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HomeMy WebLinkAbout03-00500167- 00076251 7 M.H.B.R. Joint Venture DRAINAGE REPORT ASHFORD SQUARE SUBDIVISION College Station, Texas May 1983 Ashford Square Subdivision DRAINAGE REPORT 1. LOCATION AND DESCRIPTION This is a 16.16 acre tract located on the south side of South- west Parkway, about 560' east of Texas Ave., College Station, Texas. It lies in the Morgan Rector League, Abstract No. 46, Brazos County, Texas. Exhibit One shows the location of the tract, its natural topography and its proposed develop- ment. The soil is a slightly pervious sandy clay covered mostly with grass. The eastern portion, along the creek that marks the eastern boundary, contains trees. 2. PURPOSE OF THE REPORT The purpose of this report is threefold as follows: a) Establish the optimum width of a proposed drainage easement on the inner side of the eastern boundary marked by the creek, which is a tributary of Bee Creek. b) Estimate the increased surface runoff caused by the proposed development of the tract and delineate an on- s i to detention system to mitigate the impact of the re- sulting increased runoff rate. c) Provide the guidelines that will enable each future lot owner to build its own lot runoff detention facility so as to comply with the overall development /drainage scheme. The subsequent sections of this report address the first two purposes I i sted above. 3. CREEK EASEMENT The Federal Insurance Administration's Floodway Boundary/ Floodway Maps do not cover the portion of the previously referred creek, implying that under existing conditions said creek has no 100 year flood plain. GOLDEN KEY LEARNING CENTER 21 -03 DRAINAGE REPORT 1. TRACT DESCRIPTION This project covers Lots 8D and 8E, Block D, Replat of Block D, Replat of Lot 8, Block D, Ashford Square. The total area studied is 0.36 acre. The project is located just off of Southwest Parkway west of the intersection with Texas Ave. Access to the site is through concrete private streets. The project area is currently vacant except for portions of existing concrete drives and parking area. The Owner plans to develop the tract into a Learning Center that is currently being designed by Mann Design. A separate 24 "x36" sheet, Grading and Drainage Plan, is part of this report and will be referred here as Exhibit 1. The adopted Flood Insurance Study does not identify the existence of a 100 -yr flood plain affecting this tract (Map # 48041 C 0144 C, July 2, 1992). 2. STORMWATER RUNOFF All of this tract's runoff flows in a general easterly direction, as sheet flow, through the existing parking areas in adjoining Lot 7, Block D. Exhibit 1 shows the tract, its location and existing spot elevations. This exhibit also shows the proposed construction project and the proposed detention pond grading. Topographic data was developed under the supervision of the undersigned. The tract has been divided into three drainage sections: Section 1 - Existing parking and driving area along frontage concrete street - 0.127 acre, Section 2 - Proposed playground /detention pond and rear yard - 0.128 acre, Section 3 - Proposed building area - 0.101 acre Exhibit 2 shows the runoff calculations for 2, 5, 10, 25, 50 and 100 -year rainfalls for each of the sections under pre and post development conditions. Detention has Page 2 been calculated using the 100 -year return period and therefore the maximum allowed runoff after development is 1.65 cfs. In order to mitigate the effect of the increase runoff (Q100 3.01 cfs) a detention facility is proposed at the location of the playground area. Runoff from the parking and driveways area of Section 1 will discharge into the detention pond through three 3.0' no -curb sections along the front of the project's internal driveway. Runoff from the building area, Section 3, will flow into the pond as sheet flow. The remaining area of Section 1 will drain into the pond as sheet flow or through roof downspouts. Exhibit 3 offers the characteristics of this flume designed to convey approximately 50% (5.8 cfs) of the 100 year total Q for this Section. Under these conditions the water depth in this flume is calculated at 0.38'. 3. INFLOW HYDROGRAPHS Haestad Methods Quick Tr -55 V. 5.47 was used for the analysis given in Exhibit 3 (in seven pages). This Exhibit graphically shows individual hydrographs for all storm frequencies. The estimated required storage for the 100 -yr storm is calculated at 0.02- ac -ft. 4. DETENTION FACILITY The pond will be built as shown in Exhibit 1. The top of the pond is set at 274.0 while the weir flow line elevation is set at 272.8. Exhibit 4 shows that the available storage for the proposed grading reaches 0.04 ac -ft. Therefore the storage available will be larger than the storage required. The weir will be of the vertical - rectangular type consisting of a 0.67' wide and 1.20' high concrete structure that will drain into the parking lot in adjoining Lot 7 though a trapezoidal concrete flume as shown in Exhibit 1. Haestad Methods Pondpack V. 5.21 was used in the ponding calculations. Exhibit 5 (in two pages) shows the input data and estimated performance of the proposed Vertical - Rectangular weir described above. Exhibit 6 (in three pages) shows the routing calculations for a multiple storm. Peak outflows for each frequency do not exceed pre- development conditions. Page 3 The following is the routing summary in terms of maximum outflow allowed (pre - development conditions) and peak attained: Storm Max. Allowed Peak Attained Max. Elevation 5 -year 1.09 1.08 273.58 10 -year 1.23 1.15 273.64 25 -year 1.40 1.25 273.70 50 -year 1.58 1.36 273.77 100 -year 1.65 1.40 273.80 A concrete spillway 0.2' high and extending 1.0 ft on either side of the weir will also be constructed at elevation 273.8. Besides providing 0.2' of free board this spillway will be able to discharge an additional 3.46 cfs in overflows. See Exhibit 7. Discharge velocity at the weir for Q100 is calculated at 2.1 fps. At maximum flow, assuming full use of the spillway, the aggregated discharge velocity would be 4.0 fps. The flume carrying the outflow from the pond will be a trapezoidal concrete flume, 3' wide by 0.3'. The characteristics of this flume are given in Exhibit 8. 5. CERTIFICATION This report and design conform to the City of College Station Drainage Policy and Design Standards. CHRISTIAN A. GALINDO, P.E. # 53425, R.P.L.S. # 4473 July 3, 2003 • ..........• -1.9 I • 4 �CHR! TbAN A. GALINDO/ Page 4 '11 �; . hG It I a§' o00 ) to M EXHIBIT 2 1 11 0 I n r- N CO CO O CO 11 t t N U) ' 10 N N CO I CO IIIAAA 11 a O O O 1 .- 0 0 I N O II p p O � 11 ( IA In V' a i co ((0 / M C 11 a O O O - .- 0 0 N IO 11 U1 r II N N 4I II El M N 0) LO O N N II a T 0 0 0 .- 000 N O v = • II cj E co f co O O O O 0) ( ' CD o ' a 0 0 0 O .- O O O e- 7 i ! I U 8 II 11 N M M N 0 N 0 10 ( 0 ( 11 O O O O O j O O O C N • II E M M M M Cr) 0 CO 0 - f0 (D. (D (D (D CI II I O 4 W 00 00 w .cr — I to t 1 p p — > . 1 (0 0 ( 0 I W co co 0 11 d O O N I O O O O O O � I O (D O co 1 1 T I M M M M M M I 8 v (D (0 (0 (D (D (D 1 >^ O N U) O O 1 00 00 00 I 00 00 00 1 + I j a O 00 O _ ` I m 0)) 0 0) i ) 0) 0) 0)) O .1) O W — T I (0 (D (0 (D U) (D II IT O t` In 2 IA r-: n n h i n n s id N O O ro 1 j !E S 8 O Z M ( CO N Z Ill I N N • () (7 M > i O n (n N 2 (0 (D (D 2 I (D co (D • C O 6 I O O 00 I= 12 U 0 0 ? co _! 0 0 0 W 1 0 0 0 , O (f) Q Z > 0 0 0 W 0 0 0 w T 8 ONO 8 H E . O ^ Q N ( n 0 O CO g a __ W w v0 (p D al i ( n (O 0 v U) v 0 O 0 N O -I In o I o V 0- 0o a 000 U ;. 8ao8 I n O Y FWI.. CO i U I I CO H LL Z u_ pp p W I c O O 8 1 0 0 0 Z O J } 7 1 C - N N CO ..-- .0 OI O 1 0 cc 0 m U I-' I 1 0 a 888 888 I > N N N 00 N 1 1 ■ 8 8 8 1 8 8 8 1 0 v v v CO (7 CO 0 0 0 1 0 0 0 I 1 n a0 ( 0 n co 10 I a 0 .-.- 0 M I- �° M I Q 0 0 0 0 0 0 0 O - y c v m co 'O w J z 0 10 Q co I._ .o. 01 0 0) O M 0 7 7 7 0 C o, E H c o N O IY d d d 1- 7 MI O o? ' o 0. 0- 0 In U m 1 0 r " 11 ▪ tV I C N CO C N M II II II 2 ) 8 1 co 0 0 11 EXHIBIT 3 Quick TR -55 Ver.5.47 S /N: Executed: 17:16:28 07 -02 -2003 MODIFIED RATIONAL METHOD - - -- Graphical Summary for Maximum Required Storage - - -- First peak outflow point assumed to occur at Tc hydrograph recession leg. GOLDEN KEY LEARNING CENTER *************************************** * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ** * RETURN FREQUENCY: 5 yr I Allowable Outflow: 1.09 cfs * 'C' Adjustment: 1.000 1 Required Storage: 0.013 ac -ft * * * * Peak Inflow: 1.79 cfs Inflow .HYD stored: 5IN .HYD * *************************************** * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ** 1 Td = 13 minutes 1 Return Freq: 5 yr / Approx. Duration for Max. Storage / C adj.factor: 1.00 I I I I Tc= 10.00 minutes 1 I = 7.693 in /hr 1 Area (ac): 0.36 . Q = 1.99 cfs 1 Weighted C: 0.73 •I• I Adjusted C: 0.73 F 1 L I • I . Required Storage 1 O 1 . -- 0.013 ac -ft 1 Td= 13 minutes W I I • I I I= 6.903 in /hr • x x x x x x xlx x x x x x x x x x x Q= 1.79 cfs c 1 1 f 1 x x s I 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Q= 1.09 cfs x o 1• Ix (Allow.0utflow) I 0 1 . x o 1 NOT TO SCALE 1 x I . 0 1 . 1 0 1 • 1 1 14.53 minutes 16.91 minutes Quick TR -55 Ver.5.47 S /N: Executed: 17:16:28 07 -02 -2003 MODIFIED RATIONAL METHOD - - -- Graphical Summary for Maximum Required Storage - - -- First peak outflow point assumed to occur at Tc hydrograph recession leg. GOLDEN KEY LEARNING CENTER *************************************** * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ** * RETURN FREQUENCY: 10 yr I Allowable Outflow: 1.23 cfs * * 'C' Adjustment: 1.000 1 Required Storage: 0.015 ac -ft * * * * Peak Inflow: 2.01 cfs Inflow .HYD stored: 10IN .HYD * *************************************** * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ** I Td = 13 minutes 1 Return Freq: 10 yr / Approx. Duration for Max. Storage / C adj.factor: 1.00 I I I 1 I Tc= 10.00 minutes I I I = 8.635 in /hr 1 Area (ac): 0.36 I . Q = 2.24 cfs 1 Weighted C: 0.73 I •1• 1 Adjusted C: 0.73 F I I L 1 . I . Required Storage 1 O I . -- 0.015 ac -ft 1 Td= 13 minutes W 1 • 1 1 1 I= 7.770 in /hr I • x x x x x x xlx x x x x x x x x x x Q= 2.01 cfs c I I f 1 x x s I 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Q= 1.23 cfs I x o 1. Ix (Allow.Outflow) 1 o I . 1 I x o 1. NOT TO SCALE I x I . o I • I 1 o I • 1 x 1 1 14.50 minutes 16.89 minutes Quick TR -55 Ver.5.47 S /N: Executed: 17:16:28 07 -02 -2003 MODIFIED RATIONAL METHOD - - -- Graphical Summary for Maximum Required Storage - - -- First peak outflow point assumed to occur at Tc hydrograph recession leg. GOLDEN KEY LEARNING CENTER *************************************** * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ** * RETURN FREQUENCY: 25 yr 1 Allowable Outflow: 1.40 cfs * * 'C' Adjustment: 1.000 1 Required Storage: 0.017 ac -ft * * * * Peak Inflow: 2.30 cfs Inflow .HYD stored: 25IN .HYD * *************************************** * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ** 1 Td = 13 minutes 1 Return Freq: 25 yr / Approx. Duration for Max. Storage / C adj.factor: 1.00 1 1 Tc= 10.00 minutes 1 I = 9.861 in /hr 1 Area (ac): 0.36 . Q = 2.55 cfs 1 Weighted C: 0.73 .1. 1 Adjusted C: 0.73 F I . 1 L 1 • 1 • Required Storage 1 O .-- 0.017 ac -ft 1 Td= 13 minutes W 1 1 1 1 I= 8.885 in/hr I xxxxxxxlxxxxxxxxxxx Q= 2.30 cfs c I . I f 1 x x s 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Q= 1.40 cfs x o 1. Ix (Allow.Outflow) 0 1 . 1 x o 1. NOT TO SCALE 1 x I . 0 1 . 1 0 1 1 x I I 14.52 minutes 16.92 minutes Quick TR -55 Ver.5.47 S /N: Executed: 17:16:28 07 -02 -2003 MODIFIED RATIONAL METHOD - - -- Graphical Summary for Maximum Required Storage - - -- First peak outflow point assumed to occur at Tc hydrograph recession leg. GOLDEN KEY LEARNING CENTER *************************************** * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ** * RETURN FREQUENCY: 50 yr I Allowable Outflow: 1.58 cfs * * 'C' Adjustment: 1.000 1 Required Storage: 0.019 ac -ft * * * * Peak Inflow: 2.61 cfs Inflow .HYD stored: 50IN .HYD * *************************************** * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ** 1 Td = 13 minutes 1 Return Freq: 50 yr / Approx. Duration for Max. Storage / C adj.factor: 1.00 1 1 Tc= 10.00 minutes 1 I = 11.148 in /hr 1 Area (ac): 0.36 . Q = 2.89 cfs 1 Weighted C: 0.73 .1. 1 Adjusted C: 0.73 F I . . L I . I • Required Storage 1 O .-- 0.019 ac -ft 1 Td= 13 minutes W 1 1 1 1 I= 10.056 in/hr I x x x x x x xlx x x x x x x x x x x Q= 2.61 cfs c 1 1 f I . x x s 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Q= 1.58 cfs x o 1. Ix (Allow.Outflow) 0 1 . 1 x o 1• NOT TO SCALE 1 x I . o 1 • 1 1 0 1 1 x . 1 I 14.53 minutes 16.94 minutes Quick TR -55 Ver.5.47 S /N: Executed: 17:16:28 07 -02 -2003 MODIFIED RATIONAL METHOD - - -- Graphical Summary for Maximum Required Storage - - -- First peak outflow point assumed to occur at Tc hydrograph recession leg. GOLDEN KEY LEARNING CENTER *************************************** * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ** * RETURN FREQUENCY: 100 yr I Allowable Outflow: 1.65 cfs * * 'C' Adjustment: 1.000 I Required Storage: 0.020 ac -ft * * * * Peak Inflow: 2.72 cfs Inflow .HYD stored: 100IN .HYD * *************************************** * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ** 1 Td = 13 minutes I Return Freq: 100 yr / Approx. Duration for Max. Storage / C adj.factor: 1.00 • I I Tc= 10.00 minutes I I = 11.639 in /hr I Area (ac): 0.36 • Q = 3.02 cfs I Weighted C: 0.73 •1. I Adjusted C: 0.73 F I I L 1 • I • Required Storage I O . -- 0.020 ac -ft I Td= 13 minutes W I 1 1 I= 10.495 in /hr I xxxxxxxlxxxxxxxxxxx Q= 2.72 cfs c I I f 1 x x s 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Q= 1.65 cfs x o 1. Ix (Allow.Outflow) I o I . I x o 1 NOT TO SCALE I x I . o I • I l 0 I • I x . I I 14.53 minutes 16.93 minutes Quick TR -55 Ver.5.47 S /N: Executed: 17:16:28 07 -02 -2003 ***************************************** * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ** ***************************************** * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ** * * * * * MODIFIED RATIONAL METHOD * * - - -- Grand Summary For All Storm Frequencies - - -- * * * * * ***************************************** * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ** ***************************************** * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ** First peak outflow point assumed to occur at Tc hydrograph recession leg. GOLDEN KEY LEARNING CENTER Area = 0.36 acres Tc = 10.00 minutes VOLUMES Frequency Adjusted Duration Intens. Qpeak Allowable 1 Inflow Storage (years)' 'C' minutes in /hr cfs cfs i (ac -ft) (ac -ft) 5 0.728 13 6.903 1.79 1.09 1 0.032 0.013 10 0.728 13 7.770 2.01 1.23 1 0.036 0.015 25 0.728 13 8.885 2.30 1.40 1 0.041 0.017 50 0.728 13 10.056 2.61 1.58 1 0.047 0.019 100 0.728 13 10.495 2.72 1.65 1 0.049 0.020 POND -2 Version: 5.21 EXHIBIT 4 S /N: GOLDEN KEY LEARNING CENTER CALCULATED 07 -02 -2003 17:12:41 DISK FILE: C: \1DATA \DATA2003 \21 -03 \POND \21 -03 .VOL Planimeter scale: 1 inch = 1 ft. * Elevation Planimeter Area Al +A2 +sgr(Al *A2) Volume Volume Sum (ft) (sq.in.) (acres) (acres) (acre -ft) (acre -ft) 272.80 0.00 0.00 0.00 0.00 0.00 273.00 300.00 0.01 0.01 0.00 0.00 274.00 3,400.00 0.08 0.11 0.04 0.04 * Incremental volume computed by the Conic Method for Reservoir Volumes. Volume = (1/3) * (EL2 -EL1) * (Areal + Area2 + sq.rt.(Areal *Area2)) where: EL1, EL2 = Lower and upper elevations of the increment Areal,Area2 = Areas computed for EL1, EL2, respectively Volume = Incremental volume between EL1 and EL2 Outlet Structure File: 21 -03 .STR POND -2 Version: 5.21 S /N: Date Executed: Time Executed: * * * * * * * * * * * * * * * * * * * * * * * * ** GOLDEN KEY LEARNING CENTER * * * * * * * * * * * * * * * * * * * * * * * * ** * * * ** COMPOSITE OUTFLOW SUMMARY * * ** Elevation (ft) Q (cfs) Contributing Structures 272.80 0.0 1 273.00 0.2 1 273.20 0.5 1 273.40 0.8 1 273.60 1.1 1 273.80 1.4 1 274.00 1.7 1 Outlet Structure File: 21 -03 .STR POND -2 Version: 5.21 S /N: Date Executed: Time Executed: Outlet Structure File: C: \1DATA \DATA2003 \21 -03 \POND \21 -03 .STR Planimeter Input File: C: \1DATA \DATA2003 \21 -03 \POND \21 -03 .VOL Rating Table Output File: C: \1DATA \DATA2003 \21 -03 \POND \21 -03 .PND Min. Elev.(ft) = 272.8 Max. Elev.(ft) = 274 Incr.(ft) = .2 Additional elevations (ft) to be included in table: * * * * * * * * * * * * * * * * * * * * * * * * * * *************** * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ** SYSTEM CONNECTIVITY *************** * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ** Structure No. Q Table Q Table WEIR -VR 1 -> 1 Outflow rating table summary was stored in file: C: \1DATA \DATA2003 \21 -03 \POND \21 -03 .PND EXHIBIT 5 Outlet Structure File: 21 -03 .STR POND -2 Version: 5.21 S /N: Date Executed: Time Executed: * * * * * * * * * * * * * * * * * * * * * * * * ** GOLDEN KEY LEARNING CENTER * * * * * * * * * * * * * * * * * * * * * * * * ** » »» Structure No. 1 ««« (Input Data) WEIR -VR Weir - Vertical Rectangular El elev.(ft)? 272.8 E2 elev.(ft)? 274.001 Weir coefficient? 3.087 Weir elev.(ft)? 272.8 Length (ft)? 0.666667 Contracted /Suppressed (C /S)? C Outlet Structure File: 21 -03 .STR POND -2 Version: 5.21 S /N: Date Executed: Time Executed: Outflow Rating Table for Structure #1 WEIR -VR Weir - Vertical Rectangular * * * ** INLET CONTROL ASSUMED * * * ** Elevation (ft) Q (cfs) Computation Messages 272.80 0.0 H =0.0 273.00 0.2 H =.2 273.20 0.5 H =.4 273.40 0.8 H =.6 273.60 1.1 H =.8 273.80 1.4 H =1.0 274.00 1.7 H =1.2 C = 3.087 L (ft) = .666667 H (ft) = Table elev. - Invert elev. ( 272.8 ft ) Q (cfs) = C * (L -.2H) * (H * *1.5) -- Contracted Weir EXHIBIT 6 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ** * * * GOLDEN KEY LEARNING CENTER * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * ** POND -2 Version: 5.21 S /N: Page 1 EXECUTED: 07 -02 -2003 17:09:45 STORM # 1 Return Freq: 5 years * * * * * * * * * * * * * * * * ** SUMMARY OF ROUTING COMPUTATIONS * * * * * * * * * * * * * * * * ** Pond File: C: \1DATA \DATA2003 \21 -03 \POND \21 -03 .PND Inflow Hydrograph: C: \1DATA \DATA2003 \21 -03 \POND \5IN .HYD Outflow Hydrograph: C: \1DATA \DATA2003 \21 -03 \POND \5 OUT .HYD Starting Pond W.S. Elevation = 272.80 ft * * * ** Summary of Peak Outflow and Peak Elevation * * * ** Peak Inflow = 1.79 cfs Peak Outflow = 1.08 cfs Peak Elevation = 273.58 ft * * * ** Summary of Approximate Peak Storage * * * ** Initial Storage = 0.00 ac -ft Peak Storage From Storm = 0.01 ac -ft Total Storage in Pond = 0.01 ac -ft EXECUTED: 07 -02 -2003 17:09:45 STORM # 2 Return Freq: 10 years * * * * * * * * * * * * * * * * ** SUMMARY OF ROUTING COMPUTATIONS * * * * * * * * * * * * * * * * ** Pond File: C: \1DATA \DATA2003 \21 -03 \POND \21 -03 .PND Inflow Hydrograph: C: \1DATA \DATA2003 \21 -03 \POND \10IN .HYD Outflow Hydrograph: C: \1DATA \DATA2003 \21 -03 \POND \10 OUT .HYD Starting Pond W.S. Elevation = 272.80 ft * * * ** Summary of Peak Outflow and Peak Elevation * * * ** Peak Inflow = 2.01 cfs Peak Outflow = 1.15 cfs Peak Elevation = 273.64 ft * * * ** Summary of Approximate Peak Storage * * * ** Initial Storage = 0.00 ac -ft Peak Storage From Storm = 0.02 ac -ft Total Storage in Pond = 0.02 ac -ft POND -2 Version: 5.21 S /N: Page 2 EXECUTED: 07 -02 -2003 17:09:45 STORM # 3 Return Freq: 25 years * * * * * * * * * * * * * * * * ** SUMMARY OF ROUTING COMPUTATIONS * * * * * * * * * * * * * * * * ** Pond File: C: \1DATA \DATA2003 \21 -03 \POND \21 -03 .PND Inflow Hydrograph: C: \1DATA \DATA2003 \21 -03 \POND \25IN .HYD Outflow Hydrograph: C: \1DATA \DATA2003 \21 -03 \POND \25 OUT .HYD Starting Pond W.S. Elevation = 272.80 ft * * * ** Summary of Peak Outflow and Peak Elevation * * * ** Peak Inflow = 2.30 cfs Peak Outflow = 1.25 cfs Peak Elevation = 273.70 ft * * * ** Summary of Approximate Peak Storage * * * ** Initial Storage = 0.00 ac -ft Peak Storage From Storm = 0.02 ac -ft Total Storage in Pond = 0.02 ac -ft EXECUTED: 07 -02 -2003 17:09:45 STORM # 4 Return Freq: 50 years * * * * * * * * * * * * * * * * ** SUMMARY OF ROUTING COMPUTATIONS * * * * * * * * * * * * * * * * ** Pond File: C: \1DATA \DATA2003 \21 -03 \POND \21 -03 .PND Inflow Hydrograph: C: \1DATA \DATA2003 \21 -03 \POND \50IN .HYD Outflow Hydrograph: C: \1DATA \DATA2003 \21 -03 \POND \50 OUT .HYD Starting Pond W.S. Elevation = 272.80 ft * * * ** Summary of Peak Outflow and Peak Elevation * * * ** Peak Inflow = 2.61 cfs Peak Outflow = 1.36 cfs Peak Elevation = 273.77 ft * * * ** Summary of Approximate Peak Storage * * * ** Initial Storage = 0.00 ac -ft Peak Storage From Storm = 0.02 ac -ft Total Storage in Pond = 0.02 ac -ft POND -2 Version: 5.21 S /N: Page 3 EXECUTED: 07 -02 -2003 17:09:45 STORM # 5 Return Freq: 100 years * * * * * * * * * * * * * * * * ** SUMMARY OF ROUTING COMPUTATIONS * * * * * * * * * * * * * * * * ** Pond File: C: \1DATA \DATA2003 \21 -03 \POND \21 -03 .PND Inflow Hydrograph: C: \1DATA \DATA2003 \21 -03 \POND \100IN .HYD Outflow Hydrograph: C: \1DATA \DATA2003 \21 -03 \POND \100 OUT .HYD Starting Pond W.S. Elevation = 272.80 ft * * * ** Summary of Peak Outflow and Peak Elevation * * * ** Peak Inflow = 2.72 cfs Peak Outflow = 1.40 cfs Peak Elevation = 273.80 ft * * * ** Summary of Approximate Peak Storage * * * ** Initial Storage = 0.00 ac -ft Peak Storage From Storm = 0.02 ac -ft Total Storage in Pond = 0.02 ac -ft Rectangular Channel Analysis & Design EXHIBIT 7 Open Channel - Uniform flow Worksheet Name: GOLDEN KEY CENTER Comment: SPILLWAY CAPACITY Solve For Discharge Given Input Data: Bottom Width 2.67 ft Manning's n 0.013 Channel Slope 0.0330 ft /ft Depth 0.20 ft Computed Results: Discharge 3.46 cfs Velocity 6.47 fps Flow Area 0.53 sf Flow Top Width 2.67 ft Wetted Perimeter 3.07 ft Critical Depth 0.37 ft Critical Slope 0.0048 ft /ft Froude Number 2.55 (flow is Supercritical) Open Channel Flow Module, Version 3.21 (c) 1990 Haestad Methods, Inc. * 37 Brookside Rd * Waterbury, Ct 06708 EXHIBIT 8 Trapezoidal Channel Analysis & Design Open Channel - Uniform flow Worksheet Name: LEARNING KEY CENTER Comment: OUTFLOW FLUME Solve For Depth Given Input Data: Bottom Width 1.00 ft Left Side Slope 3.00:1 (H:V) Right Side Slope 3.00:1 (H:V) Manning's n 0.013 Channel Slope 0.0100 ft /ft Discharge 1.40 cfs Computed Results: Depth 0.24 ft Velocity 3.42 fps Flow Area 0.41 sf Flow Top Width 2.43 ft Wetted Perimeter 2.51 ft Critical Depth 0.29 ft Critical Slope 0.0044 ft /ft Froude Number 1.47 (flow is Supercritical) Open Channel Flow Module, Version 3.21 (c) 1990 Haestad Methods, Inc. * 37 Brookside Rd * Waterbur