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HomeMy WebLinkAboutWPO201700048 Plan - VSMP 2021-07-22 (3)Us, Department of Agriculture . Natural Resources Conservation Service TR 55 Worksheet 2: Runoff Curve Number and Runoff Project: Old Trall Development Creeksidee III- Phase Il Designed8y:. FGM, PE Locattom Creekslde Subdivision. Checked By: FGM, PE Check One: Present X Developed X 1. Runoff rurvo NnmhortFNi FL-6NG-21A 06/04 Date: 4AV2,012 Date: 4/12/2012 Soil name and Cover description CN (weighted) a Drainage Area hyicgmup (Covertype;.treatment, and hydrologic condition;. CN Area Product of totalproductf I Calculated Description (AAppendix A} percent Impervious; unconnected/ m connected {Acres} CN x:Araa 'S`Value ppe impervious area ratio) total area 1310FILTER B. Impervious Areas 98 2.64- '259.1 (Prop9sed) Woods in Good Condition .55 L59 87.5 70;6 416- Lawns In Good Condition (75°%+Groundcove6 61 4,0 3=5 8 _ Impervious Areas 98. 4:21 20.6- STR.83&Ditch Woods in Good Condition 55 0.07 39 6219 5.89 Lawns in good Condition75%+Groundcover) '; $R 155 216.E 2- Runoff _ 2-YearStorm 10'Yearstornr Drainage Area Description Frec uency-years 2 10 nfa Rainfall, P (24hour)- inches 3.7 5.6 n/a Runoff,Q-inches 1.17 2.55. 810FILTER(Proposed) Runoff, Q- inches 0,76 1,90 STR. 83 & Ditch Runoff, ( inches Runoff, Q- Inches Runoff, Q- Inches. Runoff, Q- inches - Runoff, Q.- Inches Runoff; Q-inches U.S. Department of Agriculture Natural Resources Conservation Service TR 55 Worksheet 3: Time of Concentration (T0) or Travel Time (T,) Project: Old Trait Development Creekside ill- Phase 11 Location: Creekslde Subdivision Check One: Present X Developed X Cheekome: T, X T, Through ttWrea n/a 814FILTER S'ift.83 kC tCli� "f Sheet Flow. (Applicable to Tr only) Woods- Light 1 Surface description (Table 3-1) underbrush Dense%ras4 2 Manning's roughness coeff., n (Table 3.1 0.4 0.24 3 Flow length; L(total L5100) (ft) 1 100 1Lt7 4 Two-year 24-hour rainfall, P2(f Q 3.7 3,7 5 land slope, s (ft/ft) 0.09 6,A1 6 Compute Tt= [0.007(nigllol / P20,5 5 0:21 0.29 � Shallow Concentrated Flow: 7 Surface description (paved or unpaved) unpaved Unpaved 8 Flow Length, L(ft) 550 400 9 Watercourse slope, s (ft/ft) 0.033 0,04 10 Average velocity, V (Figure 3-1) (ft/s) 2.9 312 11 Tt=L/3WVV 1 0.05 :003 Channel Flow: 12 Crass sectional flow area, a,(W) 13 Wetted perimeter, Pw(ft) 14 Hydraulic radius, r=a/Pw (ft) 15 Channel Slope, s (ft/ft) 16 Manning's RoughnessCoeff, n 17 V= [ 1-49ru1s°'s) / n 18 Flow length, L 00 19 Tt= L/ 36W*V 20 Watershed or subarea T, or T, (Add Ttin steps 6,11 and 19) U.S. Department of Agriculture Natural Resources Conservation Service Designed By: FGM, PE Checked 8y: FGM, PE . FL-ENG-21A 06/04. Date: 4/12/2012 Date: _4/12/2012 6 u O N F o in G 4 8 T M C v 0.05 0 0.31 Q32. TR 55 Worksheet 4': Graphical Peak Discharge.Method Project: OldTraii Develo mentCreekside Iit-Phase It Location: Creekside Subdivision Cheek One, Present X Developed X Designed By: FGM, PE Checked By: FGM, PE, Supplemental Water Quality Information (Above minimum) required standards) short Verslon limP Computations. For Workshaets1- 6 Albemarle:Gounly Wafer P.irotectlonOrdlnance ModifiedSlmpla Method _Pfau: atd:rran,craekslrte iR=:P.fiaee:R Watere_ResourcesArea: OeieidpmsntAieax PPrivarer FQM"P'E Date:_•_ 1ZApr-12 Project Orainage'Area Designation PA wn tub bLeasin L. slomt pglkttant export in pound. L (Pti?j)Ft r1211 C(,Al2•tz.l an RV meruroff coefrQ-14 t, Rv = 4:45 tA.449(f) el sgiaff stcrm oWecifoNfa0Qr;A9 t peroontimpenicusnesis. P annual precfpitatiod 4T to Albemarle r -A - or .... A- profe0#area in acrys im:sublagtdraina9aorea, � .aka. poliifantoon0antra0on, mg(I of ppm tatgef phosphoms f •factor applied to RR Y' fequiredlreetmedtWhunalncy, A,6"owrimperwarea =A(1l*P *4112jl27 Rft required On3o(ei, LOosif)-rxcipie) "/9RR ramotel aftfenoy, P1?'t00fL(ppall I..i nt+nu...rtw:..wuKzitt,w n.ei.,wt i.a rent A:'c a,'Ffnit Rem .. f •d4 velo went Area ask tleveldpment Area _ _�, , th width subtotal itoadways _ µ ____ _ _ j Length Width gubtcl I jRoad vays 1 825 8t iL6 Sidewalks t Stdd aJfss 1,515 56T6 _-t0.3375 _ 8F DatachadW'-' x' F'ootprigt na 'suCKkkN Residences .(Residences (includes walkways';, ram... 8F geEanhecf - Foot dot no. subtotal 520t1 57200' '(includes walkways, - ohes & driveways) ,4 _._...._ Tones & dd4ewa s 6,7i200 FadtibD Lots...',_..._ Rattdri -LotsY p ........4.�a 0 Gravelareas Area - Ate.#+'- x0Yr1 0 x0T0= M.. 0 .Gial;��)._._.... A idriPn BWetures.- x_xm..m,.. urea; no; sEll . ma 7-_ ubldttil Strool res Ar?a_ no7 . �At4a 0 1lli-- (7 AGb IY 9r ed pashw & AtBa ands and 0uitivated turf359gQ9;6� t 4 ff6=' 3192Q.7C ( 83,PB4 x 0 (i8' _ 22:1p0 _0 14 crop lend _wa x a25 0 r ` ix 0 a OR18r knperdpits;Aieas IrtiperytaustJ.avar t - ''= ara�a::* Routine Method: storage -indication 2-year SCS 24-hour Storm inflow (cfs) 7.364 at 12.04 (hrs) discharge (cfs) 5.000 at 12.18 (hrs) K-ENO-22C water level (ft) 701.583 at 12.28 (hrs) 06/04 storage (cY) 352.297 10-year SCS 24-hour Storm inflow (cfs) 16.028 at 22.04 (hrs) discharge (cfs) 8.811 at 22.20 (hrs) water level (ft) 702.547. at 22.20 (hrs) Date: 4/12/2012 storage (cy) 61g.592 Date: 4/12/2012 too -year SCS 24-hour Storm inflow(cfs) 34.631at 12.04(hrs) discharge (cfs) i5.198 at 12.26 (hrs) water level (ft) 704.537at 12.26(hrs) storage Icy) 1319.257 1. Data Drainage Area Description Drainage Area Description Drainage Area Description Drainage Area Description Drainage Areal Description Drainage Area Description Drainage Area Description Drainage Area Descri.ptiOn BIOFILTER (Proposed) STR.83 & Ditch Drainage Area (Am) in miles2= 0.0143 0.0060 Runoff curve number CN= 70.6 62,9 Time of concentration (Tc)= 0.31 0.32 Rainfall distribution type= it It Pond and swamp areas spread throu houtthewatershed= 3.8 0 15_19.FAfY ri"'Ifiiar. 2. Frequency -years 2 10 2 10 3. Rainfall, P (24 hour)- inches 3.7 5.6 3.7 5.6 4. Initial Abstraction, la -inches 0, 83 1 0,831 1:179 1,179 5. Compute la/P 0.22 0.15 0.52 0.21 6. unit peak discharge, Qu-csm/in 6W 650 550 us 7. Runoff, Qfrom Worksheet 2- Inches 1.17 2.55 .0 6, 190 8. Pond and Swamp adjustment factor, Fp 0,74 0.74 1 1 9. Peak Discharge, Qp- cfs where QP=Qu Am Q F Routed through swM Faeillty 2.49 7.09 IfP(e) RPRE) Basin Input Data Inflow Hydrographs 6 Contour Areas 3Inflow Hydrographs Elevation(ft) Area(sf) Computed VoQcy) Hydrograph o 700.00 4954-00 0.0 SCS 701.00 6336.00 208.5 name: 2-year SCS 24-hour Storm 702.00 7451.00 463.6 Area (acres) g.16o 704.00 10104.00 =11.3 CN 7o.600 706.00 12925.00 1962.7 Type 2 707.50 15226.00 2739.8 rainfall, P (in) 3.700 time ofconc. (hrs) 0.3100 Start_Elevation(ft) 700.00 Vol.(cy) 0.00 time increment (hrs) 0.0200 time limit (hrs) 30.000 3 Outlet Structures fudge factor 0.74 Outlet structure o routed true Culvert peak flow (cfs) 7.374 name: Barrel peak time (hrs) 1z.o3g multiple 1 volume (cy) 1o64.328 discharge out of riser Olin) i5.000 Hydrograph) h (in) o.000 SCS Length (ft) 63.500 name: %o-year SCS 24-hour Storm Slope 0.0050 Area (acres) 9.160 Manning'sn 0.020 CN 7o.600 Inlet coeff. Ke 0.500 Type 2 Equation constant set 3 rainfall, P (in) 5.600 Invert (ft) 694.000 time of cone. (hrs) 0.3100 time Increment (hrs) o.o2oo Outlet structure 1 time limit (hrs) 30.000 Curve fudge factor 0.74 name: 24" ADS Standard Grate Inlet Stage -Discharge Curve routed true multiple 1 peakflow(cfs) 16.o5o Invert(ft) 702.100 peak time (hrs) 12.039 discharge into riser volume(cy) 2316.420 file: twenty -four -ADS Grate Inlet.txt Hydrograph z Outlet structure 2 SCS Culvert name: Zoo -year SCS 24-hour Storm name: Emergency Spillway Area (acres) g.160 multiple 4 CN 7o.600 discharge through dam Type 2 D (in) 15.000 rainfall, P (in) 9.1oo h (in) 0.000 time of conc. (hrs) 0.3100 Length (ft) 20.000 time increment (hrs) o.o2oo Slope 0.010 time limit (hrs) 30.000 Manning'sn 0.013 fudge factor 0.74 Inlet coeff. Ke 0.500 routed true Equation constant set 3 - peak flow (cfs) 34.678 Invert(ft) 704.750 peak time (hrs) 12.039 volume (cy) 5005.108 iCOTY R. rCOLLIM Lie. No. 035791 5-il-IZ ZONAL FF-- w F� w O O O w 0 O 4 g c6 075 V) co O w O Z O = J a 4 pC O � O W d ®N IH Z c LU K Lu E un to m w a LU W U) U) P1% > > Irl r• N C'M c'M 0) IN d' 1 N O N Uj J J W F_ 2 U LIJ Y U) F- LU LLj LL O O N 0 0 a o d w ru E; 0 w � U• a t=ir 0 _ JOB NO. 112068 SCALE AS SHOWN SHEET NO, 1 OF 1