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HomeMy WebLinkAboutWPO201500057 Calculations 2015-12-07 AVINITY II STORMWATER MANAGEMENT CALCULATIONS PACKET Date of Calculations June 25, 2015 Revised: December 7, 2015 PREPARED BY: COLLINS ENGINEERING 200 GARRETT STREET, SUITE K CHARLOTTESVILLE, VA 22902 434.293.3719 PH 434.293.2813 FX www.collins-engineering.com DEQ Virginia Runoff Reduction Method Water Quality Calculations Virginia Runoff Reduction Method New Development Worksheet-v2.8-June 2014 _ To be used w/2011 BMP Standards and Specifications Site Data I Project Name:Avinity I & II SWM Conceptual Design Date: 10/14/14 JAI - data input cells calculation cells constant values 1. Post-Development Project& Land Cover Information Constants Annual Rainfall(inches) . mon- Target Rainfall Event(inches) 1 00 Phosphorus EMC(mg/L) 0.26 Nitrogen EMC(mg/L)111111 1.86 Target Phosphorus Target Load(Ib/acre/yr) 0.41 Pi 0.90 Land Cover (acres) A soils B Soils C Soils D Soils Totals Forest/Open Space(acres)--undisturbed, - -- protected protected forest/open space or reforested land • 0.00 0 00 0.00 0 00 0.00 Managed Turf(acres)-disturbed,graded for yards or other turf to be mowed/managed 0.00 4.22 Impervious Cover(acres) a 0 00 5.57 Total 9.79 Rv Coefficients A soils B Soils C Soils D Soils Forest/Open Space 0.02 0.03 0.04 I * 0.05 Managed Turf 0.15 0.20 0.22 0.25 Impervious Cover 0.95 0.95 0.95 0.95 Land Cover Summary Forest/Open Space Cover(acres) 0.00 ill" Weighted Rv(forest) 0 00 %Forest 0% Managed Turf Cover(acres) 4.22 Weighted Rv(turf) 0.20 %Managed Turf 43% Impervious Cover(acres) 5.57 Rv(impervious) 0.95 %Impervious 57% Total Site Area(acres) 9.79 Site Rv 0.63 Post-Development Treatment Volume(acre-ft) 0.51 Post-Development Treatment Volume cubic feet) 22,272 Post_Development Load(TP)(Ib/yr) 13.99 Post_Development Load(TN)(Ib/yrl 100.11 Total Load(TP)Reduction Required(Ib/yr) 9.98 Site Results D.A.A D.A. B D.A.C D.A.D D.A.E AREA CHECK IMPERVIOUS COVER 3 15 2 42 0 00 0 00 0 00 OK. IMPERVIOUS COVER TREATED 3 15 2 42 0 00 0 00 0 00 OK. TURF AREA 1 79 2 43 0 00 0 00 0 00 OK. TURF AREA TREATED 1 79 2 43 0 00 0 00 0 00 OK. AREA CHECK OK. OK. OK. OK OK. Phosphorus [ i TOTAL TREATMENT VOLUME(cf) 22,272 TOTAL PHOSPHORUS LOAD REDUCTION REQUIRED(LBIYEAR: 9.98 RUNOFF REDUCTION(cf) 13341 PHOSPHORUS LOAD REDUCTION ACHIEVED(LB/YR: 10.14 ADJUSTED POST-DEVELOPMENT PHOSPHORUS LOAD(TP)(Ib/yrr 3.86 REMAINING PHOSPHORUS LOAD REDUCTION(LB/YR)NEEDED CONGRATULATIONS!!YOU EXCEEDED THE TARGET REDUCTION BY 0.2 LB/YEAR! Nitrogen(for information purposes) TOTAL TREATMENT VOLUME(et) 22,2721 RUNOFF REDUCTION(cf) 13341 NITROGEN LOAD REDUCTION ACHIEVED(LB/YR) 99.99 ADJUSTED POST-DEVELOPMENT NITROGEN LOAD(TN)(Ib/yr)1 0.111 Virginia Runoff Reduction Method Worksheet Virginia Runoff Reduction Method New Development Worksheet-v2 8-June 2014 Site Data Summary Total Rainfall= 43 inches Site Land Cover Summary A Soils B Soils C Soils D Soils Total %of Total Forest(acres) 0 00 0 00 0 00 0.00 0 00 0 00 Turf(acres) 0 00 4 22 0 00 0.00 4 22 43 11 Impervious(acres) 0.00 5 57 0 00 0.00 5.57 56 89 9.79 100 00 Site Rv 0.63 Post Development Treatment Volume(ft3) 22272 Post Development TP Load(Ib/yr) 13.99 Post Development TN Load(lb/yr) 100 11 Total TP Load Reduction Required(lb/yr) 9 98 Total Runoff Volume Reduction(ft') 13341 Total TP Load Reduction Achieved(Ib/yr) 10 Total TN Load Reduction Achieved(Ib/yr) 99.99 Adjusted Post Development TP Load(Ib/yr) 3.86 Remaining Phosphorous Load Reduction(Lb/yr)Required 0.00 Drainage Area Summary D.A.A D.A.B D.A.C D.A.D D.A.E Total Forest(acres) 0 00 0.00 0.00 0 00 0 00 0 00 Turf(acres) 1.79 2.43 0 00 0 00 0.00 4.22 Impervious(acres) 3.15 2 42 0 00 0.00 0.00 5.57 9 79 Drainage Area Compliance Summary D.A.A D.A.B D.A.C D.A.D D.A.E Total TP Load Red.(Ib/yr) 4 42 5 72 0 00 0.00 0.00 1014 TN Load Red.(Ib/yr) 54 60 45 39 0.00 0.00 0.00 99 99 Summary Pnnt Virginia Runoff Reduction Method Worksheet Drainage Area A Summary Land Cover Summary A Soils B Soils C Soils D Soils Total %of Total Forest(acres) 0 00 0 00 0.00 0.00 0 00 0.00 Turf(acres) 0 00 1 79 0.00 0.00 1 79 36.23 Impervious(acres) 0 00 3 15 0.00 0.00 3 15 63.77 4 94 BMP Selections Practice Credit Area(acres) Downstream Practice 5.b.Dry Swale#2(Spec#10) Impervious: 0.22 6.a. Bioretention #1 Turf(Pervious). 0.36 6.a. Bioretention #1 6.a.Bioretention#1 or Urban Bioretention(Spec#9) Impervious: 2.93 Turf(Pervious): 1.43 Total Impervious Cover Treated(acres) 3 15 Total Turf Area Treated(acres) 1 79 Total TP Load Reduction Achieved in D.A.A(Ib/yr) 4.42 Total TN Load Reduction Achieved in D.A.A(Ib/yr) 54 60 Summary Print Virginia Runoff Reduction Method Worksheet Drainage Area B Summary Land Cover Summary A Soils B Soils C Soils D Soils Total %of Total Forest(acres) 0 00 0 00 0.00 0.00 0 00 0 00 Turf(acres) 0 00 2 43 0.00 0.00 2 43 50 10 Impervious(acres) 0 00 2 42 0.00 0.00 2 42 49.90 4 85 BMP Selections Practice Credit Area(acres) Downstream Practice 5.b.Dry Swale#2(Spec#10) Impervious: 0.04 6.b. Bioretention #2 Turf(Pervious): 0.05 6.b. Bioretention #2 6.b.Bioretention#2(Spec#9) Impervious: 2.38 None Turf(Pervious): 2.38 None Total Impervious Cover Treated(acres) 2 42 Total Turf Area Treated(acres) 2 43 Total TP Load Reduction Achieved in D.A.A(Ib/yr) 5.72 Total TN Load Reduction Achieved in D.A.A(Ib/yr) 45.39 Summary Print Virginia Runoff Reduction Method Worksheet Channel and Flood Protection Weighted CN 1-year 2-year storm 10-year storm Adjusted CN storm Adjusted Adjusted rN CN Target Rainfall Event(in) 0 00 0 00 0 00 D A.A CN 85 RN/A RN/A kN/A D A B CN 79 RN/A NN/A UN/A D A C CN 0 100 100 100 D A D CN 0 100 100 100 D A E CN 0 100 100 100 Summary Print Soils Mapping (Source: NRCS Web Soil Survey Online Database) Soil Map—Albemarle County,Virginia 3 (Avinity II Soil Survey) 719600 719650 719700 719750 719900 J j ;;Ns < Y ti om` ,. t e •'t•• 7 •' /7 'f T ��'� fey t � t� �' .,€.• • A. •r fit_ • 0 fr r. ..s. v av ," ,/y'. a jam. r , .g�' .-� •.tr � , A et if k „ �r ' R i,; tip. y,, '.al G,° • Nt. `,. % , •i P b. ` tea' l ." Y tI 0.': .' 'L •' yl'-t lb'). R x :1 rlr • 1.4,;1 i y ,!a,r-4-j•ei..4l,-r•-,''e:$''.',t 7,;'I :04.;_1 ''i. Pa,' 4 ',1 .. • • 7' •Y \ �`• ~-- _A t. \`t} .4; Ilk ri':. ' ' ' ' pi 114/1/101MOV IN rt 4f• 14` ;1 4. •r . t iiir 00, ..._1„,‘;,....w.t :41k.* ' iiir /1141141ft0-441 ° w F Np itil • .� ! —� T. ill t�. r ,t '1,. , .• ...,...,/ dy AP tte f i 00/11;Agamii j' #'r , _.• } .* ..�. 37°59'25"N ` 37°59'25 N 719500 719550 719600 719650 719700 719750 719800 3 3 rr R Map Scale:1:2,160 f printed on A portrait(8.5'x 11")sheet gl Meters N N 0 30 60 120 180 Feet A 0100rm200m 400600 Map projeaton:Web Mehor CnrnerorWnates:WGS84 Edgetia:UTM Zone 17N WGS84 [i'DA Natural Resources Web Soil Survey 1/30/2015 Conservation Service National Cooperative Soil Survey Page 1 of 3 Soil Map—Albemarle County,Virginia (Avinity II Soil Survey) MAP LEGEND MAP INFORMATION Area of Interest(A01) Spoil Area The soil surveys that comprise your AOI were mapped at 1:15,800. Area of Interest(AOI) Stony Spot Soils Warning Soil Map may not be valid at this scale. Very Stony Spot Enlargement of maps beyond the scale of mapping can cause Soil Map Unit Polygons 9 P Y PP 9 "" Wet Spot misunderstanding of the detail of mapping and accuracy of soil line Soil Map Unit Lines placement.The maps do not show the small areas of contrasting Other soils that could have been shown at a more detailed scale. Soil Map Unit Points - Special Line Features Special Point Features Please rely on the bar scale on each map sheet for map to.) Blowout Water Features measurements. Streams and Canals El Borrow Pit Source of Map: Natural Resources Conservation Service Transportation Web Soil Survey URL: http://websoilsurvey.nrcs.usda.gov Clay Spot r-t-► Rails Coordinate System: Web Mercator(EPSG 3857) Closed Depression oft,/ Interstate Highways Maps from the Web Soil Survey are based on the Web Mercator X Gravel Pit projection,which preserves direction and shape but distorts US Routes distance and area.A projection that preserves area,such as the Gravelly Spot Major Roads Albers equal-area conic projection,should be used if more accurate e Landfill Local Roads calculations of distance or area are required. Lava Flow Background This product is generated from the USDA-NRCS certified data as of the version date(s)listed below. Marsh or swamp BR Aerial Photography Soil Survey Area: Albemarle County,Virginia Mine or Quarry Survey Area Data: Version 10, Dec 11,2013 Miscellaneous Water Soil map units are labeled(as space allows)for map scales 1:50,000 Perennial Water or larger. Rock Outcrop Date(s)aerial images were photographed: May 10,2010—Jul 4, 2010 Saline Spot The orthophoto or other base map on which the soil lines were Sandy Spot compiled and digitized probably differs from the background = Severely Eroded Spot imagery displayed on these maps.As a result,some minor shifting of map unit boundaries may be evident. Sinkhole Slide or Slip ova? Sodic Spot USDA Natural Resources Web Soil Survey 1/30/2015 Conservation Service National Cooperative Soil Survey Page 2 of 3 Soil Map—Albemarle County,Virginia Avinity II Soil Survey Map Unit Legend Albemarle County,Virginia(VA003) Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 71 B Rabun clay loam,2 to 7 percent 4.0 34.5% slopes 72C3 Rabun clay,7 to 15 percent 6.7 58.1% slopes,severely eroded 72D3 Rabun clay, 15 to 25 percent 0.8 7.3% slopes,severely eroded Totals for Area of Interest 11.6 100.0% USDA Natural Resources Web Soil Survey 1/30/2015 Conservation Service National Cooperative Soil Survey Page 3 of 3 SCS TR-55 Calculations U.S.Department of Agriculture FL-ENG-21A Natural Resources Conservation Service 06/04 TR 55 Worksheet 2:Runoff Curve Number and Runoff Project Proposed Avinity II Designed By: KKW,PE Date 6/25/2015 Location: Located off Avon Street Extended,South of Avinity I Checked By KKW,PE Date: 6/25/2015 Check One: Present X Developed 1 Runoff curve Number(CN) Cover description Soil name and CN(weighted)= Drainage Area (Cover type,treatment,and hydrologic condition, Area Product of CN Calculated hydrologic group CN total product/ Description (Appendix A) percent impervious;unconnected/connected (Acres) x Area total area 'S'Value impervious area ratio) DA'A' Impervious Areas* 98 0.23 22.5 B Woods in Good Condition 55 0 55 30 3 62 6 13 (Present) Lawns in Good Condition 61 4.40 268.4 DA'B' Impervious Areas 98 0 00 0.0 B Woods in Good Condition 55 0.00 0.0 61 6.39 (Present) Lawns in Good Condition 61 3.48 212 3 DA'C' Impervious Areas 98 0 00 0 0 B Woods in Good Condition 55 0.00 0.0 61 6 39 (Present) Lawns in Good Condition 61 1.13 68 9 DA'A' Impervious Areas 98 3.15 308.7 (Developed) B Woods in Good Condition 55 0 00 0 0 85 1 82 Lawns in Good Condition 61 1 79 109.2 DA'B' Impervious Areas 98 2.42 237 2 B Woods in Good Condition 55 0 00 0 0 79 2 58 (Developed) Lawns in Good Condition 61 2 43 148 2 *The impervious areas for DA'A'(pre-development)conservatively assume the demolition of the residence for the pond construction has already occurred. 2.Runoff 1-Year Storm 2-Year Storm _ 10-Year Storm Drainage Area Description Frequency-years 1 2 10 n/a Rainfall,P(24 hour)-inches 3 5 3 7 5 6 n/a Runoff,Q-inches 0 62 0 71 1 82 DA'A'(Present) Runoff,Q-inches 0.57 0.67 1.74 DA'B'(Present) Runoff,Q-inches 0.57 0 67 1 74 DA'C' (Present) Runoff,Q-inches 1 98 2 16 3 88 DA'A'(Developed) Runoff,Q-inches 1.60 1.76 3.37 DA'B'(Developed) U.S.Department of Agriculture FL-ENG-21A Natural Resources Conservation Service 06/04 TR 55 Worksheet 3 Time of Concentration(T,)or Travel Time(T,) Project Proposed Avinity II Designed By KKW,PE Date 6/25/2015 Location Located off Avon Street Extended,South of Avinity I Checked By KKW,PE Date 6/25/2015 Check One Present X Developed X Check One T, X T, Through subarea n/a DA'A' — DA'B' DA'C' DA'A' DA'B' —I Segment ID (Present) (Present) (Present) (Developed) (Developed) Sheet Flow(Applicable to T,only) 1 Surface description(Table 3-1) Dense Grass Dense Grass Dense Grass Dense Grass Dense Grass 2 Manning's roughness coeff,n(Table 3-1 0 24 0 24 0 24 0 24 0 24 3 Flow length,L(total L c 100)(ft) 100 100 100 62 100 4 Two-year 24-hour rainfall,P2(in) 37 37 37 37 37 5 Land slope,s(ft/ft) 0 03 0 07 0 06 0 03 0 05 6 Compute T,=[0.007(n•L)ca)/PP s'^' 0 19 0 13 0 14 0 12 0 15 Shallow Concentrated Flow 7 Surface description(paved or unpaved) Unpaved Unpaved Unpaved Unpaved Unpaved 8 Flow Length,L(ft) 575 500 210 0 225 9 Watercourse slope,s(ft/ft) 0 08 013 0 09 0 00 0 04 10 Average velocity,V(Figure 3-1)(ft/s) 4 6 5 8 4 9 0 3 2 11 T,=L/3600•V 0.03 002 0.01 000 002 Channel Flow 12 Cross sectional flow area,a(ft') 3= I'' E 3 m m 3 N 13 Wetted perimeter,P„(ft) LL LL E 14 Hydraulic radius,r=a/P„(ft) c 9-Q c °. 15 Channel Slope,s(ft/ft) t a.w .c oa m 16 Manning's Roughness Coeff,n `o `o m T. 17V=[149r1's']/n $ `o n i 18 Flow length,L(ft) O' �^ O1 a 19 T,=L/3600•V I I I I 0 03 I 0.03 I 20 Watershed or subarea T,or T, (Add T,in steps 6,11 and 19) 0 22 0 15 0 15 0 15 0 21 U.S.Department of Agriculture FL-ENG-21C Natural Resources Conservation Service 06/04 TR 55 Worksheet 4.Graphical Peak Discharge Method Project Proposed Amity II Designed By: KKW,PE Date• 6/25/2015 Location Located off Avon Street Extended,South of Avinity I Checked By: KKW,PE Date. 6/25/2015 Check One: Present X Developed X Drainage Area Drainage Area Drainage Area Drainage Area Drainage Area Drainage Area 1.Data Description Description Drainage Area Description Description Description Description Description DA'A' DA'B' DA'C' DA'A' DA'B' (Present) (Present) (Present) (Developed) _ (Developed) Drainage Area(Am)in miles'= 0.0081 0.0054 0.0018 0.0077 0 0076 Runoff curve number CN= 62 0 61 0 61.0 84.6 _ 79.5 Time of concentration(Tc)= 0 22 0 15 0.15 0.15 0.21 Rainfall distribution type= ii II II II _ II Pond and swamp areas spread throughout the watershed= 0 0 0 0 0 2.Frequency-years 1 2 10 1 2 10 _ 1 2 10 1 2 10 1 2 10 3.Rainfall,P(24 hour)-inches 35 37 56 35 37 56 _ 3.5 3.7 5.6 _ 35 37 56 35 3.7 5.6 4.Initial Abstraction,la-inches 1 226 1 226 1 226 1.279 1.279 1.279 1.279 1 279 1 279 0 364 0 364 0.364 0.517 0.517 0.517 5 Compute la/P 0 35 0 33 0.22 0.37 0.35 0.23 0.37 0 35 0 23 0 10 0 10 0 07 0.15 0.14 0.09 6.Unit peak discharge,Qu-csm/in 610 650 725 710 750 850 _ 710 750 850 900 900 1000 750 760 800 7.Runoff,Q from Worksheet 2-inches 0 62 0 71 1 82 0 57 0 67 1.74 _ 0.57 0.67 1 74 _ 1 98 2 16 3 88 1 60 1.76 3.37 8.Pond and Swamp adjustment factor,Fp 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 9.Peak Discharge,Qp-cfs Routed through SWM Routed through SWM where Qp=Qu Am Q Fp 3 04 3 74 10 69 2.21 2.71 8.06 0.72 0.88 2 62 Facility Facility Note:Qu of 1000 csm/inch is the most conservative SCS TR-55 Qu Watershed Summary Pre-Development Post-Development DA 'A' 5.18 ac. 4.94 ac. DA 'B' 3.48 ac. 4.85 ac. DA 'C' 1.13 ac. - Total= 9.79 ac. 9.79 ac. Outflow Summary: (1-Year Storm Event) Pre-Development Post-Development DA 'A' 3.04 cfs 1.17 cfs DA 'B' 2.21 cfs 1.11 cfs DA'C' 0.72 cfs - Total= 5.97 cfs 2.28 cfs Outflow Summary: (2-Year Storm Event) Pre-Development Post-Development DA 'A' 3.74 cfs 3.18 cfs DA 'B' 2.71 cfs 1.52 cfs DA 'C' 0.88 cfs - Total= 7.34 cfs 4.70 cfs Outflow Summary: (10-Year Storm Event) Pre-Development Post-Development DA 'A' 10.69 cfs 20.38 cfs DA 'B' 8.06 cfs 6.35 cfs 2.62 cfs - DA 'C' Total= 21.36 cfs 26.73 cfs Bioretention & Swale Sizing Calculations BIORETENTION BASIN'A'(LEVEL I)DESIGN&REQUIREMENTS: Treatment Volume(Per VRRM Calculations) 11,551 cf Minimum Treatment Volume Required 11,551 cf Minimum Forebay Volume Required (15%of Tv) 1,733 cf Forebay Volume Provided 1,769 cf Minimum Surface Area Required(Tv/Storage Depth) 3,976 sf <-6'Mix at 25%porosity;3"pea gravel at 2%porosity, Surface Area Provided 3,981 sf 12"stone at 40%porosity&12"of ponding at 100% porosity STORMWATER MANAGEMENT FACILITY GRADING Area of Area of Filter Elevation Forebay Cell Volume Elevation Cell Contours Volume (ft) Contours(sf) (cf) (ft) (sf) (cf) 496 203 0 496 3,981 0 497 330 264 497 4,514 4,245 498 443 649 498 4,925 8,963 499 561 1,150 500 679 1,769 Area of Elevation Detention Cell Volume (ft) Contours(sf) (cf) 487 602 0 488 991 788 489 1,476 2,014 490 1,826 3,662 491 2,207 5,675 492 2,622 8,087 493 3,067 10,928 494 3,541 14,230 495 4,041 18,018 496 4,970 22,515 BIORETENTION BASIN'B'(LEVEL II)DESIGN&REQUIREMENTS: Treatment Volume(Per VRRM Calculations; 10,005 cf Minimum Treatment Volume Requirec 12,506 cf Minimum Forebay Volume Required(15%of Tv; 1,876 cf Forebay Volume Provided 1,935 cf Minimum Surface Area Required(Tv/Storage Depth 4,305 sf <-6'Mix at 25%porosity;3"pea gravel at 2%porosity, Surface Area Provided 4,320 sf 12"stone at 40%porosity&12"of ponding at 100% porosity STORMWATER MANAGEMENT FACILITY GRADING Area of Area of Filter Elevation Forebay Cell Volume Elevation Cell Contours Volume (ft) Contours(sf) (cf) (ft) (sf) (cf) 496 222 0 496 4,320 0 497 484 345 497 4,823 4,569 498 793 977 498 5,325 9,641 499 1,133 1,935 499 5,827 15,215 Area of Elevation Detention Cell Volume (ft) Contours(sf) (cf) 486 488 0 488 894 1,362 490 1,418 3,654 492 2,062 7,114 494 2,828 11,983 495 3,258 15,024 496 3,719 18,510 497 4,139 22,437 498 4,710 26,858 499 5,314 31,867 DRY TREATMENT#1 SWALE DESIGN&REQUIREMENTS: Treatment Volume(Per VRRM Calculations) 188 cf Minimum Treatment Volume Required 207 cf Minimum Surface Area Required(Tv/Storage Depth) 96 cf <-3'Mix at 25%porosity;3"pea gravel at 2%porosity, Surface Area Provided 436 cf 12"stone at 40%porosity&12"of ponding at 100% Minimum'Approximate'Surface Area 3%-10%of CDA porosity Surface Area Provided Relative to CDA 10.0% NOTE:Gutters shall outfall onto a concrete downspout splash block,where it shall flow to the dry swale via the rear yard's grassy lawn upland of the facility STORMWATER MANAGEMENT FACILITY GRADING Dry Swale Elevation Contours Volume (ft) (sf) (cf) 558 436 0 559 894 651 560 1,409 1,793 DRY TREATMENT SWALE#2 DESIGN&REQUIREMENTS Treatment Volume(Per VRRM Calculations; 1,020 cf Minimum Treatment Volume Requirec 1,122 cf Minimum Surface Area Required(Tv/Storage Depth 521 cf <-3'Mix at 25%porosity;3"pea gravel at 2%porosity, Surface Area Provided 746 cf 12"stone at 40%porosity&12"of ponding at 100% Minimum'Approximate'Surface Area 3%-10%of CDA porosity Surface Area Provided Relative to CDP 3.0% NOTE:Gutters shall outfall onto a concrete downspout splash block,where runoff shall then flow into the grass channel pretreatment upland of to the dry swale. STORMWATER MANAGEMENT FACILITY GRADING Dry Swale Elevation Contours Volume (ft) (sf) (cf) 520 746 0 521 1,172 951 522 1,662 2,361 Post-Development Routing Calculations Subarea A Routing Calculations BasinFlow printout INPUT: Basin: Subarea A Routing Calculations 10 Contour Areas Elevation(ft) Area(sf) Computed Vol . (cy) 487.00 602.00 0.0 488.00 991.00 29.2 489.00 1476.00 74.6 490.00 1826.00 135.6 491.00 2207.00 210.2 492.00 2622.00 299.5 493.00 3067.00 404.8 494.00 3541.00 527.0 495.00 4041.00 667.3 496.00 4970.00 833.9 Start_Elevation(ft) 487.00 vol . (cy) 0.00 5 Outlet Structures Outlet structure 0 Orifice name: Orifice area (sf) 0.022 diameter or depth (in) 2.000 width for rect. (in) 0.000 coefficient 0.500 invert (ft) 487.000 multiple 1 discharge into riser Outlet structure 1 Orifice name: Mid-flow orifice area (sf) 0.049 diameter or depth (in) 3.000 width for rect. (in) 0.000 coefficient 0. 500 invert (ft) 488.920 multiple 2 discharge into riser Outlet structure 2 Weir name: Riser diameter (in) 36.000 side angle 0.000 coefficient 3.300 invert (ft) 494. 580 multiple 1 discharge into riser transition at (ft) 0.912 orifice coef. 0.500 orifice area (sf) 7.069 Outlet structure 3 Culvert name: Barrel multiple 1 discharge out of riser D (in) 24.000 Page 1 Subarea A Routing Calculations h (in) 0.000 Length (ft) 84.000 Slope 0.005 Manning's n 0.013 Inlet coeff. Ke 0.500 Equation constant set 3 Invert (ft) 487.000 Outlet structure 4 weir name: Emergency spillway length (ft) 55.000 side angle 0.000 "r ('M coefficient 3,OQQ._-.__._ l invert (ft) 495 30 - multiple 1 , discharge through dam � 4 Inflow Hydrographs Hydrograph 0 SCS name: 1-yr 24-hr Peak SCS TR-55 Storm Event Area (acres) 4.940 CN 85.000 Type 2 rainfall , P (in) 3. 500 time of conc. (hrs) 0.1500 time increment (hrs) 0.0200 time limit (hrs) 30.000 fudge factor 1.00 routed true peak flow (cfs) 11.598 peak time (hrs) 11.930 volume (cy) 1338.149 Hydrograph 1 SCS name: 2-yr 24-hr Peak SCS TR-55 Storm Event Area (acres) 4.940 CN 85.000 Type 2 rainfall , P (in) 3.700 time of conc. (hrs) 0.1500 time increment (hrs) 0.0200 time limit (hrs) 30.000 fudge factor 1.00 routed true peak flow (cfs) 12.606 peak time (hrs) 11.930 volume (cy) 1454.407 Hydrograph 2 SCS name: 10-yr 24-hr Peak SCS TR-55 Storm Event Area (acres) 4.940 CN 85.000 Type 2 rainfall , P (in) 5.600 time of conc. (hrs) 0.1500 time increment (hrs) 0.0200 time limit (hrs) 30.000 fudge factor 1.00 routed true Page 2 Subarea A Routing Calculations peak flow (cfs) 22. 585 peak time (hrs) 11.930 volume (cy) 2605.797 Hydrograph 3 SCS name: 100-yr 24-hr Peak SCS TR-55 Storm Event Area (acres) 4.940 CN 85.000 Type 2 rainfall , P (in) 9.100 time of conc. (hrs) 0.1500 time increment (hrs) 0.0200 time limit (hrs) 30.000 fudge factor 1.00 routed true peak flow (cfs) 41.867 peak time (hrs) 11.930 volume (cy) 4830.413 OUTPUT: Routing Method: storage-indication Hydrograph 0 Routing Summary of Peaks: 1-yr 24-hr Peak SCS TR-55 Storm Event inflow (cfs) 11. 588 at 11.94 (hrs) discharge (cfs) 1.165 at 12.28 (hrs) water level (ft) 494. 571 at 12.34 (hrs) storage (cy) 604.875 Hydrograph 1 Routing Summary of Peaks: 2-yr 24-hr Peak SCS TR-55 Storm Event inflow (cfs) 12. 594 at 11.94 (hrs) discharge (cfs) 3.183 at 12.16 (hrs) water level (ft) 494.741 at 12.16 (hrs) storage (cy) 629.139 Hydrograph 2 Routing Summary of Peaks: 10-yr 24-hr Peak SCS TR-55 Storm Event inflow (cfs) 22. 564 at 11.94 (hrs) discharge (cfs) 20.382 at 11.98 (hrs) water level (ft) 495.304 at 11.98 (hrs) storage (cy) 714.293 Hydrograph 3 Routing Summary of Peaks: 100-yr 24-hr Peak SCS TR-55 Storm Event inflow (cfs) 41.828 at 11.94 (hrs) discharge (cfs) 41.388 at 11.96 (hrs) water level (ft) 495. 512 at 11.96 (hrs) storage (cy) 748.246 Tue Oct 13 17:23: 53 EDT 2015 Page 3 Subarea B Routing Calculations-Bioretention Cell BasinFlow printout INPUT: Basin: Subarea B Routing Calculations - Bioretention Cell 4 Contour Areas Elevation(ft) Area(sf) Computed vol . (cy) 496.00 4320.00 0.0 497.00 4823.00 169.2 498.00 5325.00 357.1 499.00 5827.00 563. 5 Start_Elevation(ft) 496.00 vol . (cy) 0.00 1 outlet Structures Outlet structure 0 weir name: Bioretention Cell Spillway length (ft) 55.000 side angle 26.770 coefficient 3.000 invert (ft) 497.000 multiple 1 discharge through dam 5 Inflow Hydrographs Hydrograph 0 SCS name: 1-yr 24-hr Peak SCS TR-55 Storm Event Area (acres) 4.850 CN 79.000 Type 2 rainfall , P (in) 3. 500 time of conc. (hrs) 0.2100 time increment (hrs) 0.0200 time limit (hrs) 30.000 fudge factor 1.00 routed true peak flow (cfs) 8.142 peak time (hrs) 11.982 volume (cy) 1020.145 Hydrograph 1 SCS name: 2-yr 24-hr Peak SCS TR-55 Storm Event Area (acres) 4.850 CN 79.000 Type 2 rainfall , P (in) 3.700 time of conc. (hrs) 0.2100 time increment (hrs) 0.0200 time limit (hrs) 30.000 fudge factor 1.00 routed true peak flow (cfs) 8.957 peak time (hrs) 11.982 volume (cy) 1122.347 Hydrograph 2 SCS name: 10-yr 24-hr Peak SCS TR-55 Storm Event Area (acres) 4.850 Page 1 Subarea B Routing Calculations-Bioretention Cell CN 79.000 Type 2 rainfall , P (in) 5.600 time of conc. (hrs) 0.2100 time increment (hrs) 0.0200 time limit (hrs) 30.000 fudge factor 1.00 routed true peak flow (cfs) 17.285 peak time (hrs) 11.982 volume (cy) 2165.824 Hydrograph 3 scs name: 25-yr 24-hr Peak SCS TR-55 Storm Event Area (acres) 4.850 CN 79.000 Type 2 rainfall , P (in) 7.000 time of conc. (hrs) 0.2100 time increment (hrs) 0.0200 time limit (hrs) 30.000 fudge factor 1.00 routed true peak flow (cfs) 23.835 peak time (hrs) 11.982 volume (cy) 2986.459 Hydrograph 4 SCS name: 100-yr 24-hr Peak SCS TR-55 Storm Event Area (acres) 4.850 CN 79.000 Type 2 rainfall , P (in) 9.100 time of conc. (hrs) 0.2100 time increment (hrs) 0.0200 time limit (hrs) 30.000 fudge factor 1.00 routed true peak flow (cfs) 34.000 peak time (hrs) 11.982 volume (cy) 4260.150 OUTPUT: Routing Method: storage-indication Hydrograph 0 Routing Summary of Peaks: 1-yr 24-hr Peak SCS TR-55 Storm Event inflow (cfs) 8.136 at 11.98 (hrs) discharge (cfs) 7.688 at 12.00 (hrs) water level (ft) 497.129 at 12.00 (hrs) storage (cy) 192.497 Hydrograph 1 Routing Summary of Peaks: 2-yr 24-hr Peak SCS TR-55 Storm Event inflow (cfs) 8.951 at 11.98 (hrs) discharge (cfs) 8.631 at 12.00 (hrs) water level (ft) 497.140 at 12.00 (hrs) storage (cy) 194.374 Hydrograph 2 Page 2 subarea B Routing Calculations-Bioretention Cell Routing Summary of Peaks: 10-yr 24-hr Peak SCS TR-55 Storm Event inflow (cfs) 17.273 at 11.98 (hrs) discharge (cfs) 16.819 at 11.98 (hrs) water level (ft) 497.218 at 11.98 (hrs) storage (cy) 208. 599 Hydrograph 3 Routing Summary of Peaks: 25-yr 24-hr Peak SCS TR-55 Storm Event inflow (cfs) 23.817 at 11.98 (hrs) discharge (cfs) 23.449 at 11.98 (hrs) water level (ft) 497.272 at 11.98 (hrs) storage (cy) 218.485 Hydrograph 4 Routing Summary of Peaks: 100-yr 24-hr Peak SCS TR-55 Storm Event inflow (cfs) 33.975 at 11.98 (hrs) discharge (cfs) 33.663 at 11.98 (hrs) water level (ft) 497.346 at 11.98 (hrs) storage (cy) 232.123 Fri Oct 16 14:51: 53 EDT 2015 Page 3 Subarea B Routing Calculations-Detention Cell BasinFlow printout INPUT: Basin: Subarea B Routing Calculations 10 Contour Areas Elevation(ft) Area(sf) Computed vol . (cy) 486.00 488.00 0.0 488.00 894.00 50.4 490.00 1418.00 135.3 492.00 2062.00 263.5 494.00 2828.00 443.8 495.00 3258.00 556.4 496.00 3719.00 685.6 497.00 4139.00 831.0 498.00 4710.00 994.8 499.00 5314.00 1180.3 Start_Elevation(ft) 486.00 Vol . (cy) 0.00 5 outlet Structures Outlet structure 0 Orifice name: Orifice area (sf) 0.110 ✓ diameter or depth (in) 4.500 width for rect. (in) 0.000 coefficient 0. 500 invert (ft) 486.000 multiple 1 discharge into riser Outlet structure 1 Orifice name: Mid-flow orifice area (sf) 0.196 diameter or depth (in) 6.000 width for rect. (in) 0.000 coefficient 0.500 invert (ft) 492.670 multiple 4 discharge into riser Outlet structure 2 weir name: Riser diameter (in) 30.000 side angle 0.000 coefficient 3.300 invert (ft) 496.670 ✓" multiple 1 discharge into riser transition at (ft) 0.760 orifice coef. 0. 500 orifice area (sf) 4.909 Outlet structure 3 Culvert name: Barrel multiple 1 discharge out of riser D (in) 15.000 ✓/ Page 1 Subarea B Routing Calcu ations-Detention Cell h (in) 0.000 Length (ft) 80.000 Slope 0.005 Manning's n 0.013 Inlet coeff. Ke 0.500 Equation constant set 3 Invert (ft) 486.000 Outlet structure 4 weir name: Emergency Spillway/ length (ft) 45.000 side angle 63.430 coefficient 3.000 invert (ft) 497.750 multiple 1 discharge through dam 5 Inflow Hydrographs Hydrograph 0 Curve name: ROUTED OUTFLOW 1-yr 24-hr Peak SCS TR-55 Storm Event time incr (minIhrs) 0.02 time limit (minIhrs) 30.00 file: 1 YEAR-0.02 hr intervals.txt volume (cy) 500.93 routed true time in hours true Hydrograph 1 Curve name: ROUTED OUTFLOW 2-yr 24-hr Peak SCS TR-55 Storm Event time incr (minIhrs) 0.02 time limit (minIhrs) 30.00 file: 2 YEAR-0.02 hr intervals.txt volume (cy) 572.95 routed true time in hours true Hydrograph 2 Curve name: ROUTED OUTFLOW 10-yr 24-hr Peak SCS TR-55 Storm Event time incr (minIhrs) 0.02 time limit (minIhrs) 30.00 file: 10 YEAR-0.02 hr intervals.txt volume (cy) 1339.02 routed true time in hours true Hydrograph 3 Curve name: ROUTED OUTFLOW 25-yr 24-hr Peak SCS TR-55 Storm Event time incr (minlhrs) 0.02 time limit (minIhrs) 30.00 file: 25 YEAR-0.02 hr intervals.txt volume (cy) 1982.64 routed true time in hours true Hydrograph 4 SCS name: 100-yr 24-hr Peak SCS TR-55 Storm Event Area (acres) 4.850 Page 2 Subarea B Routing Calculations-Detention Cell CN 79.000 Type 2 rainfall , P (in) 9.100 time of conc. (hrs) 0.2100 time increment (hrs) 0.0200 time limit (hrs) 30.000 fudge factor 1.00 routed true peak flow (cfs) 34.000 peak time (hrs) 11.982 volume (cy) 4260.150 OUTPUT: Routing Method: storage-indication Hydrograph 0 Routing Summary of Peaks: ROUTED OUTFLOW 1-yr 24-hr Peak SCS TR-55 Storm Event inflow (cfs) 7.688 at 12.00 (hrs) discharge (cfs) 1.107 at 12.28 (hrs) water level (ft) 492.433 at 12.32 (hrs) storage (cy) 297.806 Hydrograph 1 Routing Summary of Peaks: ROUTED OUTFLOW 2-yr 24-hr Peak SCS TR-55 Storm Event inflow (cfs) 8.631 at 12.00 (hrs) discharge (cfs) 1.515 at 12.26 (hrs) water level (ft) 492.834 at 12.26 (hrs) storage (cy) 331.789 Hydrograph 2 Routing Summary of Peaks: ROUTED OUTFLOW 10-yr 24-hr Peak SCS TR-55 Storm Event inflow (cfs) 16.819 at 11.98 (hrs) discharge (cfs) 6.350 at 12.18 (hrs) water level (ft) 495.442 at 12.18 (hrs) storage (cy) 611.387 Hydrograph 3 Routing Summary of Peaks: ROUTED OUTFLOW 25-yr 24-hr Peak SCS TR-55 Storm Event inflow (cfs) 23.449 at 11.98 (hrs) discharge (cfs) 12.017 at 12.14 (hrs) water level (ft) 496.968 at 12.14 (hrs) storage (cy) 826.158 Hydrograph 4 Routing Summary of Peaks: 100-yr 24-hr Peak SCS TR-55 Storm Event inflow (cfs) 33.975 at 11.98 (hrs) discharge (cfs) 28.923 at 12.04 (hrs) water level (ft) 497.920 at 12.04 (hrs) storage (cy) 980.935 Fri Oct 16 15:01:22 EDT 2015 Page 3 KKw, Pe • 10122_115- aVR-c03 - O — Lae ehannyl erbkaibo Comp 1. anC2 fby CSC -hr -u{rn E otry+ 60.-1 c ice) ecr Se�t��n 'C)3 , Q oev ShckR be : otv c Q tokze C D6v c IF x ( Qe2E )6ITVeRE ' / RvAOST- where. 1 F O. 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