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HomeMy WebLinkAboutWPO202100003 Calculations 2021-01-19STARBUCKS - 2231 SEMINOLE LANE ALBEMARLE COUNTY, VIRGINIA VSMP DESIGN CALCULATIONS & NARRATIVE JANUARY 19, 2021 TIMMONS GROUP YOUR VISION ACHIEVED THROUGH OURS. Prepared by: Craig Kotarski, PE Timmons Group 608 Preston Ave, Suite 200 Charlottesville, VA 22903 434.327.1688 7�@iI-TH fir^ b (zzr Q CRAIG W. J. KOTARSKI Lic. No. 0402048507 01/19/2021 Table of Contents Section Title Project Narrative 2.1 LD-204 Inlet Calculations 2.2 LD-229 Pipe Calculations 2.3 LD-347 Hydraulic Grade Line Analysis Pre -Developed HydroCAD Calculations Post -Developed HydroCAD Calculations NOAA Atlas 14 Rainfall Chart Virginia Runoff Reduction Method Re -Development Worksheet Project Narrative: This project includes the construction of a new building, parking area, utilities and associated site work. The limits of clearing and grading are 0.574 acres. Water Qua]&: The total disturbed area of the project is 0.57 acres. The existing site has been developed and currently includes an office building, a parking lot and utilities. The existing managed turf area is 0.16 acres and the impervious area is 0.42 acres. In the proposed condition there will be 0.15 acres of managed turf and 0.43 acres of impervious cover. The 0.11 lb/yr of phosphorus removal required based on future development will be achieved through the purchase of nutrient credits. Water Quantity The site currently drains north towards route 29 where it is collected in several inlets. In the proposed condition the area is captured and detained in an underground detention system. Per code section 9VAC25-870-66 B. Lb, the allowable 1-year peak flow rate for this outfall utilizing the energy balance equation was determined. The underground detention detains the 1-year post - developed peak flow below the allowable peak flow rate. Per code section 9VAC25-870- 66C.2.b, the post -developed 10-year peak flow has been detained below the pre -developed 10- year peak flow. FORM LD 200 STORMWATER INLET COMPUTATIONS SHEET OF ROUTE PROJECT Slar &,, 29 DESIGNER: J. DENKO DATE 1M312021 CHECKED: C. KOTARSKI UNITS'.NGLISH milli INLETSOFT BY ENSOFTEC DATE: 111=021 STORM SEWER DESIGN COMPUTATIONS STORM FREQUENCY 10 PROJECT: LOCATION: COUNTY: Starbucks_29 Albemarle Designed by: J. DENKO Checked by: C.KOTARSKI UNITS ENGLISN PPE NO FROMPOWT T Ik) f DRAPI. AREA 'A' Aqe (3) RUNOFF COEFF. 'C' (a) CA TOTAL MET TIME Mi s (7) RAPT FALL RJHr (8) RUNOFF Q CFS (9) RJVERTELEVATIONS LENGTH ofAii Ft (12) SLOPE FLIFt. (13) SIZE (Dia Or SpaNRsse) M (16) SHAPE Capacity CFS (15) Friction slope FVFt VEL V. Ft5m (16) FLOW TIME Mud (17) REMARKS (IB) PICRE-ACCUM- MENT (5) ULATED (6) ADDTL CA UPPER END (10) LOWER END (11) REFERENCE (1) STA. REFERENCE (2) STA. 103 UGD 102 0m 0000 0000 0309 0.209 6000 6230 1302 615000 61TW 6.535 0.021 I5" cn¢ 100% 0000 5.616 0019 101 102 EX-100 0100 0]a0 00]6 0263 0.000 6019 6226 U62 617,9W 616T 1 11 0.037 15000 Cn¢ 13633 0001 T590 0.IP 115 116 114 0040 0T10 0.031 0.031 0.000 6000 6230 0192 623886 6239W 90M 0.016 12M Cn¢ 6.850 OW 3.008 0050 113 114 112 0020 05W 0.012 0.083 0.000 6050 6215 0265 623M3 623328 15]39 0.020 12M Circular 5657 OM 3.596 00/3 111 112 110 0000 0000 01 0.083 0.000 6.123 6194 02M 623230 622800 2L515 0.020 12M Crider 565] OM 3.593 0.100 109 110 108 0020 06/0 0.013 0.056 0.000 6223 6165 03 s 622800 622622 8.889 0.020 12M Crcular 5657 OM 3.891 0038 117 118 108 0010 0900 0.009 0.009 0.000 6000 6230 0056 623839 622550 ba.d69 0.020 12M Crcular 565] OM2250 06]] 10] 108 106 0000 0000 0.000 OW0.000 66T! 6093 0396 621820 621 pW 38.8]6 0.020 12000 CGculer 5J65 0000 A.05] 0.1W 105 106 UGD 0220 0830 0.183 02A8 0.000 6616 6. 1698 6209W 620 ]00 BJdb 0.02] 13000 Circular 6.391 0002 6.658 0022 PROJECT: StsrbuCks 29 DESIGNED BY: J. DENKO HYDRAULIC GRADE LINE ANALYSIS Checked: C. KOTARSKI INCIDENCE PROBABILITY 10 Year INLET OR JUNCTION INLET STATION OUTLET WATER SURFACE ELEV. OIA PIPE Do (F) DESIGN DISGH, CO ICES) LENGTH PIPE Ln (FQ FRICTION SLOPE. So, (FT/FT) FRICTION LOSS Hf (F) JUNCTION LOSS FINAL H (Ft) INef Water �Hoce F fion RM Elev Cgnmen% Vn HA (ED OI m DM MN18 HI Angle HG HI 1.3 Hf 1 05 Hl 102 415.79 15 1 1.T6 80.46 0.06% 0.1 7.59 0.22 1.3 5.68 �.39 0.5 0.18 89.�9 0.35 D.T$ 0.97 FALSE 1.02 416.82 426.74 OK -9.93 UGD 418.86 15 1.3 S. 0.03% 0 5.68 0.13 0 0 0 0 0 0 1 0 0.13 0 1 FALSE OK -7.98 106 422.74 12 1.5 8.75 0.15% 0.01 6.66 0.17 0.4 4.06 1.61 0.26 0.09 90.16 0.18 0.44 0.57 TRUE 0.3 423.04 427.52 OK 4.48 108 423.04 12 0.4 38.88 0.01% 0 4.06 0.06 0.35 3.89 1.34 0.24 0.08 55.43 0.13 0.28 0 TRUE 0.14 423.18 427.95 OK 4.T1 110 423.42 12 0.35 8.89 0.01% 0 3.89 0.06 0.26 3.59 0.95 0.2 0.07 52.18 0.1 0.23 0.3 TRUE 0.15 423.57 427.99 OK 4.41 112 Ed 423.6 12 0.26 21.52 0.00% 0 3.59 0.05 0.26 3.6 0.95 0.2 0.07 69.51 0.12 0.24 0 TRUE 0.12 423.72 428.54 OK 4.82 114 424.13 12 0.26 15.74 0.00% 0 3.6 0.05 0.19 3.01 0.58 0.14 0.05 59.46 0.08 0.18 0.23 TRUE 0.12 424.24 427.83 OK -3.58 116 424.54 12 0.19 9.08 0.00% 0 3.01 0.04 0 0 0 0 0 0 0 0.04 0.05 TRUE 0.02 424.56 428.E OK 4.04 118 423.35 12 0.06 64.45 0.00Y. 1 0 1 225 1 0.02 1 0 1 0 1 0 1 0 1 0 1 0 1 0 0.02 0.03 FALSE 0.03 423.38 1 430.61 1 OK -7.23 1S PRE AREA 1A 2S �` 5L PRE AREA 1 B AP1 4S PRE AREA 1-OFF 3S PRE AREA 2 Subcat Reach on Link Routing Diagram for 47165 PRE Prepared by Timmons Group, Printed 1/14/2021 FHyd,,GAD(D 10.00-20 s/n 08663 © 2017 HydroCAD Software Solutions LLC 47165 PRE Prepared by Timmons Group Printed 1/14/2021 Area Listing (all nodes) Area CN Description (acres) (subcatchment-numbers) 0.439 61 >75% Grass cover, Good, HSG B (1S, 2S, 3S, 4S) 0.041 80 >75% Grass cover, Good, HSG D (3S) 0.507 98 Paved parking, HSG D (1S, 2S, 3S, 4S) 0.987 81 TOTAL AREA 47165 PRE Prepared by Timmons Group Printed 1/14/2021 Soil Listing (all nodes) Area Soil Subcatchment (acres) Group Numbers 0.000 HSG A 0.439 HSG B 1S, 2S, 3S, 4S 0.000 HSG C 0.548 HSG D 1S, 2S, 3S, 4S 0.000 Other 0.987 TOTAL AREA 47165 PRE Prepared by Timmons Printed 1/14/2021 Panes d Ground Covers (all nodes) HSG-A HSG-B HSG-C HSG-D Other Total Ground Subcatchment (acres) (acres) (acres) (acres) (acres) (acres) Cover Numbers 0.000 0.439 0.000 0.041 0.000 0.480 >75% Grass cover, Good 1S, 2S, 3S, 4S 0.000 0.000 0.000 0.507 0.000 0.507 Paved parking 1S, 2S, 3S, 4S 0.000 0.439 0.000 0.548 0.000 0.987 TOTAL AREA 47165 PRE Type II 24-hr 10 YR Rainfall=5.50" Prepared by Timmons Group Printed 1/14/2021 HydroCAD® 10.00-20 s/n 08663 ©2017 HydroCAD Software Solutions LLC Page 5 Time span=0.00-30.00 hrs, dt=0.05 hrs, 601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment1S:PRE AREA1A Runoff Area=0.246ac 89.84%Impervious Runoff Depth=4.80" Tc=6.0 min CN=94 Runoff=1.82 cfs 0.098 of Subcatchment2S: PRE AREA 11113 Runoff Area=0.159 ac 88.68% Impervious Runoff Depth=4.80" Tc=6.0 min CN=94 Runoff=1.17 cfs 0.064 of Subcatchment3S: PRE AREA2 Runoff Area=0.169 ac 33.73% Impervious Runoff Depth=3.14" Tc=6.0 min CN=78 Runoff=0.91 cfs 0.044 of Subcatchment4S: PRE AREA 1 -OFF Runoff Area=0.413ac 21.31%Impervious Runoff Depth=2.33" Tc=6.0 min CN=69 Runoff=1.68 cfs 0.080 of Link 5L: AN Inflow=4.64 cfs 0.242 of Primary=4.64 cfs 0.242 of Total Runoff Area = 0.987 ac Runoff Volume = 0.286 of Average Runoff Depth = 3.48" 48.63% Pervious = 0.480 ac 51.37% Impervious = 0.507 ac 47165 PRE Prepared by Timmons Type II 24-hr 10 YR Rainfall=5.50" Printed 1/14/2021 Summary for Subcatchment 1S: PRE AREA 1A Runoff = 1.82 cfs @ 11.96 hrs, Volume= 0.098 af, Depth= 4.80" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 10 YR Rainfall=5.50" Area (ac) CN Description 0.221 98 Paved parking, HSG D 0.025 61 >75% Grass cover, Good, HSG B 0.246 94 Weighted Average 0.025 10.16% Pervious Area 0.221 89.84% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, E Subcatchment 1S: PRE AREA 1A Hydrograph �T i i i i i i i i i i i i i i i ■Runoff Type II 24ihr 10 YR RaiinfallT5.507 R6nbff Au66=0.246 at, Runoff', V.ol',ulrne=',0.',0$8', at Runoff DepthF4410 " T'c=6,0': n1in PN='94 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) 47165 PRE Prepared by Timmons Type II 24-hr 10 YR Rainfall=5.50" Printed 1/14/2021 Summary for Subcatchment 2S: PRE AREA 1 B Runoff = 1.17 cfs @ 11.96 hrs, Volume= 0.064 af, Depth= 4.80" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 10 YR Rainfall=5.50" Area (ac) CN Description 0.018 61 >75% Grass cover, Good, HSG B 0.141 98 Paved parking, HSG D 0.159 94 Weighted Average 0.018 11.32% Pervious Area 0.141 88.68% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 2S: PRE AREA 1 B Hydrograph ❑ Runoff Type II 24-hr 10 YR Rainfall=5.50" Runoff Area=0.159 ac Runoff Volume=0.064 of Runoff Depth=4.80" Tc=6.0 min CN=94 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) 47165 PRE Prepared by Timmons Type II 24-hr 10 YR Rainfall=5.50" Printed 1/14/2021 Summary for Subcatchment 3S: PRE AREA 2 Runoff = 0.91 cfs @ 11.97 hrs, Volume= 0.044 af, Depth= 3.14" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 10 YR Rainfall=5.50" Area (ac) CN Description 0.071 61 >75% Grass cover, Good, HSG B 0.057 98 Paved parking, HSG D 0.041 80 >75% Grass cover, Good, HSG D 0.169 78 Weighted Average 0.112 66.27% Pervious Area 0.057 33.73% Impervious Area Tc Length Capacity Description 6.0 Direct Entry, Subcatchment 3S: PRE AREA 2 Hydrograph ❑ Runoff Type II 24-hr 10 YR Rainfall=5.50" Runoff Area=0.169 ac Runoff Volume=0.044 of Runoff Depth=3.14" Tc=6.0 min CN=78 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) 47165 PRE Prepared by Timmons Type II 24-hr 10 YR Rainfall=5.50" Printed 1/14/2021 Summary for Subcatchment 4S: PRE AREA 1-OFF Runoff = 1.68 cfs @ 11.98 hrs, Volume= 0.080 af, Depth= 2.33" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 10 YR Rainfall=5.50" Area (ac) CN Description 0.325 61 >75% Grass cover, Good, HSG B 0.088 98 Paved parking, HSG D 0.413 69 Weighted Average 0.325 78.69% Pervious Area 0.088 21.31% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 4S: PRE AREA 1-OFF Hydrograph I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I in v 1 I I I I I I I I I I I I I I I I I I I I LL I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I i Type II 24-hr 10 YR Rainfall=5.50" Runoff Area=0.413 ac Runoff Volume=0.'080'af Runoff Depth=2.33" Tc=6.0 min CN=69 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) ❑ Runoff 47165 PRE Prepared by Timmons Type II 24-hr 10 YR Rainfall=5.50" Printed 1/14/2021 Summary for Link 5L: AP1 Inflow Area = 0.818 ac, 55.01 % Impervious, Inflow Depth = 3.55" for 10 YR event Inflow = 4.64 cfs @ 11.97 hrs, Volume= 0.242 of Primary = 4.64 cfs @ 11.97 hrs, Volume= 0.242 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Link 5L: AN Hydrograph ❑ Inflow ❑ Primary 5 4 64 4Md, crs Inflow Area=0.818 ac 4 3 _I__I_i_I__I__I__I__i_I__i__I__I__i_I____I__ Lam" i l l i l i l I l l i l l l l i l i l l i l i l 3 l l l l l -T-,--I--� _r_r_7__I__ l l l l l l l l l l l -I--I-r_r_7-I-T_r_r-7--i--I _r_r_7__I__i - p i LL I I I I I I I I I I I I I I I I I 2 1 i I 1 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) 1S POST ARE 1A 2S 4P POST AREA 1 B SWM A 5S 6L AP1 POST AREA 1 C (4S POST AREA 1-OFF POST AREA 2 S4 Reach Aon Llnk 47165 POST Prepared by Timmons Area Listing (all nodes) Area CN Description (acres) (subcatchment-numbers) 0.464 61 >75% Grass cover, Good, HSG B (1S, 2S, 4S, 5S) 0.004 80 >75% Grass cover, Good, HSG D (3S) 0.519 98 Paved parking, HSG D (1S, 2S, 3S, 4S, 5S) 0.987 81 TOTAL AREA Printed 1/14/2021 47165 POST Prepared by Timmons Area Soil Soil Listing (all nodes) Subcatchment (acres) Group Numbers 0.000 HSG A 0.464 HSG B 0.000 HSG C 0.523 HSG D 0.000 Other 0.987 1S, 2S, 4S, 5S 1S, 2S, 3S, 4S, 5S TOTAL AREA Printed 1/14/2021 47165 POST Prepared by Timmons Ground Covers (all nodes) Printed 1/14/2021 HSG-A HSG-B HSG-C HSG-D Other Total Ground Subcatchment (acres) (acres) (acres) (acres) (acres) (acres) Cover Numbers 0.000 0.464 0.000 0.004 0.000 0.468 >75% Grass cover, Good 1S, 2S, 3S, 4S, 5S 0.000 0.000 0.000 0.519 0.000 0.519 Paved parking 1S, 2S, 3S, 4S, 5S 0.000 0.464 0.000 0.523 0.000 0.987 TOTAL AREA 47165 POST Prepared by Timmons Pipe Listing (all nodes) Printed 1/14/2021 Line# Node In -Invert Out -Invert Length Slope n Diam/Width Height Inside -Fill Number (feet) (feet) (feet) (ft/ft) (inches) (inches) (inches) 1 4P 418.00 417.66 9.7 0.0351 0.013 15.0 0.0 0.0 47165 POST Type II 24-hr 10 YR Rainfall=5.50" Prepared by Timmons Group Printed 1/14/2021 HydroCAD® 10.00-20 s/n 08663 ©2017 HydroCAD Software Solutions LLC Page 6 Time span=0.00-30.00 hrs, dt=0.05 hrs, 601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment1S:POSTAREA1A Runoff Area=0.108ac 68.52%Impervious Runoff Depth=3.94" Tc=6.0 min CN=86 Runoff=0.70 cfs 0.035 of Subcatchment2S:POSTAREA16 Runoff Area=0.296ac 76.01%Impervious Runoff Depth=4.25" Tc=6.0 min CN=89 Runoff=2.03 cfs 0.105 of Subcatchment3S: POSTAREA2 Runoff Area=0.022 ac 81.82% Impervious Runoff Depth=4.92" Tc=6.0 min CN=95 Runoff=0.16 cfs 0.009 of Subcatchment4S:POSTAREAI-OFF Runoff Area=0.413ac 21.31 % Impervious Runoff Depth=2.33" Tc=6.0 min CN=69 Runoff=1.68 cfs 0.080 of Subcatchment5S:POSTAREAIC Runoff Area=0.148ac 77.03%Impervious Runoff Depth=4.36" Tc=6.0 min CN=90 Runoff=1.03 cfs 0.054 of Pond 4P: SWM A Peak Elev=422.74' Storage=0.019 of Inflow=2.03 cfs 0.105 of Outflow=1.30 cfs 0.105 of Link 6L: AN Inflow=4.56 cfs 0.274 of Primary=4.56 cfs 0.274 of Total Runoff Area = 0.987 ac Runoff Volume = 0.283 of Average Runoff Depth = 3.44" 47.42% Pervious = 0.468 ac 52.58% Impervious = 0.519 ac 47165 POST Prepared by Timmons Type II 24-hr 10 YR Rainfall=5.50" Printed 1/14/2021 Summary for Subcatchment 1S: POST AREA 1A Runoff = 0.70 cfs @ 11.97 hrs, Volume= 0.035 af, Depth= 3.94" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 10 YR Rainfall=5.50" Area (ac) CN Description 0.074 98 Paved parking, HSG D 0.034 61 >75% Grass cover, Good, HSG B 0.108 86 Weighted Average 0.034 31.48% Pervious Area 0.074 68.52% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 1S: POST AREA 1A I I .I }_y _I _F_{_y _I _h_{_y 0.iQ 0.7 = = = = -,- ; ; :Type 11 2�4-hr 0.65 {-------------}-.-{--I 10 YR Rainfall=5.50" 0.6 .-I --_-_-_-' 0.55 I I I I I I I I I I I Runoff Area=0.108ac 05 , Runoff Volume=0.035 of � 0.45 I I I I I I I I I I ,- I- r-,-,----r-,-,- Runoff Depth=3.94" 0.4 i----IJ-'-----L-i-�- -i-----`-� ° 0.35 I I I I I I I I I I " I I I I I I I I I Tc=6.0 min v. I I I I I I I I I I I I I I I I I I -I 0.25 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 02 0.15 -r-�--r-r-�-�--r-r-r-r- -r--I--r-r-i--I--r-r-7--I--r-r-7--r-r-r-7- 01 11 I 1 I 1 I I I I I I 1 I 1 1 1 1 I 1 I 1 I 1 1 1 I 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) ■ Runoff 47165 POST Prepared by Timmons Type II 24-hr 10 YR Rainfall=5.50" Printed 1/14/2021 Summary for Subcatchment 2S: POST AREA 1 B Runoff = 2.03 cfs @ 11.96 hrs, Volume= 0.105 af, Depth= 4.25" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 10 YR Rainfall=5.50" Area (ac) CN Description 0.071 61 >75% Grass cover, Good, HSG B 0.225 98 Paved parking, HSG D 0.296 89 Weighted Average 0.071 23.99% Pervious Area 0.225 76.01% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 2S: POST AREA 1 B Hydrograph ❑ Runoff Type II 24-hr 10 YR Rainfall=5.50" Runoff Area=0.296 ac Runoff Volume=0.105 of Runoff Depth=4.25" Tc=6.0 min CN=89 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) 47165 POST Prepared by Timmons Type II 24-hr 10 YR Rainfall=5.50" Printed 1/14/2021 Summary for Subcatchment 3S: POST AREA 2 Runoff = 0.16 cfs @ 11.96 hrs, Volume= 0.009 af, Depth= 4.92" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 10 YR Rainfall=5.50" Area (ac) CN Description 0.018 98 Paved parking, HSG D 0.004 80 >75% Grass cover, Good, HSG D 0.022 95 Weighted Average 0.004 18.18% Pervious Area 0.018 81.82% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 3S: POST AREA 2 0.18 ----- I I ---------- I I I 1 I I 1 -r-�--r-r-7-r--r-r-r--� 017 I 1F1 - r- r--r-r-�- r--r-r-r-r 0.16 0.15 1 014 'I 0.11 I 1 I I I I I I I I I I N V 0.1 0.09 -I 1 r-1 v: 0.08 I 1 -r-r--r-r-1-l--I r-T-r_ 0.07 0.06 0.05 0.04 I 0.03 I I I I I I I I I I 1 0.02 11 11 11 11 11 11 11 Hydrograph --------------- I I I I I I I I I I I 1 7--1--r r-I--r-r-r-1--r-r-r-r- I I I I I I I I I I I I I I I I I I I I I I I I I I y I I I I I I I I I I I ~1110YR-Rahlnfaif:;5 7 SO"- ...... - l I Rulnbff-Arta=0,0212 ad- R"n0ff /oflume=-0.-00111of 1 ______ __________ 11r I Rulnof Depth--442'! I 1 1 1 y^FI I I ,ny l -i-1-_1__1-_r-i__1__ TtT Vi�r�lll• -�--I--r-r-�--1--r-r-�--1--r-r-�--r-r-r-�- I I I I I I I I I I I I I I 1 I I I 1 1 1 1 I 1 I 1 I 1 1 1 1 1 I I I 1 1 1 1 I 1 I 1 I 1 1 1 1 1 I I I 1 1 1 1 I 1 I 1 I 1 1 1 1 1 1 1 1 1 1 1 1 __I__7- 1'. 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) ■ Runoff 47165 POST Prepared by Timmons Type II 24-hr 10 YR Rainfall=5.50" Printed 1/14/2021 Summary for Subcatchment 4S: POST AREA 1-OFF Runoff = 1.68 cfs @ 11.98 hrs, Volume= 0.080 af, Depth= 2.33" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 10 YR Rainfall=5.50" Area (ac) CN Description 0.325 61 >75% Grass cover, Good, HSG B 0.088 98 Paved parking, HSG D 0.413 69 Weighted Average 0.325 78.69% Pervious Area 0.088 21.31% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 4S: POST AREA 1-OFF Hydrograph I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I in v 1 I I I I I I I I I I I I I I I I I I I I LL I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I i Type II 24-hr 10 YR Rainfall=5.50" Runoff Area=0.413 ac Runoff Volume=0.'080'af Runoff Depth=2.33" Tc=6.0 min CN=69 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) ❑ Runoff 47165 POST Prepared by Timmons Type II 24-hr 10 YR Rainfall=5.50" Printed 1/14/2021 Summary for Subcatchment 5S: POST AREA 1C Runoff = 1.03 cfs @ 11.96 hrs, Volume= 0.054 af, Depth= 4.36" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 10 YR Rainfall=5.50" Area (ac) CN Description 0.034 61 >75% Grass cover, Good, HSG B 0.114 98 Paved parking, HSG D 0.148 90 Weighted Average 0.034 22.97% Pervious Area 0.114 77.03% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 5S: POST AREA 1 C Hydrograph ❑ Runoff 1 Type II 24-hr 10 YR Rainfall=5.50" Runoff Area=0.148 ac Runoff Volume=0.054 of Runoff Depth=4.36" Tc=6.0 min CN=90 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) 47165 POST Prepared by Timmons Type II 24-hr 10 YR Rainfall=5.50" Summary for Pond 4P: SWM A Printed 1/14/2021 Inflow Area = 0.296 ac, 76.01 % Impervious, Inflow Depth = 4.25" for 10 YR event Inflow = 2.03 cfs @ 11.96 hrs, Volume= 0.105 of Outflow = 1.30 cfs @ 12.05 hrs, Volume= 0.105 af, Atten= 36%, Lag= 4.9 min Primary = 1.30 cfs @ 12.05 hrs, Volume= 0.105 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Peak Elev= 422.74' @ 12.05 hrs Surf.Area= 0.004 ac Storage= 0.019 of Plug -Flow detention time= 6.3 min calculated for 0.105 of (100% of inflow) Center -of -Mass det. time= 6.2 min ( 794.1 - 787.9 ) Volume Invert Avail.Storage Storage Description #1 418.00' 0.022 of 72.0" Round Pipe Storage L= 34.0' Device Routing Invert Outlet Devices #1 Primary 418.00' 15.0" Round Culvert L= 9.7' CMP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 418.00' / 417.66' S= 0.0351 T Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.23 sf #2 Device 1 418.00' 3.5" Vert. Orifice/Grate C= 0.600 #3 Device 1 420.50' 4.0" Vert. Orifice/Grate C= 0.600 #4 Device 1 422.74' 4.9' long Sharp -Crested Rectangular Weir 2 End Contraction(s) Primary OutFlow Max=1.29 cfs @ 12.05 hrs HW=422.72' (Free Discharge) L1=Culvert (Passes 1.29 cfs of 9.44 cfs potential flow) 2=Orifice/Grate (Orifice Controls 0.69 cfs @ 10.30 fps) 3=Orifice/Grate (Orifice Controls 0.60 cfs @ 6.90 fps) =Sharp -Crested Rectangular Weir( Controls 0.00 cfs) 47165 POST Prepared by Timmons 2 1 I I i LL Type 11 24-hr 10 YR Rainfall=5.50" Printed 1/14/2021 Pond 4P: SWM A Hydrograph ■Inflow ❑ Primary Infl' W1 1 06=0.296 ac P0Ak; r'l0v :422''; 74' Stbragii=6.O19 of --- - ---- - - - ---- --- - ---- ---- 4 5 6 7 8 8 10 11 12 13 14 15 16 ' Time (hours) 47165 POST Prepared by Timmons Type II 24-hr 10 YR Rainfall=5.50" Printed 1/14/2021 Summary for Link 6L: AP1 Inflow Area = 0.965 ac, 51.92% Impervious, Inflow Depth = 3.41" for 10 YR event Inflow = 4.56 cfs @ 11.98 hrs, Volume= 0.274 of Primary = 4.56 cfs @ 11.98 hrs, Volume= 0.274 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs 5 4 3 i I l i l i I 3 LL 1 Link 6L: AN Hydrograph ■ Inflow ■ Primary Inflow Area=0.965 as l i l i l l i l i l I I__I__i -F -1 1 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) NOAA Atlas 14, Volume 2, Version 3 Location name: Charlottesville, Virginia, USA* Latitude: 3levati °, : 435.4utle:-78.4641° Elevation: fl" } ESRI Me,. sau : USGS POINT PRECIPITATION FREQUENCY ESTIMATES G.M. gamin, O. Marlin, B. Lin, T. Parzybok, M.Yekta, and D. Rlley NOM, National weather Servica, Silver Spring, Maryland PF tabular I PF graphical I Maps & aerials PF tabular PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches)1 Average recurrence interval (years) Duration 000 10 251 50-rrl 100 200 500 1000 0.357 0.419 0.492 0.554 0.623 0.678 0.729 0.778 0.838 0.886 5-min (0.317-0.390) (0.379-0.465) (0.443-0.545) (0.497-0.612) (0.558-0.688) (0.604-0.747) (0.646-0.804) (0.684-0.858) (0.72a-0.96) (0.764-0S82) 133 10-min 0.506-0.622 0.8 5-0]44 0.70f0-0872 0.795-09]9 0.889--11..10 0.962-18.19 1.03-1128 1.09-2130 : 15-IA6 1.2041055 15-Into 0.701 0.843 0.997 1.12 1.26 1.37 F1AT 1.56 1.67 1.75 (0.633-0.]]8) (0.761-0.935) (0.898-1.10) 1 (1.01-1.24) 1 (1.13-1.39) 1 (1.22-1.51) 1 (1.30-1.61) 1 (1.37-1.72) 1 1 (1.51-1.94) 206 30-min 0.8684207 1.05-1L29 1.28-1.57 1,464279 1.67-2?D6 1.83-2.27 1. 9�4] 2.13220 2.31-22..93 2.44-94.14 F60 n 60-min (1.08-2123 1.32-�62 1.642.01) 1. 0-12.34 2.2�74 2:9-3.08 2.]43g41 2.9430.75 3.314.21 3.57-4.59 2-hr 1A4 F 1.75 F 2.19 F 2.58 F 3.07 F 3.48 F 3.91 F 4.38 F 4.98 5.51 (1.27-1.64) 1 (1.54-1.9) 1 (1.98-2.49) 1 (2.27-2.91) (2.693.47) (3.08-3.94) 1 (3.384.41) 1 (3144.91) 1 (4.23-5.62) 1 (4.63-6.24) 3-hf 1.391.81 1.68319 2: 0-2.75 2. 5321 2.913.82 3.293.33 3.67480 4.0 5.44 4.606.23 5.0s-6.91 2.01 2.43 3.02 3.55 4.27 4.90 5.56 6.27 7.30 8.19 F6-hr (1.78-2.28) (2.15-2.76) (2.6fi-3.42) (3.114.02) (3.72433) (4.24-5.52) (4.76-6.27) (5.32-7.0) (6.10-8.24) (6.75-9.27) 380 112 12-hr 2. 3 2289 2. 9348 3.34-0.34 3.94-5912 4. 5627 5.45-7.19 6. 8 825 6.979.47 8. 08141.2 9.09- 2.8 3.01 3.64 4.85 5.50 6.75 7.83 9.02 10.3 12.3 74.0 24-hr 2.70-3.38 3.274.9 4.16-5.22 4.91-6.16 5.984.54 8.89-8]2 87-10.0 8.91-11.5) 104-13.8 11.7-15.5 3.55 4.30 5.47 GA3 7.82 8.99 10.3 11.6 13.6 15.3 2-day (3.19-3.97) (1874.81) (4.90-6.10) (5.75-].1]) p&94d]0) (7.2-9.98) 1 (8.95-11.4) (10.1-12.9) (11.7-152) (13.0-17A) 3•day 3.34819 4.55.07 5.2 8.44 6.68.58 7.469.17 8.51-0.5 9.6312.0 10.8-8.8 12.58.0 13.19-8.0 4.01 4.86 6.18 7.24 8.80 10.1 11.5 13.0 15.2 17.1 4-day (3.6R4.42) (4.445.34) (5.63-6.78) 1 (6.60-7.95) (7.98-9.65) (9.11-11.1) 1 (10.3-12A) (11.6-14.3) (13.4-16.8) (14.9-18S) 7-deY 4.2 5609 5. 5313 6. 2]'67 .468692 8. 2-810.] 10.1' 2.2 114-13.8 1274--15.6 14.5-18.1 16.10- 0.2 10-13.1 74 10day 4.8]59]3 5. 58.88 7. 18848 8. 09419 9.83- 1.8 11.84 12.13-14.] 13.18--16.4 15.14- 8.9 16.1g- 0.9 6.94 8.28 10.00 11.4 13.2 14.6 16.1 17.6 19.6 21.2 20day (6.49-7.44) (7355.88) (9.34-10.7) 1 (10.6-12.2) 1 (12.3-14.1) 1 (13.5-15.7) 1 (14.9-1].3) 1 (16.2-18.9) 1 (179-212) 1 (19.2-210) 30daY 8,01 9,08 9.49-10.8 112-12.7 125-14.2 14216.2 15.4-7.6 16.17- 9.1 17.19- 0.5 194-22.5 20.5- 3.9 10.6 12.6 14.7 16.3 18.3 19.8 21.2 22.6 244 25.8 day 10.0-11.3 (11.8-13.3) 13.8-15.5) 1 (15.3-1].2) 1 (17.2-19.4) 1 (18.6-21.0) 1 (19.9-22.5) 1 (21.1-24.0) 22.7-0.0) 1 (23.8-27.5) 12.5 14.7 16.9 18.6 20.8 22.4 23.9 25.3 27.1 28.5 60day 11.8-13.2 13.9-15.5 16.A17.9 17.E-19.7 19.E-21.9 21.1-23.6 2.4-25.2 23.7-26.8 L2iL288LJ 26.5-30.2 1 Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS). Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency estimates em a given duration and average recurrence interval) will be greater then the upper bound (or less than the lower bound) Is 5%. Estimates at upper bounds ere not chill against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values. Please refer to Nil Atlas 14 document for more information. Back to Top PF graphical PDS-based depth -duration -frequency (DDF) curves Latitude: 38-0964', Longitude:-78.4641' 25 L 20 1 W v 0 15 n WG 10 E 2 c t r n w a 5 0 —� C C C C C T T T T T T T T T L L L L L ry g q ry q q ry qry A6AE E A �b A r d ri o a s u9. 9 Ourabon Average recurrence interval (years) NOAA Atlas 14, Volume 2, Version 3 Created (GMT): Tue Dec 816:53:24 2020 Back to Top Maps & aerials Small scale terrain _ !n •!A!BE RA9!E i� S-",3 Aa=oer - F%F 7 d 9. P 2 Westmoreland 3er i II 2.1 Large scale terrain In1arvW (ytura) 2 5 10 — 25 — 50 — 100 200 Soo 1000 Duration — "in — 2-cay — tamin — 3-day 15mm — "ay — 30min — 7-cay — 6".n — 10-day — 2-fir — 20-day — 3-f,r — 30-day — 0-hr — 45-day — 12-hr — 60-day — 24-hr t \ \ Washington, D.C� �An Ha .,.nburg . Staunron' —VIRGINIA A Rich{� � -Lynchburg 't �U 100km � 60mi � Large scale map 'i,�6altin 4;3 Anr WasD r: � �.� Hanlsaiburg �...�.v n amla Chmon oLynchburp M,rcW,urg Roanoke 00km 65mi Noriol Backto Top US DD@uatlment of Cammerce National Oceanic and Atmospheric Administration National Weather Service National Water Center 1325 East West Highway Silyer Spring, MD 20910 Questions?: HDSC.Questions�_noaa.gov Disclaimer DEQ Virginia Runoff Reduction Method Re -Development Compliance Spreadsheet -Version 3.0 02011 BMP Standards and Specifications O 2013 Draft BMW Standards and Spedficatiom don input cells Project Name: STARBUCKS 2233 SEMINOIE LN Date: JANUARY 12, 2021 -�as. values Linear Development Project? I NO I I I calculation cells Site Information Project (Treatment Volume and Loads) Enter Total Disturbed Area (acres) Unearp ?I No Land cover areas entered correctly? Total disturbed area entered? Land Cover torn lc D.m Managed Tud(a lies)-- disturbed, graeadfor yards or diner but to be mowed/managed 0.11 0.04 0.16 Impervious Cover (acres) rde1eefores7 orrdaestetl land s 0.01 Managed Tud (acres) disturbed graded for cards or other tudto be mowed manaed 0.14 0.00 0.15 Impervious Cover (Rome) 0.39 0.04 OA3 Area Check OK OK OIL OIL aw Annual Rainfall(inches) 43 ASaIIS B52 115 L 21-IS DSoa$ Target Rainfall Event (indws) CO1.ForesVOpen Spare 0.02 0.03 0.04 0.05 Total Phossolborus Ml ERIC fm¢N 1 0.26 1 Managed Turt 1 0.15 1 0.20 1 0.22 1 0.25 Pre-ReDevelopment Dated Adjusted Port Regime. a New Impervious Forest/Open Spare Cover (acres) 0.00 am Fm� Opaer c Space 0.00 Weighted Rv(forest) 0.00 am weighted Rv(finest) 0.00 %Forest 096 0% Is Forest 0% Managed Tud Cover(acres) 0.16 0.15 Managed Turt Cover 0.15 weighted Rv(tud) 0.21 0.20 weighted Rv(turf) 0.20 %Managetl Turf 2] 26% %Managed Tud 25% Impervious Cover (acres) 0A2 0.42 Impera in over 043 Bv(impervious) 0.95 0.95 Rv(impervious) 0.95 %Impervious 73% 74% %Impervious 75% Taal Site Area(aaes) 0.57 0.57 Final Site Area (Rome) 0.57 Site RV 0.75 0.76 Final Port Dev56e Rv 0.76 Treatment Volume and Nutrient Load Pre-ReoenelapmeM Treatment Volume ntire Final Port -Development (e 0.0359 0.0356 TreatmentValume acre-ft) 0.0363 Pre-ReDevelopment Treatment Volume Final Port -Development (cubic fed) 1,565 1,552 Treatment Volume 1,583 (cubic fed) Pre-ReDevelopment TP Load Final post- 0.98 0.97 Development TP Load 0.99 (lb/yr) (Ib/Ym) Fie-IIeOerelapmemlP Loaf peracre FLaIPosr-0ere1opment TP pb/naWL 171 1.73 Icait per aere 1.73 pb/aaetyq Baseline TP ised (Ib/yr) (aavbs/aae/yr applied m prereeevempment area excluding nervous a13 land peopoaed bar new impervious mrerl We ReDewlopment land cover minuspemous land rover (Jorest/open space or managM turf) acreage propmedfor new impervious rover. Adjusted total acreage is consistent with Post-ReDevelopment acreage (minus acreage of new impervious cover). Column Ishows load reduction re ludement fornew impervious cover (based on new development loadlimiq 0..41 Ibslocre/year). TP Load Reduction Required (lb/yr) lareAeDevdopmenaTN Lcrad(lb/yr) 7.03 Pod-ReDevelopmed Forest/Open Spare 000 Cover apes weighted Anatomist) 0.00 %Forest a% Managed Tud Cover acre 0.15 weighted RV (turn 0.20 %Managed Turt 26% ReDev. lmpeervirde 042 Cover( es) Nv(impervious) 0.95 %Impervious 74% Total neither. She Area acre 057 RGDw56e Rv O.76 Treatment Volume and Nutrient Load Post-ReDevelopment Treatment Volume 0.0 % (acro-fl) Pod-ReDevelopment Treatment volume 1,552 (mblefeeu Pod-ReDevelopment Load (Tel 0.97 (Ib/yq• as Raw TP wad per acre Ilblave/yr) Max. Reduction Required uld. Reaevelopme ni Mad) Post -Development New Impervious New l mpervlous Cover 0.01 e cres) Rviirmerdousl 1 0.95 Port-Developmed Treatment Volume (acre-fu Pod -Development eaMeM Vdume lah Read) Pod-DHrelopment TP Wind(lb/yr) F ad Redudianquired for TP Load Redudian veloped AreaF Required for New 0.02 (Ib/yr) Impervious Area (Ib/yr) 0.11 Nitrogen Loads (Informational Purposes Only) Final post-0ewlopmenlTN Load Site Results (Water Quality Compliance) Area Checks D.a a DA. B D.A. C D.A.0 D.& E n OEOK FOREST/OPEN SPACEJac) a a 0.00 O.m 0.00 OIL IMPERVIOUS COVER Jac) O.m 0.m 0.00 0.m 0.00 OIL IMPERVIOUSC&MRTRFATED(ac) O.m O.m 0.00 0.m 0.00 mL bLW1WED TURF ARFA(ac) O.m O.m 0.00 O.m 0.00 M MfWAGEDTURFARFATRFATED(ac) Om O.m OAO Om OAO M ARFACNECK ML OR. OK. OK. OK. Site Treatment volume (fa) 1,583 �7 Runoff Reduction volume and TP Ely Drainage Area D.A. A DA. B O.A. C D.A.0 O.A. E TOTAL RUNOFF REOUMN VOLUMEACNIEVFO(N3) 0 0 0 0 0 0 TP UMOAVAIIABM FOR REMDVAL (Ib/yr) 0.00 am am 0.00 am 0.00 TP LOAD RMMMON ACNIEVED(Ib/yr) 0.00 am am 0.00 0.00 O.m TP LOAD REMAINING (Ib/yr) 0.00 am 0.00 000 0.00 0.00 MmOGENLDADREOUCTIONACNIEVED (lb/yr)II 0.00 110.00 0.00 0.00 0.00 0.00 Total Phosphorus RhXP-OEVELOMENTTPUMD(Ib/y) a" T UNN REDUCTION REQUIRE)(Ib/yr) an TP LOAD REWOION ACNIEVED(Ib/yr) aw TP LOAD REMAINING(Ib/yr): a" REMAINING TP LOAD REOUCDON REQUIRED(Ib/yr): on Total Nitrogen (For Information Purposes) POST-MWD MENr LOAD(Ibhr) 7M MIROGFNLDADRED"ONACNIEVED (lb/yr) aw RMIMNING POST-DEVEUR+MENT NOROGEN LOAD(Ib/yr) M