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HomeMy WebLinkAboutWPO202000011 Calculations WPO VSMP 2020-02-20 TRUMP WINERY VSMP STORMWATER MANAGEMENT CALCULATIONS PACKET Date of Calculations FEBRUARY 20, 2020 PREPARED BY: (M, COLLINS ENGdOgE2RING 200 GARRETT STREET,SUITE K CHARLOTTESVILLE,VA 22902 434.293.3719 PH 434.293.2813 FX www.collins-engineering.com SCS TR-55 Calculations Soils Mapping (Source: NRCS Web Soil Survey Online Database) - N 2.. ,, \ ,. .: ...4.:,:,/,,, , \\ �%ti r `�, r 1 ...k ' :4\ . ;0.- 1 ! . .,, ....-tv; 1110:;.- „,,,,,• '44„, , t r‘i, ,,s, ,..., ,N , , , /,, ‘.. 411,, ,i...:,,,, I., 4, st Soils Table (Source: NRCS Web Soil Survey Online Database) Albemarle County, Virginia (VA003) Map Unit Percent of S rnbol Map Unit Name AOI Y 23B Yadkin clay 98.2% loam, 2 to 7 percent slopes 72D3 Rabun clay, 15 1.8% to 25 percent slopes, severely eroded Totals for Area of 100.0% Interest Note: The soils' properties witin this development are predominantly composed of hydrologic group type B soils. Precipitation Data (Source: NOAA's National Weather Service, Hydrometerorological Design Studies Center, Atlas 14 Point Precipitation Frequency Estimates) F I ;,rr+ r II' _ 1, lu rf' Map •�v. 7 j :. it:. U:Terrain ,. t ra r l i ;'+ ( t� µiw s ?, ,t' ,.�,NtRf.rVr1{I1tDr".-----,,,..._- _ .,t ',., £ l "✓ 4-y J � „ ' 'r; ' ''... Et r i� _ ' I.+ ' , - , • al. ri ..'� r - ;li - - J ids xis?. rfri �.' ''�tt , k,/ '`'� - !' .: ..., ,.,i:.yam__- .dOp``` .Y as r 4 � J f i 'a c'i POINT PRECIPITATION FREQUENCY(PF):ESTIMATES WITH 90%CONFIDENCE INTERVALS AND SUPPLEMENTARYINFORMATION"' NOAA Atlas 14,Volume 2,Version 3<`' PDS-based precipitation frequency estimates with 90%confidence Intervals(in inches)1 L_____,_ Average recurrence Interval(years) Duration I 1 �� 2--� II 5 II 10 II 25 II 50 II 100 II 200 II 500 II 1000 I 24-hr 2.99 3.62 4.62 5.47 6.73 T.80 8.99 10.3 12.3 14.0 (2.68-3.36) (3.25-4.07) (4.14 5.20) (4.88-6-13) (5-96 7.52) (6.87-8.70) (7.85-10.0) (8.90-11.5) (10.4-13.6) (11.7-15.5) U.S.Department of Agriculture FL-ENG-21A Natural Resources Conservation Service 06/04 TR 55 Worksheet 2:Runoff Curve Number and Runoff Project: Trump Winery Designed By: FGM,PE Date: 2/20/2020 Location: Winery Lane Checked By: SRC,PE y Date: 2/20/2020 • Check One: Present X Developed X �� 1,''ff 1.Runoff curve Number(CN) / I Cover description CN(weighted)= Drainage Area Soil name and hydrologic Area P oduct of CN x Calculated'S' Description group(Appendix A) (Cover type,treatment,and hydrologic condition;percent CN (Acres) Area total product/ Value impervious;unconnected/connected impervious area ratio) total area DA A Impervious Areas 98 0.11 / 11.0 (Pre-Dev.) B Lawns in Good Condition 61 1.15 70.3 68 ,4.71 Gravel in Good Condition 85 0.28 23.4 DA A Impervious Areas 98 0.34 33.4 (Post-Dev.) B Lawns in Good Condition 61 0.641 39.3 78 /2.85/ Gravel in Good Condition 85 0.56 _ 47.2 �� DA B Impervious Areas 98 0.18 18.0 B Lawns in Good Condition 61 0.04 U:1',5 2.4 91 0.96 (Not Modified) Gravel in Good Condition 85 0.01 0.6 2.Runoff 1-Year Storm 2-Year Storm 10-Year Storm Drainage Area Description Frequency-years - 1 2 10 rn/a Rainfall,P(24 hour)-inches 2.99 3.62 5.47 n/a Runoff,Q-inches 0.62 0.97 2.22 DA A(Pre-Dev.) Runoff,Q-inches 1.11 1.58 3.10 DA A(Post-Dev.) Runoff,Q-inches 2.09 2.68 4.47 DA B(Not Modified) U.S. Department of Agriculture FL-EN Natural Resources Conservation Service TR 55 Worksheet 3:Time of Concentration(Tc)or Travel Time(Ti) Project: Trump Winery Designed By: FGM, PE Date: 2/20/2020 Location: Winery Lane Checked By: SRC, PE Date: 2/20/2020 Check One: Present X Developed X Check One: Tc X Tt Through subarea n/a DAA DAA DA B Segment ID: (Pre-Dev.) (Post-Dev.) (Not Modified) Sheet Flow: (Applicable to Tc only) Dense Dense Dense 1 Surface description (Table 3-1) Grass Grass Grass 2 Manning's roughness coeff.,n (Table 3-1 0.24 0.24 0.24 3 Flow length, L(total L<100) (ft) 100 100 100 4 Two-year 24-hour rainfall, P2(in.) 3.62 3.62 3.62 5 Land slope,s(ft/ft) _ 0.07 0.07 0.10 6 Compute Tt=[0.007(n*L)o.8]/P2°3 s0.4 0.14 0.14 0.12 Shallow Concentrated Flow: 7 Surface description(paved or unpaved) Unpaved Unpaved Unpaved 8 Flow Length, L(ft) 375 350 45 9 Watercourse slope,s(ft/ft) 0.08 0.07 0.11 10 Average velocity,V(Figure 3-1) (ft/s) 4.6 4.3 5.4 11 Tt=L/3600*V 0.02 0.02 0.00 Channel Flow: ,----� 12 Cross sectional flow area,a(ft2) ,r'c\ti, '/ c •� — 3 1 / o \\ LL °0 13 Wetted perimeter, Pv,(ft) LL - m °; 14 Hydraulic radius, r=a/P,,,(ft) c u ° c b (L)c .,., CO c 2_ 15 Channel Slope,s(ft/ft) al , c6 v 0_ / 16 Manning's Roughness Coeff, n U ; 1 o y 17V= [1.49r2/3s°°5]/n o \ \ Q ED 18 Flow length, L(ft) 00 \r\� 19 Tt=L/3600*V \ 0;00 \�0.00 20 Watershed or subarea Tc or Tt (Add Tt in steps 6, 11 and 19) 0.16 0.16 0.12 U.S. Department of Agriculture Natural Resources Conservation Service TR 55 Worksheet 4:Graphical Peak Discharge Method Project: Trump Winery Designed By: FGM, PE Date: 2/20/2020 Location: Winery Lane Checked By: SRC, PE Date: 2/20/2020 Check One: Present X Developed X 1. Data Drainage Area Description Drainage Area Description Drainage Area Description DAA DAA DA B (Pre-Dev.) (Post-Dev.) (Not Modified) Drainage Area (Am)in miles2= 0.0024 0.0024 0.0004 � Runoff curve number CN= � -�(68) ( 787 91 Time of concentration(Tc)= / 0.16 0.16 0.12 Rainfall distribution type= / II II II 0 Pond and swamp areas spread f 0 0 0 throughout the watershed= ti y 1 "� 2. Frequency-years \ 1 2 10 1 2 10 1 2 10 3. Rainfall, P(24 hour)-inches 2.99 3.62 5.47 2.99 3.62 5.47 2.99 3.62 5.47 ,---1 4. Initial Abstraction, la-inches 0.94 0.94 0.94 0.57 0.57 0.57 0.19 0.19 0.19 5.Compute la/P \ 0.32 0.26 0.17 0.19 0.16 0.10 0.06 0.05 0.04 r" a 6. Unit peak discharge,Qu-csm/in 750 800 850 825 850 875 950 950 950 /i 7.Runoff,Q from Worksheet 2-inches 0.62 0.97 2.22 Z-1.11� 1.58 3.10 2.09 2.68 4.47 8. Pond and Swamp adjustment factor,Fp 1 1 1 1 1 1 1 1 1 x 9.Peak Discharge,Qp-cfs Routed Through The where Qp=Qu Am Q Fp 1.12 1.87 4.54 Detention Basin 0.71 0.92 1.53 .- c, WATERSHED SUMMARY _ it Area, 1-year Flow, 2-year Flow, 10-year Flow, CN ( ,--... ac. cfs cfs cfs DAA(Pre-Dev.) 68 1.54 1.12 1.87 4.54 t�v DAA(Post-Dev.) 78 1.54 0.48 0.55 2.70 C) Channel and Flood Protection Calculations 9 VAC 25-870-66 (Subarea A) Section B:Channel Protection "Concentrated stormwater flow shall be released into a stormwater conveyance system and shall meet the criteria in subdivision 1, 2 or 3 of this subsection..." Section B.1: Manmade stormwater conveyance systems "When stormwater from a development is discharged to a manmade stormwater conveyance system, following the land-disturbing activity, either..." a. or b.shall be met: Section B.1.b. "The peak discharge requirements for concentrated stormwater flow to natural stormwater conveyance systems in subdivision 3 of this subsection shall be met." Section B.3 "...the maximum peak flow rate from the one-year 24-hour storm following the land-disturbing activity shall be calculated either.." a. or b." Section B.3.a. In accordance with the following methodology: Q Allowed<1.F. * (Q Pre-Developed * [RV Pre-Developed))/(RV Developed) Q Allowed < 0.50 cfs Where: Q Pre-Developed= 11.12 cfs (From Worksheet 4 Watershed Summary) CN Pre-Developed= J 68 (From Worksheet 4 Watershed Summary) S Pre-Developed= \4.71 (From SCS TR-55 eq. 2-4) RV Pre-Developed= 'i 0.62 in. (From SCS TR-55 eq. 2-3) CN Post-Developed= J 78 (From Worksheet 4 Watershed Summary) I S Post-Developed= �J2.85 (From SCS TR-55 eq. 2-4) RV Post-Developed= 1.11 in. (From SCS TR-55 eq. 2-3) I.F. = J 0.80 (Factor of Safety) Q Developed = 0.48 cfs Section B.4 Limits of Analysis The analysis terminates at Subarea A since subsection B.3.a is met. 9 VAC 25-870-66 (Subarea A) Section C: Flood Protection "Concentrated stormwater flow shall be released into a stormwater conveyance system and shall meet one of the following criteria as demonstrated by use of acceptable hydrologic and hydraulic methodologies:" Section C.2.b.: The point of discharge, "releases a postdevelopment peak flow rate for the 10-year 24-hour storm event that is less than the predevelopment peak flow rate from the 10-year 24-hour storm event. Downstream stormwater conveyance systems do not require any additional analysis to show compliance with flood protection criteria if this option is utilized." 10-Year, 24-Hour Pre-Development Subarea A Peak Flow Rate= 4.54 cfs 10-Year, 24-Hour Post-Development Subarea A Peak Flow Rate= 2.70 cfs Section C.3 Limits of Analysis The flood protection analysis terminates at Subarea A since subsection C.2.b is met. Proposed Detention Basin Routings SWM Facility A Routings BasinFlow printout INPUT: Basin: SWM Facility A Routings 5 Contour Areas Elevation(ft) Area(sf) Computed Vol. (cy) 678.75 5.00 0.0 679.00 570.00 1.9 680.00 1075.00 31.9 682.00 2316.00 154.6 684.00 3803.00 379.0 Start_Elevation(ft) 678.75 Vol. (cy) 0.00 4 Outlet Structures Outlet structure 0 Orifice name: Barrel area (sf) 0.349 diameter or depth (in) 8.000 width for rect. (in) coefficient 0.500 invert (ft) 678.250 multiple 1 discharge out of riser Outlet structure 1 Orifice name: Low-Flow Orifce area (sf) 0.087 diameter or depth (in) 4.000 width for rect. (in) 0.000 coefficient 0.500 invert (ft) multiple 1 discharge into riser Page 1 SWM Facility A Routings Outlet structure 2 Weir name: Riser Top diameter (in) 24.000 side angle 0.000 coefficient 3.300 invert (ft) 68QL multiple 1 discharge into riser transition at (ft) 0.608 orifice coef. 0.500 orifice area (sf) 3.142 Outlet structure 3 Weir name: Emergency Spillway length (ft) 25.000 side angle 0.000 coefficient 3.300 invert (ft) 682.750 multiple 1 discharge through dam 4 Inflow Hydrographs Hydrograph 0 SCS name: 1-yr 24-hr SCS Design Storm Area (acres) 1.540 , CN 78.000 Type 2 rainfall, P (in) 2.990 time of conc. (hrs) 0.1600 time increment (hrs) . 0.0200 time limit (hrs) 30.000 fudge factor 1.00 routed true peak flow (cfs) 1.984 - peak time (hrs) 11.938 volume (cy) 232.019 Page 2 SWM Facility A Routings Hydrograph 1 SCS name: 2-yr 24-hr SCS Design Storm Area (acres) 1.540 CN 78.000 Type 2 rainfall, P (in) 3.620 time of conc. (hrs) 0.1600 time increment (hrs) 0.0200 time limit (hrs) 30.000 fudge factor 1.00 routed true peak flow (cfs) 2.811 peak time (hrs) 11.938 volume (cy) 328.710 Hydrograph 2 SCS name: 10-yr 24-hr SCS Design Storm Area (acres) 1.540 CN 78.000 Type 2 rainfall, P (in) 5.470 time of conc. (hrs) 0.1600 time increment (hrs) 0.0200 time limit (hrs) 30.000 fudge factor 1.00 routed true peak flow (cfs) 5.511 peak time (hrs) 11.938 volume (cy) 644.310 Hydrograph 3 SCS name: 100-yr 24-hr SCS Design Storm Area (acres) 1.540 CN 78.000 Type 2 rainfall, P (in) 8.990 time of conc. (hrs) 0.1600 time increment (hrs) 0.0200 time limit (hrs) 30.000 fudge factor 1.00 routed true peak flow (cfs) 11.168 peak time (hrs) 11.938 volume (cy) 1305.742 Page 3 SWM Facility A Routings OUTPUT: Routing Method: storage-indication 1 Hydrograph 0 Routing Summary of Peaks: 1-yr 2k-hr SCS Design Storm inflow (cfs) g1_.984/at 11.94 (hrs) discharge (cfs) _ �E 0 t 12.18 (hrs) water level (ft) �680. at 12.18 (hrs) storage (cy) 69.782 Hydrograph 1 Routing Summary of Peaks: 2-yr _24 hr SCS Design Storm inflow (cfs) c 81O�,at 11.94 (hrs) discharge (cfs) 0:550-at 12.20 (hrs) water level (ft) 681.385 at 12.22 (hrs) storage (cy) 106.853 Hydrograph 2 ' Routing Summary of Peaks: 10-yn, 4-hr SCS Design Storm inflow (cfs) 508 at 11.94 (hrs) discharge (cfs) �2 69t 12.10 (hrs) water level (ft) 682.2D9 at 12.10 (hrs) storage (cy) 181.313 Hydrograph 3 Routing Summary of Peaks: 100..-_y 24-hr SCS Design Storm inflow (cfs) 41.163)at 11.94 (hrs) discharge (cfs) 10:189 at 11.98 (hrs) water level (ft) 682.960 at 11.98 (hrs) storage (cy) 248.611 Thu Feb 20 13:23:41 EST 2020 \ O‘ nn _ gzE Page 4 Detention Basin Outlet Protection Calculations t A t. 1-111"rt r% . 1-1)::' 61 "D l e 1 . ktsi, 1-• .Z),;) i.,s_t --I- ,A. tr,c,IIIN il \Isla:'-'s i <--. •-x-e, 1,Atir\t,y‘, Lcv,-.•.I S \` I,ZdRiT.. 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SdvD N .a.\/N r-s!):4,7,.5-f0 v'-3a0 c;-D^ s'o� -- d rc.L 5a9-dVI-Ps'1(s r•13-AN_ -o Cr37 } a�c� ll' 9rt 1 (c'1) nw3 a ac `+3' 7 ,b r 8\ N is ` -.4tO k,e116 Virginia Runoff Reduction Method Water Quality Calculations Water Quality Notes: 1. Compliance is met through the best management practice of releasing runoff in a sheet flow manner to a conservation area with A/B soils. 2. The boundary for the ESC limits of disturbance is used to define the boundary for the VRRM water quality calculations in the 'Site'tab of the spreadsheet.This is standard practice in Albemarle County. 3. The area (post-development subarea A) being treated via the sheet flow to a conserved area with A/B soils //-e4(,4) is greater than the VRRM water quality boundary described above in#2.Applying the full subarea to the FDA A'VRRM spreadsheet tab would yield inaccurate results since the drainage area would exceed the g24, aCsite's land cover area.This would falsely show a higher phosphorous removal rate credit.This is because it would incorrectly show the treatment of the upland, undisturbed area.As a result,this upland, �Hac undisturbed area was omitted from the 'DA A'water quality analysis tab.This design approach is Q appropriate since the development is required to treat the areas of proposed improvements/ disturbances.This design approach is also conservative because in actuality the phosphorous removed from the sheet flow to conserved areas with A/B soils is greater than what is depicted in the calculations. L.OD = ('37 p,c The applicant wanted to bring this information to the reviewer's attention for his/her benefit. DEQ Virginia Runoff Reduction Method Re-Development Compliance Spreadsheet-Version 3.0 D 2011 BMP Standards and Specifications 13 2013 Draft BMP Standards and Specifications Project Name: Trump Winery data input cells Date: 2/20/2020 constantvalues Linear Development Project?I No I . calculation cells Site Information final results Post-Development Project(Treatment Volume and Loads) Enter Total Disturbed Area(acres) 41 1.37 I Check: BMP Design Specifications List: 2013 Draft Stds&Specs Maximum seduction required: 20% Linear project? No The site's net increase in impervious cover(acres)is: 0.51 Land cover areas entered correctly? Post-Development TP Load Reduction for Site(Ib/yr): 0.99 Total disturbed area entered? Pre-ReDevelopment Land Cover (acres) ASoils BSoils CSoils DSoils Totals Forest/Open Space(acres)—undisturbed, protected forest/open space or reforested land 0.00 Managed Turf(acres)—disturbed,graded for 1.33 yards or other turf to be mowed/managed - 1.33 Impervious Cover(acres) 0.04 0.04 1.37 . Post-Development Land Cover (acres) -- -_-- - --_ ASoils BSolls CSoils DSoils Totals Forest/Open Space(acres)—undisturbed, protected forest/open space or reforested land 0.00 Managed Turf(acres)—disturbed,graded for yards or other turf to be mowed/managed 0.82 0.82 —Impervious Cover(acres) 0.55 0.55 Area Check OK. OK. OK. OK. 1.37 Constants Runoff Coefficients(Rv) Annual Rainfall(inches) "43 -- -- - - A Soils B Soils C Soils D Soils Target Rainfall Event(inches) -• --1.00 Forest/Open Space - 0.02 - -0.03.>., -0.04 - _ 0.05 Total Phosphorus(TP)EMC(mg/L) 0.26'.- Managed Turf - 0.15 - - 0.20.- 0.22 • 0.25 Total Nitrogen(TN)EMC(mg/L) -'1.86 Impervious Cover - 0.95 ' , '0.95.- 0.95 ... .-_'0.95 Target TP Load(Ib/acre/yr) - Pj(unitiess correction factor) LAND COVER SUMMARY-- PRE-REDEVELOPMENT 11.1M1 LAND COVER SUMMARY--POST DEVELOPMENT Land Cover Summary-Pre Land Coversummane-Post(Final) Land Cover Summary-Post Land Cover Summary-Post _ Pre-ReDevelopment I Listed Adjusted' Post ReDev.8 New Impervious Port-ReDevelopment Past-Development New Impervious Forest/Open Space Cover Forest/Open Space %,a'-)`>:y_:x ,'%; `''t ',' Forest/Open Space Cover(acres) 0.00 0.00 0.00 0.00 ;`{,T,rry, ;-- -n a'�z'.'s',' (acres) Cover(acres) _... .__.__.. 's'`S`-`'''�fs'r';y'i«°•:v?,.'•,'.✓,hi Weighted Rv(forest) 0.00 ' 0.00 Weighted Rv(forest) 0.00 Weighted Rvlforest) 0.00 ',''`'':'i +• vg^;: r`;',>s.;;'> %Forest 0% 0% %Forest 0% %Forest 0% '''`'.�`<'t'x';+%",i,'i'`t'r.'i.'';v' - rz"x x>r>y. Managed Turf Cover(acres) 1.33 0.82 Managed Turf Cover 082 Managed Turf Cover 082 y7,y.�-,'r,z�s"y,>-„A�,.,�,11 ;�y' , - ".. (acres) (acres) s. :;<:5'0''':;'`-'i,''ga;'„`.�.'>,ry.,c Weighted Rvltur0 0.20 0.20 Weighted Rv to 0.20 Weighted Rv to 0.20 2" h r�'s,,F>,''if '` `•,'., }..k,:".'K,:,4 - __.P 0 Jc`/,'�,F`<"•' %Managed Turf 97% 95% %Managed Turf 60% %Managed Turf 95% r c' ��'•5'''':-y �' ReDev.Impervious New Impervious Cover Impervious Cover(acres) 0.04 0.04 Impervious Cover(acres) 0.55 0.51 Cover(aces) 0.04 (acre) Rv(impervious) 0.95 0.95 Rv)lmpervious) 0.95 Rv(impervious) 0.95 Rv(impervious) I 0.95 %Impervious 3% 5% %Impervious 40% %Impervious 5% Total ReDev.Ske Area > "i i. TatalSke Area aces 3.37 0.86 anal Site Area aces 1.37 0.86 ` aces• � ':. -?; ^,',, Site Rv 0.22 0.23 Final Post Dev Site Rv 0.50 ReDev Site M l----0.23 )Y ..r; . ./2,,}:,' Treatment Volume and Nutrient Load , - _ - Treatment Volume and Nutrient Load Pre-ReDevelopment Treatment Volume Final Post-Development - Post-ReDevelopment I Post-Development (acre-k) 0.0253 0.0168 - Treatment Volume 0.0572 _ Treatment Volume 0.0168 ''.1 Treatment Volume 0.0404 i (acre-ft) I (ace-k) i'!, (acre-ft) i Pre-ReDevelopment Treatment Volume Final Post-Development , - _ '1 Pont-ReDevelopment t ' Post-Development lcubkfee 1,104 733 Treatment Volume 2,492 . ; Treatment Volume 733. °Treatment Volume(cubic 1,759 (cubic feet) .- (cubic feet) feet) Pre-ReDevel meat 7P Load Final Post- Post-ReDevelopment ap `Post-Development TP Load 0.69 0.46 Development TP Load 1.57 - toad(TP) 0.46 .-- 1.11 (Ib/yr) _ -- (ib/yrl' PrrReDeveioPment TP Load per Final Port-Development TP - Post-ReDevelopmentTP - - _-- _- _ (lb/acre/at) 0.5acre1 0.54 Load per acre L14 _ Load per acre 0.54 pb/ane/yr) 0/ate/Td Baseline TP Load(Ib/yr) Man.Reduction Required (0.418as/ate/yr applied to pre-redevelopment areaevcluding pervious 0.35 (Below Pre- 20% land proposed for new Impervious cover) ReDevelopment Load) _- __ TP Load Reduction ' 'Adjusted Land CoverSummaty: TP Load Reduction Pre ReDevelopment land cover minus pervious land rover(forest/open space or managed Req III uired for Redeveloped Area 0.09 Required for New 0.90 tur/)oceage proposed for new impervious caves p Impervious Area(Ib/yr) (Ib/yr) Adjusted total acreage In consistent with Post-ReDevelopment acreage(minus acreage of - new impervious cover). Column 1 shows land reduction requriement for new impervious cover(based on new development land limit.0.411bs/ace/year). Post-Development Requirement for Site Area TP Load Reduction Required(Ib/yr) 0.99 Nitrogen Loads(Informational Purposes Only) r Final Post-Development TN Load - , Pre-ReDevelopment TN Load(lb/yr) 4.96 (Port-ReDevelopment&New Impervious) 11.20 ' - (Ib/yr) I i I ' Puss _Tmm DAP Drainage Area A CLEAR RMP AREAS Dea [e Area A land Cover(Moe) PWM Inas [SON DSOs TvbN smMravmh • emeaMpena0me lanes) ram 0.03 MvuPedTud Iran) 0.31 031 0.20 n CususAoe) 0.55 055 0.95 Total Phephow Mashie for Removal In DA Aim/M 133 Total 036 post DeveepmentTmatrmntVeblm In PAP(13.) 2333 Stormwater Best Management Practices(RR=Runoff Reduction) -select from dmpdown Nts- Runan Managed Ted Imerebus Volume from PUMI Remaebg Total MVP Phosphor. Pbmphormlaad Untreated MmsphoMs RLmaulet Dowmbem Pnmk. ba rel0Oged Nsogen Load Untreated N.D. Rmbsloa Practice Redaction Cnedltkm Cover Coedit Upstream Rm m c000oue 'Treatment Removal from Upstream eM lo ad ad Renewed Ely Phosphoms mad Remael from Upstream Nitrogen Mad bad Removed By Mermen load Ceemt all lame) Area(ales) Practice Redectim u.' vol.. roammyltll UmMem0bl toenmtwlel Mac.Eel Ml Em° Efficiency lxl Practice PM Macom lea) Macao Meal (Dal 1.Vegetated Roof(RRl 1.Vegetated gooffeol �,�c.,y� .A •'ti::•� -'Y•' Cm am ram •a'i: lave°emNamluDpmrsl �. -`���c'��a :;:•,: i{;:ti• o ° a ...,. ,...' J.,.{:h;•.;. . ... .�$:{�°.ii am ram ram 14 Vegetated aoM.lDpese) _, - x'.CiY<+(rpt .evZ:g1': 0 D 0 '•'•:i:•e•:•:i.: ram ram ram M';gal j am am am I.emhap Disconnection ISM 0.eary.mmmtmlmmwsma 0 0 0 •,�hyJ- 00mM1 o ram am ram ram am - ram ram ram 10.sm,w.1sconn.nanmw5m1 . '••,,,,,,' - - 15npn1 a a o o am ram 0m ram ° am am am am '' l•wwiwsnml""70 _ .- 0 0 a � m m a a ram am _ ... am am am 16TOmywecmrmrh era IL <RA•a,4n? 0 0 0 0 .. - am ram 0.m am 'I5 Lmowae.wnppmnl Mao ram am mo .T mywea r afie":nn , el. �' 0 0 a 0 am am cm ram . . „ .. ram , Dm am am Me Vim.TOw Gard.St •q Isncel �p 4 0 0 a a . .... am am am ram ., 0m mo ram ram rnwA nrwdena; m to n UPm el t�.4.tt� o 0 0 .. am 0m ao° ram ...ram;"t ram am ram ram L4 To Rammer MeresOnalSpecobl a a 0 0 0 OM ram am am ,+t,;:a:, am DLO 0m am 2Lamtmmamfamn• ""„F a - .'E" am ram ram m om unm tbnlsnte.bm�alcal `. "' a a D - .... .. am 0m 3.Permeable Pavement IRRI �����` 1eable Pavement IRRI 3aMmaahm Pennant atlspma) 'x .'L ° ° 0 0. °m ram ram 111 ram ram Om 3.4 Perm....Mvmentar(Wean „ .s k�±ay''�na's+d-S •..•..••.•.J D a ° 13 v.-. •.d?..5:•:::L•: m am am Mil {:.••e 'tb ram ..11:111 am .Grass Channel(RR) a.Gross Channel IRRI ...ma m 05 anelsam lsoman - ..a .. ¢m ME WIN am .armw.awrmtape.m 0 0 0 0 - ram mooam am am 0 am k .ayrmmmane,deeenm ram - am Mal a Demme m.spmMl o 0 E. _ am am am OMram Dry Swale INN S.Dry Swale Oft) Sa°gaets 010m Dlal _ 0 - D a o ., 20.._.. am °m am ram am aao OM s.e.evs03enlbmna) ,,so 1. 0 ° n 0 OW am ram Om Mil um ram am ndbn(OM don(Sal nmree s.ameen a.emeAenwnnmarleoamaewmram --m ° D 0 a ... "is....,: am ra m ram• am am ME °.m ram eummnnl WM odem elm ae.mmeAenam 13Pmnl Mp m mmnn ..., a a ° ° .. ram ram am ram ECIE ram ram .:111 ram T.Infiltration OM) p.Infiltration WO 7...In/Stream eo0.ee) m „ a a ° o as OM am ram ram ® m mD am ee.mnraaan al Upee sal m. 0 0 0 0 ram DM °m am ME ram am UM ram .Extended DetentMn Pmd(Re) a.handed Detention Pond(OR) a..mn)spm ale -. 0 0 0 a am 030 cm 0m Mtill am ram NM ram an EOM(Wale) 1s - 0 I 0 1s am °a° am nao Elial ram Dm ram rave '.Shearlow to Rhee/open spare 100 9.Sbeetflow to Filter/open sore MP) 9a Amman l�M. .• ... all esv 0 L103 Sm L131 - _ 003 L33 100 - 033 ME am 353 ® 33a pa aaaw5m, _m l5pmm a D 0 ... ..- ram ram . Dos aaD Dos ram ram y� mreg mw ma.smp.Asmtm'.....m rmmpaamewed wos0m o 0 a 0 ram ram - am am SEI Dos open a mq ... _ VRRY R.a._Y>_0.0 DAD TOTAL IMPERVIOUS COVER TREATED(0) 055 AREA CHEQ:0L TOTAL MANAGED TURF AREA TREATED lac) 031 AREA OECD OR. TOTAL RUNOFF REDUCRON IN DA A)Nr) 1$91 TOTAL PHOSPHORUS AVMIABLF FOR REMOVAL IN DA A 00/y0 133 TOTAL PHOSPHORUS REMOVED WITHRUN0FF REDUCTION PRACTICES IN DA A(1T/wl 100 TOTAL RUNOFF REDUCTION IN DA A(N') 1.391 TOTAL PHOSPHORUS REMAINING AFTER APPLYING RUNOFF REDUCTION PRACITCES IN DA A(0/yr) 033 NITROGEN REMOVED WOH RUNOFF REDUCTION PRACTICES IN DA A OR/yr) MS SEE WATER QUALITY COMPLIANCE TAB FOR SITE COMPLIANCE CALCULATIONS SEE WATER QUALITY COMPLIANCE TAD FOR SITE CALCULATIONS(Oaf ama0On Only) I 10.wetSW01e(n0 R.1 lo.wet 5w0le(Coastal Plal1)00 RR) IDA we s.ata FL DewDewat) ...0 s. 0 0 0 0 .m am 0m am m0 ® 0m am WM Um IAA Wet WaYRlsl.c all) 0 0 0 0 00 003 0m 000 0m Mill om 0m M. Om l I.010On.Practices(m RR) t..(no Rltl tt.Flnare♦Nm.s (Y.0 alalt) , 0 0 0 0 0 ... Om 000 000 000 WINai 0.m 0m Em 0 111.11rte00P/lab e3 New.) 0 0 0 0 - - 000 Om ow 000 ® Om Om m M. 0 12.Construct.Wetland(no AR) 11 Construed Wetland(no RR) u..mmmn.dwed.M n Ism n01 L 0 0 0 a 000 am 0m am Mil Om m0 WM DOD 02.100000:a weaandnlsomal3) I 0 0 0 0 am om Om am ® Om 0.00 nm I3..Wet Ponds(n0 RR) IDaWn NW nl3pcalq - 0 0 A .. OW0,03 o0f 0.000.00 OW 603 0.00 13A Wes Pond R(Cm.n NAM lSaaalal 0 0 0 0 - O.m Om Am Am Om 0.m OM 0.00 11c.w0Pore111100.•010 ., ,,- 0 0 A 0 Y09_ a 0.00 000 000 ,, ._ 0m 0.00 0.00 IA&Wet Pa2BOW 0. Plw)M...) D _ 0 0 0 0N O -- 003 mo am om om Om 0m Om DI. Manufactured WW.(no 3111 t4Mel.daea.aTn.umnurs M. om om Om am M. Ian Mn.dm.3nemv 0.1e0.0.1. ' 0 0 0 0 m 000 003 00, 003 om m 0m 1109el.ad.mo.dn..R.000.900eu. 0 0 0 0 20 .0am am . ICE 0m am om TOTAL UMW.COVER SAEATFDIeA - OSS AREA01E00 OIL TOTAL MANAGEDTUNF AREA TREATED(a0) 031 ARM CHECK:OR. TOTAL PHOSPHORUS REMOVAL REQUIRED ON snub/Ill TOTAL PH 05PH0RUSAVASABIE FOR REMOVAL IN DA A Phi _-0.33 TOTAL PHOSPHORUS REMOVEDWRHOOTRUNOEF REDUCTION PMCIICFSIN DA.A(W/yr) 0.00 TOTAL PHOSPHORUSREMOVED MN(WNW REDUCTION PRACTICES IN OA A(Ib/yr) 100 TOTAL PHOSPHORUS LOAD REDUCTION ACHIEVED INDA A0bM) 100 TOTAL PHOSPHORUS REMAINING AFTFRAPPLYTNG IMP LOAD REDUCTIONS IN DA.A(Ib/Yr) '0.33 SEE WATER QUALITY COMPLIANCE TAB FOR SITE COMPLIANCE CALCULATIONS NITROGEN REMOVEOWLIH RUNOFF REDUCTION PRACTICES IN DAABb/yr) 7.14 NITROGEN REMOVED WITHOUT RUNOFF REDUCTION PRACTICES IN DA A(W/yN MOO TOTAL NITROGEN REMOVED IN DA.A(WAN) 7.14 Site Results (Water Quality Compliance) Area Checks D.A.A D.A.B D.A.C _ D.A.D D.A.E AREA CHECK FOREST/OPEN SPACE(ac) 0.00 0.00 0.00 0.00 0.00 OK. IMPERVIOUS COVER(ac) 0.55 0.00 0.00 0.00 0.00 OK. IMPERVIOUS COVER TREATED(ac) 0.55 0.00 0.00 0.00 0.00 OK. MANAGED TURF AREA(ac) 0.31 0.00 0.00 0.00 0.00 OK. 1 MANAGED TURF AREA TREATED(ac) 0.31 0.00 0.00 0.00 0.00 OK. AREA CHECK OK. OK. OK. OK. OK. Site Treatment Volume(ft3) 2,492 Runoff Reduction Volume and TP By Drainage Area D.A.A D.A.B D.A.C D.A.D _ D.A.E TOTAL RUNOFF REDUCTION VOLUME ACHIEVED(ft3) 1,591 0 0 0 0 1,591 TP LOAD AVAILABLE FOR REMOVAL (Ib/yr) 1.33 0.00 0.00 - 0.00 0.00 1.33 TP LOAD REDUCTION ACHIEVED (Ib/yr) 1.00 0.00 0.00 0.00 0.00 1.00 TP LOAD REMAINING (Ib/yr) 0.33 0.00 - 0.00 0.00 0.00 I 033 i 1I I I NITROGEN LOAD REDUCTION ACHIEVED (Ib/yr) 7.14 0.00 . 0.00 0.00 - . -. 0.00 l 7.14 Total Phosphorus FINAL POST-DEVELOPMENT TP LOAD(Ib/yr) 1.57 TP LOAD REDUCTION REQUIRED(Ib/yr) 0.99 TP LOAD REDUCTION ACHIEVED (Ib/yr) 1.00 TP LOAD REMAINING(Ib/yr):L 0.57 REMAINING TP LOAD REDUCTION REQUIRED(Ib/yr): 0.00 ** **TARGET TP REDUCTION EXCEEDED BY 0.01 LB/YEAR** Total Nitrogen(For Information Purposes) POST-DEVELOPMENT LOAD(Ib/yr) 11.20 NITROGEN LOAD REDUCTION ACHIEVED (Ib/yr) 7.14 REMAINING POST-DEVELOPMENT NITROGEN LOAD(Ib/yr) 4.06 Virginia Runoff Reduction Method Worksheet DEQ Virginia Runoff Reduction Method Re-Development Compliance Spreadsheet-Version 3.0 BMP Design Specifications List: 2013 Draft Stds&Specs Site Summary Total Rainfall(in): 43 Total Disturbed Acreage: 1.37 Site Land Cover Summary Pre-ReDevelopment Land Cover (acres) NiMi,'.M:0-7ENRiAAMM A soils B Soils C Soils D Soils Totals %of Total Forest/Open(acres) 0.00 0.00 0.00 0.00 0.00 0 Managed Turf(acres) 0.00 1.33 0.00 0.00 1.33 97 Impervious Cover(acres) 0.00 0.04 0.00 0.00 0.04 3 1.37 100 Post-ReDevelopment Land Cover (acres) "r 1':'^s i<iV M%`";:n::': A soils B Soils C Soils D Soils Totals %of Total Forest/Open(acres) 0.00 0.00 0.00 0.00 0.00 0 Managed Turf(acres) 0.00 0.82 0.00 0.00 0.82 60 Impervious Cover(acres) 0.00 0.55 0.00 0.00 0.55 40 1.37 100 Site Tv and Land Cover Nutrient Loads ,nvy, ti:z:%< Pre- <1.tr>;::is •>s"':ii• �'=:?bW:.;. Final Post-Development Post-ReDevelopmentTP Eili ;je>., .;,.; . . ....,. .,r Final Post-Development Post- p :aj <$j:'e:yC •,.�,:^j;;;;:.:',:;�r I;>;:-Z$i:.: Post- Adjusted Pre- ReDevelopment :t: ; ;.:.;r -^ .r '; ;:. (Post-ReDevelopment Development TP Load per acre Load per acre > ve.f;;.,+,,,..:•sr-,.;;,;, > ;;; ? ReDevelopment ReDevelopment TP Load per acre r ..,.. :,....4,..>,....,,.,..5•. &New Impervious) (New Impervious) (Ib/acre/yr) (lb/acre/yr) (Ib/acre/yr) Site Rv 0.50 0.23 0.95 0.23 0.54 1.14 0.54 Treatment Volume(ft3) 2,492 733 1,759 733 TP Load(lb/yr) 1.57 0.46 1.11 0.46 Total TP Load Reduction Required(Ib/yr) 0.99 0.09 0.90 .;. `• Kea:'f,g0M ;f,;. Final Post-Development Load Pre- ^' t ;''" (Post-ReDevelopment&New Impervious) ReDevelopment TN Load(Ib/yr) 11.20 4.96 Summary Print Virginia Runoff Reduction Method Worksheet Site Compliance Summary Maximum%Reduction Required Below 209' Pre-ReDevelopment Load Total Runoff Volume Reduction(ft3) 1,591 Total TP Load Reduction Achieved(Ib/yr) 1.00 Total TN Load Reduction Achieved(Ib/yr) 7.14 Remaining Post Development TP Load 0.57 (Ib/yr) Remaining TP Load Reduction(Ib/yr) 0.00 **TARGET TP REDUCTION EXCEEDED BY 0.01 LB/YEAR** Required Summary Print Virginia Runoff Reduction Method Worksheet -- ------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Drainage Area Summary <'ys'<: '% "'``"� ;< yL;>;`:£r,.;, D.A.A D.A.B D.A.C D.A.D D.A.E . ,. ., .•.r:.�s^•'s<.. _... ........ ... . Total Forest/Open(acres) 0.00 0.00 0.00 0.00 0.00 0.00 Managed Turf(acres) 0.31 0.00 0.00 0.00 0.00 0.31 Impervious Cover(acres) 0.55 0.00 0.00 0.00 0.00 0.55 Total Area(acres) 0.86 0.00 0.00 0.00 0.00 0.86 Drainage Area Compliance Summary '`? ......:?x^ >,agNiii ..........,.... D.A.A D.A.B D.A.C D.A.D D.A.E Total TP Load Reduced(Ib/yr) 1.00 0.00 0.00 0.00 0.00 1.00 TN Load Reduced(Ib/yr) 7.14 0.00 0.00 0.00 0.00 7.14 Summary Print Virginia Runoff Reduction Method Worksheet Drainage Area A Summary • Land Cover Summary j:.y'; :,,,__,, .,y'?`:;g;r-;.,,,, .,,:;', :_IM. A Soils B Soils C Soils D Soils Total %of Total Forest/Open(acres) 0.00 0.00 0.00 0.00 0.00 0 Managed Turf(acres) 0.00 0.31 0.00 0.00 0.31 36 Impervious Cover(acres) 0.00 0.55 0.00 0.00 0.55 64 0.86 BMP Selections Managed Turf Impervious TP Load from BMP Treatment Untreated TP Load TP Removed TP Remaining Downstream Treatment Practice Credit Area Cover Credit s Upstream Volume(ft) to Practice(Ibs) (Ib/yr) (Ib/yr) to be Employed ____ (acres) Area(acres) Practices(Ibs) 9.a.Sheetflow to Conservation Area,A/B 0.31 0.55 2,121.74 0.00 1.33 1.00 0.33 Soils(Spec#2) Total Impervious Cover Treated(acres) 0.55 Total Turf Area Treated(acres) 0.31 Total TP Load Reduction Achieved in D.A. 1.00 (Ib/yr) Total TN Load Reduction Achieved in D.A. 7,14 (Ib/yr) Summary Print Virginia Runoff Reduction Method Worksheet Runoff Volume and CN Calculations .•?..Z:E'lif,M;M::',.ZZOMP"gaN 1-year storm 2-year storm 10-year storm Target Rainfall Event(in) 2.99 3.62 5.47 Drainage Areas RV&CN Drainage Area A Drainage Area B Drainage Area C Drainage Area D Drainage Area E CN Mitang 85 0 0 0 0 RR(ft3) ENMS: 1,591 0 0 0 0 RV wo RR(ws-In) 1.58 0.00 0.00 0.00 0.00 1-year-return period RV w RR(ws-In) 1.07 0.00 0.00 0.00 0.00 _i -• i.., CN adjusted 77 0 0 0 0 - . RV wo RR(ws-in) 2.12 0.00 0.00 0.00 0.00 2-year return period -• RV w RR(ws-in) 1.61 0.00 0.00 0.00 0.00 , CN adjusted 78 . 0 0 0 0 RV wo RR(ws-In) 3.80 0.00 0.00 0.00 0.00 .._.., . 10-year return period RV w RR(ws-In) 3.30 0.00 0.00 0.00 0.00 CN adjusted 80 0 0 0 0 Summary Print