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HomeMy WebLinkAboutDrainage ReportREVIEWED FOR t CONAPLIAN E "I'll" COLLEGE STATION ENGINEERING DRAINAGE COMPUTATIONS For University Lutheran Chapel 0.59 Acre Tract College Station, Brazos County, Texas *** REVISED FOR FINAL REVIEW *** Prepared for Pastor Krueger University Lutheran Chapel College Station, Texas 77842 Prepared by: Garrett Engineering 4444 Carter Creek Parkway - Suite 108 Bryan, Texas 77802 Telephone: (409) 846-2688 * August, 2000 * Garnett Englneatlng-444E Caner Qeek POMwpy S.0 IM-&y.nj.x.s nW2-T.I.ph..:O09) 2688 -Gac (409) 84b3W4 - P.,.I -- DRAINAGE COMPUTATIONS for University Lutheran Chapel College Station, Brazos County, Texas * August, 2000* The subject project is situated on the southwest corner of the intersection of Old College Main and Louis Avenue. The project consists of a total of 0.59 acres of land owned by University Lutheran Chapel and which is currently undeveloped. A building expansion and associated drive and parking area, sidewalks and detention pond are planned to be constructed on the subject 0.59 acre tract. The incorporation of the aforementioned detention pond is intended to minimize impact of stormwater run-off on adjacent downstream properties. The metering device will consist of a one foot (P) wide reinforced concrete weir constructed at the downstream end of the proposed detention facility. The total area tributary to the proposed detention facility is 0.57 acres. 0.02 acres of land will "free -flow" into Louis Avenue unmetered. Computations presented on page 2 present the estimated pre -development peak discharge rates generated by the 2, 5, 10, 25, 50 and 100-year storm events. The pre -development run-off coefficient was assumed to be 0.30 based on a total tributary drainage basin area of 0.59 acres of which is currently undeveloped (C = 0.30). A 10-minute time of concentration (T/c) was estimated utilizing topographic maps and field reconnaissance. The Rational Method was employed exclusively throughout this document to compute the estimated peak storm water 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, "p' is the storm intensity in inches per hour, and "A" is the area of the tributary drainage basin in acres. A 30-minute total storm event duration was utilized exclusively throughout this report. - - From the computations on page 3, based on the total tributary area of 0.59 acres, the post -development weighted run-off coefficient being assumed at 0.57, and a minimum time of concentration of 10 minutes, the relative post -development peck discharge rates ("Q") were determined and presented in tabular form. The Rational Method was again utilized to compute the estimated peak post -development discharge rates. Computations depicted on page 3 assume no detention. Pages 14 - 16 depict pre -development and post - development hydrographs for the 2, 5, 10, 25, 50 and 100-year storm events with no detentions considered. A comparison between the peak pre -development discharge rates and post -development discharge rates is included to aid in establishing a preliminary "target' for the volume requirements for the proposed _ detention facility. This preliminary estimate is computed by determining the volume generated from the difference of the pre -development and post -development hydrographs. Please note that the post -development hydrograph shown on these same graphs assumes no detention at this point in the computational process. Page 1-1 - Page 4 provides computations that determine the post -development storm water run-off which is allowed to flow from the subject site unmetered and page 5 provides computations that determine the post - development run-off that is routed through the proposed detention facility. The "free -flow" run-off computations presented on page 4 are based on a time of concentration of 10 minutes (minimum) and in this design since there is no design "free -flow" from the subject property, this page is not utilized. The run-off routed through the proposed detention facility as presented on page 5 is calculated based on a time of concentration of 10 minutes. Pages 6-7 and pages 8-9 are tabulations of the pre -development bydrographs and the post -development hydrographs respectively, based on the computations performed on pages 2 & 3. The post -development hydrograph assumes no detention to facilitate direct comparison in the pre- and post -development conditions. Pages 10-11 and pages 12-13 are tabulations of the post - development hydrograph for "free -flow" storm water run-off and storm water run-off directed through the detention facility respectively. Having derived the preliminary volume requirements as presented on page 3 and "allowable peak" discharge rate as present on page 2 it is now possible to design the final detention facility and outlet control structure. Page 17 presents a tabulation and depth versus volume graph of the detention facility as proposed. The maximum pond volume necessary to provide sufficient storage for the 100-year storm condition was estimated to be approximately 1,841 cubic feet (page 3). The actual design for the proposed detention pond supplies 4,208 cubic feet at a water surface elevation of 350.00 (Top Of Detention Pond Berm). Page 18 presents a tabulation and rating curve for the proposed outlet control structure. A one foot (1.00') wide weir outlet control structure was chosen due to depth verses discharge ratio characteristics associated with the anticipated headwater depth and convenience of construction. Page 19 presents a tabulation of the relationship between discharge from the detention and the dimensionless quantity 2S/t-O. Also included is the Storage Indication Curve for the proposed detention facility based on the aforementioned physical characteristics of the detention pond, storage volume, inflow hydrographs, and -- rating curve for the outlet structure. The storage indication curve as shown on page 19 is a graphical solution to the equation presented as follows: - 2sl 2s2 (11 + 12) + (--------------- - 01) _ ( ----- + 02) dt dt Pages 20-22, 23-25, 26-28, 29-31, 32-34, and 35-37 present simulations for the 2, 5, 10, 25, 50 and 100- year storm events. The first and second pages of each storm frequency simulation represents the tabulated data for the storm event. The third page of each storm simulation represents the pre -development bydrograph, the post -development hydrograph (with no detention), the post -development hydrograph as routed through the detention pond and the post -development "free -flow" hydrograpb for each storm event. Pages 38 - 43 provide total inflow/outflow hydrographs for the 2, 5, 10, 25, 50 and 100-year pre - development and post -development storm events. It can be determined from these same hydrographs that the post -development peak discharge rates have been significantly reduced from those peak pre - development discharge rates due to the incorporation of the proposed detention facility. _ . Page 44 is a graph that summates the depths, volumes, and percent of "utilized" storage volumes for the 2, 5, 10, 25, 50 and 100-year storm events. The construction of the proposed detention facility will minimize the effects of this development on downstream property owners and will actually decrease the peak discharge rates for the range of storm events of interest within this report. Page 1-2 Tributary Area ("A"): 0.59 Acres Pervious Area: 0.59 Acres c= 0.30 Impervious Area: 0.00 Acres c= 0.90 Run -Off Coefficient ("Cwt"): 0.30 Time Of Concentration ("T/c"): Woodlands: Low Elevation: 0.00 High Elevation: 0.00 Distance (Feet): 0.00 Slope (% Grade): 0.00 Velocity ("Vw"): 0.00 Feet / Second Time: 0.00 Minutes Pastures: Low Elevation: 0.00 High Elevation: 0.00 Distance (Feet): 0.00 Slope (% Grade): 0.00 Velocity ("Vp"): 0.00 Feet / Second Time: 0.00 Minutes Pavements: Low Elevation: High Elevation: Distance (Feet): Slope (% Grade): Velocity ("Vpave"): Time: 0.00 0.00 0.00 0.00 0.00 Feet / Second 0.00 Minutes Total Travel Time: 10.00 Minutes Hourly Intensity Rates ("I"): 2-Year: 6.33 Inches / Hour 5-Year: 7.69 Inches / Hour 10-Year: 8.63 Inches / Hour 25-Year: 9.86 Inches / Hour 50-Year: 11.15 Inches / Hour 100-Year: 12.63 Inches / Hour Peak Discharge Rate ("O"): 2-Year: 1.12 Cubic Feet / Second 5-Year: 1.36 Cubic Feet / Second 10-Year: 1.53 Cubic Feet / Second 25-Year: 1.75 Cubic Feet / Second 50-Year: 1.97 Cubic Feet / Second 100-Year: 2.24 Cubic Feet / Second Gaeett Engheod,g 444G CaRet Creek Pa .,Suffe lOB- Bryan,Texas 7M2-Telephone:(4 >) 26W - Po- (e)e) Bd 4 -page2 Tributary Area ("A"): 0.59 Acres Pervious Area: 0.32 Acres c= 0.30 Impervious Area: 0.27 Acres c=0.90 Run -Off Coefficient ("Cwt"): 0.57 - - Time Of Concentration (7/c"): 10 Minutes Hourly Intensity Rates ("I"): 2-Year: 6.33 Inches / Hour 5-Year: 7.69 Inches / Hour 10-Year: 8.63 Inches / Hour 25-Year: 9.86 Inches / Hour 50-Year: 11.15 Inches / Hour 100-Year: 12.63 Inches / Hour Peak Discharge Rate ("Q"): 2-Year: 2.14 Cubic Feet / Second 5-Year: 2.61 Cubic Feet / Second 10-Year: 2.93 Cubic Feet / Second 25-Year: 3.34 Cubic Feet / Second 50-Year: 3.78 Cubic Feet / Second 100-Year: 4.28 Cubic Feet / Second Predevelopment Post -Development Increase 2-Year: 1.12 Ft3/sec 2.14 Ft3/sec 1.02 Ft3/sec 5-Year: 1.36 Ft3/sec 2.61 Ft3/sec 1.25 Ft3/sec - 10-Year: 1.53 Ft3/sec 2.93 Ft3/sec 1.40 Ft3/sec 25-Year: 1.75 Ft3/sec 3.34 Ft3/sec 1.60 Ft3/sec 50-Year: 1.97 Ft3/sec 3.78 Ft3/sec 1.81 Ft3/sec -- 100-Year: 2.24 Ft3/sec 4.28 Ft3/sec 2.05 Ft3/sec 2-Year: 1.02 Ft3/sec x (30.0 Min, x 60 Sec. / 2) = 922 Cubic Feet 5-Year: 1.25 Ft3/sec x (30.0 Min. x 60 Sec. / 2 )= 1,122 Cubic Feet 10-Year: 1.40 F13/sec x (30.0 Min. x 60 Sec. / 2 )= 1,259 Cubic Feet 25-Year: 1.60 Ft3/sec x (30.0 Min. x 60 Sec. / 2) = 1,438 Cubic Feet 50-Year: 1.81 Ft3/sec x (30.0 Min. x 60 Sec. / 2) = 1,625 Cubic Feet -- 100-Year: 2.05 F,�t3///s,,��ec�/�..x,�J xnn60 Sec. ) _� 1,841 Cubic Feet T(l30.0 1Min. Time Base (T*F "X41/,QddV4 TUMP SLif1• //T2 B X94 . Pago3 Tributary Area ("A"): 0.02 Acres Pervious Area: 0.00 Acres c= 0.30 Impervious Area: 0.02 Acres c= 0.90 Run -Off Coefficient ("Cwt"): 0.90 Time Of Concentration ("T/c"): 10 Minutes (Min.) Hourly Intensity Rates ("I"): 2-Year: 6.33 Inches / Hour 5-Year: 7.69 Inches / Hour 10-Year: 8.63 Inches / Hour 25-Year: 9.86 Inches / Hour 50-Year: 11.15 Inches/ Hour 100-Year: 12.63 Inches / Hour Peak Discharge Rate ("a"): 2-Year: 0.11 Cubic Feet / Second 5-Year: 0.14 Cubic Feet / Second 10-Year: 0.16 Cubic Feet / Second 25-Year: 0.18 Cubic Feet / Second 50-Year: 0.20 Cubic Feet / Second 100-Year: 0.23 Cubic Feet / Second G.."Engh.,Ing-4444 C.O.,C,e PaA w Sutt. 109-&yan,iexpz 11-T.I.phme:(4 )8 26W -Pox (4 ) 8463J94 - Pgge4 Tributary Area ("A"): 0.57 Acres Pervious Area: 0.32 Acres c=0.30 Impervious Area: 0.25 Acres c= 0.90 Run -Off Coefficient ("Cwt"): 0.56 Time Of Concentration (7/c"): 10 Minutes Hourly Intensity Rates ("I"): 2-Year: 6.33 Inches / Hour 5-Year: 7.69 Inches / Hour 10-Year: 8.63 Inches / Hour 25-Year: 9.86 Inches/ Hour 50-Year: 11.15 Inches / Hour 100-Year: 12.63 Inches / Hour Peak Discharge Rate ("O"): 2-Year: 2.03 Cubic Feet / Second 5-Year: 2.47 Cubic Feet / Second 10-Year: 2.77 Cubic Feet / Second 25-Year: 3.17 Cubic Feet / Second 50-Year: 3.58 Cubic Feet / Second 100-Year: 4.05 Cubic Feet / Second Goen"Ineermg-4444Corter Qee PorvwW$ute 10.- yon.rexos r2-ielephme:(4 )B 269 x:(4 )e4bd 4 -Ppe5 Current Condition (Predevelopment) 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 0.11 0.14 0.15 0.17 0.20 0.22 2 0.22 0.27 0.31 0.35 0.39 0.45 3 0.34 0.41 0.46 0.52 0.59 0.67 4 0.45 0.54 0.61 0.70 0.79 0.89 5 0.56 0.68 0.76 0.87 0.99 1.12 6 0.67 0.82 0.92 1.05 1.18 1.34 7 0.78 0.95 1.07 1.22 1.38 1.56 8 0.90 1.09 1.22 1.40 1.58 1.79 9 1.01 1.23 1.38 1.57 1.78 2.01 10 1.12 1.36 1.53 1.75 1.97 2.24 - 11 1.06 1.29 1.45 1.66 1.87 2.12 12 1.01 1.23 1.38 1.57 1.78 2.01 13 0.95 1.16 1.30 1.48 1.68 1.90 14 0.90 1.09 1.22 1.40 1.58 1.79 15 0.84 1.02 1.15 1.31 1.48 1.68 16 0.78 0.95 1.07 1.22 1.38 1.56 17 0.73 0.89 0.99 1.13 1.28 1.45 18 0.67 0.82 0.92 1.05 1.18 1.34 19 0.62 0.75 0.84 0.96 1.09 1.23 20 0.56 0.68 0.76 0.87 0.99 1.12 21 0.50 0.61 0.69 0.79 0.89 1.01 -- 22 0.45 0.54 0.61 0.70 0.79 0.89 23 0.39 0.48 0.53 0.61 0.69 0.78 24 0.34 0.41 0.46 0.52 0.59 0.67 - 25 0.28 0.34 0.38 0.44 0.49 0.56 26 0.22 0.27 0.31 0.35 0.39 0.45 27 0.17 0.20 0.23 0.26 0.30 0.34 28 0.11 0.14 0.15 0.17 0.20 0.22 29 0.06 0.07 0.08 0.09 0.10 0.11 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 Garnett Engineering- AGM Caner Creak Pa ., Sint. IM-Bryan, Texas nW2-ieleph..:<4 )8 26W-fa (")Bh6 4 -Page6 46 0.00 0.00 0.00 0.00 0.00 0.00 47 0.00 0.00 0.00 0.00 0.00 0.00 48 0.00 0.00 0.00 0.00 0.00 0.00 49 0.00 0.00 0.00 0.00 0.00 0.00 50 0.00 0.00 0.00 0.00 0.00 0.00 51 0.00 0.00 0.00 0.00 0.00 0.00 52 0.00 0.00 0.00 0.00 0.00 0.00 53 0.00 0.00 0.00 0.00 0.00 0.00 54 0.00 0.00 0.00 0.00 0.00 0.00 55 0.00 0.00 0.00 0.00 0.00 0.00 56 0.00 0.00 0.00 0.00 0.00 0.00 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 Garnett Engineering-4444 CoOer Craek Partway surco 108-&ryan, Texas nW2-relephme(d09)E 26B x,(eW>8G 4 -Poge] 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 0.21 0.26 0.29 0.33 0.38 0.43 2 0.43 0.52 0.59 0.67 0.76 0.86 3 0.64 0.78 0.88 1.00 1.13 1.28 4 0.86 1.04 1.17 1.34 1.51 1.71 5 1.07 1.30 1.46 1.67 1.89 2.14 6 1.29 1.56 1.76 2.01 2.27 2.57 7 1.50 1.83 2.05 2.34 2.65 3.00 8 1.72 2.09 2.34 2.67 3.02 3.43 9 1.93 2.35 2.63 3.01 3.40 3.85 10 2.14 2.61 2.93 3.34 3.78 4.28 11 2.04 2.48 2.78 3.18 3.59 4.07 12 1.93 2.35 2.63 3.01 3.40 3.85 13 1.82 2.22 2.49 2.84 3.21 3.64 14 1.72 2.09 2.34 2.67 3.02 3.43 15 1.61 1.96 2.20 2.51 2.83 3.21 16 1.50 1.83 2.05 2.34 2.65 3.00 17 1.39 1.70 1.90 2.17 2.46 2.78 18 1.29 1.56 1.76 2.01 2.27 2.57 19 1.18 1.43 1.61 1.84 2.08 2.35 20 1.07 1.30 1.46 1.67 1.89 2.14 21 0.97 1.17 1.32 1.50 1.70 1.93 22 0.86 1.04 1.17 1.34 1.51 1.71 23 0.75 0.91 1.02 1.17 1.32 1.50 24 0.64 0.78 0.88 1.00 1.13 1.28 25 0.54 0.65 0.73 0.84 0.94 1.07 26 0.43 0.52 0.59 0.67 0.76 0.86 27 0.32 0.39 0.44 0.50 0.57 0.64 28 0.21 0.26 0.29 0.33 0.38 0.43 29 0.11 0.13 0.15 0.17 0.19 0.21 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 0t��.n0/�0 0(��.�00� 0.00/�� 01..0�00(�� 01.001 Ga 45jlneerN9-4444CDQCreek � GaMwy0.0e 108-W.0.0077W2.T"p".Q4r ^0n.^0^0n � )8 2688O4QN )8 30Q.OR9e8 46 0.00 0.00 0.00 0.00 0.00 0.00 47 0.00 0.00 0.00 0.00 0.00 0.00 48 0.00 0.00 0.00 0.00 0.00 0.00 49 0.00 0.00 0.00 0.00 0.00 0.00 50 0.00 0.00 0.00 0.00 0.00 0.00 51 0.00 0.00 0.00 0.00 0.00 0.00 52 0.00 0.00 0.00 0.00 0.00 0.00 53 0.00 0.00 0.00 0.00 0.00 0.00 54 0.00 0.00 0.00 0.00 0.00 0.00 55 0.00 0.00 0.00 0.00 0.00 0.00 56 0.00 0.00 0.00 0.00 0.00 0.00 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 GarteH Englnee�ing-4444 Corter Geak GaMway Sutte IM-Wn,T..o / - T.Ieh.:(4W) BO 2-G.(4)84b 4-Po. 9 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 0.01 0.01 0.02 0.02 0.02 0.02 2 0.02 0.03 0.03 0.04 0.04 0.05 3 0.03 0.04 0.05 0.05 0.06 0.07 4 0.05 0.06 0.06 0.07 0.08 0.09 " 5 0.06 0.07 0.08 0.09 0.10 0.11 6 0.07 0.08 0.09 0.11 0.12 0.14 7 0.08 0.10 0.11 0.12 0.14 0.16 - 8 0.09 0.11 0.12 0.14 0.16 0.18 9 0.10 0.12 0.14 0.16 0.18 0.20 10 0.11 0.14 0.16 0.18 0.20 0.23 - 11 0.11 0.13 0.15 0.17 0.19 0.22 "-- 12 0.10 0.12 0.14 0.16 0.18 0.20 13 0.10 0.12 0.13 0.15 0.17 0.19 -- 14 0.09 0.11 0.12 0.14 0.16 0.18 15 0.09 0.10 0.12 0.13 0.15 0.17 16 0.08 0.10 0.11 0.12 0.14 0.16 17 0.07 0.09 0.10 0.12 0.13 0.15 18 0.07 0.08 0.09 0.11 0.12 0.14 19 0.06 0.08 0.09 0.10 0.11 0.13 20 0.06 0.07 0.08 0.09 0.10 0.11 21 0.05 0.06 0.07 0.08 0.09 0.10 22 0.05 0.06 0.06 0.07 0.08 0.09 23 0.04 0.05 0.05 0.06 0.07 0.08 24 0.03 0.04 0.05 0.05 0.06 0.07 25 0.03 0.03 0.04 0.04 0.05 0.06 26 0.02 0.03 0.03 0.04 0.04 0.05 27 0.02 0.02 0.02 0.03 0.03 0.03 28 0.01 0.01 0.02 0.02 0.02 0.02 29 0.01 0.01 0.01 0.01 0.01 0.01 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 4774 0.00 ..... GartertMylneering-44LG2di'b�Craek /0(./00/(0��./0(/0/ Gokwby-SGM4108-RyarviAr.MN]802-TgepHdnO[�m)8462688 10t.101/0� /0.0/0� /0�./0/0� KM�(a09)��M1'•+R�ga 10 46 0.00 0.00 0.00 0.00 0.00 0.00 47 0.00 0.00 0.00 0.00 0.00 0.00 48 0.00 0.00 0.00 0.00 0.00 0.00 49 0.00 0.00 0.00 0.00 0.00 0.00 50 0.00 0.00 0.00 0.00 0.00 0.00 51 0.00 0.00 0.00 0.00 0.00 0.00 52 0.00 0.00 0.00 0.00 0.00 0.00 53 0.00 0.00 0.00 0.00 0.00 0.00 54 0.00 0.00 0.00 0.00 0.00 0.00 55 0.00 0.00 0.00 0.00 0.00 0.00 56 0.00 0.00 0.00 0.00 0.00 0.00 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 cortex Engineerhg-4444 carter creek vaikww Butte 108-&yon.T..0 77802-raeptiw»()P 26B8-Wx: cOJ9)846 4 -Page 11 Post -Development Flow Routed Through Detention Pond 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 0.20 0.25 0.28 0.32 0.36 0.41 2 0.41 0.49 0.55 0.63 0.72 0.81 3 0.61 0.74 0.83 0.95 1.07 1.22 4 0.81 0.99 1.11 1.27 1.43 1.62 5 1.02 1.23 1.39 1.58 1.79 2.03 6 1.22 1.48 1.66 1.90 2.15 2.43 7 1.42 1.73 1.94 2.22 2.50 2.84 8 1.62 1.98 2.22 2.53 2.86 3.24 9 1.83 2.22 2.49 2.85 3.22 3.65 10 2.03 2.47 2.77 3.17 3.58 4.05 11 1.93 2.35 2.63 3.01 3.40 3.85 12 1.83 2.22 2.49 2.85 3.22 3.65 13 1.73 2.10 2.36 2.69 3.04 3.45 14 1.62 1.98 2.22 2.53 2.86 3.24 15 1.52 1.85 2.08 2.37 2.68 3.04 16 1.42 1.73 1.94 2.22 2.50 2.84 17 1.32 1.61 1.80 2.06 2.33 2.64 18 1.22 1.48 1.66 1.90 2.15 2.43 19 1.12 1.36 1.52 1.74 1.97 2.23 20 1.02 1.23 1.39 1.58 1.79 2.03 21 0.91 1.11 1.25 1.42 1.61 1.82 22 0.81 0.99 1.11 1.27 1.43 1.62 23 0.71 0.86 0.97 1.11 1.25 1.42 24 0.61 0.74 0.83 0.95 1.07 1.22 25 0.51 0.62 0.69 0.79 0.89 1.01 26 0.41 0.49 0.55 0.63 0.72 0.81 27 0.30 0.37 0.42 0.47 0.54 0.61 28 0.20 0.25 0.28 0.32 0.36 0.41 29 0.10 0.12 0.14 0.16 0.18 0.20 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 G..nE ghn ,-4444 C.O.r0.0 P.h.W S R. 100-Bry mTexos 77002-T4h.n.(4 )8 2688-Fax:(409) 84b 4 -Page 12 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 46 0.00 0.00 0.00 0.00 0.00 0.00 47 0.00 0.00 0.00 0.00 0.00 0.00 48 0.00 0.00 0.00 0.00 0.00 0.00 49 0.00 0.00 0.00 0.00 0.00 0.00 50 0.00 0.00 0.00 0.00 0.00 0.00 51 0.00 0.00 0.00 0.00 0.00 0.00 52 0.00 0.00 0.00 0.00 0.00 0.00 53 0.00 0.00 0.00 0.00 0.00 0.00 54 0.00 0.00 0.00 0.00 0.00 0.00 55 0.00 0.00 0.00 0.00 0.00 0.00 56 0.00 0.00 0.00 0.00 0.00 0.00 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 Gaff ENI.. h,-"M Carter Ceak Partway Butte 108-Bryan. Texas 77W2- TelepM1me:(403) 8Gb2-E.:(409)806 4 -Page 13 2.50 v c 2.00 N N d m 1.50 m W U .Q U 1.00 m rn r 0.50 U h .1 0.00 $ n 811 a 2.50 Z v .. 2.00 3 � U u 1.50 N D 1.00 a t 0.50 0 Total Current Development Vs. Total Post -Development (No Detention) Peak Discharge Rates 2-Year Storm Event I on �n nn an 4n Current Development Hydrograph Total Post -Development Hydrograph Total Current Development Vs. Total Post -Development (No Detention) Peak Discharge Rates 5-Year Storm Event 0.00 Y i i 9 I i Y 0 10 20 30 40 50 60 Time (Minutes) Current Development Hydrograph Post -Development Outflow Hydrograph Without Detention Garnett Engheering-4444 Caner Creak P.h ,SUM. 108-&Van,Te..s7 02-Tel "p .:(409>8G 88-F :(4 )8G68094 -Page 14 Total Current Development Vs. Total Post -Development (No Detention) Peak Discharge Rates 10-Year Storm Event a 2.50 Z a 2.00 LL U ^6 ,Q �j 1.50 N N °1 1.00 O t U 0 0.50 0.00 0 10 20 Offf, a 3.00 v 2.50 LL U a 2.00 3 U y 1.50 rn Current Development Hydrograph 30 40 50 60 Time (Minutes) Post -Development Outflow Hydrograph Without Detention Total Current Development Vs. Total Post -Development (No Detention) Peak Discharge Rates 25-Year Storm Event t 1.00 U 0 0.50 0.00 0 10 20 30 40 50 60 Time (Minutes) Current Development Hydrograph Post -Development Outflow Hydrograph Without Detention Garett EngNeering-4444 Carter Creek P.M W5uke 108-Bryon,Texas])B02-Tel h...(40)B 2W-Wc<4 )846 4 -Page 75 Total Current Development Vs. Total Post -Development (No Detention) Peak Discharge Rates 50-Year Storm Event 4.00 c 3.50 0 0 'n 3.00 d d 2.50 m u 2.00 n U_ 1.50 0 0 1.00 t 0.50 0 i 0 1' Current Development Hydrograph Post -Development Outflow Hydrograph Without Detention Total Current Development Vs. Total Post -Development (No Detention) Peak Discharge Rates 100-Year Storm Event 4.50 4.00 3.50 3.00 U °0 2.50 m �n 2.00 a a 1.50 y 1.00 0 0.50 0.00 0 10 20 30 40 50 60 Time (Minutes) Current Development Hydrograph Post -Development Outflow Hydrograph Without Detention Garrett EnBineer6lg-aa44 Carter Creek P.kw Su. 108-"n,Tex.x TW2-Tei ne:(4 )8 2688-Fa <( )BGb 4 -Page 16 "Is MW W-1 0.70 FI tiWIM 0.30 0.20 1 Elevation Depth Volume (Feet) (Ft3) 349.00 0.00 0 349.25 0.25 199 349.50 0.50 1,003 349.75 0.75 2,464 349.90 0.90 3,502 350.00 1.00 4,208 Detention Pond Depth Vs. Volume 0 500 1,000 1,500 2,000 2,500 3,000 3,500 4,000 4,500 Detention Pond Volume (Cubic Feet) Game#Engh..1,g- 44E4 CarterCreek P.h WSU. 108-Pryon. Texa577W2. Tel,p .(4 )8G ZM-F :(9 )8463094 -Page 17 1.00 0.90 0.80 0.70 C1Z.S0" we] )uTieT L;onir01 JtrUCture �z i�r Weir: 1_00 (Feet Wide) y;� 12.00 (inches Wide) Elevation Depth Discharge (Feet) Ft3/Sec 349.00 0.00 0.00 349.25 0.25 0.39 349.50 0.50 1.09 349.75 0.75 2.01 349.90 0.90 2.64 350.00 1.00 3.09 Rating Curve For Outlet Control Structure Depth Vs. Volume 0.50 1.00 1.50 2.00 2.50 Discharge (Cubic Feet Per Second) 3.00 3.50 Garrett Englr wing-4444 Carter Creek Pw WSune ID8-&yan,iexax)7W2-Tel h.ne:(4 )8 2688-Po.:(4 )&b 4 -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 0.25 199 0.39 6.63 7.02 0.50 1,003 1.09 33.43 34.52 0.75 2,464 2.01 82.13 84.14 0.90 3,502 2.64 116.73 119.37 1.00 4,208 3.09 140.27 143.35 Storage Indication Curve 3.50 3.00 P�Wolf 0.50 0.00 0.00 20.00 40.00 60.00 80.00 100.00 120.00 140.00 160.00 2s/t+O (Cubic Feet Per Second) GmettBghewng-44M Codor Omek Partway Sute 108-&ryas. Texas 77802-T4ephonc:( )8 2688 -Pov (409) 8463094 -Page 19 Inflow / 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 0.00 349.00 1 0.20 0.20 0.18 0.20 0.01 0.01 349.01 2 0.41 0.61 0.70 0.79 0.04 0.03 349.03 3 0.61 1.02 1.53 1.72 0.09 0.06 349.06 4 0.81 1.42 2.63 2.95 0.16 0.11 349.11 5 1.02 1.83 3.96 4.45 0.24 0.16 349.16 6 1.22 2.23 5.52 6.20 0.34 0.22 349.22 7 1.42 2.64 7.33 8.16 0.42 0.26 349.26 8 1.62 3.05 9.43 10.37 0.47 0.28 349.28 9 1.83 3.45 11.81 12.88 0.54 0.30 349.30 10 2.03 3.86 14.45 15.67 0.61 0.33 349.33 11 1.93 3.96 17.06 18.41 0.68 0.35 349.35 12 1.83 3.76 19.33 20.81 0.74 0.38 349.38 13 1.73 3.55 21.30 22.89 0.79 0.39 349.39 14 1.62 3.35 22.98 24.65 0.84 0.41 349.41 15 1.52 3.15 24.37 26.12 0.88 0.42 349.42 16 1.42 2.94 25.50 27.32 0.91 0.43 349.43 17 1.32 2.74 26.38 28.25 0.93 0.44 349.44 18 1.22 2.54 27.03 28.92 0.95 0.45 349.45 19 1.12 2.34 27.45 29.36 0.96 0.45 349.45 20 1.02 2.13 27.65 29.58 0.96 0.46 349.46 21 0.91 1.93 27.65 29.58 0.96 0.46 349.46 22 0.81 1.73 27.46 29.37 0.96 0.45 349.45 23 0.71 1.52 27.08 28.98 0.95 0.45 349.45 24 0.61 1.32 26.53 28.40 0.93 0.44 349.44 25 0.51 1.12 25.82 27.65 0.92 0.44 349.44 26 0.41 0.91 24.95 26.73 0.89 0.43 349.43 27 0.30 0.71 23.93 25.66 0.86 0.42 349.42 28 0.20 0.51 22.77 24.44 0.83 0.41 349.41 29 0.10 0.30 21.48 23.08 0.80 0.40 349.40 30 0.00 0.10 20.07 21.59 0.76 0.38 349.38 31 0.00 0.00 18.63 20.07 0.72 0.37 349.37 32 0.00 0.00 17.26 18.63 0.68 0.36 349.36 33 0.00 0.00 15.96 17.26 0.65 0.34 349.34 34 0.00 0.00 14.73 15.96 0.62 0.33 349.33 35 0.00 0.00 13.56 14.73 0.58 0.32 349.32 36 0.00 0.00 12.46 13.56 0.55 0.31 349.31 37 0.00 0.00 11.41 12.46 0.53 0.30 349.30 38 0.00 0.00 10.41 11.41 0.50 0.29 349.29 39 0.00 0.00 9.46 10.41 0.47 0.28 349.28 40 0.00 0.00 8.57 9.46 0.45 0.27 349.27 41 0.00 0.00 7.71 8.57 0.43 0.26 349.26 42 0.00 0.00 6.91 7.71 0.40 0.26 349.26 43 0.00 0.00 6.15 6.91 0.38 0.25 349.25 44 0.00 0.00 5.47 6.15 0.34 0.22 349.22 45 0.00 0.00 4.87 5.47 0.30 0.19 349.19 GmeM Engineering-AG4G CORef C,..k P.M wSuk. 108-&yaRiexas 77& -TA h..(A )8 26W-Fax: W)84b 4 -Pagew 46 0.00 0.00 4.33 4.87 0.27 0.17 349.17 47 0.00 0.00 3.86 4.33 0.24 0.15 349.15 48 0.00 0.00 3.43 3.86 0.21 0.14 349.14 49 0.00 0.00 3.06 3.43 0.19 0.12 349.12 50 0.00 0.00 2.72 3.06 0.17 0.11 349.11 51 0.00 0.00 2.42 2.72 0.15 0.10 349.10 52 0.00 0.00 2.15 2.42 0.13 0.09 349.09 53 0.00 0.00 1.92 2.15 0.12 0.08 349.08 54 0.00 0.00 1.71 1.92 0.11 0.07 349.07 55 0.00 0.00 1.52 1.71 0.09 0.06 349.06 56 0.00 0.00 1.35 1.52 0.08 0.05 349.05 57 0.00 0.00 1.20 1.35 0.07 0.05 349.05 58 0.00 0.00 1.07 1.20 0.07 0.04 349.04 59 0.00 0.00 0.95 1.07 0.06 0.04 349.04 60 0.00 0.00 0.85 0.95 0.05 0.03 349.03 Gortett EtglneerFg-4444 Caner Creek CarkwoW Butte 108-&Wan. Texas 77W2ITNO,, one:(409)84b 88 Fax: (G09)8G6 4 -page 21 2.50 - 2.00 - 0.50 - Inflow/Outflow Simulation 2-Year Storm Event E 0 $ $ a S $Y $ $ E 5 a a a A r c $ A 4 8 g a A 8 a v a a Y a a $ Y 8 a 8 Y a A a a P a { a 0.00 0 10 20 30 40 50 6C Time (Minutes) Pre- - - - - Post- Post- — - — - - Post - Development Development Development Development Hydrograph Outflow Outflow With "Free -Flow" Hydrograph Detention Without Detention C� ett E,h.ing-4 Caner Creek Parkway Sake 108-&yan,Tex.s77W2-TelepM1wie:(E )$4b26$$-Wc(4 )$4b 4 -Pagen Inflow / 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 0.00 349.00 1 0.25 0.25 0.22 0.25 0.01 0.01 349.01 2 0.49 0.74 0.85 0.96 0.05 0.03 349.03 3 0.74 1.23 1.86 2.09 0.11 0.07 349.07 4 0.99 1.73 3.19 3.59 0.20 0.13 349.13 5 1.23 2.22 4.82 5.42 0.30 0.19 349.19 6 1.48 2.72 6.74 7.54 0.40 0.25 349.25 7 1.73 3.21 9.03 9.95 0.46 0.28 349.28 8 1.98 3.70 11.67 12.73 0.53 0.30 349.30 9 2.22 4.20 14.64 15.86 0.61 0.33 349.33 10 2.47 4.69 17.93 19.33 0.70 0.36 349.36 11 2.35 4.82 21.16 22.74 0.79 0.39 349.39 12 2.22 4.57 24.00 25.73 0.87 0.42 349.42 13 2.10 4.32 26.46 28.32 0.93 0.44 349.44 14 1.98 4.07 28.55 30.53 0.99 0.46 349.46 15 1.85 3.83 30.31 32.38 1.04 0.48 349.48 16 1.73 3.58 31.74 33.89 1.08 0.49 349.49 17 1.61 3.33 32.87 35.07 1.10 0.50 349.50 18 1.48 3.09 33.72 35.96 1.12 0.51 349.51 19 1.36 2.84 34.30 36.56 1.13 0.51 349.51 20 1.23 2.59 34.63 36.90 1.14 0.51 349.51 21 1.11 2.35 34.70 36.97 1.14 0.51 349.51 22 0.99 2.10 34.53 36.80 1.13 0.51 349.51 23 0.86 1.85 34.13 36.38 1.13 0.51 349.51 24 0.74 1.61 33.51 35.74 1.11 0.51 349.51 25 0.62 1.36 32.67 34.87 1.10 0.50 349.50 26 0.49 1.11 31.64 33.78 1.07 0.49 349.49 27 0.37 0.86 30.42 32.50 1.04 0.48 349.48 28 0.25 0.62 29.04 31.04 1.00 0.47 349.47 29 0.12 0.37 27.49 29.41 0.96 0.45 349.45 30 0.00 0.12 25.78 27.61 0.91 0.44 349.44 31 0.00 0.00 24.05 25.78 0.87 0.42 349.42 32 0.00 0.00 22.40 24.05 0.82 0.40 349.40 33 0.00 0.00 20.84 22.40 0.78 0.39 349.39 34 0.00 0.00 19.36 20.84 0.74 0.38 349.38 35 0.00 0.00 17.96 19.36 0.70 0.36 349.36 36 0.00 0.00 16.62 17.96 0.67 0.35 349.35 37 0.00 0.00 15.36 16.62 0.63 0.34 349.34 38 0.00 0.00 14.16 15.36 0.60 0.33 349.33 39 0.00 0.00 13.02 14.16 0.57 0.31 349.31 40 0.00 0.00 11.94 13.02 0.54 0.30 349.30 41 0.00 0.00 10.92 11.94 0.51 0.29 349.29 42 0.00 0.00 9.95 10.92 0.49 0.29 349.29 43 0.00 0.00 9.02 9.95 0.46 0.28 349.28 44 0.00 0.00 8.15 9.02 0.44 0.27 349.27 45 0.00 0.00 7.32 8.15 0.41 0.26 349.26 G ett En9lnearing.d CanerCreek PakwaY State 100-Bran. Texas 77W2-Teleplwna:(XR)8 26-Fmr(49)8 Msl-Pa,*3 46 0.00 0.00 6.53 7.32 0.39 0.25 349.25 47 0.00 0.00 5.81 6.53 0.36 0.23 349.23 48 0.00 0.00 5.17 5.81 0.32 0.21 349.21 49 0.00 0.00 4.61 5.17 0.28 0.18 349.18 50 0.00 0.00 4.10 4.61 0.25 0.16 349.16 51 0.00 0.00 3.65 4.10 0.23 0.15 349.15 52 0.00 0.00 3.25 3.65 0.20 0.13 349.13 53 0.00 0.00 2.89 3.25 0.18 0.12 349.12 54 0.00 0.00 2.57 2.89 0.16 0.10 349.10 55 0.00 0.00 2.29 2.57 0.14 0.09 349.09 56 0.00 0.00 2.04 2.29 0.13 0.08 349.08 57 0.00 0.00 1.81 2.04 0.11 0.07 349.07 58 0.00 0.00 1.61 1.81 0.10 0.06 349.06 59 0.00 0.00 1.44 1.61 0.09 0.06 349.06 60 0.00 0.00 1.28 1.44 0.08 0.05 349.05 Garett Engineering-g444 CORar Creek Gaf wSuke M-&yen. Texas 77W2- TAlph...(4W) E4S2 -Fa (4 )84b 4 -Gaga 24 3.00 2.50 0 2.00 U N N 4/ d d LL 1.50 3 0 31.00- L 0.50 Inflow/Outflow Simulation 5-Year Storm Event F F = { F { i a { e { a fi k Y k fi { I k { R g f { F e F R 4 R R a R F R 8 � a { { k { F F Y F { 0.00 0 10 20 30 40 50 6C Time (Minutes) Pre- - - - . Post- Post- - - - - - - - Post - Development Development Development Development Hydrograph Outflow Outflow With `Free -Flow" Hydrograph Detention Without Detention Goaerc Enginee1ng- 4444 Cartes Cseek P.f w5utte 108-&yam Texas ])802- Telephone, (4 )8 2688- Fax, (,Ma 846"4 -Page 25 Inflow / Outflow Simulation 10-Year Storm Event Time Inflow 11+ 12 2s/t-0 2s/t+O Outflow Depth Elevation (Minutes) (Ft3/Sec) (Ft3/Sec) (Feet) 0 0.00 0.00 0.00 0.00 0.00 0.00 349.00 1 0.28 0.28 0.25 0.28 0.02 0.01 349.01 2 0.55 0.83 0.96 1.08 0.06 0.04 349.04 3 0.83 1.39 2.09 2.35 0.13 0.08 349.08 4 1.11 1.94 3.58 4.03 0.22 0.14 349.14 5 1.39 2.49 5.41 6.08 0.33 0.22 349.22 6 1.66 3.05 7.61 8.46 0.42 0.26 349.26 7 1.94 3.60 10.23 11.22 0.49 0.29 349.29 8 2.22 4.16 13.24 14.39 0.57 0.32 349.32 9 2.49 4.71 16.62 17.95 0.67 0.35 349.35 10 2.77 5.27 20.35 21.88 0.77 0.39 349.39 11 2.63 5.40 24.02 25.75 0.87 0.42 349.42 12 2.49 5.13 27.24 29.15 0.95 0.45 349.45 13 2.36 4.85 30.03 32.09 1.03 0.48 349.48 14 2.22 4.57 32.42 34.61 1.09 0.50 349.50 15 2.08 4.30 34.45 36.72 1.13 0.51 349.51 -- 16 1.94 4.02 36.14 38.47 1.16 0.52 349.52 17 1.80 3.74 37.51 39.89 1.19 0.53 349.53 18 1.66 3.46 38.55 40.97 1.21 0.53 349.53 19 1.52 3.19 39.29 41.74 1.22 0.54 349.54 20 1.39 2.91 39.73 42.20 1.23 0.54 349.54 21 1.25 2.63 39.90 42.37 1.24 0.54 349.54 22 1.11 2.36 39.78 42.25 1.23 0.54 349.54 23 0.97 2.08 39.41 41.86 1.23 0.54 349.54 24 0.83 1.80 38.78 41.21 1.21 0.53 349.53 25 0.69 1.52 37.91 40.31 1.20 0.53 349.53 26 0.55 1.25 36.80 39.16 1.18 0.52 349.52 27 0.42 0.97 35.47 37.77 1.15 0.52 349.52 28 0.28 0.69 33.92 36.17 1.12 0.51 349.51 29 0.14 0.42 32.16 34.34 1.09 0.50 349.50 30 0.00 0.14 30.23 32.30 1.03 0.48 349.48 31 0.00 0.00 28.27 30.23 0.98 0.46 349.46 32 0.00 0.00 26.41 28.27 0.93 0.44 349.44 33 0.00 0.00 24.64 26.41 0.88 0.43 349.43 34 0.00 0.00 22.97 24.64 0.84 0.41 349.41 35 0.00 0.00 21.38 22.97 0.79 0.39 349.39 36 0.00 0.00 19.87 21.38 0.75 0.38 349.38 37 0.00 0.00 18.44 19.87 0.72 0.37 349.37 38 0.00 0.00 17.08 18.44 0.68 0.35 349.35 39 0.00 0.00 15.79 17.08 0.64 0.34 349.34 40 0.00 0.00 14.57 15.79 0.61 0.33 349.33 -- 41 0.00 0.00 13.41 14.57 0.58 0.32 349.32 42 0.00 0.00 12.31 13.41 0.55 0.31 349.31 43 0.00 0.00 11.27 12.31 0.52 0.30 349.30 44 0.00 0.00 10.28 11.27 0.49 0.29 349.29 Garrett Engheerlr,. 44Carler Creek Parkway SWfe 108-&yarr. Texas 77W2-Teiephmw:(409)B 268-Pox: (409)8 W94-Poge26 45 0.00 0.00 9.34 10.28 0.47 0.28 349.28 46 0.00 0.00 8.45 9.34 0.45 0.27 349.27 - 47 0.00 0.00 7.60 8.45 0.42 0.26 349.26 48 0.00 0.00 6.80 7.60 0.40 0.26 349.26 49 0.00 0.00 6.05 6.80 0.37 0.24 349.24 50 0.00 0.00 5.39 6.05 0.33 0.22 349.22 51 0.00 0.00 4.80 5.39 0.30 0.19 349.19 52 0.00 0.00 4.27 4.80 0.26 0.17 349.17 53 0.00 0.00 3.80 4.27 0.23 0.15 349.15 54 0.00 0.00 3.38 3.80 0.21 0.14 349.14 55 0.00 0.00 3.01 3.38 0.19 0.12 349.12 56 0.00 0.00 2.68 3.01 0.17 0.11 349.11 57 0.00 0.00 2.38 2.68 0.15 0.10 349.10 58 0.00 0.00 2.12 2.38 0.13 0.08 349.08 59 0.00 0.00 1.89 2.12 0.12 0.08 349.08 60 0.00 0.00 1.68 1.89 0.10 0.07 349.07 Go.ft- dada COrte, Cheek P.Mww B V. 108-&yon.iexo577802-Tdph .(4 )8462 -f.(4 )&I "4 -Gage 27 3.00 - 2.50 - 0 2.00 U d N Ce 0.00 0 Inflow/Outflow Simulation 10-Year Storm Event x a z } z } s } @ } 8 x8 R } } @ R i R @ 8 S 3 } R } R E z } : R R R F } R } R } E 8 R 5 } } 9 B B } R } _ R 10 20 30 40 50 60 Time (Minutes) Pre- - W m • Post- Post- - - - - - - - Post - Development Development Development Development Hydrograph Oufflow Outflow With "Free -Flow" Hydrograph Detention Without Detention Gomett Engk•.Ihl- 4440 Caner Creak Pa WSW. 108-Bryan,Texas]]802-T.lep .:(4 >) 2686-F :(4 )&W3094 -Page 28 Inflow / 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 0.00 349.00 1 0.32 0.32 0.28 0.32 0.02 0.01 349.01 2 0.63 0.95 1.10 1.23 0.07 0.04 349.04 3 0.95 1.58 2.38 2.68 0.15 0.10 349.10 4 1.27 2.22 4.09 4.60 0.25 0.16 349.16 5 1.58 2.85 6.18 6.94 0.38 0.25 349.25 6 1.90 3.48 8.75 9.66 0.45 0.27 349.27 7 2.22 4.12 11.80 12.87 0.54 0.30 349.30 8 2.53 4.75 15.29 16.55 0.63 0.34 349.34 9 2.85 5.38 19.20 20.67 0.74 0.37 349.37 10 3.17 6.01 23.50 25.21 0.85 0.42 349.42 11 3.01 6.17 27.74 29.68 0.97 0.46 349.46 12 2.85 5.86 31.46 33.60 1.07 0.49 349.49 13 2.69 5.54 34.73 37.00 1.14 0.51 349.51 14 2.53 5.22 37.57 39.95 1.19 0.53 349.53 15 2.37 4.91 40.00 42.48 1.24 0.54 349.54 16 2.22 4.59 42.04 44.59 1.28 0.55 349.55 17 2.06 4.27 43.69 46.31 1.31 0.56 349.56 18 1.90 3.96 44.98 47.65 1.33 0.57 349.57 19 1.74 3.64 45.92 48.63 1.35 0.57 349.57 20 1.58 3.32 46.52 49.25 1.36 0.57 349.57 21 1.42 3.01 46.79 49.53 1.37 0.58 349.58 22 1.27 2.69 46.75 49.48 1.37 0.58 349.58 23 1.11 2.37 46.40 49.12 1.36 0.57 349.57 24 0.95 2.06 45.77 48.46 1.35 0.57 349.57 25 0.79 1.74 44.85 47.51 1.33 0.57 349.57 26 0.63 1.42 43.65 46.27 1.31 0.56 349.56 27 0.47 1.11 42.20 44.76 1.28 0.55 349.55 28 0.32 0.79 40.50 42.99 1.25 0.54 349.54 29 0.16 0.47 38.55 40.97 1.21 0.53 349.53 30 0.00 0.16 36.37 38.71 1.17 0.52 349.52 31 0.00 0.00 34.12 36.37 1.13 0.51 349.51 32 0.00 0.00 31.96 34.12 1.08 0.50 349.50 33 0.00 0.00 29.91 31.96 1.03 0.48 349.48 34 0.00 0.00 27.96 29.91 0.97 0.46 349.46 35 0.00 0.00 26.12 27.96 0.92 0.44 349.44 36 0.00 0.00 24.37 26.12 0.88 0.42 349.42 37 0.00 0.00 22.70 24.37 0.83 0.41 349.41 38 0.00 0.00 21.13 22.70 0.79 0.39 349.39 39 0.00 0.00 19.63 21.13 0.75 0.38 349.38 40 0.00 0.00 18.21 19.63 0.71 0.36 349.36 41 0.00 0.00 16.87 18.21 0.67 0.35 349.35 42 0.00 0.00 15.59 16.87 0.64 0.34 349.34 43 0.00 0.00 14.38 15.59 0.61 0.33 349.33 44 0.00 0.00 13.23 14.38 0.57 0.32 349.32 45 0.00 0.00 12.14 13.23 0.55 0.31 349.31 Gaaett Eaglneering-4 Carter Creek Pa ay SuRo 108-&yam Texas 77802-Teleplwne: (40^s)8C62688- Fax: (4 )B96 4 -Gage 29 46 0.00 0.00 11.11 12.14 0.52 0.30 349.30 47 0.00 0.00 10.12 11.11 0.49 0.29 349.29 48 0.00 0.00 9.19 10.12 0.47 0.28 349.28 49 0.00 0.00 8.31 9.19 0.44 0.27 349.27 50 0.00 0.00 7.47 8.31 0.42 0.26 349.26 51 0.00 0.00 6.68 7.47 0.40 0.25 349.25 52 0.00 0.00 5.94 6.68 0.37 0.24 349.24 53 0.00 0.00 5.29 5.94 0.33 0.21 349.21 54 0.00 0.00 4.71 5.29 0.29 0.19 349.19 55 0.00 0.00 4.19 4.71 0.26 0.17 349.17 56 0.00 0.00 3.73 4.19 0.23 0.15 349.15 57 0.00 0.00 3.32 3.73 0.21 0.13 349.13 58 0.00 0.00 2.95 3.32 0.18 0.12 349.12 59 0.00 0.00 2.63 2.95 0.16 0.11 349.11 60 0.00 0.00 2.34 2.63 0.14 0.09 349.09 Gwoff Engineering- 4444 carter Greek PaM1 WSuke 106-Eryan. Texas 77802- Telephone.(,W) B 26W.-W (4 )8G6 4 -Page3 3.50 - 3.00 - 2.50 - S 0 0 U N N a 2.00 N d W U Q �j 1.50 0 O F- M O 1.00 0.50 - Inflow/Outflow Simulation 25-Year Storm Event kx a k i k 4 R @ ID fl k k t @ : a k 4 ¢ fl x a l S Y a a 4 8 a a x e x a 8 s a 8 k x s 4 F ID a a 8 4 F ` -- a 0.00 0 10 20 30 40 50 60 Time (Minutes) Pre- - - - ' Post- Post- - - - - - - - Post - Development Development Development Development Hydrograph Outflow Outflow With "Free -Flow" Hydrograph Detention Without Detention Gartett Enghiearing- 444@ C.Ia Creek Partway Su. 108-Bryan.Texas)]902-Tele .:(4 >) 268a-Po: (9 )8C "4 -Page 31 Inflow / 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 0.00 349.00 1 0.36 0.36 0.32 0.36 0.02 0.01 349.01 2 0.72 1.07 1.24 1.39 0.08 0.05 349.05 3 1.07 1.79 2.70 3.03 0.17 0.11 349.11 4 1.43 2.50 4.63 5.20 0.29 0.19 349.19 5 1.79 3.22 7.03 7.85 0.41 0.26 349.26 6 2.15 3.94 10.00 10.97 0.49 0.29 349.29 7 2.50 4.65 13.49 14.65 0.58 0.32 349.32 8 2.86 5.37 17.47 18.85 0.69 0.36 349.36 9 3.22 6.08 21.94 23.56 0.81 0.40 349.40 10 3.58 6.80 26.85 28.74 0.94 0.45 349.45 11 3.40 6.98 31.68 33.83 1.07 0.49 349.49 12 3.22 6.62 35.98 38.30 1.16 0.52 349.52 13 3.04 6.26 39.77 42.24 1.23 0.54 349.54 14 2.86 5.90 43.08 45.68 1.30 0.56 349.56 15 2.68 5.55 45.93 48.63 1.35 0.57 349.57 16 2.50 5.19 48.32 51.12 1.40 0.58 349.58 17 2.33 4.83 50.29 53.15 1.43 0.59 349.59 18 2.15 4.47 51.83 54.76 1.46 0.60 349.60 19 1.97 4.12 52.97 55.95 1.49 0.61 349.61 20 1.79 3.76 53.73 56.73 1.50 0.61 349.61 21 1.61 3.40 54.11 57.13 1.51 0.61 349.61 22 1.43 3.04 54.14 57.16 1.51 0.61 349.61 23 1.25 2.68 53.82 56.82 1.50 0.61 349.61 24 1.07 2.33 53.17 56.15 1.49 0.61 349.61 25 0.89 1.97 52.19 55.13 1.47 0.60 349.60 26 0.72 1.61 50.91 53.80 1.45 0.60 349.60 27 0.54 1.25 49.33 52.16 1.42 0.59 349.59 28 0.36 0.89 47.46 50.22 1.38 0.58 349.58 29 0.18 0.54 45.32 48.00 1.34 0.57 349.57 30 0.00 0.18 42.91 45.50 1.29 0.56 349.56 31 0.00 0.00 40.42 42.91 1.25 0.54 349.54 32 0.00 0.00 38.02 40.42 1.20 0.53 349.53 33 0.00 0.00 35.71 38.02 1.16 0.52 349.52 34 0.00 0.00 33.48 35.71 1.11 0.51 349.51 35 0.00 0.00 31.35 33.48 1.06 0.49 349.49 36 0.00 0.00 29.33 31.35 1.01 0.47 349.47 37 0.00 0.00 27.42 29.33 0.96 0.45 349.45 38 0.00 0.00 25.60 27.42 0.91 0.44 349.44 39 0.00 0.00 23.87 25.60 0.86 0.42 349.42 40 0.00 0.00 22.24 23.87 0.82 0.40 349.40 41 0.00 0.00 20.68 22.24 0.78 0.39 349.39 42 0.00 0.00 19.21 20.68 0.74 0.37 349.37 43 0.00 0.00 17.81 19.21 0.70 0.36 349.36 44 0.00 0.00 16.49 17.81 0.66 0.35 349.35 45 0.00 0.00 15.23 16.49 0.63 0.34 349.34 Gareth Enginearing-4YW0.0.101eek PartwayS V. 108-B,.n.T.., 77802-TN h.(4 )8 26 -F.:(4 )846. 4-Paga32 46 0.00 0.00 14.04 15.23 0.60 0.32 349.32 47 0.00 0.00 12.91 14.04 0.57 0.31 349.31 48 0.00 0.00 11.83 12.91 0.54 0.30 349.30 49 0.00 0.00 10.81 11.83 0.51 0.29 349.29 50 0.00 0.00 9.85 10.81 0.48 0.28 349.28 51 0.00 0.00 8.93 9.85 0.46 0.28 349.28 52 0.00 0.00 8.06 8.93 0.43 0.27 349.27 53 0.00 0.00 7.24 8.06 0.41 0.26 349.26 54 0.00 0.00 6.45 7.24 0.39 0.25 349.25 55 0.00 0.00 5.74 6.45 0.35 0.23 349.23 56 0.00 0.00 5.11 5.74 0.32 0.20 349.20 57 0.00 0.00 4.55 5.11 0.28 0.18 349.18 58 0.00 0.00 4.05 4.55 0.25 0.16 349.16 59 0.00 0.00 3.60 4.05 0.22 0.14 349.14 60 0.00 0.00 3.21 3.60 0.20 0.13 349.13 Garnett Engheaing-4000 0.1.,Cre Pmk Sage 108-6yay.Texas 77E02. Tele .:<4 )B 2688-Po; (G )Bf63094 -Page 33 3.50 - 3.00 - G y 2.50 N N d d LL 2.00 �1 u 1.00 - 0.50 - Inflow/Outflow Simulation 50-Year Storm Event 4E f A A B k 4 k a A � k q E 3 A X 6 p a s i 3 A k k S i A B k x i b A a k � t 8 P � 8 E S k 9 S k i k t 0.00 0 10 20 30 40 50 6C Time (Minutes) Pre- - - - Post- Post- - - - - - - - Post - Development Development Development Development Hydrograph Outflow Outflow With 'Free -Flow" Hydrograph Detention Without Detention Garetteglneerhg-4a44 toner creek GaMwW SUM.108-&yon,iexos 77W2.Telephone:(40)8 2688-Fae (409)80 "4 -G,.0 Inflow / Outflow Simulation 100-Year Storm Event Time Inflow 11+ 12 2s/1-0 2s/t+O Outflow Depth Elevation (Minutes) (Ft3/Sec) (Ft3/Sec) (Feet) 0 0.00 0.00 0.00 0.00 0.00 0.00 349.00 1 0.41 0.41 0.36 0.41 0.02 0.01 349.01 2 0.81 1.22 1.40 1.58 0.09 0.06 349.06 3 1.22 2.03 3.05 3.43 0.19 0.12 349.12 4 1.62 2.84 5.24 5.89 0.32 0.21 349.21 5 2.03 3.65 8.02 8.89 0.43 0.27 349.27 6 2.43 4.46 11.43 12.48 0.53 0.30 349.30 7 2.84 5.27 15.43 16.70 0.63 0.34 349.34 8 3.24 6.08 20.00 21.52 0.76 0.38 349.38 9 3.65 6.89 25.10 26.89 0.90 0.43 349.43 10 4.05 7.70 30.71 32.80 1.05 0.48 349.48 11 3.85 7.91 36.28 38.62 1.17 0.52 349.52 12 3.65 7.50 41.26 43.78 1.26 0.55 349.55 13 3.45 7.09 45.66 48.35 1.35 0.57 349.57 14 3.24 6.69 49.51 52.35 1.42 0.59 349.59 15 3.04 6.28 52.83 55.80 1.48 0.61 349.61 16 2.84 5.88 55.63 58.71 1.54 0.62 349.62 17 2.64 5.47 57.95 61.11 1.58 0.63 349.63 18 2.43 5.07 59.78 63.01 1.62 0.64 349.64 19 2.23 4.66 61.16 64.44 1.64 0.65 349.65 20 2.03 4.26 62.10 65.42 1.66 0.66 349.66 21 1.82 3.85 62.61 65.95 1.67 0.66 349.66 22 1.62 3.45 62.71 66.05 1.67 0.66 349.66 23 1.42 3.04 62.42 65.75 1.67 0.66 349.66 24 1.22 2.64 61.74 65.05 1.65 0.65 349.65 25 1.01 2.23 60.71 63.97 1.63 0.65 349.65 26 0.81 1.82 59.32 62.53 1.61 0.64 349.64 27 0.61 1.42 57.59 60.74 1.57 0.63 349.63 28 0.41 1.01 55.53 58.60 1.53 0.62 349.62 29 0.20 0.61 53.16 56.14 1.49 0.61 349.61 30 0.00 0.20 50.49 53.36 1.44 0.59 349.59 31 0.00 0.00 47.72 50.49 1.39 0.58 349.58 32 0.00 0.00 45.05 47.72 1.33 0.57 349.57 33 0.00 0.00 42.48 45.05 1.29 0.55 349.55 34 0.00 0.00 40.00 42.48 1.24 0.54 349.54 35 0.00 0.00 37.62 40.00 1.19 0.53 349.53 36 0.00 0.00 35.32 37.62 1.15 0.52 349.52 37 0.00 0.00 33.11 35.32 1.11 0.50 349.50 38 0.00 0.00 31.00 33.11 1.06 0.49 349.49 39 0.00 0.00 29.00 31.00 1.00 0.47 349.47 40 0.00 0.00 27.10 29.00 0.95 0.45 349.45 41 0.00 0.00 25.29 27.10 0.90 0.43 349.43 -- 42 0.00 0.00 23.59 25.29 0.85 0.42 349.42 43 0.00 0.00 21.96 23.59 0.81 0.40 349.40 44 0.00 0.00 20.43 21.96 0.77 0.39 349.39 45 0.00 0.00 18.97 20.43 0.73 0.37 349.37 Ganetf Enginearing- 4444 Carter Creak Pah ,5Wt 108-Bryan,Texas))802-ielegt .(4 )80 88-F.:(9 )BG63094 .Pg. W 46 0.00 0.00 17.58 18.97 0.69 0.36 349.36 47 0.00 0.00 16.27 17.58 0.66 0.35 349.35 48 0.00 0.00 15.02 16.27 0.62 0.33 349.33 49 0.00 0.00 13.84 15.02 0.59 0.32 349.32 50 0.00 0.00 12.72 13.84 0.56 0.31 349.31 51 0.00 0.00 11.65 12.72 0.53 0.30 349.30 52 0.00 0.00 10.64 11.65 0.50 0.29 349.29 53 0.00 0.00 9.69 10.64 0.48 0.28 349.28 54 0.00 0.00 8.78 9.69 0.45 0.27 349.27 55 0.00 0.00 7.92 8.78 0.43 0.27 349.27 56 0.00 0.00 7.10 7.92 0.41 0.26 349.26 57 0.00 0.00 6.32 7.10 0.39 0.25 349.25 58 0.00 0.00 5.63 6.32 0.35 0.23 349.23 59 0.00 0.00 5.01 5.63 0.31 0.20 349.20 60 0.00 0.00 4.46 5.01 0.28 0.18 349.18 Goff RgIneerin, 4444 Comer Creek Parkway Sude 100-6yanj..x ))002-ieleph.,(403)B 2688-F X:(4A')006 4 -Poge% 4.50 - 4.00 - 3.50 - 0 3.00 U N d a 2.50 v v LL U 3 2.00 U_ 3 0 5 1.50 LelJ 1.00 0.50 - 0.00 0 Inflow/Outflow Simulation 100-Year Storm Event F� . L 8 L f Y i a R C R R 8 a C S & a s a s R S R 8 8 S � a R a e L P f a 8 S S d S ° L e a i S F S 10 20 30 40 50 60 Time (Minutes) Pre- - - - , Post- Post- - - - - - - - Post - Development Development Development Development Hydrograph Outflow Outflow With "Free -Flow" Hydrograph Detention Without Detention Godett eglneering-4444 Caller Creek Poh o, 3u8e 108-Bryon,Texos77802-TelepM1one:(4 )8 2688-Foo(40 E4630i4 -Page 37 Inflow/Outflow Simulation 2-Year Storm Event 1.20 1.00 g 0.80 c 0 U N N N G. N 0.60 U .12 3 U_ 0 0 3 0.20 0.00 0 10 20 Pre -Development Hydrograph 30 40 50 60 Time (Minutes) Total Post -Development Hydrograph Gaff Engineering- 4444 Carter Creek PaM1 WSUF. 108-&yan.texas])8024Al h.nc(40)3 2W8 Fa (4 )84b 4 -Page 38 1.40 1.20 1.00 8 0 0 U N N m 0.80 d N N W U .Q 3 U 0.60 3 0 el u Inflow/Outflow Simulation 5-Year Storm Event 0.40 0.20 0.00 0 10 20 Pre -Development Hydrograph 30 40 50 60 Time (Minutes) Total Post -Development Hydrograph GaneR Eng4�eerhg-4444 C0Rer Creek Pahway Butte 108-Bryan, Texas 7M2-Tesgahane:(E09)8 2688-Fax:(4 )846JW4 -Page 39 1.60 1.40 1.20 d a m u 0.80 U Q 7 U 3 E0 0.60 3 u Um 0.20 0.00 0 Inflow/Outflow Simulation 10-Year Storm Event 10 20 30 40 50 60 Time (Minutes) Pre -Development Hydrograph Total Post -Development Hydrograph Garett EnglnearNg-4Gdd Caner Creek Partway Bft.108-&,m Te... 770]-T4eph.(G )Bab1b Po.:<4 )806 4 -Page 40 Inflow/Outflow Simulation 25-Year Storm Event 1.80 1.60 1.40 g 1.20 c 0 U N N a 1.00 N N LL U U 0.80 0 0 3 O 0.60 0.40 0.20 0.00 0 10 20 Pre -Development Hydrogroph 30 40 50 60 Time (Minutes) Total Post -Development Hydrograph Ganett flyin.hg-""Caner Creek PaM1 WButte 108-Bryan,Texas))802-Ta' hhorre:(4 )B4 88-Pox:(m)8468094 -Page 41 Inflow/Outflow Simulation 50-Year Storm Event 2.00 i TI 1.60 R 0 0 u „O 1.20 d a a LL 1.00 0 U 3 0.80 0 z O Miai1l 0.40 0.20 0.00 0 10 20 Pre -Development Hydrograph 30 40 50 60 Time (Minutes) Total Post -Development Hydrograph Gartett Ergineerk�g-4444 Coder Creek Poi ,Sutte 108-&yan, texas 7M-Tdlhona.(409)B 2688-(ax (409)84 "4 -Poga42 el u Inflow/Outflow Simulation 100-Year Storm Event 2.50 2.00 0.50 0.00 0 10 20 Pre -Development Hydrograph 30 40 50 60 Time (Minutes) Total Post -Development Hydrograph Gmett Enginewing-4 Carter Creek Pah fluke 108-&ryas.Texas77802-Telephwe:(4 )3 268 .-E (4 )806-3W4 -Page 43 100% 90% 80% 70% 30% 20% 10% 0% Detention Pond Storage Volumes as Percent of Maximum Volume 2-year 5-year 10-year 25-year Design Storm Storm Simulation Synopsis 50-year 100-year 2-year 5-year 10-year 25-year 50-year 100-year Storm Depth 0.46 0.51 0.54 0.58 0.61 0.66 Storm Elevation 349.46 349.51 349.54 349.58 349.61 349.66 Storm Volume 858 1043 1234 1445 1669 1931 Maximum Capacity 4208 4208 4208 4208 4208 4208 Percent of Capacity 20% 25% 29% 34% 40% 46% G..ff Engineering-4 C.O., Creek Poh W$95 a 108.&yan. ie..s 7702-Tale,hon.(9 )842W-Fo (G )8G6 4 -Page 44