 4.17 1.93 291 .08 35 0.00 0.00 163.48 171 .61 4.07 1.90 291 .05 36 0.00 0.00 155.54 163.48 3.97 1.87 291.02 37 0.00 0.00 147.80 155.54 3.87 1.84 290.99 38 0.00 0.00 140.32 147.80 3.74 1.80 290.95 39 0.00 0.00 133.08 140.32 3.62 1.76 290.91 40 0.00 0.00 126.07 133.08 3.50 1.72 290.87 41 0.00 0.00 119.30 126.07 3.39 1.68 290.83 42 0.00 0.00 112.74 119.30 3.28 1.64 290.79 43 0.00 0.00 106.39 112.74 3.17 1.61 290.76 44 0.00 0.00 100.26 106.39 3.07 1.57 290.72 45 0.00 0.00 94.32 100.26 2.97 1.54 290.69 SEVENTH DAY ADVENTIST CHURCH -PAGE 20 46 0.00 0.00 88.57 94.32 2.87 1.50 290.65 47 0.00 0.00 83.01 88.57 2.78 1.47 290.62 48 0.00 0.00 77.63 83.01 2.69 1.44 290.59 49 0.00 0.00 72.43 77.63 2.60 1.41 290.56 50 0.00 0.00 67.39 72.43 2.52 1.38 290.53 51 0.00 0.00 62.52 67.39 2.44 1.36 290.51 52 0.00 0.00 57.88 62.52 2.32 1.31 290.46 53 0.00 0.00 53.47 57.88 2.21 1.26 290.41 54 0.00 0.00 49.27 53.47 2.10 1.22 290.37 55 0.00 0.00 45.29 49.27 1.99 1.17 290.32 56 0.00 0.00 41.51 45.29 1.89 1.13 290.28 57 0.00 0.00 37.91 41.51 1.80 1.09 290.24 58 0.00 0.00 34.50 37.91 1.71 1.06 290.21 59 0.00 0.00 31.25 34.50 1.62 1.02 290.17 60 0.00 0.00 28.17 31.25 1.54 0.99 290.14 SEVENTH DAY ADVENTIST CHURCH -PAGE 21 i u -Q) Cl ... cu .c u .!!? c Inflow/Outflow Simulation 2-Year Storm Event 20.00 -----~---~--~~--~---~---~ 18.00 16.00 14.00 12.00 10.00 8.00 0 •' ' I I ' I ' ' ' ' ' I I ' ' ' I 10 20 30 40 Time (Minutes) ---Pre-Development Hydrograph Post-Development Outflow Hydrograph Without Detention ---Post-Development Outflow With Detention - - - -Post-Development "Free-Flow" SEVENTH DAY ADVENTIST CHURCH · PAGE 22 50 60 Inflow I Outflow Simulation 5-Year Storm Event Time Inflow 11+ 12 2s/t-O 2s/t+O Outflow Depth Elevation (Minutes) (Ft3/Sec) (Ft3/Sec) (Feet) 0 0.00 0.00 0.00 0.00 0.00 0.00 289.15 1 1.73 1.73 1.49 1.73 0.12 0.08 289.23 2 3.45 5.18 5.77 6.67 0.45 0.32 289.47 3 5.18 8.63 12.47 14.41 0.97 0.68 289.83 4 6.91 12.08 21.80 24.55 1.37 0.92 290.07 5 8.63 15.54 33.95 37.34 1.69 1.05 290.20 6 10.36 18.99 48.78 52.94 2.08 1.21 290.36 7 12.08 22.44 66.22 71.22 2.50 1.38 290.53 8 13.81 25.89 86.44 92.12 2.84 1.49 290.64 9 15.54 29.35 109.34 115.79 3.22 1.62 290.77 10 17.26 32.80 134.84 142.14 3.65 1.77 290.92 11 16.40 33.66 160.44 168.51 4.03 1.89 291.04 12 15.54 31.94 183.73 192.38 4.32 1.97 291.12 13 14.67 30.21 204.76 213.94 4.59 2.05 291.20 14 13.81 28.48 223.60 233.25 4.83 2.12 291.27 15 12.95 26.76 240.28 250.35 5.04 2.18 291.33 16 12.08 25.03 254.87 265.31 5.22 2.23 291.38 17 11.22 23.30 267.42 278.18 5.38 2.27 291.42 18 10.36 21.58 277.98 289.00 5.51 2.31 291.46 19 9.49 19.85 286.59 297.83 5.62 2.34 291.49 20 8.63 18.13 293.31 304.72 5.70 2.36 291.51 21 7.77 16.40 298.18 309.71 5.77 2.38 291.53 22 6.91 14.67 301.24 312.85 5.80 2.39 291.54 23 6.04 12.95 302.55 314.19 5.82 2.40 291.55 <=PEAK 24 5.18 11.22 302.14 313.77 5.82 2.40 291.55 25 4.32 9.49 300.06 311.63 5.79 2.39 291.54 26 3.45 7.77 296.34 307.82 5.74 2.37 291.52 27 2.59 6.04 291.03 302.38 5.68 2.36 291.51 28 1.73 4.32 284.17 295.35 5.59 2.33 291.48 29 0.86 2.59 275.79 286.76 5.48 2.30 291.45 30 0.00 0.86 265.94 276.65 5.36 2.27 291.42 31 0.00 0.00 255.48 265.94 5.23 2.23 291.38 32 0.00 0.00 245.28 255.48 5.10 2.19 291.34 33 0.00 0.00 235.33 245.28 4.97 2.16 291.31 34 0.00 0.00 225.63 235.33 4.85 2.12 291.27 35 0.00 0.00 216.17 225.63 4.73 2.09 291.24 36 0.00 0.00 206.93 216.17 4.62 2.06 291.21 37 0.00 0.00 197.93 206.93 4.50 2.02 291.17 38 0.00 0.00 189.14 197.93 4.39 1.99 291.14 39 0.00 0.00 180.58 189.14 4.28 1.96 291.11 40 0.00 0.00 172.22 180.58 4.18 1.93 291.08 41 0.00 0.00 164.06 172.22 4.08 1.90 291.05 42 0.00 0.00 156.11 164.06 3.98 1.88 291.03 43 0.00 0.00 148.36 156.11 3.88 1.85 291.00 44 0.00 0.00 140.86 148.36 3.75 1.80 290.95 45 0.00 0.00 133.60 140.86 3.63 1.76 290.91 SEVENTH DAY ADVENTIST CHURCH -PAGE 23 46 0.00 0.00 126.58 133.60 3.51 1.72 290.87 47 0.00 0.00 119.78 126.58 3.40 1.68 290.83 48 0.00 0.00 113.21 119.78 3.29 1.65 290.80 49 0.00 0.00 106.85 113.21 3.18 1.61 290.76 50 0.00 0.00 100.70 106.85 3.08 1.57 290.72 51 0.00 0.00 94.74 100.70 2.98 1.54 290.69 52 0.00 0.00 88.98 94.74 2.88 1.51 290.66 53 0.00 0.00 83.41 88.98 2.79 1.47 290.62 54 0.00 0.00 78.02 83.41 2.70 1.44 290.59 55 0.00 0.00 72.80 78.02 2.61 1.41 290.56 56 0.00 0.00 67.75 72.80 2.52 1.39 290.54 57 0.00 0.00 62.87 67.75 2.44 1.36 290.51 58 0.00 0.00 58.21 62.87 2.33 1.31 290.46 59 0.00 0.00 53.78 58.21 2.21 1.26 290.41 60 0.00 0.00 49.57 53.78 2.10 1.22 290.37 SEVENTI-1 DAY ADVENTIST CHURCH -PAGE 24 Inflow/Outflow Simulation 5-Year Storm Event 25.00 -----~---~---~--~---~---~ 0 10 20 30 40 Time (Minutes) ---Pre-Development Hydrograph Post-Development Outflow Hydrograph Without Detention ---Post-Development Outflow With Detention -• • • • ·Post-Development "Free-Flow" SEVENTH DAY ADVENTIST CHURCH -PAGE 25 50 60 Inflow I Outflow Simulation 10-Year Storm Event Time Inflow 11+ 12 2s/t-O 2s/t+O Outflow Depth Elevation (Minutes) (Ft3/Sec) (Ft3/Sec) (Feet) 0 0.00 0.00 0.00 0.00 0.00 0.00 289.15 1 1.94 1.94 1.68 1.94 0.13 0.09 289.24 2 3.88 5.81 6.48 7.49 0.50 0.35 289.50 3 5.81 9.69 13.99 16.17 1.09 0.76 289.91 4 7.75 13.56 24.66 27.56 1.45 0.95 290.10 5 9.69 17.44 38.47 42.10 1.81 1.10 290.25 6 11.63 21.31 55.28 59.79 2.25 1.28 290.43 7 13.56 25.19 75.17 80.47 2.65 1.43 290.58 8 15.50 29.06 98.17 104.24 3.03 1.56 290.71 9 17.44 32.94 124.16 131.11 3.47 1.71 290.86 10 19.38 36.81 153.10 160.98 3.94 1.87 291.02 11 18.41 37.78 182.27 190.89 4.31 1.97 291.12 12 17.44 35.85 208.84 218.12 4.64 2.06 291.21 13 16.47 33.91 232.86 242.75 4.94 2.15 291.30 14 15.50 31.97 254.40 264.83 5.21 2.23 291.38 15 14.53 30.03 273.53 284.44 5.45 2.29 291.44 16 13.56 28.09 290.29 301.62 5.67 2.35 291.50 17 12.59 26.16 304.75 316.45 5.85 2.40 291.55 18 11.63 24.22 316.97 328.97 6.00 2.45 291.60 19 10.66 22.28 326.99 339.25 6.13 2.48 291.63 20 9.69 20.34 334.88 347.34 6.23 2.51 291.66 21 8.72 18.41 340.69 353.29 6.30 2.53 291.68 22 7.75 16.47 344.46 357.16 6.35 2.55 291.70 23 6.78 14.53 346.25 358.99 6.37 2.55 291.70 <=PEAK 24 5.81 12.59 346.11 358.85 6.37 2.55 291.70 25 4.84 10.66 344.08 356.76 6.34 2.54 291.69 26 3.88 8.72 340.21 352.80 6.29 2.53 291.68 27 2.91 6.78 334.54 346.99 6.22 2.51 291.66 28 1.94 4.84 327.13 339.39 6.13 2.48 291.63 29 0.97 2.91 318.00 330.03 6.01 2.45 291.60 30 0.00 0.97 307.21 318.97 5.88 2.41 291.56 31 0.00 0.00 295.75 307.21 5.73 2.37 291.52 32 0.00 0.00 284.56 295.75 5.59 2.33 291.48 33 0.00 0.00 273.65 284.56 5.46 2.29 291.44 34 0.00 0.00 263.00 273.65 5.32 2.26 291.41 35 0.00 0.00 252.62 263.00 5.19 2.22 291.37 36 0.00 0.00 242.49 252.62 5.06 2.18 291.33 37 0.00 0.00 232.61 242.49 4.94 2.15 291.30 38 0.00 0.00 222.97 232.61 4.82 2.11 291.26 39 0.00 0.00 213.57 222.97 4.70 2.08 291.23 40 0.00 0.00 204.41 213.57 4.58 2.05 291.20 41 0.00 0.00 195.46 204.41 4.47 2.02 291.17 42 0.00 0.00 186.74 195.46 4.36 1.98 291.13 43 0.00 0.00 178.23 186.74 4.25 1.95 291.10 44 0.00 0.00 169.93 178.23 4.15 1.93 291.08 45 0.00 0.00 161.83 169.93 4.05 1.90 291.05 SEVENTH DAY ADVENTIST CHURCH -PAGE 26 46 0.00 0.00 153.93 161 .83 3.95 1.87 291 .02 47 0.00 0.00 146.25 153.93 3.84 1.84 290.99 48 0.00 0.00 138.82 146.25 3.72 1.79 290.94 49 0.00 0.00 131 .63 138.82 3.60 1.75 290.90 50 0.00 0.00 124.67 131 .63 3.48 1.71 290.86 51 0.00 0.00 117.94 124.67 3.37 1.67 290.82 52 0.00 0.00 111.42 117.94 3.26 1.64 290.79 53 0.00 0.00 105.12 111.42 3.15 1.60 290.75 54 0.00 0.00 99.02 105.12 3.05 1.56 290.71 55 0.00 0.00 93.13 99.02 2.95 1.53 290.68 56 0.00 0.00 87.42 93.13 2.85 1.50 290.65 57 0.00 0.00 81.90 87.42 2.76 1.47 290.62 58 0.00 0.00 76.55 81.90 2.67 1.44 290.59 59 0.00 0.00 71.38 76.55 2.58 1.41 290.56 60 0.00 0.00 66.38 71 .38 2.50 1.38 290.53 SEVENTH DAY ADVENTIST CHURCH -PAGE 27 ~ ~ CD e> C'll ~ u Cl) c Inflow/Outflow Simulation 10-Year Storm Event 25.00 -----~---~---~--~---~---~ I ' I ' ' 20.00 I ' ' ' 15.00 10.00 ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' ' •, ' ' ' ' I 0.00 .fll"-~~~+-~~~~+-~~~....:.· .... ~~~~ .... ~~~~ ..... ~~~--I 0 10 20 30 40 Time (Minutes) ---Pre-Development Hydrograph Post-Development Outflow Hydrograph Without Detention ---Post-Development Outflow With Detention - - - - - -Post-Development "Free-Flow'' SEVENTH DAY ADVENTIST CHURCH -PAGE 28 50 60 Inflow I Outflow Simulation 25-Year Storm Event Time Inflow 11+ 12 2s/t-O 2s/t+O Outflow Depth Elevation (Minutes) (Ft3/Sec) (Ft3/Sec) (Feet) 0 0.00 0.00 0.00 0.00 0.00 0.00 289.15 1 2.21 2.21 1.92 2.21 0.15 0.10 289.25 2 4.43 6.64 7.40 8.55 0.58 0.40 289.55 3 6.64 11.06 16.02 18.47 1.22 0.86 290.01 4 8.85 15.49 28.42 31 .51 1.55 0.99 290.14 5 11.06 19.92 44.40 48.33 1.97 1.16 290.31 6 13.28 24.34 63.83 68.74 2.46 1.36 290.51 7 15.49 28.77 86.90 92.59 2.85 1.49 290.64 8 17.70 33.19 113.51 120.10 3.29 1.65 290.80 9 19.92 37.62 143.54 151.13 3.80 1.82 290.97 10 22.13 42.05 177.11 185.59 4.24 1.95 291.10 11 21.02 43.15 210.93 220.26 4.67 2.07 291 .22 12 19.92 40.94 241 .75 251.86 5.05 2.18 291 .33 13 18.81 38.73 269.67 280.48 5.41 2.28 291.43 14 17.70 36.51 294.74 306.18 5.72 2.37 291.52 15 16.60 34.30 317.03 329.04 6.00 2.45 291.60 16 15.49 32.09 336.62 349.12 6.25 2.52 291 .67 17 14.38 29.87 353.57 366.50 6.46 2.58 291 .73 18 13.28 27.66 367.94 381 .23 6.64 2.63 291 .78 19 12.17 25.45 379.81 393.39 6.79 2.67 291.82 20 11 .06 23.24 389.22 403.04 6.91 2.70 291 .85 21 9.96 21.02 396.24 410.24 7.00 2.73 291.88 22 8.85 18.81 400.93 415.05 7.06 2.75 291 .90 23 7.75 16.60 403.35 417.53 7.09 2.75 291.90 24 6.64 14.38 403.55 417.73 7.09 2.76 291.91 <=PEAK 25 5.53 12.17 401.58 415.72 7.07 2.75 291.90 26 4.43 9.96 397.51 411 .54 7.02 2.73 291.88 27 3.32 7.75 391.38 405.25 6.94 2.71 291 .86 28 2.21 5.53 383.24 396.91 6.84 2.68 291 .83 29 1.11 3.32 373.14 386.56 6.71 2.65 291 .80 30 0.00 1.11 361 .13 374.24 6.56 2.60 291 .75 31 0.00 0.00 348.33 361 .13 6.40 2.56 291 .71 32 0.00 0.00 335.85 348.33 6.24 2.52 291.67 33 0.00 0.00 323.68 335.85 6.09 2.47 291.62 34 0.00 0.00 311 .81 323.68 5.94 2.43 291 .58 35 0.00 0.00 300.22 311 .81 5.79 2.39 291.54 36 0.00 0.00 288.93 300.22 5.65 2.35 291 .50 37 0.00 0.00 277.91 288.93 5.51 2.31 291 .46 38 0.00 0.00 267.16 277.91 5.37 2.27 291.42 39 0.00 0.00 256.67 267.16 5.24 2.23 291.38 40 0.00 0.00 246.45 256.67 5.11 2.20 291 .35 41 0.00 0.00 236.47 246.45 4.99 2.16 291 .31 42 0.00 0.00 226.74 236.47 4.87 2.13 291.28 43 0.00 0.00 217.25 226.74 4.75 2.09 291.24 44 0.00 0.00 207.99 217.25 4.63 2.06 291.21 45 0.00 0.00 198.96 207.99 4.52 2.03 291.18 SEVENTH DAY ADVENTIST CHURCH -PAGE 29 46 0.00 0.00 190.15 198.96 4.40 2.00 291.15 47 0.00 0.00 181.55 190.15 4.30 1.97 291.12 48 0.00 0.00 173.17 181.55 4.19 1.94 291.09 49 0.00 0.00 164.99 173.17 4.09 1.91 291.06 50 0.00 0.00 157.02 164.99 3.99 1.88 291.03 51 0.00 0.00 149.24 157.02 3.89 1.85 291.00 52 0.00 0.00 141.71 149.24 3.77 1.81 290.96 53 0.00 0.00 134.42 141.71 3.64 1.77 290.92 54 0.00 0.00 127.38 134.42 3.52 1.73 290.88 55 0.00 0.00 120.56 127.38 3.41 1.69 290.84 56 0.00 0.00 113.96 120.56 3.30 1.65 290.80 57 0.00 0.00 107.57 113.96 3.19 1.61 290.76 58 0.00 0.00 101.40 107.57 3.09 1.58 290.73 59 0.00 0.00 95.42 101.40 2.99 1.54 290.69 60 0.00 0.00 89.64 95.42 2.89 1.51 290.66 SEVENTH DAY ADVENTIST CHURCH -PAGE 30 -J!? .e Q) e cu .c u UI Ci Inflow/Outflow Simulation 25-Year Storm Event 30.00 -----~---~--~---~---~---~ 25.00 20.00 15.00 10.00 0 I\ ' I I I ' ' ' I I ' I I ' I ' I ' ' I I ' ' 10 20 30 40 Time (Minutes) ---Pre-Development Hydrograph Post-Development Outflow Hydrograph Without Detention ---Post-Development Outflow With Detention ------Post-Development "Free-Flow" SEVENTH DAY ADVENTIST CHURCH -PAGE 31 50 60 Inflow I Outflow Simulation 50-Year Storm Event Time Inflow 11+ 12 2s/t-O 2s/t+O Outflow Depth Elevation (Minutes) (Ft3/Sec) (Ft3/Sec) (Feet) 0 0.00 0.00 0.00 0.00 0.00 0.00 289.15 1 2.50 2.50 2.16 2.50 0.17 0.12 289.27 2 5.00 7.50 8.37 9.67 0.65 0.46 289.61 3 7.50 12.51' 18.31 20.88 1.28 0.88 290.03 4 10.01 17.51 32.51 35.82 1.66 1.03 290.18 5 12.51 22.51 50.76 55.03 2.13 1.23 290.38 6 15.01 27.52 73.05 78.27 2.61 1.42 290.57 7 17.51 32.52 99.46 105.57 3.06 1.57 290.72 8 20.01 37.52 129.85 136.98 3.57 1.74 290.89 9 22.51 42.53 164.22 172.37 4.08 1.90 291.05 10 25.02 47.53 202.62 211.75 4.56 2.04 291.19 11 23.76 48.78 241.30 251.40 5.05 2.18 291.33 12 22.51 46.28 276.60 287.58 5.49 2.30 291.45 13 21.26 43.78 308.58 320.37 5.90 2.42 291.57 14 20.01 41.28 337.34 349.85 6.26 2.52 291.67 15 18.76 38.77 362.95 376.11 6.58 2.61 291.76 16 17.51 36.27 385.49 399.22 6.86 2.69 291.84 17 16.26 33.77 405.04 419.26 7.11 2.76 291.91 18 15.01 31.27 421.67 436.31 7.32 2.82 291.97 19 13.76 28.77 435.47 450.44 7.48 2.86 292.01 20 12.51 26.27 446.52 461.73 7.60 2.89 292.04 21 11.26 23.76 454.90 470.29 7.70 2.92 292.07 22 10.01 21.26 460.65 476.16 7.76 2.93 292.08 23 8.76 18.76 463.82 479.41 7.79 2.94 292.09 24 7.50 16.26 464.48 480.08 7.80 2.94 292.09 <=PEAK 25 6.25 13.76 462.68 478.24 7.78 2.94 292.09 26 5.00 11.26 458.47 473.94 7.73 2.93 292.08 27 3.75 8.76 451.90 467.23 7.66 2.91 292.06 28 2.50 6.25 443.02 458.16 7.57 2.88 292.03 29 1.25 3.75 431.88 446.77 7.45 2.85 292.00 30 0.00 1.25 418.57 433.13 7.28 2.81 291.96 31 0.00 0.00 404.37 418.57 7.10 2.76 291.91 32 0.00 0.00 390.51 404.37 6.93 2.71 291.86 33 0.00 0.00 376.99 390.51 6.76 2.66 291.81 34 0.00 0.00 363.81 376.99 6.59 2.61 291.76 35 0.00 0.00 350.95 363.81 6.43 2.57 291.72 36 0.00 0.00 338.41 350.95 6.27 2.52 291.67 37 0.00 0.00 326.17 338.41 6.12 2.48 291.63 38 0.00 0.00 314.24 326.17 5.97 2.44 291.59 39 0.00 0.00 302.59 314.24 5.82 2.40 291.55 40 0.00 0.00 291.24 302.59 5.68 2.36 291.51 41 0.00 0.00 280.16 291.24 5.54 2.32 291.47 42 0.00 0.00 269.36 280.16 5.40 2.28 291.43 43 0.00 0.00 258.82 269.36 5.27 2.24 291.39 44 0.00 0.00 248.54 258.82 5.14 2.20 291.35 45 0.00 0.00 238.51 248.54 5.01 2.17 291.32 SEVENTH DAY ADVENTIST CHURCH -PAGE 32 46 0.00 0.00 228.73 238.51 4.89 2.13 291 .28 47 0.00 0.00 219.19 228.73 4.77 2.10 291 .25 48 0.00 0.00 209.88 219.19 4.65 2.07 291 .22 49 0.00 0.00 200.80 209.88 4.54 2.03 291 .18 50 0.00 0.00 191 .95 200.80 4.43 2.00 291 .15 51 0.00 0.00 183.31 191.95 4.32 1.97 291.12 52 0.00 0.00 174.89 183.31 4.21 1.94 291 .09 53 0.00 0.00 166.67 174.89 4.11 1.91 291 .06 54 0.00 0.00 158.65 166.67 4.01 1.89 291 .04 55 0.00 0.00 150.83 158.65 3.91 1.86 291 .01 56 0.00 0.00 143.25 150.83 3.79 1.82 290.97 57 0.00 0.00 135.91 143.25 3.67 1.78 290.93 58 0.00 0.00 128.82 135.91 3.55 1.74 290.89 59 0.00 0.00 121 .95 128.82 3.43 1.70 290.85 60 0.00 0.00 115.31 121 .95 3.32 1.66 290.81 SEVENIH DAY ADVENTIST CHURCH -PAGE 33 ~ ~ Q) en ... C'IS .J::. u Cl) c Inflow/Outflow Simulation 50-Year Storm Event 35.00 ----~---~--~---~------.-----, 30.00 25.00 20.00 15.00 0 ' I ' ' ' ' ' ' ' I ' I ' ' ' 10 20 30 40 Time (Minutes) ---Pre-Development Hydrograph Post-Development Outflow Hydrograph Without Detention ---Post-Development Outflow With Detention • • -• • ·Post-Development "Free-Flow" SEVENTH DAY ADVENTIST CHURCH -PAGE 34 50 60 Inflow I Outflow Simulation 100-Year Storm Event Time Inflow 11+ 12 2s/t-O 2s/t+O Outflow Depth Elevation (Minutes) (Ft3/Sec) (Ft3/Sec) (Feet) 0 0.00 0.00 0.00 0.00 0.00 0.00 289.15 1 2.61 2.61 2.26 2.61 0.18 0.12 289.27 2 5.22 7.84 8.74 10.10 0.68 0.48 289.63 3 7.84 13.06 19.19 21.80 1.30 0.89 290.04 4 10.45 18.28 34.08 37.47 1.70 1.05 290.20 5 13.06 23.51 53.19 57.58 2.20 1.26 290.41 6 15.67 28.73 76.57 81.92 2.67 1.44 290.59 7 18.28 33.95 104.25 110.53 3.14 1.59 290.74 8 20.89 39.18 136.09 143.43 3.67 1.78 290.93 9 23.51 44.40 172.13 180.49 4.18 1.93 291 .08 10 26.12 49.62 212.39 221 .76 4.68 2.08 291 .23 11 24.81 50.93 252.93 263.32 5.20 2.22 291 .37 12 23.51 48.32 289.93 301 .25 5.66 2.35 291 .50 13 22.20 45.71 323.47 335.63 6.08 2.47 291 .62 14 20.89 43.10 353.63 366.56 6.46 2.58 291 .73 15 19.59 40.48 380.51 394.12 6.80 2.67 291 .82 16 18.28 37.87 404.18 418.38 7.10 2.76 291 .91 17 16.98 35.26 424.72 439.44 7.36 2.83 291.98 18 15.67 32.65 442.26 457.37 7.56 2.88 292.03 19 14.37 30.04 456.86 472.29 7.72 2.92 292.07 20 13.06 27.42 468.60 484.28 7.84 2.95 292.10 21 11.75 24.81 477.53 493.41 7.94 2.98 292.13 22 10.45 22.20 483.71 499.73 8.01 2.99 292.14 23 9.14 19.59 487.21 503.30 8.05 3.00 292.15 24 7.84 16.98 488.08 504.19 8.05 3.00 292.15 <=PEAK 25 6.53 14.37 486.37 502.44 8.04 3.00 292.15 26 5.22 11 .75 482.14 498.12 7.99 2.99 292.14 27 3.92 9.14 475.45 491.28 7.92 2.97 292.12 28 2.61 6.53 466.34 481.98 7.82 2.95 292.10 29 1.31 3.92 454.87 470.26 7.69 2.92 292.07 30 0.00 1.31 441.08 456.17 7.55 2.88 292.03 31 0.00 0.00 426.32 441.08 7.38 2.84 291.99 32 0.00 0.00 411.93 426.32 7.20 2.79 291 .94 33 0.00 0.00 397.88 411.93 7.02 2.74 291 .89 34 0.00 0.00 384.19 397.88 6.85 2.69 291 .84 35 0.00 0.00 370.83 384.19 6.68 2.64 291.79 36 0.00 0.00 357.80 370.83 6.52 2.59 291 .74 37 0.00 0.00 345.08 357.80 6.36 2.55 291 .70 38 0.00 0.00 332.68 345.08 6.20 2.50 291 .65 39 0.00 0.00 320.59 332.68 6.05 2.46 291 .61 40 0.00 0.00 308.79 320.59 5.90 2.42 291 .57 41 0.00 0.00 297.28 308.79 5.75 2.38 291.53 42 0.00 0.00 286.06 297.28 5.61 2.34 291.49 43 0.00 0.00 275.11 286.06 5.47 2.30 291 .45 44 0.00 0.00 264.43 275.11 5.34 2.26 291 .41 45 0.00 0.00 254.01 264.43 5.21 2.22 291 .37 SEVENTH DAY ADVENTIST CHURCH -PAGE 35 46 0.00 0.00 243.85 254.01 5.08 2.19 291 .34 47 0.00 0.00 233.93 243.85 4.96 2.15 291 .30 48 0.00 0.00 224.27 233.93 4.83 2.12 291 .27 49 0.00 0.00 214.83 224.27 4.72 2.08 291 .23 50 0.00 0.00 205.63 214.83 4.60 2.05 291.20 51 0.00 0.00 196.66 205.63 4.49 2.02 291 .17 52 0.00 0.00 187.91 196.66 4.38 1.99 291 .14 53 0.00 0.00 179.37 187.91 4.27 1.96 291 .11 54 0.00 0.00 171 .04 179.37 4.16 1.93 291 .08 55 0.00 0.00 162.92 171 .04 4.06 1.90 291 .05 56 0.00 0.00 154.99 162.92 3.96 1.87 291 .02 57 0.00 0.00 147.28 154.99 3.86 1.84 290.99 58 0.00 0.00 139.81 147.28 3.73 1.80 290.95 59 0.00 0.00 132.59 139.81 3.61 1.76 290.91 60 0.00 0.00 125.60 132.59 3.49 1.72 290.87 SEVENTH DAY ADVENTIST CHURCH -PAGE 36 Inflow/Outflow Simulation 100-Year Storm Event i (,,) -Q) e> "' .r: (,,) Cl) c ' 30.00 I ' I ' ' 25.00 20.00 15.00 ' ' ' ' ' ' ' 5.00 ... r-~--1-...!_..j'#-~.~~-l-~~~,~l---~~~-+--~,.-= ..... ~1---~~~- • • . ' • • • • • ' . ' • . . ' 0.00 4'"-~~~+-~~~~+-~~~....;.·-1-~~~~+-~~~~ ... ~~~~ 0 10 20 30 40 Time (Minutes) ---Pre-Development Hydrograph Post-Development Outnow Hydrograph Without Detention ---Post-Development Outnow With Detention --• • • • Post-Development "Free-Flow" SEVENTH DAY ADVENTIST CHURCH -PAGE 37 50 60 Inflow/Outflow Simulation 2-Year Storm Event ~ Q) ei 4.00+-~~---+f---~~~+-~~~-+~--'l.,__----1f--~~~-+-~~~--l CG ~ u en 0 0 10 20 30 40 50 60 Time (Minutes) --Pre-Development Hydrograph -Total Post-Development Hydrograph SEVENTI-t DAY ADVENTIST CHURCH· PAGE 38 Inflow/Outflow Simulation 5-Year Storm Event 6.00 -.!!! ~ Q) en 5.00 ~ I'll .c u .!!? c 4.00 0 10 20 30 40 50 60 Time (Minutes) --Pre-Development Hydrograph -Total Post-Development Hydrograph SEVENTH DAY ADVENTIST CHURCH -PAGE 39 Inflow/Outflow Si mulation 10-Year Storm Event i .e cu e 6.oo --~~-.---+-+-~~~f--~~~._---'~~--+~~~~+--~~---l cu .s::. u en a 0 .00 +-~~~t-~~-t~~~-+-~~~+-~~~t-~ .... ~ 0 10 20 30 40 50 60 Time (Minutes) --Pre-Development Hydrograph -Total Post-Development Hydrograph SEVENTH DAY ADVENTIST CHURCH -PAGE 40 Inflow/Outflow Simulation 25-Year Storm Event ~ -GI e 6.oo ---------j---f------+-----t-----+------+-----l ca .r: u Cl) 0 0.00 ..,_ ___ ..,_ __ ___,..,_ __ ...,..lo--________ ...., __ _._ ..... 0 10 20 30 40 50 60 Time (Minutes) --Pre-Development Hydrograph -Total Post-Development Hydrograph SEVENTH DAY ADVENTIST CHURCH · PAGE 41 Inflow/Outflow Simulation 50-Year Storm Event -8.00 :? u -Cl) Cl ... ca .c u en c 6.00 O.OO+-------+-------+-------it--------1~------1----....i..-1 0 10 20 30 40 50 60 Time (Minutes) --Pre-Development Hydrograph -Total Post-Development Hydrograph SEVENTH DAY ADVENTIST CHURCH -PAGE 42 Inflow/Outflow Simulation 100-Year Storm Event 10.00 -:? ~ Q) Cl 8.00 ... ftl .c u Ill i5 6.00 0 10 20 30 40 50 60 Time (Minutes) --Pre-Development Hydrograph -Total Post-Development Hydrograph SEVENTH DAY ADVENTIST CHURCH -PAGE 43 Detention Pond Storage Volumes as Percent of Maximum Volume -...: LL ;:, ~ ,, c: 0 a.. -= 60% -+-~~~~~~~~~~~~ ...... a> ~m~~~~~~~H~H~ ~ 50% -r-~~~~r;;;;;;;;;;;;:;--~ ·~ m~m~mmm ct Q) CJ> l! 0 .. "' 0 20% -oe. 10% 2-year 5-year 10-year 25-year Storm Depth Storm Elevation Storm Volume Maximum Capacity Percent of Capacity Spillway Elevation Free board Design Stonn Stonn Simulation Synopsis 2-ear 5-ear 10-ear 25-ear 2.17 2.40 2.55 2. 76 291.32 291 .55 291.70 291.91 7333 9251 10579 12319 18827 18827 18827 18827 39% 292.63 1.31 Ft. 49% 292.63 1.08 Ft. 56% 292.63 0.93 Ft. 65% 292.63 0.72 Ft. SEVEmH DAY ADVENTIST CHURCH -PAGE 44 75% 292.63 0.54 Ft. 50-year 100-year 14884 18827 79% 292.63 0.48 Ft. Appendix Culvert Calculator Report DETERMINE CAPACITY OF 15" STORM SEWER Solve For: Discharge Culvert Summary Allowable HW Elevation Computed Headwater Elevation Inlet Control HW Elev 292.50 ft 292.50 ft 288.68 ft 292.50 ft Outlet Control HW Elev Grades Upstream Invert Length Hydraulic Profile Profile Slope Type Flow Regime Velocity Downstream Section Section Shape Section Material Section Size Number Sections Outlet Control Properties Outlet Control HW Elev Ke Inlet Control Properties Inlet Control HW Elev Inlet Type K M c y 285.03 ft 485.34 ft Pressure NIA NIA 8.42 ft/s Circular PVC 15 inch 1 292.50 ft 0.50 288.68 ft Square edge w/headwall 0.00980 2.00000 0.03980 0.67000 I fo f /I) £;ri. r Headwater Depth/ Height Discharge Tailwater Elevation Control Type Downstream Invert Constructed Slope Depth, Downstream Normal Depth Critical Depth Critical Slope Mannings Coefficient Span Rise Upstream Velocity Head Entrance Loss Flow Control Area Full HDS 5 Chart HDS 5 Scale Equation Form !:i;;:f t:f ? /Mi- rf!-2-18 rr ~~, Project Title: SEVENTH DAY ADVENTIST C 1'f "'~ 0 / pf --7' ~ c:\haestad\cvm\seventhd.cvm &l ., /, <"",P . ------::::;----- 08/15/01 09:00:33 AM © Haestad Mel ~ -.t-4f:) 7 r l - f1--"S i1 (f 5.98 10.33 cfs 283.50 ft Outlet Control 276.37 ft 0.017843 ft/ft 7.13 ft 0.95 ft 1.19 ft 0.013129 ft/ft 0.010 1.25 ft 1.25 ft 1.10 ft 0.55 ft Submerged 1.2 ft2 Project Engineer: Hester Engineering Company CulvertMaster v1 .0 \ (203) 755-1666 Page 1 of 1 REPORT METHODOLOGY: Computations on page 2 were performed based on the total tributary drainage area of the project (being estimated at 5 .19 acres), the pre-development run-off coefficient (being assumed at 0.30), and an estimated time of concentration of 19 minutes, the relative pre- development peak discharge rates ("Q") for the 2, 5, 10, 25, 50 and 100-year storm events were determined. The Rational Method was utilized to compute the estimated peak pre- development discharge rates. The equation that represents the Rational Method is as follows: Q = CIA where; "Q" is the peak discharge rate in cubic feet per second, "C" is the run-off coefficient, assumed to be 0.30 in the pre-development condition, "I" is the storm intensity in inches per hour, and "A" is the area of the drainage basin in acres. Computations on page 3 are based on the tributary area of 5.19 acres, the post- development run-off coefficient of 0.53 (being weighted according to the relative amounts of pervious and impervious surface area), and a minimum time of concentration of 10 minutes were used to determine the relative post-development peak discharge rates ("Q) corresponding to the 2, 5, 10, 25, 50 and 100-year post-development storm events. The Rational Method was utilized again to compute the anticipated post-development peak discharge rates. Comparison of the peak pre-development discharge rates to the post-development discharge rates is included on page 3 of this report to aid the designer in establishing a preliminary "target" for the detention pond volume required. This preliminary estimate is determined as the volume difference generated between the pre-development and post- development hydrographs. (See pages 14-16 for graphical comparison of pre- development and post-development hydrographs.) Please note that the post-development hydrographs shown on these same graphs assume no detention and reflects the "worst- case" scenario in that all run-off is assumed to "free-flow" from the site without the benefit of detention. Pages 4 and 5 provide information concerning the post-development run-off that is not routed through the detention facility and allowed to "free-flow" from the site as well as the post-development run-off that is routed through the stormwater detention facility. Pages 6 & 7 and pages 8 & 9 are tabulations of the pre-development and the post- development hydrographs respectively and are based on the computations performed on page 1 and page 2. Page Ml Pages 9 & 10 are tabulations of the post-development hydrograph for "free-flow" from the project site. Having derived the preliminary volume requirements and "allowable peak" discharge rate, it is now possible to design the final detention facility and outlet control structure. Page 17 presents a data tabulation and a depth versus volume graph for the proposed detention facility. The maximum depth of the pond was set at 3.35 feet. (With the top of berm elevation designed to be 293 . 00 msl and the emergency spillway flowline elevation designed to be at elevation 292.50 msl, and the flowline of the outlet control structure being set at elevation 289 .15 msl the 100-year design depth of the pond is calculated as follows: 292.50 msl -289.15 msl = 3.35 feet Page 18 supplies a tabulation and a rating curve for the proposed outlet control structure. A 6" wide rectangular weir was chosen as the outlet "metering" device due to depth verses discharge ratio characteristics associated with the anticipated shallow headwater depth as well as for ease of computation and installation. The outflow from the detention pond was calculated using the following equation: Q = CLH312 where; "Q" is the calculated discharge rate in cubic feet per second, "C" is the coefficient of discharge associated with a rectangular weir of the type utilized and was assumed to be 3.00 as suggested in the City of College Station's Drainage Policy and Design Standards publication. "L" is the length of the weir opening in feet and "H" is the available headwater depth in feet. Page 19 presents a tabulation of the relationship between discharge from the detention facility and the quantity 2S/t-O. Also presented is a Storage Indication Curve for the detention facility based on the aforementioned physical characteristics of the detention pond, storage volume, inflow hydrograph, and rating curve for the outlet structure. The storage indication curve as shown on page 19 is a tool to aid in the solution of the equation presented as follows : 2s1 (I 1 + I 2) + ( ----------------01) = dt 2s2 ( -----------------+ 02) dt Pages 20 -37 present simulations of the 2, 5, 10, 25, 50, and 100 year storm events. PageM2 The first and second pages of each storm simulation represents the tabulated data for the storm event. The maximum depth achieved in the detention pond during each simulation is shown as is the time at which the maximum depth occurs from the onset of the storm event. The calculated peak discharge rate corresponding to the maximum depth achieved over the duration of the storm period is also included. Additionally, the maximum water surface elevation is provided as well as the maximum metered discharge volume from the outlet of the detention pond. The second page of each storm simulation provides the pre-development, the post- development (with no detention), the post-development (routed through the detention pond) and the post-development ''free-flow" hydrographs. Pages 27 through pages 32 provide total inflow/outflow hydrographs for the 2, 5, 10, 25, 50 and 100-year pre-development and post-development storm events for direct comparison of pre and post development stormwater run-off conditions. Total post-development peak discharge rates from the detention pond outlet control structure and project site are kept at or less than the pre-development peak discharge rates due to the incorporation of the proposed detention facilities. Subsequent peak post- development discharge velocities are projected to be non-erosive. PageM3 Graphics LOCATION OF SITE V C N T Y Page VINICITY NOT TO SCALE MAP