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HomeMy WebLinkAboutSUB202000055 Calculations Road Plan and Comps. 2020-06-01SHIMP ENGINEERING, P.C. Design Focused Engineering June 1, 2020 Emily Cox, PE County of Albemarle Department of Community Development 401 McIntire Road, North Wing Regarding: SUB 202000055 Proffit Rd Townhomes North Road Plan — Drainage Cales Dear Emily, Enclosed is the drainage calculations for Proffit Rd Townhomes North Road Plan. The development property has an area of 7.59 acres and a disturbed area of 5.60 acres. The project is a private redevelopment of a site. The proposed stormwater design meets water quality requirements set forth in 9VAC25-870-65 and water quantity requirements set forth in 9VAC25-870-66-B(3) and 9VAC25-870- 66-C. The storm drains and inlets in this project comply with VDOT regulations. Note: all inlets have an assumed time of concentration. Inlet computations use the rational equation for peak flow calculations. If you have any questions about this calculation packet please do not hesitate to contact me at: keane&shimp-en in�g com or by phone at 434-299-9843. Keane Rucker, EIT Shimp Engineering, PC 912 E. High St. Charlottesville, VA 22902 1434.227.5140 1 shimp-engineering.com Contents: Road Drainage Calculations: Post-Dev Inlet Drainage Summary Post-Dev Inlet Drainage Map VDOT LD-204 Inlet Capacity VDOT LD-229 Storm Drain Capacity VDOT LD-268 Ditch Capacity Charlottesville, Virginia 22902 912 E. High St. Charlottesville, VA 22902 1434.227.5140 1 shimp-engineering.com Proffit Rd TH North Inlet Drainage Area Summary Impervious C 0.9 Pervious C 0.3 To Inlet Area Impervious Turf C A A7 10,590 7,201 3,389 0.71 0.24 A6 4,125 2,805 1,320 0.71 0.09 AS 19,540 13,287 6,253 0.71 0.45 A4A 15,260 10,377 4,883 0.71 0.35 A4 9,540 6,487 3,053 0.71 0.22 A3 3,755 2,553 1,202 0.71 0.09 A2 7,350 4,998 2,352 0.71 0.17 B7 14,180 9,642 4,538 0.71 0.33 B6 6,815 4,634 2,181 0.71 0.16 65A 19,825 13,481 6,344 0.71 0.46 B5 13,255 9,013 4,242 0.71 0.30 B4 7,830 5,324 2,506 0.71 0.18 133A 17,430 11,852 5,578 0.71 0.40 B3 9,880 6,718 3,162 0.71 0.23 D 7,775 5,287 2,488 0.71 0.18 C2 9,295 6,321 2,974 0.71 0.21 F2 684,100 113,256 570,844 0.40 15.70 G 18,560 9,880 8,680 0.62 0.43 I I I 1 / 1 / I it 1 \ 1 1 1 1 I I 1 I it it — yk It_ _ — \\\ \\ \11 \\ \\\I \\II\\ \\\ \---------' — ---- It 11 L��--_____—__— I `.` .\ � �0 Aaaz-eRTo�1:1 OTS — ----- — \ l \1\ \I \\ \ \�—\ — -----------'O _„4--- _------ — --- ------------- Ol 5016 i LOT `\ ------- — --/ * _ \ I I v / So _ 3�� LOT LOT U � ' I• —_—___' 1\ 1 ; ;� LOT �` TO DITCH 2C - .f 735 — " B \ 5005 SF BC i i 1 i LOT \ a \ 17 0A / %a ' I p 17430 SF LOT 40r \ I 54 .\ 1 ° 3IT\ ` dT` Lor LOT i it I ` / I i r \ •� i y I I 1 I �� LOT � I � LOT 35 i I I LOT ---_--- „� - % LOT I I 1 48 / _ '—\ ` \ 111111 ♦ is i A / �i'�\ I 1 1 1 111 4°i $ \\\ ` `1--\ TO\135'. �\ ' \ LOT 1STc T 1 �v �v I / A i LOT 5A M Y \ v \ 1 5 S ;°r j TO,DITICH �BAV\ �a s I� 15130,SF / ��LOT m 43 a°i 4" to to a' . or o as ael 13 J 40 iO 1 s2 9 I OT - �- LOT IF \tll I / � / I / � l i LOT / for ;81 1l1j1 i ss ROgp �— ry g P7 49' PUBLIC _ Loi yy IB7 III� 9U SF ----3a '1D5I Lor/I1 ;ill e I r r I � — I, 141 F LOT / — I 1 Lor LOT L ZT LOT L l 11 I __ 8 T r iA 1` LOT /` ` �/ 5] <d ❑ _ 5 a LOT � I TO G / qEE LOT 1 OPENSPAC�l / 18560 — i 9 A i ,z -_-------- PROFFIT RD TH NORTH POSTDEV INLET DRAINAGE MAP 80 0 80 160 240 Scale: 1 "=80' Proffit Rd TH North LD-204 Stormwater Inlet Computations Inlets on Grade Only Sag Inlets Only m E m m Q Z c� 'c Q o c d Z d o a) a o Q o w m > U >, a a� Q a p L d a U) o. F a O m t U - Y N L o Z m S � y X X U w a) 2 y ca o � = o n " m U chi F > m m m r a w c T m Q p � 2 a O iA U U c[ U Ci Ci O C7 a 0 �� o o O a 1 2 3 4 5 6 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 (ft) (ac) (in/hr) (cfs) (cfs) (cfs) ('/') (Y') ('/') (ft) (ft) (cfs) (cfs) (ft) (ft) (ft) A7 DI-3C 6 0.24 0.71 0.17 4.0 0.69 0.00 0.69 0.015 0.005 0.020 0.083 0.10 0.5 0.20 5.27 6.5 1.12 0.00 1.12 0.14 0.5 0.27 6.99 A6 131-313 8 0.09 0.71 0.07 4.0 0.27 0.00 0.27 0.015 0.025 0.020 0.083 1.53 0.10 100.0% 0.27 0.00 6.5 0.44 0.00 0.44 1.80 0.13 100.0% 0.44 0.00 A5 131-313 8 0.45 0.71 0.32 4.0 1.27 0.00 1.27 0.015 0.025 0.020 0.083 4.62 0.21 99.4 % 1.26 0.01 6.5 2.06 0.00 2.06 6.28 0.25 89.7 % 1.85 0.21 A4A DI-3C 6 0.35 0.71 0.25 4.0 0.99 0.00 0.99 0.015 0.005 0.020 0.083 0.13 0.5 0.25 6.54 6.5 1.61 0.00 1.61 0.18 0.5 0.35 8.41 A4 131-313 6 0.22 0.71 0.16 4.0 0.62 0.01 0.63 0.015 0.022 0.020 0.083 2.38 0.17 100.0% 0.63 0.00 6.5 1.01 0.21 1.22 4.49 0.20 90.0 % 1.10 0.12 A3 131-313 8 0.09 0.71 0.06 4.0 0.24 0.00 0.24 0.015 0.020 0.040 0.083 1.52 0.13 100.0% 0.24 0.00 6.5 0.40 0.12 0.52 2.16 0.17 100.0% 0.52 0.00 A2 131-313 8 0.17 0.71 0.12 4.0 0.48 0.00 0.48 0.015 0.020 0.040 0.083 1.97 0.18 100.0% 0.48 0.00 6.5 0.78 0.00 0.78 3.40 0.19 100.0% 0.78 0.00 B7 DI-3C 6 0.33 0.71 0.23 4.0 0.92 0.00 0.92 0.015 0.006 0.020 0.083 0.12 0.5 0.24 6.27 6.5 1.50 0.00 1.50 0.17 0.5 0.34 8.12 B6 DI-36 6 0.16 0.71 0.11 4.0 0.44 0.00 0.44 0.015 0.020 0.020 0.083 1.90 0.16 100.0% 0.44 0.00 6.5 0.72 0.00 0.72 3.15 0.18 100.0% 0.72 0.00 65A DI-313 8 0.46 0.71 0.32 4.0 1.29 0.00 1.29 0.015 0.020 0.333 0.333 5.04 0.22 100.0% 1.29 0.00 w.2x3Grate 6.5 2.09 0.00 2.09 6.74 0.26 100.0% 2.09 0.00 B5 DI-313 8 0.30 0.71 0.22 4.0 0.86 0.00 0.86 0.015 0.020 0.250 0.25 3.71 0.19 100.0% 0.86 0.00 6.5 1.40 0.00 1.40 5.32 0.23 99.4 % 1.39 0.01 B4 DI-3C 6 0.18 0.71 0.13 4.0 0.51 0.00 0.51 0.015 0.005 0.167 0.167 0.08 0.5 0.16 4.27 6.5 0.83 0.01 0.84 0.11 0.5 0.22 5.90 63A DI-313 8 0.40 0.71 0.28 4.0 1.13 0.00 1.13 0.015 0.060 0.084 0.084 2.84 0.18 100.0% 1.13 0.00 6.5 1.84 0.00 1.84 4.40 0.21 100.0% 1.84 0.00 B3 DI-213 8 0.23 0.71 0.16 4.0 0.64 0.00 0.64 0.015 0.060 0.001 0.001 1.79 0.16 100.0% 0.64 0.00 w.2x3Grate 6.5 1.04 0.00 1.04 2.58 0.17 100.0% 1.04 0.00 C2 GRATE 2x2 0.21 0.71 0.15 4.0 0.60 0.00 0.60 0.015 0.100 0.100 - 0.10 0.5* 0.20 2.00 6.5 0.98 0.00 0.98 0.14 0.5* 0.29 2.44 Curb height represents height of critical adjacent grade. LD-229 Storm Drain Design Computations Proffit Rd TH North From To Catch. Runoff Increment Accum. Total Total Total Up Down Pipe Invert Pipe Pipe Velocity Flow time Structure Structure Area Coef AC AC TOC Intensity Flow Invert Invert Length Slope Diameter Capacity Increment ac min in/hr cfs Elev. Elev. (ft) % in cfs ft/s min 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 A7 A6 0.24 0.71 0.17 0.17 5.00 6.81 1.17 523.80 522.00 58.51 3.08% 15 12.3 6.3 0.15 A6 A5 0.09 0.71 0.07 0.24 5.15 6.77 1.62 521.80 521.30 27.91 1.79% 15 9.4 5.7 0.08 A5 A4 0.45 0.71 0.32 0.56 5.24 6.74 3.75 520.00 516.20 129.70 2.93% 15 12.1 8.7 0.25 MA A4 0.35 0.71 0.25 0.25 5.00 6.81 1.69 519.00 517.00 34.88 5.73% 15 16.8 8.8 0.07 A4 A3 0.22 0.71 0.16 0.96 5.48 6.67 6.41 516.00 513.20 51.92 5.39% 15 15.7 12.2 0.07 A3 A2 0.09 0.71 0.06 1.02 5.56 6.65 6.79 513.00 511.00 24.00 8.33% 15 20.2 14.8 0.03 A2 Al 0.17 0.71 0.12 1.14 5.58 6.65 7.58 508.00 505.50 19.51 12.81 % 15 25.0 17.9 0.02 B7 B6 0.33 0.71 0.23 0.23 5.00 6.81 1.57 522.50 521.70 34.50 2.32% 15 10.7 6.2 0.09 B6 B5 0.16 0.71 0.11 0.34 5.09 6.78 2.31 521.50 514.20 144.97 5.04% 15 15.3 8.9 0.27 135A B5 0.46 0.71 0.32 0.32 5.00 6.81 2.19 515.00 514.20 27.09 2.95% 15 12.0 7.5 0.06 B5 B4 0.30 0.71 0.22 0.88 5.36 6.71 5.89 514.00 513.20 30.77 2.60% 15 11.3 9.3 0.06 B4 B3 0.18 0.71 0.13 1.01 5.42 6.69 6.73 513.00 509.20 127.59 2.98% 15 12.2 10.2 0.21 133A B3 0.40 0.71 0.28 0.28 5.00 6.81 1.93 510.00 509.20 28.00 2.86% 15 10.9 6.7 0.07 B3 B2 0.23 0.71 0.16 1.45 5.63 6.63 9.62 509.00 508.40 29.32 2.05% 18 16.4 9.7 0.05 D B2* 0.18 0.71 0.13 0.13 5.00 6.81 0.86 512.60 508.54 5.00 81.20% 12 34.80 - - B2 B1 0.00 0.00 0.00 1.58 5.68 6.62 10.44 508.20 505.00 166.05 1.93% 18 15.8 9.6 0.29 C2 C1 0.21 0.71 0.15 0.15 5.00 6.81 1.03 505.00 504.00 14.30 6.99% 15 18.5 8.1 0.03 F2 F1 15.70 0.40 6.27 6.27 20.00 4.17 26.17 493.10 485.70 257.00 2.88% 36 58.9 8.1 0.53 E3** E2 4.35 496.50 495.00 13.87 10.81 % 24 64.5 11.7 0.02 E2** E1 4.35 493.00 489.00 32.00 12.50% 24 69.3 12.3 0.04 G G 0.43 0.62 0.26 0.26 5.00 6.81 1.80 529.40 529.00 13.00 3.08% 12 6.8 7.3 0.03 *Connection from trench drain D to B2 is a manufactured Inserta-tee fitting **10 yr Flow from H droCAD model Proffit Rd TH North LD-347 Hydraulic Grade Line Inlet Number 1 Outlet Water Surface Elev.* 2 Do 3 Qo 4 Lo 5 S, 6 Hf 7 Junction Loss Final H 19 Inlet Water Surface Elev. 20 Rim. Elev 21 Vo (8) Ho (9) O, (10) v; (11) O;v; (12) H; (13) Angle (14) Ho (15) Ht (16) 1.3*1-It (17) 0.51-It (18) A2 509.00 1.25 7.58 19.51 1.173 % 0.229 17.9 1.741 6.79 14.8 100.8 1.197 0 0.103 3.041 1.520 1.749 510.75 523.99 A3 514.00 1.25 6.79 24.00 0.943% 0.226 14.8 1.197 6.41 12.2 78.1 0.809 80 1.525 3.531 4.591 2.295 2.521 516.52 524.02 A4 517.00 1.25 6.41 51.92 0.838% 0.435 12.2 0.809 1.69 8.8 14.8 0.416 77 0.761 1.986 2.582 1.291 1.726 518.73 526.03 MA 520.00 1.25 1 1.69 1 34.88 0.058 % 1 0.020 1 8.8 0.416 1 3.75 8.8 32.8 0.416 13 0.214 1.046 1 1.360 1 0.680 1 0.700 1 520.70 1 525.90 A5 521.00 1.25 1 6.74 1 129.70 0.929 % 1 1.204 1 8.7 0.411 1 1.62 5.7 9.2 0.177 52 0.257 0.845 1 1.099 1 0.549 1 1.754 1 522.75 1 529.35 A6 522.80 1.25 1.62 27.91 0.053% 0.015 5.7 0.177 1.17 6.3 7.4 0.216 45 0.277 0.670 0.871 0.435 0.450 523.25 529.82 A7 524.80 1.25 1.17 58.51 0.028% 0.016 6.3 0.216 1.17 0.0 0.0 0.000 0 0.000 0.216 0.280 0.140 0.157 524.96 530.80 B2 509.40 1.50 10.44 166.05 0.841 % 1.397 9.6 0.072 10.44 9.7 100.7 0.506 3 0.072 0.651 0.325 1.722 511.12 516.34 B3 511.12 1.50 9.62 29.32 0.715% 0.210 9.7 1.012 1.93 6.7 12.9 0.244 90 0.488 1.744 2.267 1.134 1.343 512.47 519.74 133A 512.47 1.25 1.93 28.00 0.076% 0.021 6.7 0.023 6.73 10.2 68.8 0.568 1 0.054 0.644 0.837 0.419 0.440 512.91 519.80 B4 514.00 1.25 6.73 127.59 0.926% 1.181 10.2 0.057 5.89 10.2 60.2 0.568 2 0.057 0.681 0.886 0.443 1.624 515.62 524.80 B5 515.62 1.25 6.71 30.77 0.919% 0.283 9.3 0.107 2.19 7.5 16.3 0.302 7 0.069 0.478 0.621 0.311 0.593 516.22 529.35 135A 516.22 1.25 2.19 27.09 0.098% 0.027 7.5 0.603 2.31 8.9 20.6 0.430 90 0.859 1.892 2.459 1.230 1.256 517.47 525.95 B6 522.50 1.25 2.31 144.97 0.109 % 0.159 8.9 0.086 1.57 6.2 9.7 0.209 6 0.042 0.337 0.438 0.219 0.377 522.88 529.50 B7 523.50 1.25 1.57 34.50 0.050% 0.017 6.2 0.018 1.57 0.0 0.0 0.000 0 0.000 0.018 0.023 0.012 0.029 1 523.53 529.35