The URL can be used to link to this page

Home My WebLink AboutSDP200900079 CalculationsTRAFFIC COUNT SUMMARY EXISTING ALBEMARLE COUNTY PARKS AVERAGE VDOT RURAL ROAD TRAFFIC COUNT FOR 29 DAYS DAILY TRAFFIC PAVEMENT WIDTH RQMT. EXISTING PARK 4 -20 -09 TO 5 -18 -09 ADT)ADT 250 - 50) MINT SPRINGS VALLEY PARK 4593 158 18' WALNUT CREEK PARK 3825 132 18' AVERAGES 8418 145 18' NOTES: 1. BOTH MINT SPRINGS AND WALNUT CREEK HAVE SWIMMING AND FISHING FACILITIES WHICH BYROM PARK WILL NOT HAVE. 2. TRAFFIC COUNTS FOR DATES SHOWN DO INCLUDE SOME FISHING TRAFFIC BUT NO SWIMMING TRAFFIC. 3. TRAFFIC COUNTS PROVIDED BY ALBEMARLE COUNTY PARKS. Short Version BMP Computations For Worksheets 2 - 6 Albemarle County Water Protection Ordinance: Modified Simple Method Plan: Byrom Forest Preserve Park Water Resources Area:Development Area Preparer: Anhold Associates Date: 15- Sep -09 Project Drainage Area Designation DA Post -3A (Areas 1 -6) L storm pollutant export in pounds, L = [P(Pj)Rv /12 ] [ C(A)2.72 ] Rv mean runoff coefficient, Rv = 0.05 + 0.009(1) Pj small storm correction factor, 0.9 percent imperviousness P annual precipitation, 43" in Albemarle A project area in acres in subject drainage area,A =172.40 C pollutant concentration, mg /1 or ppm target phosphorus f factor applied to RR required treatment volume in cy, 0.5" over imperv. area = A(I)43560(0.5/12)/27 RR required removal , L(post) - f x L(pre) RR removal efficiency , RR100 /L(post) Impervious Cover Computation (values in feet & square feet) Item pre - development Area post - development Area Roads Length Width subtotal Length Width subtotal 0 0 0 0 20 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1742 Driveways Length Width no.subtotal Length Width no.subtotal and walks 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Parking Lots 1 2 3 4 1 2 3 4 0 0 0 0 0 Gravel areas Area Area x 0.70 =0 6006 x 0.70 =4204.2 Structures Area no.subtotal Area no.subtotal 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 Actively - grazed pasture &Area Area yards and cultivated turf x 0.08 =0 44431 x 0.08 =3554.48 Active crop land Area Area x0.25=0 x025=0 Other Impervious Areas 0 0 Impervious Cover 0%0.13% l(pre)post) Rv(post) V 0.05 14.7 New Development (For Development Areas, existing impervious cover <= 20 %) C f I (pre) * Rv(pre) L(pre) L(post) RR RR Area Type 0.70 1.00 20% 0.23 243.42 54.12 189.30 350% Development Area 0.35 1.00 0% 0.05 26.46 27.06 0.60 2% Drinking Water Watersheds 0.40 1.00 1% 0.06 35.68 30.93 4.75 15% Other Rural Land min. values Redevelopment (For Development Areas, existing impervious cover > 20 %) C f I (pre)* Rv(pre) L(pre) L(post) RR RR Area Type 0.70 0.90 20% 0.23 243.42 54.12 164.96 305% Development Area 0.35 0.85 0% 0.05 26.46 27.06 4.57 17% Drinking Water Watersheds 0.40 0.85 1% 0.06 35.68 30.93 0.60 2% Other Rural Land Interim Manual, Page 70 rev. 16 Feb 1998 GEB Short Version BMP Compa`.ations For Worksheets 2 - 6 Albemarle County Water Protection Ordinance: Modified Simple Method Plan: Byrom Forest Preserve Park Water Resources Area:Development Area Preparer:Anhold Associates Date: 15- Sep -09 Project Drainage Area Designation DA Post -3B (Areas 1 -3) L storm pollutant export in pounds, L = [P(Pj)Rv /12 ) [ C(A)2.721 Rv mean runoff coefficient, Rv = 0.05 + 0.009(1) Pj small storm correction factor, 0.9 1 percent imperviousness P annual precipitation, 43" in Albemarle A project area in acres in subject drainage area,A =17.46 C pollutant concentration, mg /I or ppm target phosphorus f factor applied to RR required treatment volume in cy, 0.5" over imperv. area = A(I)43560(0.5/12)/27 RR required removal , L(post) - f x L(pre) RR removal efficiency , RR100 /L(post) Impervious Cover Computation (values in feet & square feet) Item pre - development Area post - development Area Roads Length Width subtotal Length Width subtotal 0 0 0 0 20 0 0 0 0 0 0 0 0 0 0 0 0 0 6445 Driveways Length Width no.subtotal Length Width no.subtotal and walks 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Parking Lots 1 2 3 4 1 2 3 4 0 0 0 0 0 Gravel areas Area Area x0.70=0 x0.70=0 Structures Area no.subtotal Area no.subtotal 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 Actively - grazed pasture &Area Area yards and cultivated turf x 0.08 =0 20473 x 0.08 =1637.84 Active crop land Area Area x0.25=0 x0.25=0 Other Impervious Areas 0 0 Impervious Cover 0.00%1.06% l(pre)post) Rv(post) V 0.06 12.5 New Development (For Development Areas, existing impervious cover <= 20 %) C f I (pre) * Rv(pre) L(pre) L(post) RR RR Area Type 0.70 1.00 20% 0.23 24.65 6.38 18.27 286% Development Area 0.35 1.00 0% 0.05 2 68 3.19 0.51 16% Drinking Water Watersheds 0.40 1.00 1% 0.06 3.61 3.65 0.03 1% Other Rural Land min. values Redevelopment (For Development Areas, existing impervious cover > 20 %) C f I (pre) * Rv(pre) L(pre) L(post) RR RR Area Type 0.70 0.90 20% 0.23 24.65 6.38 15.80 248% Development Area 0.35 0.85 0% 0.05 2.68 3.19 0.91 29% Drinking Water Watersheds 0.40 0.85 1% 0.06 3.61 3.65 0.58 16% Other Rural Land Interim Manual, Page 70 rev. 16 Feb 1998 GEB Short Version BMP Compa ations For Worksheets 2 - 6 Albemarle County Water Protection Ordinance: Modified Simple Method Plan: Byrom Forest Preserve Park Water Resources Area:Rural Area Preparer:Anhold Associates Date: 15- Sep -09 Project Drainage Area Designation DA Post -3C (Areas 1 -3) L storm pollutant export in pounds, L = [P(Pj)Rv /12 ] [ C(A)2.72 ] Rv mean runoff coefficient, Rv = 0.05 + 0.009(1) Pj small storm correction factor, 0.9 percent imperviousness P annual precipitation, 43" in Albemarle A project area in acres in subject drainage area,A =2.200 C pollutant concentration, mg /I or ppm target phosphorus f factor applied to RR required treatment volume in cy, 0.5" over imperv. area = A(I)43560(0.5/12)/27 RR required removal , L(post) - f x L(pre) RR removal efficiency , RR100 /L(post) Impervious Cover Computation (values in feet & square feet) Item pre - development Area post - development Area Roads Length Width subtotal Length Width subtotal 0 0 0 0 20 0 0 0 0 0 0 0 0 0 0 0 0 0 0 45939 Driveways Length Width no.subtotal Length Width no.subtotal and walks 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Parking Lots 1 2 3 4 1 2 3 4 0 0 0 0 0 Gravel areas Area Area x 0.70 =0 2614 x 0.70 =1829.8 Structures Area no.subtotal Area no.subtotal 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 Actively - grazed pasture &Area Area yards and cultivated turf x 0.08 =0 49135 x 0.08 =3930.8 Active crop land Area Area x0.25=0 x0.25=0 Other Impervious Areas 0 0 Impervious Cover 0%54% l(pre)post) Rv(post) V 0.54 79.8 New Development (For Development Areas, existing impervious cover <= 20 %) C f I (pre) * Rv(pre) L(pre) L(post) RR RR Area Type 0.70 1.00 20% 0.23 3.11 7.23 4.13 57% Development Area 0.35 1.00 0% 0.05 0.34 3.62 3.28 91% Drinking Water Watersheds 0.40 1.00 1% 0.06 0.46 4.13 3.68 89% Other Rural Land min. values Redevelopment (For Development Areas, existing impervious cover > 20 %) C f I (pre) * Rv(pre) L(pre) L(post) RR RR Area Type 0.70 0.90 20% 0.23 3.11 7.23 4.44 61% Development Area 0.35 0.85 0% 0.05 0.34 3.62 3.33 92% Drinking Water Watersheds 0.40 0.85 1% 0.06 0.46 4.13 3.75 91% Other Rural Land Interim Manual, Page 70 rev. 16 Feb 1998 GEB Short Version BMP Compilations For Worksheets 2 - 6 Albemarle County Water Protection Ordinance: Modified Simple Method Plan: Bryom Forest Preserve Park Water Resources Area:Rural Area Preparer:Anhold Associates Date: 15- Sep -09 Project Drainage Area Designation DA Post -4A (Not Including Off-site Areas) L storm pollutant export in pounds, L = [P(Pj)Rv /12 ] [ C(A)2.72 ] Rv mean runoff coefficient, Rv = 0.05 + 0 009(1) Pj small storm correction factor, 0 9 I percent imperviousness P annual precipitation, 43" in Albemarle A project area in acres in subject drainage area,A =0.06 C pollutant concentration, mg /I or ppm target phosphorus f factor applied to RR required treatment volume in cy, 0 5" over imperv. area = A(I)43560(0.5/12)/27 RR required removal , L(post) - f x L(pre) RR removal efficiency , RR100 /L(post) Impervious Cover Computation (values in feet & square feet) Item pre - development Area post - development Area Roads Length Width subtotal Length Width subtotal 0 0 0 0 20 0 0 0 0 0 0 0 0 0 0 0 0 0 87 90 Driveways Length Width no subtotal Length Width no.subtotal and walks 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Parking Lots 1 2 3 4 1 2 3 4 0 0 0 0 0 Gravel areas Area Area x070=0 x0.70=0 Structures Area no.subtotal Area no.subtotal 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 Actively- grazed pasture &Area Area yards and cultivated turf x 0.08 =0 1578 x 0.08 =126.24 Active crop land Area Area x0.25=0 x0.25=0 Other Impervious Areas 0 0 Impervious Cover 0.00%8.27% l(pre)post) Rv(post) V 0.12 0.33 New Development (For Development Areas, existing impervious cover <= 20 %) C f I (pre) * Rv(pre) L(pre) L(post) RR RR Area Type 0.70 1.00 20% 0 23 0.08 0.05 0.04 85% Development Area 0.35 1.00 0% 0.05 0.01 0.02 0.01 60% Drinking Water Watersheds 0.40 1.00 1% 0.06 0.01 0 03 0.01 53% Other Rural Land min. values Redevelopment (For Development Areas, existing impervious cover > 20 %) C f I (pre) * Rv(pre) L(pre) L(post) RR RR Area Type 0.70 0.90 20% 0.23 0.08 0.05 0.03 66% Development Area 0.35 0.85 0% 0.05 0.01 0.02 0.02 66% Dunking Water Watersheds 0.40 0.85 1% 0.06 0.01 0.03 0.02 60% Other Rural Land Interim Manual, Page 70 rev. 16 Feb 1998 GEB Short Version BMP Compations For Worksheets 2 - 6 Albemarle County Water Protection Ordinance: Modified Simple Method Plan: Byrom Forest Preserve Park Water Resources Area:Rural Area Preparer:Anhold Associates Date: 15- Sep -09 Project Drainage Area Designation DA Post 4B (Areas 1 -3, Not Including Off-site Areas) L storm pollutant export in pounds, L = [P(Pj)Rv /12 ] [ C(A)2.72 ] Rv mean runoff coefficient, Rv = 0.05 + 0.009(1) Pj small storm correction factor, 0.9 1 percent imperviousness P annual precipitation, 43" in Albemarle A project area in acres in subject drainage area,A =1.60 C pollutant concentration, mg /I or ppm target phosphorus f factor applied to RR required treatment volume in cy, 0.5" over imperv. area = A(1)43560(0.5/12)/27 RR required removal , L(post) - f x L(pre) RR removal efficiency , RR100 /L(post) Impervious Cover Computation (values in feet & square feet) Item pre - development Area post - development Area Roads Length Width subtotal Length Width subtotal 0 0 0 0 20 0 0 0 0 0 0 0 0 0 0 0 0 0 7438 Driveways Length Width no.subtotal Length Width no.subtotal and walks 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Parking Lots 1 2 3 4 1 2 3 4 0 0 0 0 0 Gravel areas Area Area 6975 x 0.70 =4882.5 x 0.70 =0 Structures Area no.subtotal Area no.subtotal 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 Actively - grazed pasture &Area Area yards and cultivated turf 12208 x 0.08 =976.64 32830 x 0.08 =2626.4 Active crop land Area Area x0.25=0 x0.25=0 Other Impervious Areas 0 0 Impervious Cover 8%14% l(pre)post) Rv(post) V 0.18 15.5 New Development (For Development Areas, existing impervious cover <= 20 %) C f I (pre)* Rv(pre) L(pre) L(post) RR RR Area Type 0.70 1.00 20% 0.23 2.26 1.77 0.49 28% Development Area 0.35 1.00 0% 0.13 0.62 0.88 0.27 30% Drinking Water Watersheds 0.40 1.00 1% 0.13 0.71 1.01 0.30 30% Other Rural Land min. values Redevelopment (For Development Areas, existing impervious cover > 20 %) C f I (pre) * Rv(pre) L(pre) L(post) RR RR Area Type 0.70 0.90 20% 0.23 2.26 1.77 0.27 15% Development Area 0.35 0.85 0% 0.13 0.62 0.88 0.36 41% Drinking Water Watersheds 0.40 0.85 1% 0.13 0.71 1.01 0.41 41% Other Rural Land Interim Manual, Page 70 rev. 16 Feb 1998 GEB