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Home My WebLink About50 DP Golden Keys Learning 03-60FOR OFFl~E USE ONLY case No. 0 Y \DDll ltD l1, Date Submitted 8-1-0 3 L......;;;..;.;.;~------------,:::==:;=:;==:;=:;;;;;:.1 5.-oottim DEVELOPMENT PERMIT MINIMUM SUBMITTAL REQUIREMENTS $200.00 development permit fee. Drainage and erosion control plan, with supporting Drainage Report two (2) copies each Notice of Intent (N.0.1.) if disturbed area is greater than 5 acres APPLICANT (Primary Contact for the Project): Name HM..10TT +.toM.e::~ . (~c . Street Address "1.-0j ~ Yl2.A (12-1 e- E-Mail ____________ _ @ AD City lou...hcC 7ti.l:r / o~ State _ _.Tf=_.._ ____ _ ZipCode ~79_4 ........ S ____ _ Phone Number G'1<0--I""\ Bl Fax Number --"0""--'q._,,3"'"'"""-__..3._~_q-=-=e,;___ __ _ PROPERTY OWNER'S INFORMATION: Name \1AJuoTT {JoM.~S , (A\c._ . E-Mail __________ _ Street Address hf1 '2.oGU..-fAA 11Lte f2-€AO City Cc>c_,,U£.G;.€ ~-rr~.J State _:nL~----Zip Code --Z 7 845 Phone Number (09. <O .-l i S 7 Fax Number ~0~~~3_,~'3~?_q~8 ____ _ ARCHITECT OR ENGINEER'S INFORMATION : Name \-\A R.!Ll{ Bo7Trc..-E-Mail ------------- Street Address ------------------------------ City (Qu,;t:.Ctt£-Srn-r1o;J State 1'f-Zip Code _______ _ Phone Number 704 ---z rS>O FaxNumber __________ _ Application is hereby made for the following development specific site/waterway alterations: ACKNOWLEDGMENTS : ' ' , .. CERTIFICATIONS: A. I, , certify that any nonresidential structure on or proposed to be on this site as part of this application is designated to prevent damage to the structure or its contents as a result of flooding from az;~J~ _J_a_L_._J?O_· ~,_2_a:::7_~----------En ~~ -= Date B. I, , certify that the finished floor elevation of the lowest floor, including any basement, of any residential structure, proposed as part of this application is at or above the base flood elevation established in the latest Federal Insurance Administration Flood Hazard Study and maps, as amended . a~ Engineer Date C . I, __ , certify that the alterations or development covered by this permit shall not diminish the flood- carrying capacity of the waterway adjoining or crossing this permitted site and that such alterations or development are consistent with requirements of the City of College Station City Code, Chapter 13 concerning encroachments of floodwa s anctof floodways fringes . ~ Engineer Date D. I, , do certify that the proposed alterations do not raise the level of the 100 year flood above elevation established in the latest Federal Insurance Administration Flood Hazard St~"'''' , _ ... ~'.,.t o F r '''e~ ~ . :~ ~"············ ... ~../: ,,, J LIL • .3tP 2ac5 : C:> .··"· •• ••• : O" l11, Dt ,,., • •' . ~'I. ae ,.-;,1 ,£,..: ··*"" ,,,,~: ~ ~ fl9••••••••••••••o ••••••••••••••••••••••••~ ~C HR!ST IAN A . GALIND O i ~·•••••(11••••~ .. •••••••••••••••••••••••a ••.,•••••••2'! Conditions or comments as part of approval : ~ ~ "· 5 3 4 2 5 .:' . 9 ~ ').)_ • A "' ' f~ 4"' ~,, 0 '•/f'it, ~ V,•' 'V ,::' #;i ;-.".,:· •• G'/STt.~ / ~~ -v1,. <-s8 ............. ·<'.i· .i!' 'to,. IOfilf\L \:.-::~:'"' ~~~\ ~\.'l;,~V'- ln accordance with Chapter 13 of the Code of Ordinances of the City of College Station , measures shall be taken to insure that debris from construction , erosion, and sedimentation shall not be deposited iri city streets , or existing drainage facilities . All development shall be in accordance with the plans and specifications " . • submitted to and approved by the City Engineer for the above named project. All of the applicable codes and ordinances of the City of College Station shall apply . 02 /20 /04 08:42 FAX 9798452074 TAMU COMP INFO SRVCS 141001 \ ~Golden Keys Learning Center, LLC A child day cattlleo.rning facility <{ '.I\ 7 4 'vi/\ February 19 , 2004 ~/Q'J_i_\_ 246 Southwest Parkway East College Station, Texas 77840 City of College Station Development Services 1101 Texas Avenue College Station. Texa.~ 77840 Re: Water flowing through playground area Attn: Ms. Jennifer RJ.':eves Dear Ms. Reeves: 1bis is in regards to the water flowing through the playground area at Goldi.en Keys Learning Center. The .water flowing from the neighboring streets and parking area!S into the required retention pond keeps the complete middle section of the playground saturated. This has created a problem for the children playing outside. So far, the main factors contributing to the saturated playground are: I. Recent heavy rains, and 2. City workeT5 draining water from nearby fire hydrant to reduce the buildup of corrosion in the lines. Note: This happened today, February 19, 2004. We care for children ages 18 months to 5 years old. The retention pond and other drainage requirements have created numerous hazards on the playground for ow children. The slope in the play area makes it hard for very young children to keep their balance. That, along with the saturated playground causes the children to slip and fall constantly. This situation makes the children more subject to serious injuries. Thcrc:fore, Golden Keys would be held liable for the costs incurred as a result of injwies. The Texas Department of Protective and Regulatory Services required us to fo11ce in the flume area to pT-event injury to the children as they play outside. This was an added expense we had to incur. We ask for your advice and help to find a solution to the problems r~aused by water flowing through the playground area. "'i\.. 24 6 Southwest Parkway E. ~!J· ·' ·Le ' P.O. Box 9105 t 'r-' .· .. O I~ ' College Station , Texas 77842 (Q;=.--;,;:• (979) 693 -9944 --~02 /20 /0 4 08 : 42 FAX 979845207 4 TAMU COMP I NFO SR VCS !41002 .. ' Suggestions include'. 1. Ins Lall a rubber speed bump or some type of blockage across the handicap parking space entry. This will force the water to flow past the handicap parking entry ~ through the adjacent parking lot to the east ~ through the drainage path behind the Ashford Square duplexes~ into the retention pond located east of the duplexes. The blockage across the entrance of the handicap parking area should be of certain dimensions so that a wheel chair can roll over it. This option would only minimize the amount of water flowing through the playground to the flume. 2. Install a drainage pipe from the fence at the end of the handicap parking to the flume. Then, cover the entire drainage pipe with dirt and sod. This will provide a more leveled play area for the children and comply with the drainage requirements . Our priority at Golden Keys is to provide a safe environment for the children. entrusted to our care. However, we understand we have to comply with the city ordinance~1. Because we are a new small busin.ess, ow funds arc very limited. Please let us know if the City of College Station will provide financial assistance . We appreciate any suggestions and assistance you and your office can provide in resolving this issue . Sincerely, ~~ Herben Booker ~b<Jok- Jacqualine Booker f'IO tJ.?~ "2i'<:1 M~H\ MO.,.:i: 1'.3.l.-V M ~Ill l > .L"i1 ~ <l3 '74S 'V1 N 3 ~l.V'JIG N k l~lt ~, ........ .. / ~->----· 1' I I<~---'----,O-Z ---~~~Jc,-( --. a.II ---"ii .. --... ( ·-... I __ ' _ 1 --"" r : :!I _,r --~ \ ( ., ( ) ' ( I I ! J ; \? 0 "" "-. "" 0 "-. 0 ""' 0 00 .. ""' w "rj g; <c --1 <c 00 ""' 01 "" 0 --1 ""' ~ ~ C! ('"l 0 l:i::: .,, ... z "rj 0 Vl ::i::i < ('"l Vl 1§1 0 0 w -, 1 RDEN vf ~ I{) -3 I -.40 GALINDO ENGINEERS AND PLANNERS, INC. 3833 South Texas Ave ., Suite 213 Bryan , Texas 77802 (979) 846-8868 July 3, 2003 Mr. Spencer Thompson Engineering Department City of College Station College Station , TX Subject: Drainage Report Golden Key Learning Center College Station, TX Dear Spencer: Pleased find enclosed the referenced report for your review. This report is to be reviewed in conjunction with the Grading and Drainage Plan for this project that is being submitted separately. This report follows the criteria established in 1983 at the time of the initial drainage report prepared by the undersigned for Ashford Square Subdivision. Please see the attached two sheets excerpted from that report. Sincerely, GALINDO ENGINEERS AND PLANNERS, INC. Christian A. Galindo, P.E., R.P.L.S. President cc: Bruce Olson M&.M Design c---- ,,,,,,,,,,~,,, __ .... t. 0 F r '•1 :-=-~ ~~············ .. t..r-1 ''~,, :c,, .. ·· * .... O' ~,, ;*.: .· \1r ~ ~*l ~.* ~ itfl!-••····································~ iCHRISTIAN A. G ALIN DO ~ ~·······-........................................ ~ ~~··. 53425 /c-/ ~-,:> ··.,p... ~~ ... 4..1., 'IA o""·".<:G 1s1c~ / .;;.·./.:: .. ,. ~... ... ~ ... ,~ -1, 'S'o . .,., ..... ~(',: .~ le u/O ... A1 t.,'( ...... - '' H ... ~";::.. \\\'''"'"''"''1'.~ cC ;;, M.H.B.R. Joint Venture DRAINAGE REPORT ASHFORD SQUARE SUBDIViSION College Station, Texas May 1983 . f Ashford Square Subdivi s ion 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- site detention system to mitigate the impact of the re- su It i ng increased runoff rate. c) Provide the guidelines that will enable each future lot owner to bui Id its own lot runoff detention faci I ity so as to comply with the overal I development/drainage scheme. The subsequent sect ions of this report address the first two purposes Ii sted above. 3. CREEK EASEMENT The Federal Insurance Administration's Floodway Boundary/ Floodway Maps do not cover the portion of the previously referred creek, imp I yi ng that under existing conditions said creek has no 100 year flood plain. 1. TRACT DESCRIPTION GOLDEN KEY LEARNING CENTER DRAINAGE REPORT This project covers Lots 80 and BE, 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 M&M 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 Page4 "'''~''"'\~\\\ ~:.--~ '\ t 0 F r ~ ~ .. , .:::-,,( ""-....... .... "'~· ,,,, fll> ... ,, •••• ••••• -, " = <=::> • • • • . • ••• cJ" 'I; ;*... \"I<~ "! .A-:' .. * ,,., .,,, J.'t.. • ~···········~··························· ~CHRIST I AN A. GALINDO~ ~'"'•••t"l '"'"'~' '· ...• ,. .... ,. r ••••n •e 11 e •e•o o••H•••••••••~ ~. :. ' "~·s ; !: "'11 "'d •. ... _, ,...... • ~ ~ v. ~p ··. . " ~ .•· '"-' liP lfA ("> • ·' <(; • '<; "" 11:i ·~·. • ••• · •• ·, .'r.·T <=\'' ••• • ~. -t J! r • '. •,, /';) \~ ,.• ":\-{,.._ -,,, ¢ ,'·· ...... ..... \\:) .: ~ ..:...; 'A c:~.. -fQt ·: • .,,~A L ~ ~ ~~~~ ~~..,. '\\\\.'\.~~"" Job : 21-03 Date : 03-Jul-03 RUNOFF CALCULATIONS -RATIONAL METHOD GOLDEN KEY LEARNING CENTER BRYAN, TEXAS (County : Brazos) Tc= 10.0 when the calculated value is less than 10.0 Section Soil Type On-Site Run -Off 1 Pasture 2 Pasture 3 Pasture Total ============ On-Site Run-Off A Acres ====== ====== c Veloc . fps ====== ====== Length ft -------------- 0.127 0.400 2 .500 220 0 .128 0 .400 2 .500 90 0 .101 0 .400 2 .500 100 0.355 ====== ====== ======= ============== ======= ======= ======= ======== ======= ======= ======= ======= T cone . in min . Cale . Used 2 yrs 5 yrs 10 yrs 25 yrs 50yrs 100yrs ======= ======= ======= ======= ======= ======= ======== ======= PRE-DEVELOPMENT 1.5 10.0 6 .327 7 .693 8 .635 9 .861 11 .148 11 .639 0.6 10.0 6.327 7 .693 8 .635 9 .861 11 .148 11 .639 0 .7 10.0 6.327 7 .693 8 .635 9 .861 11 .148 11 .639 Q 2 yrs Q 5yrs Q 10 yrs ======= ======= ======= ------- 0.32 0 .39 0 .44 0 .32 0 .39 0.44 0 .25 0 .31 0 .35 --- 0.90 1.09 1.23 ======= ======= ======= ======= ======= ======= ======== ======= ======= ======= ======= POST-DEVELOPMENT ---------------------------------------------------------- Parking Lot 0 .127 0 .900 8 .500 2 Playground 0 .128 0 .500 2 .500 3 Commercial 0.101 0 .800 7.000 ---- Sub-Total 0 .355 ============ ====== ====== County: Brazos 220 90 150 0 .4 0 .6 0 .4 10.0 6 .327 10.0 6 .327 10.0 6 .327 7 .693 8 .635 9 .861 11 .148 7 .693 8.635 9 .861 11 .148 7 .693 8.635 9 .861 11 .148 11 .639 0 .72 0 .88 0 .99 11.639 0.40 0.49 0 .55 11 .639 0 .51 0.62 0 .70 ---- 1.64 1.99 2 .23 ======= ============== ======= ======= ======= ======== ======= ======= ======= ======= Constants for use in formula : l=b/(t+d)•e 2-yr 5-yr 10-yr 25-yr 50-yr 100-yr ---------- b 65.000 76.000 80 .000 89 .000 98.000 96.000 e 0.806 0 .785 0 .763 0 .754 0 .745 0 .730 d 8.000 8 .500 8 .500 8 .500 8 .500 8 .000 Q 25 yrs ====== ====== Q 50yrs Q 100yrs ====== ====== ----------- 0.50 0 .57 0 .59 0 .50 0 .57 0.59 0.40 0.45 0 .47 ----------- 1.40 1.58 1.65 ====== ====== ---------- 1.13 1.28 1.33 0 .63 0 .71 0 .74 0 .79 0.90 0.94 --~--------- 2.55 2.88 3.01 ====== ====== EXHIBIT 3 Quick TR-55 Ver.5.47 Executed: 17:16:28 S/N: 07-02-2003 F L 0 w c f 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 'C' Adjustment: 1.000 Allowable Outflow: 1. 09 cfs 0.013 ac-ft * * Required Storage: * *--------------------------------------------------------------------* * Peak Inflow: 1. 79 cfs Inflow .H YO stored: SIN .HYO * ********************************************************************** I Td = 13 minutes I /-------Approx. Duration for Max. Storage ------/ x . I. Tc= I Q 10.00 7 .693 1. 99 minutes in/hr cfs I I I I I I I Required Storage I 0. 013 ac-ft I I x x x x x x xix x x x x x x x x x x I Return Freq: 5 yr C adj.factor: 1.00 Area (ac): Weighted C: Adjusted C: 0.36 0.73 0.73 Td= 13 minutes I 6.903 in/hr Q 1.79cfs x s o o o o o o o o o o o o o o o o Q= 1.09 cfs x o I. Ix (Allow.Outflow) o I I x o I NOT TO SCALE I x o I ============ I o I I x -----------------------1-----------------------------1------------ 14.53 minutes 16.91 minutes Quick TR-55 Ver .5.47 Executed: 17:16:28 S/N: 07-02-2003 F L 0 w c f MODIFIED RATIONAL METHOD ----Graphical Summary for Maximum Required Storage ---- First peak outflow point assumed to occur at Tc hydrograph recession leg. I GOLDEN KEY LEARNING CENTER ********************************************************************** * * RETURN FREQUENCY : 10 yr 'C' Adjustment: 1.000 Allowable Outflow : Required Storage : 1. 23 cfs 0.015 ac-ft * * *--------------------------------------------------------------------* * Peak Inflow: 2.01 cfs Inflow .HYO stored: lOIN .HYO * ********************************************************************** Td = 13 minutes I Return Freq: 10 yr /-------Approx. Duration for Max. Storage ------/ C adj.factor: 1.00 1 I I x . I. Tc= I Q 10.00 8.635 2.24 minutes in/hr cfs I I I I I I I Required Storage I 0.015 ac-ft I I x x x x x x xix x x x x x x x x x x I Area (ac): Weighted C: Adjusted C: 0.36 0.73 0.73 Td= 13 minutes I 7.770 in/hr Q 2.01 cfs x s o o o o o o o o o o o o o o o o Q= 1.23 cfs x o I. Ix (Allow.Outflow) o I I x o I NOT TO SCALE I x o I ============ I o I I x -----------------------1-----------------------------1------------ 14 .50 minutes 16.89 minutes Quick TR-55 Ver.5.47 Executed: 17:16 :28 S/N: 07-02-2003 F L 0 w c f MODIFIED RATIONAL METHOD ----Graphical Summary for Maximum Re quired Storage ---- First peak outflow point assumed to occur at Tc hydrograph recession leg. GOLDEN KEY LEARNING CENTER ********************************************************************** * RETURN FREQUENCY: 25 yr 'C' Adjustment: 1.000 Allowable Outflow: 1.40 cfs 0.017 ac-ft * * Required Storage: * *--------------------------------------------------------------------* * Peak Inflow: 2.30 cfs Inflow .HYO stored: 25IN .HYO * ********************************************************************** I Td = 13 minutes I /-------Approx. Duration for Max. Storage ------/ x . I. Tc= I Q 10.00 9.861 2.55 minutes in/hr cfs I I I I I I I Required Storage I 0.017 ac-ft I I x x x x x x x i x x x x x x x x x x x I Return Freq: 25 yr C adj.factor: 1.00 Area (ac): Weighted C: Adjusted C: 0.36 0 .73 0.73 Td= 13 minutes I 8.885 in/hr Q 2.30 cfs x s o o o o o o o o o o o o o o o o Q= 1.40 cfs x o I. Ix (Allow.Outflow) o I I x o I NOT TO SCALE I x o I ============ I o I I x -----------------------1-----------------------------1------------ 14.52 minutes 16.92 minutes Quick TR-55 Ver.5.47 Executed: 17:16:28 S/N: 07-02-2003 F L 0 w c f s 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 'C' Adjustment: 1.000 Allowable Outflow: Required Storage: 1. 58 cfs 0.019 ac-ft * * *--------------------------------------------------------------------* * Peak Inflow: 2.61 cfs Inflow .HYO stored: 50IN .HYO * ********************************************************************** I Td = 13 minutes I /-------Approx. Duration for Max. Storage ------/ . I. Tc= I Q 10.00 11 .148 2.89 minutes in/hr cf s I I I I I I I Required Storage I 0.019 ac-ft I I x x x xx x xix xx x x xx x xx x I Return Freq: 50 yr C adj.factor: 1.00 Area (ac): Weighted C: Adjusted C: 0.36 0.73 0.73 Td= 13 minutes I 10.056 in/hr Q 2.61 cfs I x x I o o o o o o o o o o o o o o o o Q= 1.58 cfs I x o I. Ix (Allow.Outflow) I o I I I x o I NOT TO SCALE I x I o I ============ I I o I I x '-----------------------1-----------------------------1------------ 14.53 minutes 16.94 minutes Quick TR-55 Ver.5.47 Executed: 17:16:28 S/N: 07-02-2003 F L 0 w c f 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 'C' Adjustment: 1.000 Allowable Outflow: 1. 65 cfs 0.020 ac-ft * * Required Storage: * *--------------------------------------------------------------------* * Peak Inflow: 2.72 cfs Inflow .HYO stored: lOOIN .HYO * ********************************************************************** I Td = 13 minutes I /-------Approx. Duration for Max. Storage ------/ x . I. Tc= I Q 10.00 11. 639 3.02 minutes in/hr cfs I I I I I I I Required Storage I 0.020 ac-ft I I x x x x x x xix x x x x x x x x x x I Return Freq: 100 yr C adj.factor: 1.00 Area (ac): Weighted C: Adjusted C: 0.36 0.73 0.73 Td= 13 minutes I 10.495 in/hr Q 2.72 cfs x s o o o o o o o o o o o o o o o o Q= 1.65 cfs x o I. Ix (Allow.Outflow) o I I x o I NOT TO SCALE I x o I ============ I o I I x -----------------------1-----------------------------1---------~-- 14.53 minutes 16.93 minutes Quick TR-55 Ver.5.47 Executed: 17:16:28 S/N: 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 I Inflow Storage (years)' 'C' minutes in/hr cfs cfs I (ac-ft) (ac-ft) ------------------------------------------------------1---------------------5 0.728 13 6.903 1.79 1.09 I 0.032 0.013 10 0.728 13 7.770 2.01 1.23 I 0.036 0.015 25 0.728 13 8.885 2.30 1.40 I 0.041 0.017 50 0.728 13 10.056 2.61 1.58 I 0.047 0.019 100 0.728 13 10.495 2.72 1.65 I 0.049 0.020 EXHIBIT 4 POND-2 Version: 5.21 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 (ft) Planimeter (sq . in.) Area (acres) Al+A2+sqr(Al*A2) (acres) Volume (acre-ft) Volume Sum (acre-ft) * 272.80 273.00 274.00 0.00 300 .00 3,400.00 0.00 0.01 0.08 0.00 0.01 0 .11 0.00 0.00 0.04 0.00 0.00 0.04 Incremental volume computed by the Conic Method for Reservoir Volumes. Volume= (1/3 ) * (EL2-EL1) * (Areal+ Area2 +sq.rt. (Areal*Area2)) where: ELl , BL2 Areal ,Area2 Volume Lower and upper elevations of the increment Areas computed for ELl , EL2, respectively Incremental volume between ELl and EL2 Outlet Structure File: 21-03 POND-2 Version: 5.21 Date Executed: .STR S/N: Time Executed: ************************** GOLDEN KEY LEARNING CENTER ************************** ***** COMPOSITE OUTFLOW SUMMARY **** Elevation (ft) Q (cfs) Contributing Structures --------------------------------------------- 272. 80 0.0 273.00 0.2 273.20 0.5 273.40 0.8 273 .60 1.1 273.80 1. 4 274.00 1. 7 Outlet Structure File: 21-03 POND-2 Version: 5.21 Date Executed: 1 1 1 1 1 1 1 .STR S/N: 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 Iner. (ft) 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 . 2 Outlet Structure File: 21-03 .STR S/N: POND-2 Version: 5.21 Date Executed: Time Executed: ************************** GOLDEN KEY LEARNING CENTER ************************** >>>>>> Structure No. 1 <<<<<< (Input Data) WEIR-VR Weir -Vertical Rectangular El elev. (ft)? E2 elev. (ft) ? Weir coefficient? Weir elev. (ft) ? Length (ft)? Contracted/Suppressed 272. 8 274.001 3 .087 272. 8 0 .666667 (C/S)? C Outlet Structure File: 21-03 .STR S/N: POND-2 Version: 5.21 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 =l. 0 274.00 1. 7 H =l. 2 C = 3.087 L (ft) = .666667 H (ft) Table elev. -Invert elev. ( 272.8 ft) Q (cfs) = C * (L-.2H) * (H**l .5) --Contracted Weir EXHIBIT 5 , EXHIBIT 6 ******************************** * * * GOLDEN KEY LEARNING CENT ER * * * ******************************** 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 Outf low 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 Inf low Peak Outflow Peak Elevation 1. 7 9 cfs 1. 08 cfs 273 .58 ft ***** Summary of Approximate Peak Storage ***** Initial Storage Peak Storage From Storm Total Storage in Pond 0.00 ac-ft 0.01 ac-ft 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 Inf low Peak Outflow Peak Elevation 2 .01 cfs 1 .15 cfs 273 .64 ft ***** Summary of Approximate Peak Storage ***** Initial Storage Peak Storage From Storm Total Storage in Pond 0.00 ac-ft 0.02 ac-ft 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 .HYO Outflow Hydrograph: C:\1DATA\DATA2003 \21-03\POND\25 OUT .HYO Starti n g Pond W.S. Elevation = 272.80 ft ***** Summary of Peak Outflow and Peak Elevation Peak Inflow Peak Outflow Peak Elevation 2.30 cfs 1. 25 cfs 273 .7 0 ft ***** Summary of Approximate Peak Storage ***** Initial Storage Peak Storage From Storm Total Storage in Pond 0.00 ac-ft 0.02 ac -ft 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 .H YO Outflow Hydrograph: C:\1DATA\DATA2003\21-03\POND\50 OUT .HYO Starting Pond W.S. Elevation = 272.80 ft ***** Summary of Peak Outflow and Peak Elevation Peak Inflow Peak Outflow Peak Elevation 2.61 cfs 1. 36 cfs 273.77 ft ***** Summary of Approximate Peak Storage ***** Initial Storage Peak Storage From Storm To tal Storage in Pond 0.00 ac-ft 0.02 ac -ft 0.02 ac -ft ***** .. POND-2 Version: 5 .21 S/N: EXECUTED : 07-02-2003 17:09:45 STORM # 5 Page 3 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 OU T .HYD Starting Pond W.S. Elevation = 272.80 ft ***** Summary of Peak Outflow and Peak Elevation Peak Inf low Peak Outflow Peak Elevation 2.72 cfs 1.40 cfs 273.80 ft ***** Summary of Approximate Peak Storage ***** Initial Storage Peak Storage From Storm Total Storage in Pond 0.00 ac-f t 0.02 ac-ft 0.02 ac-ft ***** . . . Rectangular Channel Analysis & Design Open Channel -Uniform flow Worksheet Name: GOLDEN KEY CENTER Comment: SPILLWAY CAPACITY Solve For Discharge Given Input Data: Bottom Width .... . Manning's n ..... . Channel Slope ... . Depth ........... . Computed Results: Discharge ....... . Velocity ........ . Flow Area ....... . Flow Top Width .. . Wetted Perimeter. Critical Depth .. . Critical Slope .. . Froude Number ... . 2.67 ft 0.013 0.0330 ft/ft 0.20 ft 3.46 cfs 6.47 fps 0.53 sf 2.67 ft 3.07 ft 0.37 ft 0.0048 ft/ft 2 .55 (flow is Supercritical) Open Channel Flow Module, Version 3.21 (c) 1990 EXHIBIT 7 Haestad Methods, Inc. * 37 Brookside Rd * Waterbury, Ct 06708 , ' • 6': Trapezoidal Channel Analysis & Design Open Channel -Uniform flow Worksheet Name: LEARNING KEY CENTER Comment: OUTFLOW FLUME Solve For Depth Given Input Data: Bottom Width ..... Left Side Slope .. Right Side Slope. Manning's n ..... . Channel Slope ... . Discharge ....... . Computed Results: Depth ........... . Velocity ........ . Flow Area ....... . Flow Top Width .. . Wetted Perimeter. Critical Depth .. . Critical Slope .. . Froude Number ... . 1. 00 ft 3.00:1 (H :V) 3.00:1 (H:V) 0.013 0.0100 ft/ft 1.40 cfs 0.24 ft 3.42 fps 0.41 sf 2.43 ft 2.51 ft 0 .29 ft 0.0044 ft /ft 1.47 (flow is Supercritical) Open Chartnel Flow Module, Version 3.21 (c) 1990 Haestad Methods, Inc. * 37 Brookside Rd * Waterbur EX HIBIT 8 GALINDO ENGINEERS AND PLANNERS, INC. 3833 South Texas Ave ., Suite 213 Bryan, Texas 77802 (979) 846-8868 Ms. Carol Cotter Engineering Department City of College Station College Station, TX August 4, 2003 Subject: Addendum to Drainage Report dated July 3, 2003 Golden Key Learning Center College Station, TX Dear Carol: Further to the subject Drainage Report and following our telephone review of your comments a few days ago please be advised of the criteria that I followed in its preparation: 1. The streets in this subdivision are private, concrete built and have "V" cross- section. Lot lines extend to the middle of the streets. 2. Runoff from and within these streets bypasses the individual lots as it was envisioned in the original design of may 19B3. 3. The front interior parking lot and driveways in Lots BD and BE, and also in Lots BA, BB and BC currently exist and are built in concrete. Because of their layout and grade approximately half of their runoff is expected to bypass the detention area designed for this project. 4. Most of the runoff from Lots BA, BB and BC located to the west of the subject tract drains towards the existing channel that flows through the Mobile Home Park located to the southwest. To minimize the amount of possible offsite flow into the subject tract, and to expedite the flow into the adjoining channel, a one foot high berm is proposed along the west end of the subject tract (rear of the proposed building). 5. The proposed detention facility is designed to handle the 100-yr runoff for an area equivalent to the total size of the two lots. Since in reality a substantial part of this runoff bypasses the detention pond its capacity is suitable to handle Page 1 any possible offsite runoff proceeding from lots BA, BB and BC. Sincerely, GALINDO ENGINEERS AND PLANNERS, INC. Christian A. Galindo, P .E., R.P .L.S. President cc: Bruce Olson M&M Design Page 2