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HomeMy WebLinkAbout60 Development Permit 625 Varisty FordFINAL DRAINAGE REPORT FOR THE HIGH RIDGE SUBDIVISION PARKING EXP ANSI ON & DRAINAGE IMPROVEMENTS COLLEGE STATION, BRAZOS COUNTY, TEXAS NOVEMBER, 1998 Revised: NOVEMBER 24, 1998 ~· MUNICIPAL DEVELOPMENT GRO UP I~'~ I •I!J 2551 TEXAS AVEN UE. SOUTH , STE . A COLLEGE STAT ION, TEXAS 77840 Ph: (409)693 -5359 Fx : (409) 693 -4243 ~Consu lt ing Engineers · Environmental· Surveyors· Planners TABLE OF CONTENTS 1.0 PROJECT SCOPE ................................................................................................. 4 1.1 SITE LOCATION .................................................................................................... 4 1.2 GENERAL DESCRIPTION ..................................................................................... 4 2.0 DRAINAGE BASINS & SUB-BASINS ................................................................. 4 2.1 MAJOR DRAINAGE BASIN DESCRIPTIONS ...................................................... 4 2.2 SUB-DRAINAGE BASIN DESCRIPTIONS ........................................................... 5 3.0 DRAINAGE DESIGN CRITERIA & CONSTRAINTS ....................................... 5 3 .1 STREET DRAINAGE ............................................................................................. 5 3 .2 STORM SEWER INLETS ....................................................................................... 6 3.3 STORM SEWER SYTEMS ..................................................................................... 6 3 .4 OPEN CHANNELS ................................................................................................. 7 3.5 CULVERTS ............................................................................................................. 8 3.6 DETENTION FACILITIES ..................................................................................... 8 4.0 DRAINAGE SYSTEM MODELING .................................................................... 9 4 .1 STREET DRAINAGE ............................................................................................. 9 4 .2 STORM SEWER INLETS ....................................................................................... 9 4 .3 STORM SEWER SYSTEMS ................................................................................... 9 4 .4 OPENCHANNELS ............................................................................................... 10 4.5 CULVERTS ........................................................................................................... 10 4 .6 DETENTION FACILITIES ................................................................................... 10 5.0 CONCLUDED DRAINAGE IMPROVEMENTS ............................................... 11 5.1 STORM SEWER SYSTEMS ................................................................................. 11 5.2 OPEN CHANNELS ............................................................................................... 11 5.3 GRADING & ERIOSION CONTROL ................................................................... 13 APPENDIX A -HYDRAULIC COMPUTATIONS APPENDIX B -MAPPING APPENDIX C -DRAINAGE DETAILS LIST OF TABLES DESCRIPTION PAGE NO. TABLE #1 -Proposed Discharge Outlets (10-Year Rainfall Event) .............................. 11 TABLE #2 -Proposed Discharge Outlets ( 100-Year Rainfall Event) ............................ 11 TABLE #3 -Proposed Open Channels (25-Year Rainfall Event) .................................. 12 TABLE #4 -Proposed Open Channels (100-Year Rainfall Event) ................................ 12 TABLE #5 -Proposed Pilot Channels ........................................................................... 12 Hi gh Rid ge Subdivision Drain ag e Improvem ents 1.0 PROJECT SCOPE Muni ci pa l Development Group This report outlines the drainage improvements for the High Ridge Subdivision "Varsity Ford" parking expansion . This drainage report will consist of the requirements necessary for the improvements of this site in accordance with the provisions of the City of College Station Drainage Policy and Design Standards. 1.1 SITE LOCATION The project is located on the east frontage road of State Highway No . 6 . Surrounding existing developments immediately adjacent to the project site are ; the existing Varsity Ford Motor Complex building and car lot, and the Hollywood Theatre center. The site fronts the frontage road approximately 2000 linear feet south of the State Highway No . 60 intersection . 1.2 GENERAL DESCRIPTION The subject property, being a 1.90-acre tract, is currentl y vacant. This land generally slopes to the northeast with a grade of approximatel y 3. 00 % being fairly uniformly distributed . This site is currently unimproved with native grasses, weeds , and light underbrush and some large trees . The project site is adjacent to Carter Creek and is within that drainage basin . 2.0 DRAINAGE BASINS & SUB-BASINS 2 .1 MAJOR DRAINAGE BASIN DESCRIPTIONS The drainage improvements project site is contained within the drainage- watershed of the Carter's Creek Drainage Basin. This drainage basin is illustrated on Exhibit # 1 -"Carter's Creek Drainage Basin" located in Appendix B -Mapping . The borders of this drainage basi n roughl y consist of Rock Prairie Road on the south and west, State Hwy No 30 to the east , and State Hwy No. 21 to the north . 000414-313 4 Drainage Report .doc Final Drainage Report -4 High Rid ge Subdivision Draina ge Improvem ents 2 .2 SUB-DRAINAGE BASIN DESCRIPTIONS Muni ci pal Development Group The sub-drainage basins that will determine all drainage calculations will consist of the 1. 90-acre tract that includes the parking area expansion . The Varsity Ford parking expansion will be analyzed in two separate drainage configurations . Initial the sub-basin will be examined at the current pre- development conditions . This analysis will provide for accurate pre- development runoff values . Next , the sub-basin was reconfigured to match drainage patterns of the proposed site grading . New coefficients of runoff were established with associated runoff values . From these computations the required proposed drainage structures were designed . The new sub-drainage basins are illustrated on Exhibit #2 -"Post- Development Varsity Ford Sub-Drainage Basin". Results of these calculations are shown in Section 5.0. The project site fringes the 100-year floodplain as shown on the Flood Insurance Rate Map , (FIRM) Map No . 48041C0142 C having an effective date of July 2, 1992 . An excerpt of the FIRM map with the location of the project site is illustrated on Exhibit #3 -"FIRM Map " located in Appendix B -Mapping . 3.0 DRAJNAGE DESIGN CRITERIA & CONSTRAJNTS For all development within the City of College Station, there are criteria on the use of which design storms and development conditions for type of drainage improvements . Below, in each type of improvement 's, the required design constraints are more fully detailed . All drainage improvements shall also be analyzed during the 100-year rainfall event to insure that no adverse conditions will exist. 3.1 STREETDRAINAGE Street drainage improvements shall be designed in accordance to the City of College Station 's Drainage Policy and Design Standards . Unless 000 414-3134 Drainage Report .do c Final Drainage Report -5 High Ridge Subdivision Drainage Improve m ents Muni ci pal Development Group otherwise stated , the following constraints shall dictate the design of all street grading and drainage : •!• All proposed streets shall have curb and gutter. •!• Maximum velocity not to exceed 10 ft/sec and rrummum slope of 0.4%. •!• Concrete valley gutters shall be placed at all roadway intersections where runoff is carried from one side of the roadway to the other. •!• The 100-year rainfall event shall be confined within the limits of the street right-of-way . •!• All streets permissible spread of water shall be dictated by the 10-year rainfall event. For each class of street, the following conditions will control : );;> Arterial & Parkway-One clear lane in each direction 24 foot total clearance at center of street. );;> Collector & Commercial -One clear lane 12 foot total clearance at the center of the street. );;> Local -Depth of water not to exceed the top of curb or crown, whichever is less . 3 .2 STORM SEWER INLETS Storm sewer inlets shall be designed in accordance to the City of College Station 's Drainage Policy and Design Standards. Unless otherwise stated, the following constraints shall dictate the design of all storm sewer inlets: •!• Inlets on all streets, except for residential , shall be recessed with a minimum 4" depression . •!• Curb openings shall be a minimum length of 5 feet. •!• Inlets with greater than a 5" gutter depression on streets with less than a 1. 00% grade shall be designed in sump conditions . •!• Inlets at bridges and culvert structures shall be oversized to accommodate 125% of the IO-year rainfall event. •!• Ponding at curb inlets shall not exceed 18" in depth . 3 .3 STORM SEWER SYSTEMS Storm sewer system improvements shall be designed in accordance to the City of College Station's Drainage Policy and Design Standards . Unless otherwise stated, the following constraints shall dictate the design of all storm sewer systems : 000414-3134 Drainage Report.d oc Final Drainage Report -6 High Ridge Subdivision Drainage Improvements Municipal Development Group •!• Minimum velocity allowed is 2 .5-ft/sec and maximum velocity allowed is 15 ft/sec during the 10-year rainfall event. •!• When a change in pipe or boxes size is required , the soffit or top respectively will match and a junction box shall be provided for at these points . •!• Maximum spacing of manholes shall be 300 feet for pipes of 54" diameter or smaller. Maximum spacing of manhole shall be 500 feet for pipes greater than 54 " diameter. •!• Minimum storm sewer pipe diameter of 18 ". Short laterals adjacent to inlets may be 12 " in diameter. •!• Conduits of 24 " or less shall be designed with the assumption of a 25% reduction in cross-sectional area. •!• At all inlets, manholes, and junction boxes an elevation drop of 0 .1 feet minimum will be necessary . •!• The theoretical hydraulic grade line for the 10-year rainfall event shall be a minimum of 0 .5 feet from the flowline of any curb inlet in the system . •!• The minimum width of any easement for a storm sewer system shall be 15 feet, and the centerline of the storm sewer shall be at least 5 feet from the closest side of the easement. 3 .4 OPEN CHANNELS Open channel improvements shall be designed in accordance to the City of College Station 's Drainage Policy and Design Standards. Unless otherwise stated , the following constraints shall dictate the design of all open channels : •!• Minimum grade shall be 0.4% for earth or vegetative lined channels . •!• Channel capacities shall be dictated by the design storm of the 25-year rainfall event. •!• Low-flow pilot channels shall be required for grass-lined channels with a carrying capacity of 1/3 of the peak discharge of the 5-year rainfall event. •!• Minimum permissible velocity of 2 .5 ft/sec during the 25-year rainfall event . •:• Maximum channel velocities shall be as dictated below : ~ Exposed earth at 3 .0 ft/sec . ~ Seeded grass at 4.5 ft/sec . ~ Sodded grass at 6 .0 ft/sec . ~ Impermeable surface at 10 ft/sec . •!• Maximum side slope for grass-lined earth channel is 3 : 1. •!• Channels with trapezoidal cross-section shall have a minimum bottom width of 4 feet. 000414-3134 Drainage Report .do c Final Drainage Report - 7 Hi gh Ri dge Subd ivision Dra in age Improvements Muni ci pal Devel opment Group •!• Channel shall have a minimum freeboard of 0.5 feet. •!• The 100-year rainfall event shall be contained w ithin the channel drainage easement. •!• Minimum drainage easement width shall be the channel 's top width plus 20 feet. 3.5 CULVERTS Culverts shall be designed in accordance to the City of College Station 's Drainage Policy and Design Standards . Unless otherwise stated, the following constraints shall dictate the design of culverts : •!• The design discharge for culverts shall be the 25-year rainfall event unless under a residential street in the secondary drainage system . Then the 10-year rainfall event will be the design storm . •!• Maximum headwater elevation shall be one foot less than the top of curb elevation . •!• Maximum overflow into the street shall be 2 feet in depth from the lowest point in the roadway profile . Overflow shall not exceed design conditions for street drainage . •!• The maximum allowable discharge into channels are as follows : ~ Natural channel or seeded cover at 6.0 ft /sec . ~ Sodded cover at 8.0 ft/sec . ~ Impermeable surface at 15 ft /sec . 3.6 DETENTION Detention shall be designed in accordance to the City of College Station 's Drainage Policy and Design Standards . Unless otherwise stated , the following constraints shall dictate the design of detention basins : •!• Detention facilities shall have the capacity to contain the 100-year rainfall event. •!• Maximum detention basin 's side slope shall be 4 : 1 with vegetative cover and 2 : 1 for non-vegetative cover. •!• Bottom slopes of the detention basin with vegetative cover shall be at a grade of 20 : 1 with low-flow pilot channels . •!• Minimum of 0.5 feet offreeboard during the 100-year rainfall event. •!• Detention facilities other than parking lots and rooftops shall have an increased capacity of 10% to allow for sedimentation . 000 4 14-3 134 Drainage Report.doc Final Drainage Report -8 High Ridge Subdiv ision Drainage Improve m ents 4.0 DRAINAGE SYSTEM MODELING Municipal Development Group For all drainage system modeling , the volume of runoff will be calculated . The drainage area calculations are summarized accordingly using the Rational Method : (Q=CIA) where "Q" is the runoff in cubic feet/second, "C" is the runoff coefficient, "I" is the storm intensity in inches/hour for each selected frequency , and "A" is the drainage area in acres . A minimum 10-minute time of concentration for all calculations will be assumed . The selected frequencies will be 2, 5, 10, 25 , 50, 100-year rainfall events . 4 .1 STREET DRAINAGE Street flow calculations are aided by the program Flow Master v . 5. 7 by Haestad Methods . Within this program basic geometry and characteristics of a proposed or existing curb & gutter street can be defined . From this information, Manning 's formula is then used to calculate desired parameters of the street. 4.2 STORM SEWER INLETS Storm sewer inlets are a part of the storm sewer system evaluation . As mentioned above, this was done with the (TxDOT) hydraulic program WinStorm v. 1.3 . Derivatives of Manning's formula are used within this program , pending on the geometry of the curb inlet and the condition of flow , to size inlets accordingly to the permissible spread of water on the street. 4 .3 STORM SEWER SYSTEMS Storm sewer system are evaluated with (TxDOT) hydraulic program WinStorm v . 1.3 . Within this program, basic geometry and characteristics of a storm sewer system can be defined . This would include data such as drainage basin calculations, type and configuration of several types of inlet boxes, and controlling factors of the conveyance system . From this 000414-3 134 Drainage Report .doc Final Drainage Report -9 High Ri dge Su bd ivision Drainage Impro ve m ent s Muni ci pa l Dev elopm ent Group program critical information can be determined about the storm sewer system . 4.4 OPEN CHANNELS Open channel hydraulic calculations are aided by the program FlowMaster v . 5 .7 by Haestad Methods . Within this program, basic geometry and characteristics of a proposed or existing channel can be defined . From this information, Manning 's formula is then used to calculate desired parameters of the open channel. 4 .5 CULVERTS Culverts are evaluated one of two ways : Short, singular culverts are calculated with the Texas Department of Transportation (TxDOT) hydraulic program Culverts v . 1.0 . W ithin this program, basic geometry and characteristics of a culvert can be defined . This would included data such as tailwater, geometry, and ent rance/exit losses . For each culvert investigations will be made in order to determine whether it is inlet or outlet controlled . For longer more complex culvert with bends and grade transitions the program StormCad v. 1.0 by Haestad Methods will be used . 4 .6 DETENTION Detention requirements are determined by graphical means. Tabulations of the pre-development and the post-development hydrograph s of the drainage areas are provided . The hydrographs are based on the standard SCS unit hydrograph with time to peak discharge set to equal the time of concentration and the total base time set at 3 . 00 t imes the time of concentration . 000414-3 134 Dra inage Rep ort .d oc Fina l Drainage Report -I 0 High Ri d ge Subdiv ision Drain a ge Improvem ents Muni cipa l Developm ent Group 5.0 CONCLUDED DRAINAGE IMPROVEMENTS The following drainage improvements are for the runoff of the 1.90-acre development of High Ridge Subdivision "Varsity Ford". These improvements included the grading and channeling of the proposed site . 5 .1 STORM SEWER SYSTEMS The sub-drainage basins will be drained by curb leave-outs, which will discharge runoff collected by the proposed parking expansion into the drainage channel which shall discharge into Carter Creek. The curb leave- outs were design with the 10-year rainfall event and anal yzed fo r adverse affects during the 100-year ra infall event. The results are as follo ws : TABLE#1 PROPOSED DISCHARGE OU TLETS 10-YEAR RAINFALL EVE NT) DRAINAGE DISCHARGE WIDTH D EPTH VELOCITY OUTLET cf s ft (ft) (ft/sec) 81 82 83 1 .729 2 0 .23 3.75 2 .696 2 0 .31 4.36 5 .715 4 0 .30 4 .70 TABLE#2 PROPOSED DISCHARGE OUTLETS 100-YEAR RAINFALL EVENT) -----DRAINAGE DISCHARGE WIDTH DEPTH OUTLET cfs ft 1 {ft) 81 2 .330 2 0.28 82 3 .635 2 0.38 83 7 .704 4 0.37 5.2 OPEN CHANNELS The proposed parking lot runoff will be collected into a small drainage channel , which will discharge into Carter Creek. This channel was design with two options for construction . Option # 1 design will consist of a typical concrete pilot channel with seeded lined banks at a sid e slope of 00 0414-3134 Drainage Report.doc Fina l Drainage Report -11 High Ridge Subdivision Drainage Impro vements Muni cipal Development Group 4 : 1. Option #2 will be a concrete rip-rap channel cross-section with 4 : 1 side slopes. Below are the results of both channel options : TABLE#3 PROPOSED OPEN CHANNELS 25-YEAR RAINFALL EVEN OPTION#1 OPTION#2 DRAINAGE DISCHARGE DEPTH VELOCITY DEPTH VELOCITY BASIN cfs ft ft/sec fl ft/sec 81 2.805 0 .58 2 .12 0 .64 1 .71 82 5 .054 0.72 2 .45 0.80 1 .98 83 11.581 0 .98 3.02 1 .09 2 .43 TABLE#4 PROPOSED OPEN CHANNELS 100-YEAR RAINFALL EVENT OPTION#1 OPTION#2 DRAINAGE DISCHARGE DEPTH TOP WIDTH DEPTH TOP WIDTH BASIN cf s ft ft ft ft 81 3 .311 0 .61 4.90 0 .68 5 .46 82 . 5.965 0 .76 6 .11 0 .85 6 .81 83 13 .669 1.04 8 .34 1 .16 9 .29 In addition to the open-channel design for the Option # 1 cross-section, low flow pilot channels were design to be constructed from the proposed drainage outlets, along the centerline of the channel and to the confluence of Carter Creek. The results and design criteria for the pilot channels are as follows : DRAINAGE BASIN 81 82 83 000414-3134 Drainage Report .doc TABLE#S PROPOSED PILOT CHANNELS OPTION #1 -CROSS SECTIONS DISCHARGE DEPTH TOP WIDTH cfs ft fl 0.422 0.21 1.65 1 .314 0 .32 2.53 3 .011 0 .43 3 .46 DESIGN WIDTH ft 2.00 3 .00 4.00 Final Drainage Report -12 High Ri dge Subdivision Drain age Improve m ents 5.3 GRADING & EROSION CONTROL Muni ci pal Development Group Erosion control shall be where indicated and m placed until grass , by seeding, is established . Erosion control details are provided in Appendi x c. 000414-3 134 Drainage Report.d oc Final Drainage Rep ort -13 000414-3134 Drainage Report.doc APPENDIX A HYDRAULIC COMPUTATION DESCRIPTION APPENDIX A TABLE OF CONTENTS PAGE NO. Pre-Development Runoff Calculations ........................................................................ A-1 Post-Development Runoff Calculations ....................................................................... A-2 Curb Leave-out Area Bl (10 year) .............................................................................. A-3 Curb Leave-out Area B 1 (100 year) ............................................................................ A-4 Curb Leave-out Area B2 (10 year) .............................................................................. A-5 Curb Leave-out Area B2 (100 year) ............................................................................ A-6 Curb Leave-out Area B3 (10 year) .............................................................................. A-7 Curb Leave-out Area B3 (100 year) ............................................................................ A-8 Open Channel Area Bl (25 year): Option #1 .............................................................. A-9 Open Channel Area Bl (100 year): Option #1 .......................................................... A-10 Open Channel Area B2 (25 year): Option #1 ............................................................ A-11 Open Channel Area B2 (100 year): Option #1 .......................................................... A-12 Open Channel Area B3 (25 year): Option #1 ............................................................ A-13 Open Channel Area B3 (100 year): Option #1 .......................................................... A-14 Open Channel Area B 1 (25 year): Option #2 ............................................................ A-15 Open Channel Area B 1 (100 year): Option #2 .......................................................... A-16 Open Channel Area B2 (25 year): Option #2 ............................................................ A-17 Open Channel Area B2 (100 year): Option #2 .......................................................... A-18 Open Channel Area B3 (25 year): Option #2 ............................................................ A-19 Open Channel Area B3 (100 year): Option #2 .......................................................... A-20 Pilot Channel Area B 1 ............................................................................................... A-21 Pilot Channel Area B2 ............................................................................................... A-22 Pilot Channel Area B3 ............................................................................................... A-23 000414-3 134 Drainage Report.do c -------------------"" DRAINAGE AREA -PRE-DEVELOPMENT GENERAL INFORMATION Description: Drainage area of site before development. Drainage Area (A PRE ) = 1.226 acres TIME OF CONCENTRATION CTc> GIVEN Maximum Travel Distance (DP RE) Velocity of Runoff (VPRE ) = Coefficient of Runoff (CP RE) = 315 ft It 2 .00 fsec 0.38 **NOTE : Minimum T c allowed = 1 O min . 2 YEAR FREQUENCY. RA TE OF DISCHARGE (Q) Coefficient (e ) = 0.806 Coefficient {b ) = 65 Coefficient (d) = 8 5 YEAR FREQUENCY. RA TE OF DISCHARGE (Q) Coefficient (e) = 0.785 Coefficient (b) = 76 Coefficient (d ) = 8.5 10 YEAR FREQUENCY. RA TE OF DISCHARGE (Q) Coefficient (e ) = Coefficient (b) = Coefficient (d) = 0.763 80 8.5 25 YEAR FREQUENCY. RA TE OF DISCHARGE (Q) Coefficient (e) = Coefficient (b) = Coefficient (d) = 0.754 89 8.5 50 YEAR FREQUENCY. RA TE OF DISCHARGE (Q) Coefficient (e ) = Coefficient (b) = Coefficient (d } = 0.745 98 8.5 100 YEAR FREQUENCY. RATE OF DISCHARGE (Q) Coefficient (e) = 0.73 Coefficient (b) = Coefficient (d) = 3134-000414 Drainage Runoff Evalu ati on.xis 96 8 RESULT T c(PRE J = 2 .6 min . Rainfall Intensity (1 2) = 6 .327 i%r :si :\!: •:•:,::::=:,:.::•::,::=•\,=::•:=:=.=.==:==:=:== ===::., ? : ·: :::::::•1~t:1~:q;'-r• n Rainfall Intensity (1 10) = 8.635 in /hr . :.a.:.:.·.·-•-·.:_'_l.=·_,_1_=_._:·_._·.=_·.:_=_._•·-· .. _=_·_._·· •:: :,. xc==::: • : J e ,::: ::. •' r: ::: a.;os.&. &.ts < = -r:U. ::::::::::::::::::::::::::::: :·:·:·:·:·:·:·:·:·:·:·:·:-:-:-:-:·:-:·:·:·:·:-:· ··:·:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:.:-:-:-:-:·:·:·:<·:·: Rainfall Intensity (1 25) = 9.861 in /hr · .• a.: ... · .. •.· .. ·.· .. ~.·=·.-~.·'=.:_•= .• · .... i: .. ·.: .. ·.: .. ·_.-.•..•.•. _ •.•. _._••-··-·: · ==•==···==·= : .. ::.: :=:• 1 • • •%Ui33 ::iiis r•< ,.g :::::::::::::::::::::::~:::~{:~=~=~=~=~=~=~=~=~=~== ::::. :-:-:·:···:·:·:·:·:-:-:-:-:-:-:-:-:-:-:-:-:-:·:·:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:-:·:··· Rainfall Intensity (1 50) = 11 .148 i%r •.Jl.'.•.•.· .. iQ=_•:.:=.~.=•.•·.:::: ::::;:::::>c =::: : : ::::< ::•:1:1::=2az:Eks 1• ~ :·:-:-:·:-:··-:-:.:-:-:·:-:-:-:-:·:· Rainfall Intensity (1 100) 11 .639 i%r :am :a-.•• r> J:•• :::,::::::::::,:::::::::::::r:•::::::.~1=~1 :1!:• :•::: DRAINAGE AREA -POST-DEVELOPMENT GENERAL INFORMATION Description : Drainage area of site after development Drainage Area (81) = 0.209 acres (developed area) Drainage Area (82) = 0.326 acres (developed area) Drainage Area (83) = 0.691 acres (developed area) TIME OF CONCENTRATION <Tc} GIVEN RESULT Maximum Travel Distance (D 1) = 100 ft Tc1 = 0 .6 min . Velocity of Runoff (V1) = ft 3 .00 fsec Coefficient of Runoff (C 1) = 0 .95 Maximum Travel Distance (D 2) = 100 ft Tc2 = 0 .6 min . Velocity of Runoff (V2) = ft 3.00 fsec Coefficient of Runoff (C 2) = 0 .95 Maximum Travel Distance (D 3) = 175 ft Tc3 = 1 .0 min . Velocity of Runoff (V3) = ft 3.00 fsec Coefficient of Runoff (C 3) = 0 .95 -NOTE: Minimum Tc allowed= 10 min. T C(POST) = 2 .1 min. 3134-000414 Drainage Runoff Evaluation.xis DRAINAGE AREA -POST-DEVELOPMENT 2 YEAR FREQUENCY. RA TE OF DISCHARGE (Q) Coefficient (e) = Coefficient (b) = Coefficient (d) = 0.806 65 8 5 YEAR FREQUENCY. RA TE OF DISCHARGE (Q) Coefficient (e) = 0 .785 Coefficient (b) = Coefficient (d) = 76 8 .5 10 YEAR FREQUENCY. RATE OF DISCHARGE (Q) Coefficient (e) = Coefficient (b) = Coefficient (d) = 0.763 80 8.5 25 YEAR FREQUENCY. RA TE OF DISCHARGE (Q) Coefficient (e) = Coefficient (b) = Coefficient (d) = 0 .754 89 8.5 50 YEAR FREQUENCY. RA TE OF DISCHARGE (Q) Coefficient (e) = Coefficient (b) = Coefficient (d) = 0.745 98 8 .5 100 YEAR FREQUENCY. RA TE OF DISCHARGE (Q) Coefficient (e) = Coefficient (b) = Coefficient (d) = 3134-000414 Drainage Runoff Evaluation.xis 0 .73 96 8 Rainfall Intensity (1 2) = 6 .327 in/hr QAREA 1 = 1 .267 cfs QAREA 2 = 1 .976 cfs QAREA 3 = 4 .188 cfs i'lj:a ::: ·.:.::.:,·:•::•::::::::: t> ::::: rm:t1~1:_•ii$m m:1 Rainfall Intensity (1 5) = 7.693 i%r QAREA 1 = 1 .540 cfs QAREA 2 = 2 .402 cfs QAREA 3 = 5.092 cfs :,:.:,1.u_:,'.•,:_•,'.'.''.'.'.:,•.~,•.','.•,•.•,•.•,•.:,•.•,•.:,•.•,•.•,•.•,•.:,•.•,• ::: ''>'' ' : ::::::::::::::::: .•: .... •.••.:.•.•.•.•.•.•.•.s .. · .. ·.:.~.'.m .. : .. · ... :_:.· .. ·.:•.::.:.:•.••.•~-·:.•.t.:.$..·: .. ·•.•: .. • ,,,,,,,,, ~ :::::::::::::::::::;:;:;:;::::::::::::::: .. ;.:-:·>>:·:·:·:·:·:• ..... Rainfall Intensity (Im) = 8 .635 i%r QAREA 1 = 1 . 729 cfs QAREA 2 = 2 .696 cfs QAREA 3 = 5 .715 cfs ••l jia •· ,:;::,;::::tin: •1 ... Ii:t •ii~lii :ii ••::: Rainfall Intensity (1 25 ) = QAREA 1 = QAREA 2 = QAREA3 = 9 .861 in/hr 1 .974 cfs 3 .080 cfs 6 .528 cfs ·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·. :-:-:-:-:-:::::··-·.·.···· ::91:11 :: •• •••••••••••••tI: /: ,•.•.• ... •.•.:_,_:_•.'.•.•. ,'.:,'.•,'.•,'.•,'.•,'.•.:.·.•.·.'.:, .. ,.••,• .. :,•.1,:_.', UU1 as f • ::::::::: :::::::::·::::: :::::::-:-:-:-:·:-'·'.·~·'.•'•"•"•" ... Rainfall Intensity (1 50) = QAREA 1 = QAREA2 = 11 .148 i%r 2.232 cfs 3 .481 cfs Q AR EA3 = 7 .379 cfs ::R.•a:r '•.:,••-:· :: : j::·•·\ :: . : ·:. :1~~-~ Pt! •J Rainfall Intensity (1100) QAREA 1 = in/ 11.639 hr 2 .330 cfs QAREA 2 = 3 .635 cfs QAREA3 = 7 .704 cfs ·:-:-:-:-:-:-:-:-:-:-:-:-:-;.:-:-·.·.·.·.·.··:·:::;:::·:-:-:···· .... :: ::::::::::::::::::::::::::: ........................ . ]I.~~•*••••<••••••'•\:::,, •:: •• ... ::::::::::~:~;~~·••m :::: ·. Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Bottom Width Discharge Results Depth Flow Area Wetted Perimeter Top Width Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is supercritical. APPENDIX A-HYDRAULIC COMPUTATIONS Worksheet for Rectangular Channel i:\projects\400\3134-varsity\3134t1 ra.fm2 Curb Leaveout Area 81 (10 yr) Rectangular Channel Manning's Formula Channel Depth 0.013 1.00 % 2.00 ft 1.729 cfs 0.23 ft 0.46 ft2 2 .46 ft 2 .00 ft 0 .29 ft 0 .005227 ft/ft 3 .75 ft/s 0.22 ft 0.45 ft 1.37 Municipal Development Group 11/24198 10:32 :11 AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster v5.07 Page 1 of 1 Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Bottom Width Discharge Resu lts Depth Flow Area Wetted Perimeter Top W idth Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is supercritica l. APPENDIX A -HYDRAULIC COMPUTATIONS Worksheet for Rectangular Channel i:\projects\400\3134-varsity\3134t1 ra . fm2 Curb Leaveout Area B 1 ( 100 yr) Rectangular Channel Manning's Formula Channel Depth 0.013 1.00 % 2 .00 ft 2.330 cfs 0 .28 ft 0 .56 ft2 2 .56 ft 2 .00 ft 0 .35 ft 0 .005213 ft/ft 4 .15 ft/s 0 .27 ft 0.55 ft 1.38 Municipal Development Group 11 /2419 8 10:32:39 AM Haestad Met hods, Inc . 37 Brookside Road Waterbury, CT 06708 (203) 755-1 666 FlowMaster v5.07 Page 1 of 1 Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Bottom Width Discharge Results Depth Flow Area Wetted Peri meter Top W idth Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is supercritica l. APPENDIX A -HYDRAULIC COMPUTATIONS Worksheet for Rectangular Channel i:\projects\400\3134-varsity\3134t1 ra.fm2 Curb Leaveout Area 82 (10 yr) Rectangular Channel Manning's Formula Channel Depth 0.013 1.00 % 2.00 ft 2 .696 cfs 0 .31 ft 0.62 ft2 2 .62 ft 2 .00 ft 0 .38 ft 0.005225 ft/ft 4 .36 ft/s 0.30 ft 0.60 ft 1.38 Municipal Development Group 11 /24198 10:33:08 AM Haestad Methods, Inc . 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster v5.07 Page 1 of 1 Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Bottom Width Discharge Results Depth Flow Area Wetted Perimeter Top Width Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is supercritical. APPENDIX A-HYDRAULIC COMPUTATIONS Worksheet for Rectangular Channel i:\projects\400\3134-varsity\3134t1 ra .fm2 Curb Leaveout Area 82 (100 yr) Rectangular Channel Manning's Formula Channel Depth 0.013 1.00 % 2.00 ft 3.635 cfs 0.38 ft 0 .75 ft2 2.75 ft 2.00 ft 0 .47 ft 0 .005292 ft/ft 4 .82 ft/s 0.36 ft 0.74 ft 1.38 Municipal Development Group 11124198 10:33:33AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster v5 .07 Page 1 of 1 Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Bottom Width Discharge Results Depth Flow Area Wetted Perimeter Top W idth Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is supercritical. APPENDIX A -HYDRAULIC COMPUTATIONS Worksheet for Rectangular Channel i:\projects\400\3134-varsity\3134t1 ra. fm2 Curb Leaveout Area 83 (10 yr) Rectangular Channel Manning's Formula Channel Depth 0.013 1.00 % 4.00 ft 5.715 cfs 0 .30 ft 1.22 ft2 4 .61 ft 4 .00 ft 0 .40 ft 0 .004263 tuft 4 .70 tus 0 .34 ft 0.65 ft 1.50 Municipal Development Group 11 /24198 10:34:14AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster v5 .07 Page 1 of 1 Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Bottom Width Discharge Results Depth Flow Area Wetted Perimeter Top Width Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is supercritical. APPENDIX A-HYDRAULIC COMPUTATIONS Worksheet for Rectangular Channel i:\projects\400\3134-varsity\3134t1 ra. fm2 Curb Leaveout Area 83 (100 yr) Rectangular Channel Manning's Formula Channel Depth 0 .013 1 .00 % 4 .00 ft 7.704 cfs 0.37 ft 1.47 ft2 4 .74 ft 4 .00 ft 0.49 ft 0 .004186 ft/ft 5.24 ft/s 0 .43 ft 0 .79 ft 1.52 Municipal Development Group 11/24198 10:34:40AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster v5 .0 7 Page 1 of 1 Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Left Side Slope Right Side Slope Discharge Results Depth Flow Area Wetted Perimeter Top Width Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is subcritical. Notes : Area= 81 APPENDIX A -HYDRAULIC COMPUTATIONS Worksheet for Triangular Channel i:\projects\400\3134-varsity\3134t1 ra .fm2 Open-Channel Area 81 (25 yr}: Option #1 Triangular Channel Manning's Formula Channel Depth 0 .030 1.00 % 4 H :V 4 H :V 2 .805 cfs 0 .58 ft 1.33 ft2 4.75 ft 4.61 ft 0.50 ft 0.021708 tuft 2.12 tus 0 .07 ft 0.65 ft 0.70 Municipal Development Group 11/24198 11:05:03 AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster v5 .07 Page 1 of 1 11 /24198 Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Left Side Slope Right Side Slope Discharge Results Depth Flow Area Wetted Perimeter Top Width Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is subcritical. Notes : Area= 81 APPENDIX A-HYDRAULIC COMPUTATIONS Worksheet for Triangular Channel i:\projects\400\3134-varsity\3134t1 ra. fm2 Open-Channel Area 81 (100 yr): Option #1 Triangular Channel Manning's Formula Channel Depth 0.030 1.00 % 4 H :V 4 H :V 3.311 cfs 0.61 ft 1.50 ft2 5.05 ft 4.90 ft 0.53 ft 0.021233 ft/ft 2.21 ft/s 0.08 ft 0.69 ft 0.70 Municipal Development Group 11 :05:59 AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster v5.07 Page 1 of 1 Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Left Side Slope Right Side Slope Discharge Results Depth Flow Area Wetted Perimeter Top Width Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is subcritical. Notes : Area= 81 + 82 APPENDIX A-HYDRAULIC COMPUTATIONS Worksheet for Triangular Channel i:\projects\400\3134-varsity\3134t1 ra.fm2 Open-Channel Area 82 (25 yr): Option #1 Triangular Channel Manning's Formula Channel Depth 0 .030 1.00 % 4 H :V 4 H :V 5.054 cfs 0.72 ft 2 .06 ft2 5.92 ft 5.74 ft 0.63 ft 0.020071 ft/ft 2.45 ft/s 0 .09 ft 0.81 ft 0.72 Municipal Development Group 11/24198 11 :07:47 AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster v5.07 Page 1 of 1 Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Left Side Slope Right Side Slope Discharge Results Depth Flow Area Wetted Perimeter Top Width Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is subcritical. Notes : Area= 81 + 82 APPENDIX A-HYDRAULIC COMPUTATIONS Worksheet for Triangular Channel i :\projects\400\3134-varsity\3134t1 ra. fm2 Open-Channel Area 82 (100 yr): Option #1 Triangular Channel Manning's Formula Channel Depth 0.030 1 .00 % 4 H :V 4 H :V 5 .965 cfs 0 .76 ft 2 .33 ft2 6 .30 ft 6 .11 ft 0.67 ft 0 .019632 ft/ft 2 .56 ft/s 0 .10 ft 0.87 ft 0.73 Municipal Development Group 11 /24198 11 :10:20AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster v5 .07 Page 1 of 1 11124198 Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Left Side Slope Right Side Slope Discharge Results Depth Flow Area Wetted Perimeter Top Width Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is subcritical. Notes : Area = 81 + 82 + 83 APPENDIX A-HYDRAULIC COMPUTATIONS Worksheet for Triangular Channel i:\projects\400\3134-varsity\3134t1 ra .fm2 Open-Channel Area 83 (25 yr): Option #1 Triangular Channel Manning's Formula Channel Depth 0 .030 1.00 % 4 H :V 4 H :V 11.581 cfs 0.98 ft 3 .84 ft2 8.08 ft 7.84 ft 0.88 ft 0.017969 ft/ft 3.02 ft/s 0.14 ft 1.12 ft 0.76 Municipal Development Group 11 :11 :09 AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster v5.07 Page 1 of 1 11124198 Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Left Side Slope Right Side Slope Discharge Results Depth Flow Area Wetted Perimeter Top Width Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is subcritical. Notes : Area= 81 + 82 + 83 APPENDIX A -HYDRAULIC COMPUTATIONS Worksheet for Triangular Channel i :\projects\400\3134-varsity\3134t1 ra . fm2 Open-Channel Area 83 (100 yr): Option #1 Triangular Channel Manning's Formula Channel Depth 0 .030 1.00 % 4 H :V 4 H :V 13.669 cfs 1.04 ft 4.35 ft2 8.60 ft 8.34 ft 0.94 ft 0.017576 ft/ft 3.14 ft/s 0.15 ft 1.20 ft 0.77 Municipal Development Group 1 1 :1 1 :42 AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster v5 .07 Page 1 of 1 11/24198 Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Left Side Slope Right Side Slope Discharge Results Depth Flow Area Wetted Perimeter Top Width Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is subcritical. Notes : Area= 81 APPENDIX A-HYDRAULIC COMPUTATIONS Worksheet for Triangular Channel i :\projects\400\3134-varsity\3134t1 ra . fm2 Open-Channel Area 81 (25 yr): Option #2 Triangular Channel Manning's Formula Channel Depth 0.040 1.00 % 4 H :V 4 H :V 2.805 cfs 0.64 ft 1.64 ft2 5.29 ft 5.13 ft 0.50 ft 0.038595 ft/ft 1.71 ft/s 0.05 ft 0.69 ft 0 .53 Municipal Development Group 11 :13:46 AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster v5 .07 Page 1 of 1 Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Left Side Slope Right Side Slope Discharge Results Depth Flow Area Wetted Perimeter Top Width Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is subcritical. Notes : Area= 81 APPENDIX A-HYDRAULIC COMPUTATIONS Worksheet for Triangular Channel i :\projects\400\3134-varsity\3134t1 ra . fm2 Open-Channel Area 81 (100 yr): Option #2 Triangular Channel Manning's Formula Channel Depth 0.040 1.00 % 4 H :V 4 H :V 3.311 cfs 0 .68 ft 1.86 ft2 5.63 ft 5.46 ft 0 .53 ft 0 .037751 ft/ft 1.78 ft/s 0 .05 ft 0 .73 ft 0 .54 Municipal Development Group 11124198 11 :14:54AM Haestad Methods , Inc . 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster v5 .07 Page 1 of 1 Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Left Side Slope Right Side Slope Discharge Results Depth Flow Area Wetted Perimeter Top Width Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is subcritical. Notes : Area= 81 + 82 APPENDIX A -HYDRAULIC COMPUTATIONS Worksheet for Triangular Channel i :\projects\400\3134-varsity\3134t1 ra .fm2 Open-Channel Area 82 (25 yr): Option #2. Triangular Channel Manning's Formula Channel Depth 0 .040 1.00 % 4 H :V 4 H :V 5.054 cfs 0.80 ft 2 .56 ft2 6 .59 ft 6 .40 ft 0.63 ft 0 .035681 ft/ft 1.98 ft/s 0 .06 ft 0.86 ft 0 .55 Municipal Development Group 11 /24198 1 1:16:15AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster v5.07 Page 1 of 1 11 /24198 Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Left Side Slope Right Side Slope Discharge Results Depth Flow Area Wetted Perimeter Top Width Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is subcritical. ·Notes: Area= 81 + 82 APPENDIX A -HYDRAULIC COMPUTATIONS Worksheet for Triangular Channel i:\projects\400\3134-varsity\3134t1 ra.fm2 Open-Channel Area 82 (100 yr): Option #2 Triangular Channel Manning's Formula Channel Depth 0.040 1.00 % 4 H :V 4 H :V 5.965 cfs 0.85 ft 2 .90 ft2 7.02 ft 6 .81 ft 0.67 ft 0.034900 ft/ft 2.06 ft/s 0.07 ft 0 .92 ft 0 .56 Municipal Development Group 11 :17:00 AM Haestad Methods , Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster v5 .07 Page 1 of 1 Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Left Side Slope Right Side Slope Discharge Results Depth Flow Area Wetted Perimeter Top Width Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is subcritical. Notes : Area= 81 + 82 + 83 APPENDIX A-HYDRAULIC COMPUTATIONS Worksheet for Triangular Channel i :\projects\400\3134-varsity\3134t1 ra.fm2 Open-Channel Area 83 (25 yr): Option #2 Triangular Channel Manning's Formula Channel Depth 0 .040 1.00 % 4 H :V 4 H :V 11 .581 cfs 1.09 ft 4.76 ft2 9.00 ft 8.73 ft 0.88 ft 0.031944 ft/ft 2 .43 ft/s 0.09 ft 1.18 ft 0.58 Municipal Development Group 11/24198 11 :17:50AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster v5 .07 Page 1 of 1 11124198 Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Left Side Slope Right Side Slope Discharge Results Depth Flow Area Wetted Perimeter Top Width Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is subcritical. Notes : Area = 81 + 82 + 83 APPENDIX A-HYDRAULIC COMPUTATIONS Worksheet for Triangular Channel i:\projects\400\3134-varsity\3134t1 ra . fm2 Open-Channel Area 83 (100 yr): Option #2 Triangular Channel Manning's Formula Channel Depth 0.040 1.00 % 4 H :V 4 H :V 13 .669 cfs 1.16 ft 5.39 ft2 9.58 ft 9 .29 ft 0.94 ft 0 .031246 ft/ft 2 .53 ft/s 0.10 ft 1.26 ft 0.59 Municipal Development Group 11 :18:34 AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster v5 .07 Page 1 of 1 Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Left Side Slope Right Side Slope Discharge Results Depth Flow Area Wetted Perimeter Top Width Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is supercritical. Notes : Area= 81 APPENDIX A-HYDRAULIC COMPUTATIONS Worksheet for Triangular Channel i:\projects\400\3134-varsity\3134t1 ra.fm2 Pilot Channel Area 81 Triangular Channel Manning's Formula Channel Depth 0 .013 1.00 % 4 H :V 4 H:V 0.422 cfs 0.21 ft 0.17 ft2 1.71 ft 1.65 ft 0.23 ft 0.005248 ft/ft 2 .47 ft/s 0 .09 ft 0.30 ft 1.35 Municipal Development Group 11 /24198 11 :28:19AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster v5 .07 Page 1 of 1 Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Left Side Slope Right Side Slope Discharge Results Depth Flow Area Wetted Perimeter Top Width Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is supercritical. Notes : Area= 81 + 82 APPENDIX A-HYDRAULIC COMPUTATIONS Worksheet for Triangular Channel i:\projects\400\3134-varsity\3134t1 ra . fm2 Pilot Channel Area 82 Triangular Channel Manning's Formula Channel Depth 0.013 1.00 % 4 H :V 4 H :V 1.314 cfs 0.32 ft 0 .40 ft2 2 .61 ft 2 .53 ft 0.37 ft 0.004510 ft/ft 3.28 ft/s 0.17 ft 0.48 ft 1.45 Municipal Development Group 11124198 11 :28:47 AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster v5.07 Page 1 of 1 Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Left Side Slope Right Side Slope Discharge Results Depth Flow Area Wetted Perimeter Top Width Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is supercritical. Notes : Area= 81 + 82 + 83 APPENDIX A-HYDRAULIC COMPUTATIONS Worksheet for Triangular Channel i:\projects\400\3134-varsity\3134t1 ra.fm2 Pilot Channel Area 83 Triangular Channel Manning's Formula Channel Depth 0.013 1.00 % 4 H :V 4 H :V 3.011 cfs 0 .43 ft 0 .75 ft2 3.56 ft 3 .46 ft 0 .51 ft 0.004038 ft/ft 4.03 ft/s 0.25 ft 0.68 ft 1.53 Municipal Development Group 11 /24198 11 :29:16AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster v5.07 Page 1 of 1 000414-3134 Drainage Report.doc APPENDIXB MAPPING DESCRIPTION APPENDIXB TABLE OF CONTENTS PAGE NO. Exhibit # 1 -Carter's Creek Drainage Basin ................................................................ B-1 Exhibit #2 -Post-Development Varsity Ford Sub-Drainage Basin .............................. B-2 Exhibit #3 -FIRM Map .............................................................................................. B-3 000414-3134 Drainage Report.d oc ZONE X Rd er to t1 dt·termin £ 0 1 depths To determ im urance . 000414-3134 Drainage Report.doc APPENDIXC DRAINAGE DETAILS DESCRIPTION APPENDIXC TABLE OF CONTENTS PAGE NO. Curb Leave-out Detail ................................................................................................. C-1 Open Channel Cross-Section (Option#!) .................................................................... C-2 Open Channel Cross-Section (Option #2) .................................................................... C-3 Pilot Channel Detail .................................................................................................... C-4 Silt Fencing Detail.. ..................................................................................................... C-5 000414-3 134 Drainage R ep ort.doc -111 -I 11 111 ·_111~ _I ll~ I 111 111-~I I 1==111----r CUR B LAYDOWN -I l_ill_...:.__:_1 --P - --==-L --; DISCHARG E FLUME WID TH VAR IES TYP ICAL CONCRETE CURB & GUTTER PARKING AREA 6 " . 0 I ...., CURB LEAVE-OUT DETAIL N.T.S. 12" #3 DOWEL #3 BARS \'QI 12" O.C.E • CROSS SECTION TOP WIDTH VARIES 15' (MAX) EXISTNG GROUND r PROPOSED GRADE -----r VARIES; .,...S-EE--=--P-LA_N_S -1----------- ......_.. I tO 6" #3 BARS @ 18" O.C.E.W. STANDARD OPEN CHANNEL (ALTERNATE 1) EXISTNG GROUND TOP WIDTH VARIES 15' (MAX) PROPOSED GRADE CONCRETE RIP RAP STANDARD OPEN CHANNEL (ALTERNATE 2) I~ VARIES SEE PLANS #3 BA RS @ 18" O.C .E.W. CONCRETE PILOT CHANNEL (CROSS-SECTION) LLEGE RB NT .RD >-a::~ VIEW AT PITCH WHEN JOINING TWO OR MORE "SILT-STOP" FENCES TIE THE TWO END POSTS TOGETHER WITH EXISTING NYLON CORD . GROUND LINE ffi ~ 7t"'<-:l<'T:i"<""<'7Mff1,.....,...,"M"<"~ .~~~~loli'ttt~~~ <O EXISTING GROUND FRONT VIEW WOODEN POST . MIN. 3 ' LENGTH (1 1/2' EXPOSED) SILT FEN CE, "SILT STOP " OR APPROVED EQUAL MIN . 24" OVERALL MAX . SPACING 1 O' O.C. EXISTING GROUND PROPOSED TOE SLOPE 6 "x 6" TRENCH COMPACT TRENCH BACKFILL TO PREVENT "WASHOUT" BURY TOE OF SILT FENCE 6" BELOW PROPOSED GRADE SIDE VIEW SILT EENCING N.T.S. 18 /02 '99 12:33 FAX 409 693 4243 M D G ~ • ~001 Gfo~ I MUNICIPAL DEVELOPMENT 2551 TUMjlll!. Sou.th, Su.A• Co/ltgeSta1ion, TULH 77840 • 409-69.3-5159 •FAX: 409-69342'1-3 •EMAJL:llU1go@glt..net I I Engineering, Surveying, Planning and Environmental Consultants I 1 S!>'f .?f-{ &f "'v: 4 /7 ) ff.I h; FAX# 'QW . ~V· -' NO.PAGESTOFOLLOW ~ DATE~'q TO ~!U\ \flttM~ I FROM I kaNr (/\ I \ If tliere is a problem witlz this trasmissionJ please call us at 409 693-5359 / , ,/ 18 /02 '99 ' I., ...... 12 :33 FAX 409 693 4243 MD G I I . JUNJCJPAL DEVELOPMENT GROUP 1 ·aas kve. Sou.th. Su. A • CoUege Starion, T ezas 77840 • 409-695-5359 •FAX: 409·693-4243 •E-mail: nui~nu December 23, 1998 Veronica Morgan, P .E. City of College Station I P .O. Box 9960 Engineering. Surveying , Planning and Environmental Consultants College St~tion, TX 77842 I I Re: Lett~r of Comfort-Varsity Ford Parking Expansion Drainage MDG Job No. 000414-3135 I I Dear Verolnica : I Per my m~eting with Rabon Metcalf on December 22, 1998 I am in agreement with the attached drainage r~alignment changes. I am currently working with M'r. Tony Majors at Varsity Ford to adjust the ~rainage easement which crosses my property. As I understand it, Rabon has already contacted Jeff; at your office, and discussed these changes. I . Please con~act Rabon at 696-5359 should you have any questions. I Sincerely, / ~K~ -..1:1. o .1 .. e . ;.vJte avi~~;~·~-+ c.,~ ! ~~,.,,,,, "":t:~c_ RM/tm I i I I i I I I I 000414.c.15.doc I I I MDG-1 ~002 •' i I i / FAX 409 693 4243 M D G 100' 141003 ~ C)f¥'~t'\.£_ ~!AC- ~ t---r lit.Jt C lf..E..E~ Rll'-RAP LAJO AS COURSED RUBBLE ALONG CARTER CREEX BANK AS SHOWN; S" THICK PIECES MAX 50% E:c?OSURE RIP-RAP LAID RA111DOMLY; s• THICK PIECES :.-.L-f-~"llNIMUM 12· IN 01HER DIMENSIONS. SMALL.ER PIECES MAY BE INCORPORATED AS LONG AS COMPLETE CO~GE IS ACHJE\S> 'MTI-1 SPE:CIFIED P1EC£S. Re..~L..\&N~ ~1NAU£ c AA ~Ti.-L. Lc:.ckit c tlj " I!) N > w r;j 8 0 ;1 I I I £ngioeuing, Surveying, Planninir and Environmental Consultants TO FROM Uc->~ I ! If there is a problem witli this trasmission, please call us at 409 693-5359 I I CO.'!\FID,ENTIALITY ~vonCE: This facsimile message and accompanying communications and/07 d~cuments are intended/or the e:r.cusive and confzdential use oftlze i.11dividual or entity to which tlze me.ssge is addressed. I I I co~NTS ~ f?J7Cu%fP 1(-fc~ { r-M#&E-A FP-W V~ ,4€,o. -:Cr-+HIS tS, 4a:.~~f:. U:E u.)I LL .·;.. .-_·of·: ~004 DEVELOPMENT PERMIT PERMIT NO. 625 Varsity Ford Parking FOR AREAS INSIDE THE SPECIAL FLOOD HAZARD AREA RE: CHAPTER 13 OF THE COLLEGE STATION CITY CODE SITE LEGAL DESCRIPTION: High Ridge Subdivision, Lot Two, Block One OWNER: Varsity Ford 135 E . Bypass College Station, Texas 77840 409-779-0664 DRAINAGE BASIN: Carter Creek SITE ADDRESS: 135 E. Bypass TYPE OF DEVELOPMENT:This permit is valid for construction of 2 buildings and parking lot as shown on approved plans. The Contractor shall take all necessary precautions to prevent silt and debris from leaving the immediate construction site in accordance with the approved erosion control plan as well as the City of College Station Drainage Policy and Design Criteria. The Owner and/or Contractor shall assure that all disturbed areas are sodden and establishment of vegetation occurs prior to removal of any silt fencing or hay bales used for temporary erosion control. The Owner and/or Contractor shall also insure that any disturbed vegetation be returned to its original condition, placement and state. The Owner and/or Contractor shall be responsible for any damage to adjacent properties, city streets or infrastructure due to heavy machinery and/or equipment as well as erosion, siltation or sedimentation resulting from the permitted work. Any trees required to be protected by ordinance or as part of the landscape plan must be completely fenced before any operations of this permit can begin. In 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 in city streets, or existing drainage facilities. I hereby grant this permit for development of an area inside the special flood hazard area. All development shall be in accordance with the plans and specifications submitted to and approved by the City Engineer in the di ent permit application for the above named project and all of the codes and ord· ances of the 1 of liege Station that apply. Date Date Figure Xll Development Permit City of College Station, Texas Site Legal Description: H\.6\\-\ ?.\'O&e ~'80t\J\filct\J J Lo\ tv...>Q) gCAX .. ¥; ON'E. Site Owner: V'Ats\\'{ fo-e..o Address : l'Z>5 E, ~"'l'PA~'& Telephone: ('fo:f) "'119-cto<pY Archit e ct/ Nof..-n..\ g. 9'\t.OE..u...1J"2.. Addr~ss : Z551 lt'ff\S AvE S. Ste A Engi ne er: r/1\jN\Cl'"AL. Re.Ve:~~., ~Telephon e N o : (t.-\{)Qt) (sf\3-51,59 Date Application Fi,led : J 7/ z/ t:/8 _ c;,, Application is hereby m d1l ~ Q~1 tJ AVIE-I MJ)il.c\ ') • On<:.'tl =to =tl1 E. Co {T'- 0 0 0 0 0 Application Fe e Signed Certificat Drainage and ere Site and Constru Other: ---- A C KNOWLEDGME N l ~ 1terway alterations : -'CfA N $1 ~ ± DAA1NP<=5E. R.eport two (2) copies each . : two (2) copies each . I , No-e..-n...\ e. €>Ai.\?E.u.. ;~'2-' design e ngineer.lGWR8f , hereby acknowled g e or affirm that: The information and conclusions contained in the above plans and supporting documents comply wi th the current requiremen t s of the City of College Station, Texas City Code, Chapter 13 and its a s sociate d Drainage Po licy and Design Standards . As a condition of approval of this permit application, I agree to construct the improvements proposed in this application according to these documents and the requirements of Chapter 13 of the College Station City Code. f!!d1J!Al3~ r Contractor ~N~\..iF-EJL ., I I";. "' . . . .. . '• .' . , ) ~ .. ' . . . .. \ ; .. . . f ' )' I ' ' " Figure XU Continued CERTlFICATlONS : (for proposed alterations within designated flood hazard areas .) A. I, "1t-ni e,.W?AW~ ~. , certify that any nonresidential structure on or proposed to be on this site as part of this a~plication is designated to prevent damage to the structure or its contents as a result of flooding from the 100 year stonn . Erb# f3_ fLIHL~ Date 8 . I, NC€.'1\1 e. &wr;.u.. ,\ft. 'certify that the finished floor elevatio~ of the lowest floor, including any basement, of any residential structure, proposed as part of this application is at or above the base flood elevation established in the latest Federal Insurance Administration Flood Hazard Study and maps, as amended . ~13 . ~ //'. ~. 2-Lf llftf$ Engineer r Date C. I, ~\?F-.t.l. J' . certify that the alterations or development covered by this permit shall not diminish the cod-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 flood ways and of floodway fringes . ~8~{, I Engineer Date I, No~'"1~ f?, &Ag.\)f....\.L.. ;r~. , do certify that the proposed alterations do not raise the level of the l 00 year flood above elevation established in the latest Federal Insurance Administration Flood Hazard Study. ~f3.&M0 , Engineer Date Conditions or comments as part of approval ------------------- In 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, a!td sedimentation shall not be deposited in city streets, or existing drainage facilities . I hereby grant this permit for development. 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 . I . ,• .-r ... .. f:'.P.~-~~};:~_f'.9-:f.~-~~;--yiiil•i_ElfiiL_-_:_:_-_:_:_-_-_-_:_:_:_:_:_-_:_:_: ______________ :_-_-_-_-_:_-_-_-_-___ -___ -__ --_-_--_-___ -_-_-_-________ -_-_-_-_-_-_-_-_-_-_-_-:-:-::---:~-:'.-_:-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_'.·_-:-_-:-:~---_-_-_'.-_:-_-_:-_-_-_-_-:_-_-_-:_::-_:-_:-_-_-:-_:-_:-_::-_:-:-_-::-:-_:-_:-_-_-_-_-_-_-_-_-_:-_-_-_ -_-_-_-_J'.-~_9_~:fl From: To: Date: Subject: Shirley Volk Deborah Grace 12/14/98 12:31PM Varsity Ford This is the 3rd review of these plans and this proposal. Included in this submittal is the redlined drainage report, the revised drainage report, redlined construction docs, 3 revised set of construction docs, a letter outlining the changes made, an 8 Yz x 11 City topo, and an 8 Yz x 11 copy of FEMA-FIRM map. Larry wants a call when this is approved so he can bring in additional copies for "approval" stamp. Thanks. CC: Jeff Tondre, Jessica Jimmerson, Sabine Mccully, ... LETTER OF TRANSMITTAL MUNICIPAL DEVELOPMENT GROUP TO : FROM: DAm til11 l1C6 MDG JOB NUMBER: 4-J 4 --?J-7+ ATIACHED PLEASE FIND : NO. OF COP IES : DESCRIPTION : THESE ITEMS ARE TRANSMITIED AS CHECKED BELOW: ?FOR APPROVAL 0 FOR YOUR USE 0 AS REQUESTED 0 OTHER: COMMENTS : SIGNED: MUNICIPAL DEVELOPMENT GROUP 2551 Texas Ave. South, Ste. A• College Station, Texas 77840 • 409-693-5359 •FAX: 409-693-4243 • EMAJL:mdgcs@gte.net Engineering, Surveying, Planning and Environmental Consultants MEMORANDUM TO: Development Services, COCS FROM: Larry Wells SUBJECT: Varsity Ford Site Revisions The following changes have been incorporated in revision "C": The revision number and date have been included in the title block on both the grading and site plan sheets. The detail sheet remains at revision level "B ". The base flood elevation has been marked at two locations on both the grading and site plan sheets . A typographic error in the third line of the first paragraph of "SITE PLAN NOTES" has been corrected in the site plan . A note has been added to the grading and drainage plan to reflect that contours shown are those for existing conditions . A note has been modified at Section A-A in the grading and drainage plan to refer to minimum sizes for random and for coursed rip-rap. The plan view of the drainage way intersection at Carter Creek has been modified to graphically depict the rip-rap styles to be used and a note added to specify minimum sizes for random rip-rap and minimum exposures (and thus, minimum size in one dimension) of the coursed rip-rap . The base flood elevation has been marked at two locations in exhibit drawings in the drainage report. ::•··-·---... ·u"" """' --------------·------·------------·-- CITY OF COLLEGE STATIO~I . TE XAS -.-.-.... -~ ZONE X A \ \ \ FINAL DRAINAGE REPORT FOR THE HIGH RIDGE SUBDIVISION PARKING EXPANSION & DRAINAGE IMPROVEMENTS COLLEGESTATION,BRAZOSCOUNTY,TEXAS NOVEMBER, 1998 Revised: NOVEMBER 24 , 1998 ~· MUNICIPAL DEVEL OPMENT GROUP I ~'~ I •I!J 2551 TEXAS AVENUE . SOUTH , STE. A COLLEGE STAT IO N, TEXAS 77 8 40 Ph : (4 09 )69 3 -53 59 Fx : (4 0 9) 693-4243 ~Consu l ting Engi n eers · Environmen tal · Surveyors· P lanners TABLE OF CONTENTS 1.0 PROJECT SCOPE ................................................................................................. 4 1.1 SITE LOCATION .................................................................................................... 4 1.2 GENERAL DESCRIPTION ..................................................................................... 4 2.0 DRAINAGE BASINS & SUB-BASINS ................................................................. 4 2 .1 MAJOR DRAINAGE BASIN DESCRIPTIONS ...................................................... 4 2.2 SUB-DRAINAGE BASIN DESCRIPTIONS ........................................................... 5 3.0 DRAINAGE DESIGN CRITERIA & CONSTRAINTS ....................................... 5 3 .1 STREET DRAINAGE ............................................................................................. 5 3 .2 STORM SEWER INLETS ....................................................................................... 6 3 .3 STORM SEWER SYTEMS ..................................................................................... 6 3 .4 OPEN CHANNELS ................................................................................................. 7 3 .5 CULVERTS ............................................................................................................. 8 3 .6 DETENTION FACILITIES ..................................................................................... 8 4.0 DRAINAGE SYSTEM MODELING .................................................................... 9 4 .1 STREET DRAINAGE ............................................................................................. 9 4 .2 STORM SEWER INLETS ....................................................................................... 9 4 .3 STORM SEWER SYSTEMS ................................................................................... 9 4.4 OPEN CHANNELS ............................................................................................... 10 4 .5 CULVERTS ........................................................................................................... 10 4 .6 DETENTION FACILITIES ................................................................................... 10 5.0 CONCLUDED DRAINAGE IMPROVEMENTS ............................................... 11 5.1 STORM SEWER SYSTEMS ................................................................................. 11 5.2 OPEN CHANNELS ............................................................................................... 11 5.3 GRADING & ERIOSION CONTROL. .................................................................. 13 APPENDIX A-HYDRAULIC COMPUTATIONS APPENDIX B -MAPPING APPENDIX C -DRAINAGE DETAILS LIST OF TABLES I DESCRIPTION PAGE NO. TABLE # 1 -Proposed Discharge Outlets (10-Y ear Rainfall Event) .............................. 11 TABLE #2 -Proposed Discharge Outlets (100-Year Rainfall Event) ............................ 11 TABLE #3 -Proposed Open Channels (25-Year Rainfall Event) .................................. 12 TABLE #4 -Proposed Open Channels (100-Year Rainfall Ev ent) ................................ 12 TABLE #5 -Proposed Pilot Channels ........................................................................... 12 High Rid ge Subdiv ision Drainage Improvem ents 1.0 PROJECT SCOPE Municipal Development Group This report outlines the drainage improvements for the High Ridge Subdivision "Varsity Ford" parking expansion . This drainage report will consist of the requirements necessary for the improvements of this site in accordance with the provisions of the City of College Station Drainage Policy and Design Standards. 1.1 SITE LOCATION The project is located on the east frontage road of State Highway No . 6. Surrounding existing developments immediately adjacent to the project site are ; the existing Varsity Ford Motor Complex building and car lot, and the Hollywood Theatre center. The site fronts the frontage road approximately 2000 linear feet south of the State Highway No . 60 intersection. 1.2 GENERAL DESCRIPTION The subject property, being a 1.90-acre tract, is currently vacant. This land generally slopes to the northeast with a grade of approximately 3 . 00% being fairly uniformly distributed . This site is currently unimproved with native grasses, weeds, and light underbrush and some large trees . The project site is adjacent to Carter Creek and is within that drainage basin . 2.0 DRAINAGE BASINS & SUB-BASINS 2 .1 MAJOR DRAINAGE BASIN DESCRIPTIONS The drainage improvements project site is contained within the drainage- watershed of the Carter's Creek Drainage Basin . This drainage basin is illustrated on Exhibit # 1 -"Carter's Creek Drainage Basin" located in Appendix B -Mapping . The borders of this drainage basin roughly consist of Rock Prairie Road on the south and west, State Hwy No 30 to the east, and State Hwy No. 21 to the north . 000414-3134 Drainage Report.do c Final Drainage Report - 4 High Ri dge Subdivision Drainage Improvements 2 .2 SUB-DRAINAGE BASIN DESCRIPTIONS Muni cip al Development Group The sub-drainage basins that will determine all drainage calculations will consist of the 1. 90-acre tract that includes the parking area expansion . The Varsity Ford parking expansion will be analyzed in two separate drainage configurations . Initial the sub-basin will be examined at the current pre- development conditions . This analysis will provide for accurate pre- development runoff values . Next, the sub-basin was reconfigured to match drainage patterns of the proposed site grading . New coefficients of runoff were established with associated runoff values . From these computations the required proposed drainage structures were designed . The new sub-drainage basins are illustrated on Exhibit #2 -"Post- Development Varsit y Ford Sub-Drainage Basin". Results of these calculations are shown in Section 5.0 . The project site fringes the 100-year floodplain as shown on the Flood Insurance Rate Map , (FIRM) Map No. 48041C0142 C hav ing an effective date of Jul y 2, 1992 . An excerpt of the FIRM map with the location of the project site is illustrated on Exhibit #3 -"FIRM Map" located in Appendi x B -Mapping . 3.0 DRAINAGE DESIGN CRITERIA & CONSTRAINTS For all development within the City of College Station, there are criteria on the use of which design storms and development conditions for type of drainage improvements . Below, in each type of improvement's, the required design constraints are more fully detailed . All drainage improvements shall also be analyzed during the 100-year rainfall event to insure that no adverse conditions will ex ist. 3 .1 STREET DRAINAGE Street drainage improvements shall be designed in accordance to the City of College Station 's Drainage Policy and Design Standards . Unless 000414-3 134 Dra in age Report .doc Final Drainage Report -5 I High Ri dge Subdi vision Drainage Improvements Muni cip a l Developm ent Group otherwise stated, the following constraints shall dictate the des ign of all street grading and drainage : •:• All proposed streets shall have curb and gutter. •:• Maximum velocity not to exceed 10 ft/sec and mm1mum slope of 0.4%. •:• Concrete valley gutters shall be placed at all roadway intersections where runoff is carried from one side of the roadway to the other. •:• The 100-year rainfall event shall be confined within the limit s of the street right-of-way . •:• All streets permissible spread of water shall be dictated by the 10-year rainfall event. For each class of street, the following conditions will control : ~ Arterial & Parkway-One clear lane in each direction 24 foot total clearance at center of street. ~ Collector & Commercial -One clear lane 12 foot total clearance at the center of the street. ~ Local -Depth of water not to exceed the top of curb or crown, whichever is less . 3 .2 STORM SEWER INLETS Storm sewer inlets shall be designed in accordance to the City of College Station 's Drainage Policy and Design Standards . Unless otherwise stated, the following constraints shall dictate the design of all storm sewer inlets : •:• Inlets on all streets, except for residential , shall be recessed with a minimum 4" depression . •:• Curb openings shall be a minimum length of 5 feet. •:• Inlets with greater than a 5" gutter depression on streets with less than a 1. 00% grade shall be designed in sump conditions. •:• Inlets at bridges and culvert structures shall be oversized to accommodate 125% of the 10-year rainfall event. •:• Ponding at curb inlets shall not exceed 18 " in depth . 3 .3 STORM SEWER SYSTEMS Storm sewer system improvements shall be designed in accordance to the City of College Station 's Drainage Policy and Design Standards . Unless otherwise stated, the following constraints shall dictate the design of all storm sewer systems : 000414-31 34 Drainage Rep ort.doc Fin a l Drainage Report - 6 I High Ridge Subdivision Drainage Improvements Municipal Development Group 3.4 •!• Minimum velocity allowed is 2 .5-ft/sec and maximum velocity allowed is 15 ft/sec during the 10-year rainfall event. •!• When a change in pipe or boxes size is required , the soffit or top respectively will match and a junction box shall be provided for at these points. •!• Maximum spacing of manholes shall be 300 feet for pipes of 54 " diameter or smaller. Maximum spacing of manhole shall be 500 feet for pipes greater than 54" diameter. •!• Minimum storm sewer pipe diameter of 18 ". Short laterals adjacent to inlets may be 12" in diameter . •!• Conduits of 24" or less shall be designed with the assumption of a 25% reduction in cross-sectional area . •!• At all inlets , manholes , and junction boxes an elevation drop of 0.1 feet minimum will be necessary . •!• The theoretical hydraulic grade line for the I 0-year rainfall event shall be a minimum of 0.5 feet from the flowline of any curb inlet in the system . •!• The minimum width of any easement for a storm sewer system shall be 15 feet, and the centerline of the storm sewer shall be at least 5 feet from the closest side of the easement. OPEN CHANNELS Open channel improvements shall be designed in accordance to the City of College Station 's Drainage Policy and Design Standards. Unless otherwise stated, the following constraints shall dictate the design of all open channels: •!• Minimum grade shall be 0.4% for earth or vegetative lined channels . •!• Channel capacities shall be dictated by the design storm of the 25-year rainfall event. •!• Low-flow pilot channels shall be required for grass-lined channels with a carrying capacity of 1/3 of the peak discharge of the 5-year rainfall event. •!• Minimum permissible velocity of 2.5 ft/sec during the 25-year rainfall event. •!• Maximum channel velocities shall be as dictated below : );i-Exposed earth at 3.0 ft/sec . );i-Seeded grass at 4 .5 ft/sec. );i-Sodded grass at 6.0 ft/sec. );i-Impermeable surface at 10 ft/sec . •!• Maximum side slope for grass-lined earth channel is 3 : 1. •!• Channels with trapezoidal cross-section shall have a minimum bottom width of 4 feet. 000414-3134 Drainage Report.do c Final Drainage Report -7 I High Ri dge Subdivision Drainage Improvement s Muni ci pa l Development Group 3 .5 •!• Channel shall have a minimum freeboard of 0 .5 feet. •!• The 100-year rainfall event shall be contained within the channel drainage easement. •!• Minimum drainage easement width shall be the channel 's top width plus 20 feet. CULVERTS Culverts shall be designed in accordance to the City of College Station 's Drainage Policy and Design Standards . Unless otherwise stated, the following constraints shall dictate the design of culverts : •!• The design discharge for culverts shall be the 25-year rainfall event unless under a residential street in the secondary drainage system . Then the 10-year rainfall event will be the design storm . •!• Maximum headwater elevation shall be one foot less than the top of curb elevation . •!• Maximum overflow into the street shall be 2 feet in depth from the lowest point in the roadway profile . Overflow shall not exceed design conditions for street drainage . •!• The maximum allowable discharge into channels are as follows : );;>-Natural channel or seeded cover at 6 .0 ft/sec . );;>-Sodded cover at 8.0 ft/sec . );;>-Impermeable surface at 15 ft/sec . 3 .6 DETENTION Detention shall be designed in accordance to the City of College Station 's Drainage Policy and Design Standards . Unless otherwise stated , the following constraints shall dictate the design of detention basins : •!• Detention facilities shall have the capacity to contain the 100-year rainfall event. •!• Maximum detention basin 's side slope shall be 4 : 1 with vegetative cover and 2 : 1 for non-vegetative cover. •!• Bottom slopes of the detention basin with vegetative cover shall be at a grade of 20 : 1 with low-flow pilot channels . •!• Minimum of 0 .5 feet of freeboard during the 100-year rainfall event. •!• Detention facilities other than parking lots and rooftops shall have an increased capacity of 10% to allow for sedimentation . 000414-3 134 Drainage Rep ort.do c Final Drainage Report -8 I I High Ridge Subdi vision Drainage Improvem ents Municipal Development Group 4.0 DRAINAGE SYSTEM MODELING For all drainage system modeling , the volume of runoff will be calculated . The drainage area calculations are summarized accordingly using the Rational · Method : (Q=CIA) where "Q" is the runoff in cubic feet/second , "C" is the runoff coefficient, "I" is the storm intensity in inches/hour for each selected frequency , and "A" is the drainage area in acres . A minimum 10-minute time of concentration for all calculations will be assumed . The selected frequencies will be 2, 5, 10, 25, 50, 100-year rainfall events. 4 .1 STREET DRAINAGE Street flow calculations are aided by the program FlowMaster v . 5.7 by Haestad Methods . Within this program basic geometry and characteristics of a proposed or existing curb & gutter street can be defined . From this information, Manning's formula is then used to calculate desired parameters of the street. 4 .2 STORM SEWER INLETS Storm sewer inlets are a part of the storm sewer system evaluation . As mentioned above, this was done with the (TxDOT) hydraulic program WinStorm v. 1.3 . Derivatives of Manning's formula are used within this program, pending on the geometry of the curb inlet and the condition of flow, to size inlets accordingly to the permissible spread of water on the street. 4 .3 STORM SEWER SYSTEMS Storm sewer system are evaluated with (TxDOT) hydraulic program WinStorm v . 1.3 . Within this program, basic geometry and characteristics of a storm sewer system can be defined . This would include data such as drainage basin calculations, type and configuration of several types of inlet boxes , and controlling factors of the conveyance system . From this 00 041 4-3134 Drainage Report.do c Final Drainage Report -9 High Ri dge Subd ivision Drainage Impro vements Muni cipal Developm ent Group program critical information can be determined about the storm sewer system . 4.4 OPEN CHANNELS Open channel hydraulic calculations are aided by the program FlowMaster v . 5.7 by Haestad Methods . Within this program, basic geometry and characteristics of a proposed or existing channel can be defined . From this information, Manning 's formula is then used to calculate desired parameters of the open channel. 4 .5 CULVERTS Culverts are evaluated one of two ways : Short, singular culverts are calculated with the Texas Department of Transportation (TxDOT) hydraulic program Culverts v. 1.0 . Within this program, basic geometry and characteristics of a culvert can be defined . This would included data such as tailwater, geometry, and entrance/exit losses. For each culvert investigations will be made in order to determine whether it is inlet or outlet controlled . For longer more complex culvert with bends and grade transitions the program StormCad v . 1.0 by Haestad Methods will be used . 4 .6 DETENTION Detention requirements are determined by graphical means . Tabulations of the pre-development and the post-development hydrographs of the drainage areas are provided . The hydrographs are based on the standard SCS unit hydrograph with time to peak discharge set to equal the time of concentration and the total base time set at 3 . 00 times the time of concentration. 000 4 14-3134 Drainage Report .do c Final Drainage Report -l 0 High Ri dge Subdiv ision Drain age Impro ve m ents Muni ci pal Development Grou p 5.0 CONCLUDED DRAINAGE IMPROVEMENTS The following drainage improvements are for the runoff of the 1.90-acre development of High Ridge Subdivision "Varsity Ford". These improvements included the grading and channeling of the proposed site . 5.1 STORM SEWER SYSTEMS The sub-drainage basins will be drained by curb leave-outs, which will discharge runoff collected by the proposed parking expansion into the drainage channel which shall discharge into Carter Creek. The curb leave- outs were design with the 10-year rainfall event and analyzed for adverse affects during the 100-year rainfall event. The results are as follows : DRAINAGE OUTLET 81 82 83 TABLE#1 PROPOSED DISCHARGE OUTLETS 10-YEAR RAINFALL EVENT DISCHARGE WIDTH DEPTH cffi ft ft 1.729 2 0.23 2 .696 2 0 .31 5.715 4 0 .30 TABLE#2 PROPOSED DISCHARGE OUTLETS (100-YEAR RAINFALL EVENT) VELOCITY ft/sec 3 .75 4 .36 4 .70 DRAINAGE DISCHARGE WIDTH DEPTH OUTLET (cfs) (ft) (ft) 81 2.330 2 0 .28 82 3.635 2 0 .38 83 7 .704 4 0 .37 5.2 OPENCHANNELS The proposed parking lot runoff will be collected into a small drainage channel , which will discharge into Carter Creek. This channel was design with two options for construction . Option # 1 design will consist of a typical concrete pilot channel with seeded lined banks at a side slope of 000414-313 4 Drainage Report .d oc Fina l Drainage Report -11 High Ri dge Su bdivision Drainage Improve m ents Muni cipal Developm ent Group 4 : 1. Option #2 will be a concrete rip-rap channel cross-section with 4 : 1 side slopes . Below are the results of bot~ channel options : TABLE#3 PROPOSED OPEN CHANNELS 25-YEAR RAINFALL EVEN OPTION#1 OPTION#2 DRAINAGE DISCHARGE DEPTH VELOCITY DEPTH VELOCITY BASIN cf s ft ft/sec ft ft/sec 81 2 .805 0.58 2 .12 0.64 1.71 82 5.054 0.72 2.45 0.80 1.98 83 11.581 0.98 3.02 1.09 2 .43 ; TABLE#4 PROPOSED OPEN CHANNELS ,, (100-YEAR RAINFALL EVENT .c ~ OPTION#1 OPTION#2 DRAINAGE DISCHARGE DEPTH TOP WIDTH DEPTH TOP WIDTH BASIN (cfs} (ft} (ft) (ft) (ft} 81 3.311 0.61 4 .90 0.68 5.46 82 5.965 0.76 6 .11 0.85 6.81 83 13.669 1.04 8.34 1.16 9.29 In addition to the open-channel design for the Option # 1 cross-section, low flow pilot channels were design to be constructed from the proposed drainage outlets, along the centerline of the channel and to the confluence of Carter Creek. The results and design criteria for the pilot channels are as follows : TABLE#& PROPOSED PILOT CHANNELS c> OPTION #1 -CROSS SECTIONS DRAINAGE DISCHARGE DEPTH TOP WIDTH DESIGN WIDTH BASIN (cfs) (ft) (ft) (ft) 81 0 .422 0.21 1.65 2.00 B2 1.314 0 .32 2.53 3.00 83 3.011 0.43 3.46 4.00 000414-3 134 Drainage Report.doc Fina l Drainage Report -12 High Ri dge Subdivision Drain age Improveme nt s 5.3 GRADING & EROSION CONTROL Muni ci pa l Development Group Erosion control shall be where indicated and in placed until grass, by seeding, is established . Erosion control details are provided in Appendi x C . 000414-3 134 Drainage Report.d oc Final Drainage Report -13 00041 4-3 134 Drainage Report.doc APPENDIX A HYDRAULIC COMPUTATION DESCRIPTION APPENDIX A TABLE OF CONTENTS PAGE NO. Pre-Development Runoff Calculations ........................................................................ A-1 Post-Development Runoff Calculations ....................................................................... A-2 Curb Leave-out Area B 1 (10 year) .............................................................................. A-3 Curb Leave-out Area B 1 (100 year) ............................................................................ A-4 Curb Leave-out Area B2 (10 year) .............................................................................. A-5 Curb Leave-out Area B2 (100 year) ............................................................................ A-6 Curb Leave-out Area B3 (10 year) .............................................................................. A-7 Curb Leave-out Area B3 (100 year) ............................................................................ A-8 Open Channel Area Bl (25 year): Option #1 .............................................................. A-9 Open Channel Area Bl (100 year): Option #1 .......................................................... A-10 Open Channel Area B2 (25 year): Option #1 ............................................................ A-11 Open Channel Area B2 (100 year): Option #1 .......................................................... A-12 Open Channel Area B3 (25 year): Option #1 ............................................................ A-13 Open Channel Area B3 (100 year): Option #1 .......................................................... A-14 Open Channel Area Bl (25 year): Option #2 ............................................................ A-15 Open Channel Area Bl (100 year): Option #2 .......................................................... A-16 Open Channel Area B2 (25 year): Option #2 ............................................................ A-17 Open Channel Area B2 (100 year): Option #2 .......................................................... A-18 Open Channel Area B3 (25 year): Option #2 ............................................................ A-19 Open Channel Area B3 (100 year): Option #2 .......................................................... A-20 Pilot Channel Area B 1 ............................................................................................... A-21 Pilot Channel Area B2 ............................................................................................... A-22 Pilot Channel Area B3 ............................................................................................... A-23 000414-3134 Drainage R eport .doc DRAINAGE AREA -PRE-DEVELOPMENT GENERAL INFORMATION Description : Drainage area of site before development. Drainage Area (APRE) = 1.226 acres TIME OF CONCENTRATION CTc> GIVEN Maximum Travel Distance (DPRE) Velocity of Runoff (VPRE) = Coefficient of Runoff (CPR E) = 315 ft 2.00 n.fsec 0.38 -NOTE: Minimum T c allowed = 1 O min . 2 YEAR FREQUENCY, RA TE OF DISCHARGE (Q) Coefficient (e) = 0.806 Coefficient (b) = 65 Coefficient (d) = 8 5 YEAR FREQUENCY. RA TE OF DISCHARGE (Q) Coefficient (e) = 0.785 Coefficient (b) = 76 Coefficient (d) = 8.5 10 YEAR FREQUENCY. RATE OF DISCHARGE (Q) Coefficient (e) = Coefficient (b) = Coefficient (d) = 0.763 80 8.5 25 YEAR FREQUENCY. RA TE OF DISCHARGE (Q) Coefficient (e) = Coefficient (b) = Coefficient (d) = 0.754 89 8.5 50 YEAR FREQUENCY, RA TE OF DISCHARGE (Q) Coefficient (e) = Coefficient (b) = Coefficient (d) = 0 .745 98 8.5 100 YEAR FREQUENCY. RATE OF DISCHARGE (Q) Coefficient (e) = 0.73 Coefficient (b) = 96 Coefficient (d) = 8 3134-000414 Drainage Runoff Eval uation.xis RESULT TqPRE) = 2.6 min. Rainfall Intensity (1 2) = 6 .327 in/hr :•.a,=_·,=_.,:.,·.·.~_·==.•.•,~.:,•.:,•.:,•.•.·.•.••, ••=······ -==============================•,::::::::=:::::=•=:::.,:.:=:=:=:=···:::::<=r><z~9.ii2:••:asrr?• .... ;::::::::::::::::::::::;:::::::::::::::::~=~=~=~=~=~=~:~=~=~=~=~=~=~=~=~=~=~ ::::::::::::::::::·:·:· ·:·:·:·:·:·:·:·:·:·:·:·:·:·:·:·:·:·:·:·:·:·: Rainfall Intensity (1 5) = 7.693 i%r .!_$.'._ •. ·.·.:_·.=_·~.=•=_: __ =:_• ... =.· .•. ·.·.·.·.•.·.•.=.•.•.•.:.:_ •. :. •• •• ••Ii:::-=: ••••< .•.•.•.•.•.•.•.•.•.-.•.•.•.• =_;_.-.=' . .=.i_:'.='.:.:_.: .. _•.:.i_;_ •... · .• i~iii i'''i:' w. ·:·:·:·:·:···:·:·:·:·:·:·:·:·:·:·:·:·:·:·:·:·:·:·:·:·: ·.·.·.·.·.·.•.·.·.·.·.·.·.·.·.·.·.·.·.·.· Rainfall Intensity (1 10) = 8.635 in /hr ~,:_a,=_=,·_·,·.,·.· .•. ~=.·.~-~-=.=·,~.f,~.~-•.:,:_:·,:_(,~_(_~_(,~_f_1.f_(.~~--(_(_(.~.1~_(_~-.1~1f.1~~~(\i/r·=.~_r.~.~.1.1.~_(_(_(_(_(_(_(_(_(_1_~~--.(_(_1:_:._j·_~_t·.1:_(.1:_(.t_(_(tr\iff~t a1os&[\~ititrrr ''"-::::: :-:·:·:·:·:·:·;.:.;-:.;.;.; ... ·.··:···:.:.:.:···:·:·:·:·:·:·:·:·:·:···:·:······ Rainfall Intensity (1 25 ) = 9.861 in/hr ....... ·.·•················· :·:·:·:·:·:·:·:·:·:·:·:·:·:·:·:·:·:·:· ·.·•·.·.· .. ·.·.·.·.· .· .. · .. ·.:·:·:·····:·:·:·:·:·:·:·:····· .. ··.·.···.·.·.·.· .. •.·•• .. :@~~:! ••••Z : :•r• ::t•tt••Htil.1~~f~t••• Rainfall Intensity (1 50 ) = 11 .148 i%r :l~~.e···· ;.; Jt• :.:::: ==:.::::::::::•• :== ·•·•••••::: ·••• ~~~ ~~ nr: Rainfall Intensity (1 100) 11 .639 i%r ···:·:·:·:·:·:·:·:·:·:·:·:·:·:·:·:·:·:·:·:·:·:·:·:·:·:·:·:·:·: ···········:·:·:·:·:-:·:·:·:·:·:·:.:·:.:::;:::·:·:·: ·: .. ·:·:·:·············:·····:·············.·.·.·.·.·.· ..... ·. !Qffil •ffi •:::•::••:•:•:•• ??::?? :::t:\iIIl1=111~~1•••• DRAINAGE AREA -POST-DEVELOPMENT GENERAL INFORMATION Description : Drainage area of site after development Drainage Area (81) = 0.209 acres (developed area) Drainage Area (82) = 0 .326 acres (developed area) Drainage Area (83) = 0.691 acres (developed area) TIME OF CONCENTRATION <T cl GIVEN RESULT Maximum Travel Distance (D 1) = 100 ft Tc1 = 0 .6 min . Velocity of Runoff CV1) = ft 3 .00 lsec Coefficient of Runoff (C 1) = 0 .95 Maximum Travel Distance (D 2) = 100 ft T c2 = 0 .6 min. Velocity of Runoff (V2) = ft 3 .00 fsec Coefficient of Runoff (C 2) = 0 .95 Maximum Travel Distance (D 3) = 175 ft T c3 = 1 .0 min . Velocity of Runoff (V3) = ft 3.00 lsec Coefficient of Runoff (C 3) = 0 .95 -NOTE: Minimum Tc allowed= 10 min . T C(POST) = 2 .1 min . 3134-000414 Drain age Runoff Evalu ation .xis I DRAINAGE AREA -POST-DEVELOPMENT 2 YEAR FREQUENCY. RA TE OF DISCHARGE (Q) Coefficient (e) = Coefficient (b) = Coefficient (d) = 0 .806 65 8 5 YEAR FREQUENCY. RA TE OF DISCHARGE (Q) Coefficient (e) = 0.785 Coefficient (b) = Coefficient (d) = 76 8.5 10 YEAR FREQUENCY. RATE OF DISCHARGE (Q) Coefficient (e) = Coefficient (b) = Coeffic ient (d) = 0 .763 80 8.5 25 YEAR FREQUENCY. RA TE OF DISCHARGE (Q) Coefficient (e) = Coeffi cient (b) = Coefficient (d) = 0 .754 89 8.5 50 YEAR FREQUENCY. RA TE OF DISCHARGE (Q) Coefficient (e ) = Coefficient (b) = Coefficient (d) = 0.745 98 8.5 100 YEAR FREQUENCY. RATE OF DISCHARGE (Q) Coefficient (e ) = Coefficient (b) = Coefficient (d) = 3134-000414 Drain age Runoff Evalu at ion .xis 0.73 96 8 Rainfall Intensity (Ii} = Q ARE A 1 = QAREA2 = 6 .327 i%r 1.267 cfs 1.976 cfs Rainfall Intensity (1 5) = 7.693 i%r QARE A 1 = 1.540 cfs QAREA 2 = 2 .402 cfs QAREA 3 = 5.092 cfs ::li:a ::.]:,]-::,:::.:l•=]]:.].:.• It·• J.•: -:I•] ·. t i~ii1 us ::: Rainfall Intensity (1 10) = QAREA 1: QAREA 2 = Q AREA 3 = 8.635 in /hr 1.729 cfs 2.696 cfs 5.715 cfs •.=•.·.•.:.•·.:_:_:.·_ ... =.•·.·.~-·-·.=.•.:.•.~.=.'.'_:.•.•.•.:.•.:.·.:.·.:.•.·.•.:.•.'.•.·.·.•.•.•.•.•.•.:.•.:.•.•.•.•.•.:.•.: ,,,,,,,, ,,, ,,, = • :.• 1 •oaio._=···· ai r ... :~ .·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.····-·.·.·-:-:-:-:-:-:-:-:· .·.·.·.·.·.·.·.·.·.·.·.·.·.·.···· Rainfall Intensity (1 25) = 9.861 in /hr Q AREA 1 = 1.974 cfs Q ARE A 2 = 3.080 cfs Q AREA 3 = 6 .528 cfs •:11:·1 ······:····:·•·::·:.:.:::::.:·:·::::: •. :.:.1.:-:-:=:.:::::. : •.• : •• : •..• •:-:::1~.~U,j::~ •....•• J Rainfall Intensity (1 50) = 11 .148 in /hr QAREA 1 = 2 .232 cfs QAR EA 2 = 3.481 cfs QARE A 3 = 7.379 cfs ..................................... ·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.·.· ................ ···.·.·.·.· .. ·.·.·.·.·•· ........ . : ·0:_·_·.·.···"':····::::···;a;·::::...,. ..... ...,...,....,..,......,,...,.,....,,,,,,,,,,,,,. ········ =,= . .=,.= ... ,='_•:,.' ... ,=' ... ,=' ... ,=' ... ,=' ... ,='_;.,.-_·_·.•,;_:!t:_ ... ·_·.=,= ... _.=_=M,·_·_.-_=,= .. ·.·.·_ .. ',=.2 ....... ·.= .• = . .=_.,_.=.c.' ... '.·_r: .. ·.·.s.·_=.·_=.=.==.=_:'_•'.='.•'.:'.t .t .t.:: ~ :::::::::::::::::::::::;:::::=:::::;:::::::::;:;:::;:;:;:: )ft~~~ ::t 'iii. v.~ Rainfall Intensity (1 100) 11 .639 i%r Q AREA 1 = 2 .330 cfs QAREA 2 = 3.635 cfs QAREA 3 = 7. 704 cfs ············.··· .............. :.:-:-·-·.·.·.·.·.·.·.·.·.·.·.·.•.· .·.·.·.·.·.·.· ................ ·.·.·.•.•.·.· ................... . :•1~••¥]) ...... ::::::.::.:::.:::]• ::y •••1•1~•1 ~·· :} Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Bottom W idth Discharge Results Depth Flow Area Wetted Perimeter Top Width Critical Depth Critical Slope Velocity Veloc ity Head Specific Energy Froude Number Flow is supercritica l. APPENDIX A-HYDRAULIC COMPUTATIONS Worksheet for Rectangular Channel i:\projects\400\3134-varsity\3134t1 ra.fm2 Curb Leaveout Area 81 (10 yr) Rectangular Channel Manning's Formula Channel Depth 0.013 1.00 % 2 .00 ft 1.729 cfs 0.23 ft 0.46 ft2 2 .46 ft 2 .00 ft 0 .29 ft 0.005227 ft/ft 3 .75 ft/s 0.22 ft 0.45 ft 1.37 Municipal Development Group 11124198 10:32:11 AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMast er v5 .07 Page 1 of 1 Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Bottom Width Discha rge Results Depth Flow Area Wetted Perimeter Top W idth Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is supercritical. APPENDIX A-HYDRAULIC COMPUTATIONS Worksheet for Rectangular Channel i:\projects\400\3134-varsity\3134t1 ra.fm2 Curb Leaveout Area B 1 (100 yr) Rectangular Channel Manning's Formula Channel Depth 0.013 1.00 % 2.00 ft 2 .330 cfs 0 .28 ft 0 .56 ft 2 2 .56 ft 2 .00 ft 0 .35 ft 0.005213 ft/ft 4 .15 ft/s 0.27 ft 0 .55 ft 1.38 Municipal Development Group 11/24198 10:32:3 9 AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666. FlowMaster v5 .0 7 Page 1 of 1 Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Bottom Width Discharge Results Depth Flow Area Wetted Perimeter Top Width Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is supercritical. APPENDIX A -HYDRAULIC COMPUTATIONS Worksheet for Rectangular Channel i :\projects\400\3134-varsity\3134t1 ra .fm2 Curb Leaveout Area 82 (10 yr) Rectangular Channel Manning's Formula Channel Depth 0.013 1.00 % 2.00 ft 2 .696 cfs 0.31 ft 0 .62 ft2 2 .62 ft 2 .00 ft 0 .38 ft 0 .005225 ft/ft 4 .36 ft/s 0 .30 ft 0 .60 ft 1.38 Municipal Development G roup 11/24198 10:33 :08 AM Haestad Methods, Inc . 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster v5.07 Page 1 of 1 Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Bottom Width Discharge Results Depth Flow Area Wetted Perimeter Top Width Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is supercritical. APPENDIX A-HYDRAULIC COMPUTATIONS Worksheet for Rectangular Channel i :\projects\400\3134-varsity\3134t1 ra.fm2 Curb Leaveout Area 82 (100 yr) Rectangular Channel Manning's Formula Channel Depth 0.013 1.00 % 2.00 ft 3 .635 cfs 0 .38 ft 0 .75 ft2 2.75 ft 2 .00 ft 0.47 ft 0 .005292 ft/ft 4 .82 ft/s 0 .36 ft 0 .74 ft 1.38 Municipal Development Group 11/24198 10:33:33 AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster v5 .07 Page 1 of 1 Project Descriptio n Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Bottom Width Discharge Results Depth Flow Area Wetted Perimeter Top W idth Critical Depth Critical Slope Velocity ' Velocity Head Specific Energy Froude Number Flow is supercritica l. APPENDIX A -HYDRAULIC COMPUTATIONS Worksheet for Rectangular Channel i :\projects\400\3134-varsity\3134t1 ra.fm2 Curb Leaveout Area 83 (10 yr) Rectangular Channel Manning's Formula Channel Depth 0.013 1.00 % 4.00 ft 5 .715 cfs 0.30 ft 1.22 ft2 4.61 ft 4.00 ft 0 .40 ft 0.004263 ft/ft 4 .70 ft/s 0.34 ft 0 .65 ft 1.50 Municipal Development Group 11/24198 10 :34:14AM Haest ad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaste r v5 .07 Page 1 of 1 I Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Bottom Width Discharge Results Depth Flow Area Wetted Perimeter Top Width Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is supercritical. APPENDIX A-HYDRAULIC COMPUTATIONS Worksheet for Rectangular Channel i:\projects\400\3134-varsity\3134t1 ra . fm2 Curb Leaveout Area 83 (100 yr) Rectangular Channel Manning's Formula Channel Depth 0.013 1.00 % 4.00 ft 7 .704 cfs 0 .37 ft 1 .47 ft2 4 .74 ft 4.00 ft 0.49 ft 0.004186 ft/ft 5.24 ft/s 0 .43 ft 0 .79 ft 1.52 Municipal Development Group 11124198 10:34:40AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster v5 .07 Page 1 of 1 I Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Left Side Slope Right Side Slope Discharge Results Depth Flow Area Wetted Perimeter Top Width Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is subcritical. Notes : Area= 81 APPENDIX A -HYDRAULIC COMPUTATIONS Worksheet for Triangular Channel i:\projects\400\3134-varsity\3134t1 ra.fm2 Open-Channel Area 81 (25 yr): Option #1 Triangular Channel Manning's Formula Channel Depth 0 .030 1.00 % 4 H :V 4 H :V 2 .805 cfs 0 .58 ft 1.33 ft2 4.75 ft 4.61 ft 0.50 ft 0.021708 ft/ft 2 .12 ft/s 0 .07 ft 0 .65 ft 0 .70 Municipal Development Group 11124198 11 :05:03AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster v5.07 Page 1 of 1 I Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Left Side Slope Right Side Slope Discharge Results Depth Flow Area Wetted Perimeter Top Width Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is subcritical. Notes : Area= 81 + 82 APPENDIX A -HYDRAULIC COMPUTATIONS Worksheet for Triangular Channel i:\projects\400\3134-varsity\3134t1 ra.fm2 Open-Channel Area 82 (25 yr): Option #1 Triangular Channel Manning's Formula Channel Depth 0.030 1.00 % 4 H :V 4 H :V 5 .054 cfs 0 .72 ft 2 .06 ft2 5.92 ft 5.74 ft 0.63 ft 0 .020071 ft/ft 2 .45 ft/s 0 .09 ft 0.81 ft 0 .72 Municipal Development Group 11/24198 11 :07 :47 AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster v5.07 Page 1 of 1 I Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Left Side Slope Right Side Slope Discharge Results Depth Flow Area Wetted Perimeter Top Width Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is subcritical. Notes : Area= 81 + 82 APPENDIX A -HYDRAULIC COMPUTATIONS Worksheet for Triangular Channel i :\projects\400\3134-varsity\3134t1 ra.fm2 Open-Channel Area 82 (100 yr): Option #1 Triangular Channel Manning's Formula Channel Depth 0 .030 1.00 % 4 H :V 4 H :V 5 .965 cfs 0.76 ft 2 .33 ft2 6.30 ft 6 .11 ft 0 .67 ft 0.019632 ft/ft 2 .56 ft/s 0.10 ft 0 .87 ft 0.73 Municipal Development Group 11124198 11 :10:20AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster v5 .07 Page 1 of 1 Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Left Side Slope Right Side Slope Discharge Results Depth Flow Area Wetted Perimeter Top Width Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is subcritical. Notes : Area = 81 + 82 + 83 APPENDIX A-HYDRAULIC COMPUTATIONS Worksheet for Triangular Channel i :\pro j ects\400\3134-varsity\31 34 t1 ra .fm2 Open-Channel Area 83 (25 yr): Option #1 Triangular Channel Manning's Formula Channel Depth 0.030 1.00 % 4 H :V 4 H :V 11 .581 cfs 0.98 ft 3.84 ft2 8.08 ft 7.84 ft 0.88 ft 0.017969 ft/ft 3.02 ft/s 0.14 ft 1.12 ft 0.76 Municipal Development Group 11/24198 11:11 :09 AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster v5.07 Page 1 of 1 Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Left Side Slope Right Side Slope Discharge Results Depth Flow Area Wetted Perimeter Top Width Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is subcritical. Notes : Area = 81 + 82 + 83 APPENDIX A -HYDRAULIC COMPUTATIONS Worksheet for Triangular Channel i:\projects\400\3134-varsity\3134t1 ra.fm2 Open-Channel Area 83 (100 yr): Option #1 Triangular Channel Manning's Formula Channel Depth 0.030 1.00 % 4 H :V 4 H :V 13 .669 cfs 1.04 ft 4 .35 ft2 8.60 ft 8.34 ft 0.94 ft 0.017576 ft/ft 3.14 ft/s 0.15 ft 1.20 ft 0 .77 Municipal Development Group 11124198 11 :11 :42AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster v5 .07 Page 1 of 1 Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Left Side Slope Right Side Slope Discharge Results Depth Flow Area Wetted Perimeter Top Width Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is subcritical. Notes : Area= 81 APPENDIX A-HYDRAULIC COMPUTATIONS Worksheet for Triangular Channel i :\projects\400\3134-varsity\3134t1 ra.fm2 Open-Channel Area 81 (25 yr): Option '#2. Triangular Channel Manning's Formula Channel Depth 0.040 1.00 % 4 H :V 4 H :V 2 .805 cfs 0 .64 ft 1.64 ft2 5.29 ft 5.13 ft 0 .50 ft 0 .038595 ft/ft 1.71 ft/s 0.05 ft 0.69 ft 0.53 Municipal Development Group 11 /2419 8 11 :13:46AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster v5 .07 Page 1 of 1 Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Left Side Slope Right Side Slope Discharge Results Depth Flow Area Wetted Perimeter Top Width Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is subcritical. Notes: Area= 81 APPENDIX A-HYDRAULIC COMPUTATIONS Worksheet for Triangular Channel i:\projects\400\3134-varsity\3134t1 ra .fm2 Open-Channel Area 81 (100 yr): Option #2 Triangular Channel Manning's Formula Channel Depth 0 .040 1.00 % 4 H :V 4 H :V 3.311 cfs 0.68 ft 1.86 ft2 5.63 ft 5.46 ft 0.53 ft 0.037751 ft/ft 1.78 ft/s 0.05 ft 0.73 ft 0.54 Municipal Development Group 11/24198 11 :14:54AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster v5 .07 Page 1 of 1 Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Left Side Slope Right Side Slope Discharge Results Depth Flow Area Wetted Perimeter Top Width Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is subcritical. Notes : Area= 81 + 82 APPENDIX A-HYDRAULIC COMPUTATIONS Worksheet for Triangular Channel i:\projects\400\3134-varsity\3134t1 ra. fm2 Open-Channel Area 82 (25 yr): Option #2 Triangular Channel Manning's Formula Channel Depth 0.040 1.00 % 4 H :V 4 H :V 5.054 cfs 0.80 ft 2.56 ft2 6 .59 ft 6 .40 ft 0 .63 ft 0 .035681 ft/ft 1.98 ft/s 0.06 ft 0.86 ft 0.55 Municipal Development G roup 11 /24198 11 :16 :15AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster v5.07 Page 1 of 1 Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Left Side Slope Right Side Slope Discharge Results Depth Flow Area Wetted Perimeter Top Width Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is subcritical. Notes : Area= 81 + 82 APPENDIX A -HYDRAULIC COMPUTATIONS Worksheet for Triangular Channel i:\projects\400\3134-varsity\3134t1 ra . fm2 Open-Channel Area 82 (100 yr): Option #2 Triangular Channel Manning's Formula Channel Depth 0.040 1.00 % 4 H:V 4 H:V 5.965 cfs 0.85 ft 2 .90 ft2 7.02 ft 6 .81 ft 0.67 ft 0.034900 ft/ft 2 .06 ft/s 0.07 ft 0.92 ft 0.56 Municipal Development G roup 11 /24198 11 :17:00AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster v5.07 Page 1 of 1 Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Left Side Slope Right Side Slope Discharge Results Depth Flow Area Wetted Perimeter Top W idth Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is subcritical. Notes : Area = 81 + 82 + 83 APPENDIX A-HYDRAULIC COMPUTATIONS Worksheet for Triangular Channel i :\projects\400\3134-varsity\3134t1 ra . fm2 Open-Channel Area 83 (25 yr): Option #2 Triangular Channel Manning's Formula Channel Depth 0.040 1.00 % 4 H :V 4 H :V 11.581 cfs 1.09 ft 4 .76 ft2 9.00 ft 8.73 ft 0 .88 ft 0.031944 ft/ft 2 .43 ft/s 0.09 ft 1.18 ft 0.58 Municipal Development Group 11 /24198 11 :17 :50AM Haestad Methods , Inc . 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster v5 .07 Page 1 of 1 Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Left Side Slope Right Side Slope Discharge Results Depth Flow Area Wetted Perimeter Top Width Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is subcritical. Notes : Area= 81 + 82 + 83 APPENDIX A-HYDRAULIC COMPUTATIONS Worksheet for Triangular Channel i:\projects\400\3134-varsity\3134t1 ra. fm2 Open-Channel Area 83 (100 yr): Option #2 Triangular Channel Manning's Formula Channel Depth 0.040 1.00 % 4 H :V 4 H :V 13.669 cfs 1 .16 ft 5.39 ft2 9.58 ft 9.29 ft 0.94 ft 0.031246 ft/ft 2.53 ft/s 0.10 ft 1.26 ft 0 .59 Municipal Development Group 11/24198 11 :18:34AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster v5.07 Page 1 of 1 I 11/24198 Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Left Side Slope Right Side Slope Discharge Results Depth Flow Area Wetted Perimeter Top Width Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is supercritical. Notes: Area= 81 APPENDIX A -HYDRAULIC COMPUTATIONS Worksheet for Triangular Channel i:\projects\400\3134-varsity\3134t1 ra. fm2 Pilot Channel Area 81 Triangular Channel Manning's Formula Channel Depth 0.013 1.00 % 4 H:V 4 H :V 0.422 cfs 0.21 ft 0.17 ft2 1.71 ft 1.65 ft 0.23 ft 0.005248 ft/ft 2.47 ft/s 0 .09 ft 0.30 ft 1.35 Municipal Development Group 11 :28 :19 AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster vS .07 Page 1 of 1 Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Left Side Slope Right Side Slope Discharge Results Depth Flow Area Wetted Perimeter Top Width Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is supercritical. Notes : Area= 81 + 82 APPENDIX A-HYDRAULIC COMPUTATIONS Worksheet for Triangular Channel i:\projects\400\3134-varsity\3134t1 ra. fm2 Pilot Channel Area 82 Triangular Channel Manning's Formula Channel Depth 0.013 1.00 % 4 H :V 4 H:V 1.314cfs 0.32 ft 0.40 ft2 2 .61 ft 2.53 ft 0 .37 ft 0.004510 ft/ft 3.28 ft/s 0.17 ft 0.48 ft 1.45 Municipal Development Group 11124198 1 1:28:47 AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster v5.07 Page 1 of 1 Project Description Project File Worksheet Flow Element Method Solve For Input Data Mannings Coefficient Channel Slope Left Side Slope Right Side Slope Discharge Results Depth Flow Area Wetted Perimeter Top Width Critical Depth Critical Slope Velocity Velocity Head Specific Energy Froude Number Flow is supercritical. Notes : Area= 81 + 82 + 83 APPENDIX A-HYDRAULIC COMPUTATIONS Worksheet for Triangular Channel i :\projects\400\3134-varsity\3134t1 ra.fm2 Pilot Channel Area 83 Triangular Channel Manning's Formula Channel Depth 0.013 1.00 % 4 H :V 4 H :V 3.011 cfs 0 .43 ft 0 .75 ft2 3 .56 ft 3.46 ft 0.51 ft 0.004038 ft/ft 4.03 ft/s 0.25 ft 0.68 ft 1.53 Municipal Development Group 11/24198 11 :29 :16AM Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 (203) 755-1666 FlowMaster v5.07 Page 1 of 1 000414-3134 Drainage Report .doc APPENDIXB MAPPING DESCRIPTION APPENDIXB TABLE OF CONTENTS PAGE NO. Exhibit # 1 -Carter's Creek Drainage Basin ................................................................ B-1 Ex hibit #2 -Post-Development Varsity Ford Sub-Drainage Basin .............................. B -2 Exhib it #3 -FIRM Map .............................................................................................. B -3 000414-3 134 Drainage Report.d oc ZONE X Rder lo 1· dt ·term in £ or d epths To deterrr i n ~ur a nce . 000414-3134 Drainage Report .do c APPENDIXC DRAINAGE DETAILS I I DESCRIPTION APPENDIXC TABLE OF CONTENTS PAGE NO. Curb Leave-out Detail ................................................................................................. C-1 Open Channel Cross-Section (Option#!) .................................................................... C-2 Open Channel Cross-Section (Option #2) .................................................................... C-3 Pilot Channel Detail .................................................................................................... C-4 Silt Fencing Detail. ...................................................................................................... C-5 000414-3134 Drainage Report.doc CURB LAYDOWN DISCHARGE FLUME WIDTH VARIES • 0 I 6" .,,., TYPICAL CONCRETE CURB & GUTTER PARKING AREA CURB LEAVE-OUT DETAIL N.T.S. -------- 12" #3 DOWEL /13 BARS ~ 12" O.C.E • CROSS SECJJON I I I TOP WIDTH VARIES 15' (MAX) EXISTNG GROUND r PROPOSED GRADE -----r VARIES~ SEE PLANS ._-r-~.~~~l--~~------------ 1.0 6" 18" O.C.E .W. STANDARD OPEN CHANNEL (ALTERNATE 1) I I I EXISTNG GROUND TOP WIDTH VARIES 15' (MAX) PROPOSED GRADE CONCRETE RIP RAP STANDARD OPEN CHANNEL (ALTERNATE 2) ,~ VARIES SEE PLANS -1 .·3 #3 BARS @ 18" O.C.E.W . CONCRETE PILOT CHANNEL (CROSS -SECTION) ------ I I I LLEGE RB NT .RD )-, a::- VIEW AT PITCH WHEN JOINING TWO OR MORE "SILT-STOP" FENCES TIE THE TWO END POSTS TOGETHER WITH EXISTING NYLON CORD. GROUND LINE ~ ~ 7'1-<"~~~'""""'"~.-.¥<! . ~~~~~~~~ <D EXISTING GROUND FRONT VIEW WOO DEN POST. MIN . 3 ' LENGTH (1 1/2' EXPOSED ) S1LT FEN CE, "SILT STOP" OR APPROVED EQUAL MIN . 24" OVERALL MAX . SPACING 1 O' O.C . EXISTING GROUND 6~x 6" TRENCH COMPACT TRENCH BACKFILL TO PREVENT "WASHOUT" BURY TOE OF SILT FENCE 6" BELOW PROPOSED GRADE SIPE VIEW SILT fEHCING N.T.S . LETTER OF TRANSMITTAL YUNICIPAL DEVELOPMENT GROUP ~ 1~'A1 •rei ~~llE~A~~ ~~7~ A Ph: (409)693 -5359 Fx: (409)693-4243 Engineering · Planning · Surveying re, @~l&t Vofk:_ FROM: /4rfVV( DATE: l ! /113I1~ I I MDG JOB NUMBER: ~g -~l/rq A TI ACHED PLEASE FIND : NO . OF COPIES : DESCRIPTION: THESE ITEMS ARE TRANSMITIED AS CHECKED BELOW: f1' FOR APPROVAL 0 FOR YOUR USE )23 AS REQUESTED