Loading...
HomeMy WebLinkAboutWPO202000027 Correspondence 2020-09-23SHIMP ENGINEERING, P.C. Design Focused Engineering September 23r", 2020 Regarding: Eldon Farm Residence —SWM Calculation Packet Dear Reviewer, Enclosed is the stormwater calculation packet for the Eldon Farm Residence in Albemarle County, VA. This site will disturb an area of 3.07 acres. The proposed stormwater design meets the runoff requirements set forth in 9VAC25- 870-65 and 9VAC25-870-66. The conditions of subsection D of 9VAC25-870-66 Water Quantity have been met for this site. Three (3) Level Spreaders are utilized for areas of concentrated flow to create sheet flow conditions to the receiving stream. All other area of the site is managed through sheet flow directly offsite. Per Albemarle County specifications, the Water Quality is not addressed for this project, as it is a single family residence and is therefore exempt from the Water Quality Requirements. If you have any questions please do not hesitate to contact me at: Justin@shimp-engineedng.com or by phone at 434-227-5140 ext. 3. Regards, Justin Shimp, P.E. Shimp Engineering, P.C. Contents: Pre -Development Runoff Quantity Calculations: Pre-Dev Drainage Map Pre-Dev HydroCAD Report Pre-Dev Time of Concentration Calculations Post-Dev Runoff Quantity Calculations: Post-Dev Drainage Map Post-Dev Time of Concentration Calculations VDOT LD-229 Culvert Capacity VDOT LD-268 Ditch Capacity Post-Dev HydroCAD Report Independent Reports: Excerpt from NRCS Soils Report NOAA Precipitation Report Post-Dev Runoff Quantity Calculations: Pre-Dev Drainage Map Post-Dev Drainage Map Post-Dev Drainage Summary Post-Dev HydroCAD Report -- ----'------ ------------ HSG g '- ------------------------ - --------------------', r—----------------------- — N, Ilk Flo \. v —' LIMITS OF DISTURBANCE---� "'�t':(:;�— `:� ♦' \���� � \ \I HSGE3 TJIP -43 415 PC 6fo rerr ss_ ; f: j 1 i f/ B lid 10 -• `— — —BBB-- �, ww — �I / / / / / / / / ----- -- Eldon Farm Pre -Development — — — — 1— ---- ------ ------------- — ----- -- �__- __ _ __ __ t- _________- __, ---_- /''•�—_r REVISED:6 112020 -- �„ SHIMPENGINEERM,, P. C. 80 0 80 160 240 ENGINEERING-L9NDPLANNM6- PROJECT MANAGEMENT 912 E MION ST PHONE: (434) 227-5140 SCALE: 1 "-80' CHARLO? ESMLLE. VA 22902 JUSTINO HIMP-ENGINEERING.COM a, ---- a, HSG g __-------- ------------- r' '' _--------- L5-I ., LIP= 3-FT a„ 'Ilk �� ',♦ --------SHEETFLOW /�� SHEETFLOW -------- i LIMITS OF DISTURBANCE H 3.07 AC - - \��W. LS-3 �A11� r DA - , ♦} LIP-13-FT i / ♦ - .- \ 0.G2 AC ` \ 1 I \ , - HSG ..: •. % l \ �.• zl5pft dj r-ram-_ 0.38AC I / iE e It O6 D ss_zc -T _ \ \ DA-2 I r 618 O \ 0.80 AC TM-.A2 2 84Ap ♦ �Il d- i" % 0is j Drainage Area Land Cover Summary DA Cover s( ac Building 2116 0.05 Road 2920 007 1 InperHous 5036 0.12 Turf 2192300 om Woods 0 0 Total 26959 0.62 DA Cover s( ac Building 0 0-00 Road 65M OAS 2 Impervious 6500 0.15 Turf 28527 065 Woods 0 0-00 Total 3SD27 0.80 DA Cover s/ ac Building 3292 008 Road 11016 0,25 3 Impervious 14308 0-33 Turf 2127 0,05 Woods 0 0-00 Total 16435 0.38 Eldon Farm / ---------- - •. / jl ------ LIP= - ------ - ---- - / / P - n t _ os eve opme _____________ ______ __ - ' SWM DA Map ( - - == _ ------------ -------------- ______ REVISED:6-I I-2020 _______________________ _- ---�,�------------ --- ----------------------- ----____________=------- / � c SHIMPENGIN MY6, P.C, K11 ------ 80 0 80 160 240 r ENGINEERING-L AT MAT7NW -PROJECT MANAOMENT HIGH ST PHONE: I 227-5140 SCALE: 1 "=80' CHARLOT SVILLE. VA 22902 JVSTNC HIMP-ENGNEERINGSC M Drainage Area Land Cover Summary DA Cover sf ac Building 2116 0.05 Road 2920 0.07 1 Impervious 5036 0.12 Turf 21923.00 0.50 Woods 0 0 Total 26959 0.62 DA Cover sf ac Building 0 0.00 Road 6500 0.15 2 Impervious 6500 0.15 Turf 28527 0.65 Woods 0 0.00 Total 35027 0.80 DA Cover sf ac Building 3292 0.08 Road 11016 0.25 3 Impervious 14308 0.33 Turf 2127 0.05 Woods 0 0.00 Total 16435 0.38 DA Runoff Flowrates 1-in cfs 1-YR cfs 10-YR cfs 0.001 0.82 2.57 1-YR cfs 10-YR cfs 100-YR cfs 0.001 0.99 3.2 1-YR cfs 10-YR cfs 100-YR cfs 0.3 1.25 2.45 Level Spreaders Computed Level Spreader Lip Length (ff) Provided Level Spreader Lip Length (ff) 0.013 13 Computed Level Spreader Lip Length (ff) Provided Level Spreader Lip Length (ff) 0.013 13 Computed Level Spreader Lip Length (ft) Provided Level Spreader Lip Length (ff) 3.9 13 '13-Rpercfs(1-in Storm) (13-ftmin.) 1S DA-1 2R � POOL- 3P Eldon Farm Residence Post -Development HydroCAD Report 4/24/2020 5S DA-2 9S DA-3 6R 1OR IL POOL 2 L -POOL-3 A°B ce 7P 11 LS LIP-1 LS LIP-2 LS LIP-3 S4 Reach Aon Llnk Eldon Farm Residence Postdevelopment ELDON FARM Type 1124-hr 1-in Rainfall- 1. 00" Prepared by Shimp Engineering Printed 4/24/2020 HydroCAD®10.10-3b s/n M21870 © 2020 HydroCAD Software Solutions LLC Paae 2 Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method SubcatchmentlS: DA-1 Runoff Area=0.620ac 19.35%Impervious Runoff Depth>0.02" Tc=9.0 min CN=75 Runoff=0.00 cfs 0.001 of Subcatchment5S: DA-2 Runoff Area=0.800ac 18.75%Impervious RunoffDepth>0.02" Tc=9.0 min CN=74 Runoff=0.00 cfs 0.001 of Subcatchment9S: DA-3 Runoff Area=0.380ac 86.84%Impervious RunoffDepth>0.46" Tc=9.0 min CN=94 Runoff=0.30 cfs 0.015 of Reach 2R: LS POOL - 1 Avg. Flow Depth=0.00' Max Vet=0.09 fps Inflow=0.00 cfs 0.001 of n=0.025 L=10.0' S=0.0010 7 Capacity=64.74 cfs Outflow=0.00 cfs 0.001 of Reach 6R: LS POOL 2 Avg. Flow Depth=0.00' Max Vet=0.09 fps Inflow=0.00 cfs 0.001 of n=0.025 L=10.0' S=0.0010 ? Capacity=79.75 cfs Outflow=0.00 cfs 0.001 of Reach 10R: LS-POOL-3 Avg. Flow Depth=0.04' Max Vet=0.22 fps Inflow=0.30 cfs 0.015 of n=0.025 L=10.0' S=0.0010 7 Capacity=60.99 cfs Outflow=0.29 cfs 0.015 of Pond 3P: LS LIP-1 Peak EIev=1.00' Inflow=0.00 cfs 0.001 of Outflow=0.00 cfs 0.001 of Pond 7P: LS LIP-2 Peak Elev=1.00' Inflow=0.00 cfs 0.001 of Outflow=0.00 cfs 0.001 of Pond 11 P: LS LIP-3 Peak EIev=1.02' Inflow=0.29 cfs 0.015 of Outflow=0.29 cfs 0.015 of Total Runoff Area =1.800 ac Runoff Volume = 0.017 of Average Runoff Depth = 0.11" 66.67% Pervious =1.200 ac 33.33% Impervious = 0.600 ac ELDON FARM Summary for Subcatchment 1S: DA-1 Runoff = 0.00 cfs @ 12.95 hrs, Volume= 0.001 at Depth> 0.02" Eldon Farm Residence Postdevelopment Type 1124-hr 1-in Rainfall- 1. 00" Printed 4/24/2020 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1-in Rainfall=1.00" 0.120 98 Impervious 0.500 69 50-75% Grass cover, Fair, HSG B 0.620 75 Weighted Average 0.500 80.65% Pervious Area 0.120 19.35% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.0 Direct Entry, Summary for Subcatchment 5S: DA-2 Runoff = 0.00 cfs @ 13.50 hrs, Volume= 0.001 at Depth> 0.02" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1-in Rainfall=1.00" Area (ac) CN Description ' 0.150 98 Impervious 0.650 69 50-75% Grass cover, Fair, HSG B 0.800 74 Weighted Average 0.650 81.25% Pervious Area 0.150 18.75% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.0 Direct Entry, Summary for Subcatchment 9S: DA-3 Runoff = 0.30 cfs @ 12.01 hrs, Volume= 0.015 at Depth> 0.46" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1-in Rainfall=1.00" 0.330 98 Impervious 0.050 69 50-75% Grass cover, Fair, HSG B 0.380 94 Weighted Average 0.050 13.16% Pervious Area 0.330 86.84% Impervious Area ELDON FARM Eldon Farm Residence Postdevelopment Type 1124-hr 1-in Rainfall-1.00" Printed 4/24/2020 Tc Length Slope Velocity Capacity Description (min) (feet) (fl/tt) (ft/sec) (cfs) 9.0 Direct Entry, Summary for Reach 2R: LS POOL • 1 Inflow Area = 0.620 ac 19.35%Impervious, Inflow Depth > 0.02" for 1-in event Inflow = 0.00 cfs @ 12.95 hrs, Volume= 0.001 of Outflow = 0.00 cfs @ 13.01 hrs, Volume= 0.001 af, Atten= 01/q Lag= 3.8 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 0.09 fps, Min. Travel Time= 1.9 min Avg. Velocity = 0.09 fps, Avg. Travel Time=1.9 min Peak Storage= 0 cf @ 12.98 hrs Average Depth at Peak Storage= 0.00' , Surface Width= 34.00' Bank -Full Depth= 1.00' Flow Area= 36.0 sf, Capacity= 64.74 cfs 34.00' x 1.00' deep channel, n= 0.025 Rubble masonry, cemented Side Slope Z-value= 2.0 ? Top Width= 38.00' Length=10.0' Slope= 0.0010 ? Inlet Invert= 0.00', Outlet Invert= -0.01' Summary for Reach 6R: LS POOL 2 Inflow Area = 0.800 ac 18.75%Impervious, Inflow Depth > 0.02" for 1-in event Inflow = 0.00 cfs @ 13.50 hrs, Volume= 0.001 of Outflow = 0.00 cfs @ 13.57 hrs, Volume= 0.001 af, Atten= 0% Lag= 4.1 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 0.09 fps, Min. Travel Time= 1.9 min Avg. Velocity = 0.09 fps, Avg. Travel Time=1.9 min Peak Storage= 0 cf @ 13.53 hrs Average Depth at Peak Storage= 0.00' , Surface Width= 42.00' Bank -Full Depth= 1.00' Flow Area= 44.0 sf, Capacity= 79.75 cfs 42.00' x 1.00' deep channel, n= 0.025 Rubble masonry, cemented Side Slope Z-value= 2.0 ? Top Width= 46.00' Length=10.0' Slope= 0.0010 ? Inlet Invert=0.00', Outlet Invert=-0.01' ELDON FARM Summary for Reach 1 OR: LS-POOL-3 Eldon Farm Residence Postdevelopment Type H 24-hr 1-in Rainfall-1.00" Printed 4/24/2020 Inflow Area 0.380ac 86.84%Impervious, Inflow Depth > 0.46" for 1-in event Inflow = 0.30 cfs @ 12.01 hrs, Volume= 0.015 of Outflow = 0.29 cfs @ 12.03 hrs, Volume= 0.015 af, Atten= 4% Lag= 1.3 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 0.22 fps, Min. Travel Time= 0.7 min Avg. Velocity = 0.09 fps, Avg. Travel Time= 1.8 min Peak Storage=13 cf @ 12.01 hrs Average Depth at Peak Storage= 0.04' , Surface Width= 32.17' Bank -Full Depth= 1.00' Flow Area= 34.0 sf, Capacity= 60.99 cis 32.00' x 1.00' deep channel, n= 0.025 Rubble masonry, cemented Side Slope Z-value= 2.0 ? Top Width= 36.00' Length=10.0' Slope= 0.0010'P Inlet Invert-- 0.00', Outlet Invert=-0.01' Summary for Pond 3P: LS LIP-1 Inflow Area = 0.620 ac 19.35%Impervious, Inflow Depth > 0.02" for 1-in event Inflow = 0.00 cfs@ 13.01 hrs, Volume= 0.001 of Outflow = 0.00 cfs @ 13.01 hrs, Volume= 0.001 af, Atten= 0% Lag= 0.0 min Primary = 0.00 cfs@ 13.01 hrs, Volume= 0.001 of Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev=1.00'@ 13.01 hrs Device Routing Invert Outlet Devices #1 Primary 1.00' 34.0' long LS Lip (6" X 6" Stacked Timber) 2 End Contraction(s) Primary OutFlow Max=0.00 cis@ 13.01 hrs HW=1.00' (Free Discharge) L1=LS Lip (6" X 6" Stacked Timber) (Weir Controls 0.00 cfs @ 0.05 fps) ELDON FARM Summary for Pond 7P: LS LIP-2 Eldon Farm Residence Postdevelopment Type H 24-hr 1-in Rainfall-1.00" Printed 4/24/2020 Inflow Area = 0.800 ar; 18.75%Impervious Inflow Depth > 0.02" for 1-in event Inflow = 0.00 cfs @ 13.57 hrs Volume= 0.001 of Outflow = 0.00 cfs @ 13.57 hrs Volume= 0.001 af, Atten= 01/q Lag= 0.0 min Primary = 0.00 cfs @ 13.57 hrs Volume= 0.001 of Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev=1.00'@ 13.57 hrs Device Routing Invert Outlet Devices #1 Primary 1.00' 42.0' long LS Lip (6" X 6" Stacked Timber) 2 End Contraction(s) Primary OutFlow, Max=0.00 cis@ 13.57 hrs HW=1.00' (Free Discharge) t-9=LS Lip (6" X 6" Stacked Timber) (Weir Controls 0.00 cfs @ 0.04 fps) Summary for Pond 11 P: LS LIP-3 Inflow Area = 0.380 ar; 86.84%Impervious Inflow Depth > 0.46" for 1-in event Inflow = 0.29 cfs @ 12.03 hrs Volume= 0.015 of Outflow = 0.29 cfs @ 12.03 hrs Volume= 0.015 af, Atten= 01/q Lag= 0.0 min Primary = 0.29 cfs @ 12.03 hrs Volume= 0.015 of Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev=1.02'@ 12.03 hrs Device Routing Invert Outlet Devices #1 Primary 1.00' 32.0' long LS Lip (6" X 6" Stacked Timber) 2 End Contraction(s) Primary OutFlow Max=0.28 cfs@ 12.03 hrs HW=1.02' (Free Discharge) L1=LS Lip (6" X 6" Stacked Timber) (Weir Controls 0.28 cfs @ 0.45 fps) Eldon Farm Residence Postdevelopment ELDON FARM Type 11 24-hr 1-yr Rainfall=2.85" Prepared by Shimp Engineering Printed 4/24/2020 HydroCAD®10.10-3b s/n M21870 ©2020 HydroCAD Software Solutions LLC Paoe 7 Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1 S: DA-1 Runoff Area=0.620 ac 19.35% Impervious Runoff Depth>0.78" Tc=9.0 min CN=75 Runoff=0.82 cfs 0.040 of Subcatchment 5S: DA-2 Runoff Area=0.800 ac 18.75% Impervious Runoff Depth>0.73" Tc=9.0 min CN=74 Runoff=0.99 cfs 0.049 of Subcatchment9S: DA-3 Runoff Area=0.380 ac 86.84% Impervious Runoff Depth>2.07" Tc=9.0 min CN=94 Runoff=1.25 cfs 0.065 of Reach 2R: LS POOL -1 Avg. Flow Depth=0.07' Max Vet=0.32 fps Inflow=0.82 cfs 0.040 of n=0.025 L=10.0' S=0.0010'f Capacity=64.74 cfs Outflow=0.80 cfs 0.040 of Reach 6R: LS POOL 2 Avg. Flow Depth=0.07' Max Vet=0.32 fps Inflow=0.99 cfs 0.049 of n=0.025 L=10.0' S=0.0010'f Capacity=79.75 cfs Outflow=0.96 cfs 0.049 of Reach 1OR: LS-POOL-3 Avg. Flow Depth=0.10' Max Vet=0.40 fps Inflow=1.25 cfs 0.065 of n=0.025 L=10.0' S=0.0010'f Capacity=60.99 cfs Outflow=1.22 cfs 0.065 of Pond 3P: LS LIP-1 Peak EIev=1.04' Inflow=0.80 cfs 0.040 of Outflow=0.80 cfs 0.040 of Pond 7P: LS LIP-2 Peak EIev=1.04' Inflow=0.96 cfs 0.049 of Outflow=0.96 cfs 0.049 of Pond 11P: LS LIP-3 Peak EIev=1.05' Inflow=1.22 cfs 0.065 of Outflow=1.22 cfs 0.065 of Total Runoff Area =1.800 ac Runoff Volume = 0.154 of Average Runoff Depth =1.03" 66.67% Pervious =1.200 ac 33.33% Impervious = 0.600 ac ELDON FARM Summary for Subcatchment 1S: DA-1 Runoff = 0.82 cfs @ 12.01 hrs, Volume= 0.040 at Depth> 0.78" Eldon Farm Residence Postdevelopment Type // 24-hr 1-yr Rainfall=2.85" Printed 4/24/2020 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1-yr Rainfall=2.85' 0.120 98 Impervious 0.500 69 50-75% Grass cover, Fair, HSG B 0.620 75 Weighted Average 0.500 80.65% Pervious Area 0.120 19.35% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.0 Direct Entry, Summary for Subcatchment 5S: DA-2 Runoff = 0.99 cfs @ 12.02 hrs, Volume= 0.049 at Depth> 0.73" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1-yr Rainfall=2.85' Area (ac) CN Description ' 0.150 98 Impervious 0.650 69 50-75% Grass cover, Fair, HSG B 0.800 74 Weighted Average 0.650 81.25% Pervious Area 0.150 18.75% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.0 Direct Entry, Summary for Subcatchment 9S: DA-3 Runoff = 1.25 cfs @ 12.00 hrs, Volume= 0.065 at Depth> 2.07" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 1-yr Rainfall=2.85' 0.330 98 Impervious 0.050 69 50-75% Grass cover, Fair, HSG B 0.380 94 Weighted Average 0.050 13.16% Pervious Area 0.330 86.84% Impervious Area ELDON FARM Eldon Farm Residence Postdevelopment Type // 24-hr 1-yr Rainfall=2.85" Printed 4/24/2020 Tc Length Slope Velocity Capacity Description (min) (feet) (fl/fl) (ft/sec) (cfs) 9.0 Direct Entry, Summary for Reach 2R: LS POOL • 1 Inflow Area = 0.620 ac 19.35%Impervious, Inflow Depth > 0.78" for 1-yr event Inflow = 0.82 cfs @ 12.01 hrs, Volume= 0.040 of Outflow = 0.80 cfs @ 12.03 hrs, Volume= 0.040 af, A@en= 31/q Lag= 0.9 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 0.32 fps, Min. Travel Time= 0.5 min Avg. Velocity = 0.10 fps, Avg. Travel Time= 1.6 min Peak Storage= 25 cf @ 12.02 hrs Average Depth at Peak Storage= 0.07' , Surface Width= 34.29' Bank -Full Depth= 1.00' Flow Area= 36.0 sf, Capacity= 64.74 cfs 34.00' x 1.00' deep channel, n= 0.025 Rubble masonry, cemented Side Slope Z-value= 2.0 ? Top Width= 38.00' Length=10.0' Slope= 0.0010 ? Inlet Invert= 0.00', Outlet Invert= -0.01' Summary for Reach 6R: LS POOL 2 Inflow Area = 0.800 ac 18.75%Impervious, Inflow Depth > 0.73" for 1-yr event Inflow = 0.99 cfs @ 12.02 hrs, Volume= 0.049 of Outflow = 0.96 cfs @ 12.03 hrs, Volume= 0.049 af, Atten= 3% Lag= 0.9 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 0.32 fps, Min. Travel Time= 0.5 min Avg. Velocity = 0.10 fps, Avg. Travel Time= 1.6 min Peak Storage= 30 cf @ 12.02 hrs Average Depth at Peak Storage= 0.07' , Surface Width= 42.29' Bank -Full Depth= 1.00' Flow Area= 44.0 sf, Capacity= 79.75 cfs 42.00' x 1.00' deep channel, n= 0.025 Rubble masonry, cemented Side Slope Z-value= 2.0 ? Top Width= 46.00' Length=10.0' Slope= 0.0010 ? Inlet Invert=0.00', Outlet Invert=-0.01' ELDON FARM Summary for Reach 1 OR: LS-POOL-3 Eldon Farm Residence Postdevelopment Type/1 24-hr 1-yr Rainfall=2.85" Printed 4/24/2020 Inflow Area = 0.380 ac 86.84%Impervious, Inflow Depth > 2.07" for 1-yr event Inflow = 1.25 cfs @ 12.00 hm Volume= 0.065 of Outflow = 1.22 cfs @ 12.01 hrs, Volume= 0.065 af, Aften= 2% Lag= 0.6 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 0.40 fps, Min. Travel Time= 0.4 min Avg. Velocity = 0.10 fps, Avg. Travel Time= 1.6 min Peak Storage= 31 cf @ 12.00 hrs Average Depth at Peak Storage= 0.10' , Surface Width= 32.39' Bank -Full Depth= 1.00' Flow Area= 34.0 sf, Capacity= 60.99 cis 32.00' x 1.00' deep channel, n= 0.025 Rubble masonry, cemented Side Slope Z-value= 2.0 ? Top Width= 36.00' Length=10.0' Slope= 0.0010'P Inlet Invert=0.00', Outlet Invert=-0.01' Summary for Pond 3P: LS LIP-1 Inflow Area = 0.620 ac 19.35%Impervious, Inflow Depth > 0.77" for 1-yr event Inflow = 0.80 cfs @ 12.03 hrs, Volume= 0.040 of Outflow = 0.80 cfs @ 12.03 hrs, Volume= 0.040 af, Atten= 0% Lag= 0.0 min Primary = 0.80 cfs @ 12.03 hrs, Volume= 0.040 of Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev=1.04'@ 12.03 hrs Device Routing Invert Outlet Devices #1 Primary 1.00' 34.0' long LS Lip (6" X 6" Stacked Timber) 2 End Contraction(s) Primary OutFlow Max=0.77 cis@ 12.03 hrs HW=1.04' (Free Discharge) L1=LS Lip (6" X 6" Stacked Timber) (Weir Controls 0.77 cfs @ 0.62 fps) ELDON FARM Summary for Pond 7P: LS LIP-2 Eldon Farm Residence Postdevelopment Type // 24-hr 1-yr Rainfall=2.85" Printed 4/24/2020 Inflow Area = 0.800 ar; 18.75%Impervious, Inflow Depth > 0.73" for 1-yr event Inflow = 0.96 cfs @ 12.03 hrs, Volume= 0.049 of Outflow = 0.96 cfs @ 12.03 hrs, Volume= 0.049 af, Atten= 01/q Lag= 0.0 min Primary = 0.96 cfs @ 12.03 hrs, Volume= 0.049 of Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev=1.04'@ 12.03 hrs Device Routing Invert Outlet Devices #1 Primary 1.00' 42.0' long LS Lip (6" X 6" Stacked Timber) 2 End Contraction(s) Primary OutFlow Max=0.92 cis@ 12.03 hrs HW=1.04' (Free Discharge) t-1=LS Lip (6" X 6" Stacked Timber) (Weir Controls 0.92 cfs @ 0.62 fps) Summary for Pond 11 P: LS LIP-3 Inflow Area = 0.380 ar; 86.84%Impervious, Inflow Depth > 2.07" for 1-yr event Inflow = 1.22 cfs @ 12.01 hrs, Volume= 0.065 of Outflow = 1.22 cfs @ 12.01 hrs, Volume= 0.065 af, Atten= 01/c, Lag= 0.0 min Primary = 1.22 cfs @ 12.01 hrs, Volume= 0.065 of Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev=1.05'@ 12.01 hrs Device Routing Invert Outlet Devices #1 Primary 1.00' 32.0' long LS Lip (6" X 6" Stacked Timber) 2 End Contraction(s) Primary OutFlow Max=1.20 cfs@ 12.01 hrs HW=1.05' (Free Discharge) L1=LS Lip (6" X 6" Stacked Timber) (Weir Controls 1.20 cfs @ 0.74 fps) Eldon Farm Residence Postdevelopment ELDON FARM Type 1124-hr 10-yr Rainfall-5.22" Prepared by Shimp Engineering Printed 4/24/2020 HydroCAD®10.10-3b s/n M21870 © 2020 HydroCAD Software Solutions LLC Paae 12 Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method SubcatchmentlS: DA-1 Runoff Area=0.620ac 19.35%Impervious Runoff Depth>2.42" Tc=9.0 min CN=75 Runoff=2.57 cfs 0.125 of Subcatchment5S: DA-2 Runoff Area=0.800ac 18.75%Impervious RunoffDepth>2.33" Tc=9.0 min CN=74 Runoff=3.20 cfs 0.156 of Subcatchment9S: DA-3 Runoff Area=0.380ac 86.84%Impervious RunoffDepth>4.23" Tc=9.0 min CN=94 Runoff=2.45 cfs 0.134 of Reach 2R: LS POOL - 1 Avg. Flow Depth=0.14' Max Vet=0.51 fps Inflow=2.57 cfs 0.125 of n=0.025 L=10.0' 5=0.0010 7 Capacity=64.74 cfs OuHlow=2.52 cfs 0.125 of Reach 6R: LS POOL 2 Avg. Flow Depth=0.15' Max Vet=0.52 fps Inflow=3.20 cfs 0.156 of n=0.025 L=10.0' 5=0.0010 7 Capacity=79.75 cfs Outflow=3.15 cfs 0.155 of Reach 10R: LS-POOL-3 Avg. Flow Depth=0.15' Max Vet=0.52 fps Inflow=2.45 cfs 0.134 of n=0.025 L=10.0' 5=0.0010 7 Capacity=60.99 cfs Outflow=2.41 cfs 0.134 of Pond 3P: LS LIP-1 Peak EIev=1.08' Inflow=2.52 cfs 0.125 of Outflow=2.52 cfs 0.125 of Pond 7P: LS LIP-2 Peak EIev=1.08' Inflow=3.15 cfs 0.155 of Outflow=3.15 cfs 0.155 of Pond 11 P: LS LIP-3 Peak EIev=1.08' Inflow=2.41 cfs 0.134 of Outflow=2.41 cfs 0.134 of Total Runoff Area =1.800 ac Runoff Volume = 0.414 of Average Runoff Depth = 2.76" 66.67% Pervious =1.200 ac 33.33% Impervious = 0.600 ac ELDON FARM Summary for Subcatchment 1S: DA-1 Runoff = 2.57 cfs @ 12.01 hrs, Volume= 0.125 af, Depth> 2.42" Eldon Farm Residence Postdevelopment Type 1124-hr 10-yr Rainfall-5.22" Printed 4/24/2020 Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10-yr Rainfall=5.22" 0.120 98 Impervious 0.500 69 50-75% Grass cover, Fair, HSG B 0.620 75 Weighted Average 0.500 80.65% Pervious Area 0.120 19.35% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.0 Direct Entry, Summary for Subcatchment 5S: DA-2 Runoff = 3.20 cfs @ 12.01 hrs, Volume= 0.156 at Depth> 2.33" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10-yr Rainfall=5.22" Area (ac) CN Description ' 0.150 98 Impervious 0.650 69 50-75% Grass cover, Fair, HSG B 0.800 74 Weighted Average 0.650 81.25% Pervious Area 0.150 18.75% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.0 Direct Entry, Summary for Subcatchment 9S: DA-3 Runoff = 2.45 cfs @ 12.00 hrs, Volume= 0.134 at Depth> 4.23" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type II 24-hr 10-yr Rainfall=5.22" 0.330 98 Impervious 0.050 69 50-75% Grass cover, Fair, HSG B 0.380 94 Weighted Average 0.050 13.16% Pervious Area 0.330 86.84% Impervious Area ELDON FARM Eldon Farm Residence Postdevelopment Type 1124-hr 10-yr Rainfall=-5.22" Printed 4/24/2020 Tc Length Slope Velocity Capacity Description (min) (feet) (fl/fl) (ft/sec) (cfs) 9.0 Direct Entry, Summary for Reach 2R: LS POOL -1 Inflow Area = 0.620 ac 19.35%Impervious, Inflow Depth > 2.42" for 10-yr event Inflow = 2.57 cfs @ 12.01 him Volume= 0.125 of Outflow = 2.52 cfs @ 12.01 him Volume= 0.125 af, Aden= 21/c, Lag= 0.5 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 0.51 fps, Min. Travel Time= 0.3 min Avg. Velocity = 0.13 fps, Avg. Travel Time= 1.2 min Peak Storage= 50 cf @ 12.01 hrs Average Depth at Peak Storage= 0.14' , Surface Width= 34.58' Bank -Full Depth= 1.00' Flow Area= 36.0 sf, Capacity= 64.74 cfs 34.00' x 1.00' deep channel, n= 0.025 Rubble masonry, cemented Side Slope Z-value= 2.0 ? Top Width= 38.00' Length=10.0' Slope= 0.0010 ? Inlet Invert= 0.00', Outlet Invert= -0.01' Summary for Reach 6R: LS POOL 2 Inflow Area = 0.800 ac 18.75%Impervious, Inflow Depth > 2.33" for 10-yr event Inflow = 3.20 cfs @ 12.01 him Volume= 0.156 of Outflow = 3.15 cfs @ 12.01 him Volume= 0.155 af, Atten= 2% Lag= 0.5 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 0.52 fps, Min. Travel Time= 0.3 min Avg. Velocity = 0.14 fps, Avg. Travel Time=1.2 min Peak Storage= 62 cf @ 12.01 hrs Average Depth at Peak Storage= 0.15' , Surface Width= 42.58' Bank -Full Depth= 1.00' Flow Area= 44.0 sf, Capacity= 79.75 cfs 42.00' x 1.00' deep channel, n= 0.025 Rubble masonry, cemented Side Slope Z-value= 2.0 ? Top Width= 46.00' Length=10.0' Slope= 0.0010 ? Inlet Invert=0.00', Outlet Invert=-0.01' ELDON FARM Summary for Reach 1 OR: LS-POOL-3 Eldon Farm Residence Postdevelopment Type 1124-hr 10-yr Rainfall-5.22" Printed 4/24/2020 Inflow Area = 0.380 ar; 86.84%Impervious, Inflow Depth > 4.23" for 10-yr event Inflow = 2.45 cfs @ 12.00 hrs, Volume= 0.134 of Outflow = 2.41 cfs @ 12.00 hrs, Volume= 0.134 af, Atten= 2% Lag= 0.4 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Max. Velocity= 0.52 fps, Min. Travel Time= 0.3 min Avg. Velocity = 0.13 fps, Avg. Travel Time= 1.3 min Peak Storage= 47 cf @ 12.00 hrs Average Depth at Peak Storage= 0.15' , Surface Width= 32.58' Bank -Full Depth= 1.00' Flow Area= 34.0 sf, Capacity= 60.99 cis 32.00' x 1.00' deep channel, n= 0.025 Rubble masonry, cemented Side Slope Z-value= 2.0 ? Top Width= 36.00' Length=10.0' Slope= 0.0010'P Inlet Invert=0.00', Outlet Invert=-0.01' Summary for Pond 3P: LS LIP-1 Inflow Area = 0.620 ar; 19.35%Impervious, Inflow Depth > 2.42" for 10-yr event Inflow = 2.52 cfs @ 12.01 hrs, Volume= 0.125 of Outflow = 2.52 cfs @ 12.01 hrs, Volume= 0.125 af, Atten= 0% Lag= 0.0 min Primary = 2.52 cfs @ 12.01 hrs, Volume= 0.125 of Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev=1.08'@ 12.01 hrs Device Routing Invert Outlet Devices #1 Primary 1.00' 34.0' long LS Lip (6" X 6" Stacked Timber) 2 End Contraction(s) Primary OutFlow Max=2.46 cis@ 12.01 hrs HW=1.08' (Free Discharge) L1=LS Lip (6" X 6" Stacked Timber) (Weir Controls 2.46 cfs @ 0.92 fps) ELDON FARM Summary for Pond 7P: LS LIP-2 Eldon Farm Residence Postdevelopment Type 1124-hr 10-yr Rainfall-5.22" Printed 4/24/2020 Inflow Area = 0.800 ar; 18.75%Impervious, Inflow Depth > 2.33" for 10-yr event Inflow = 3.15 cfs @ 12.01 hrs, Volume= 0.155 of Outflow = 3.15 cfs @ 12.01 hrs, Volume= 0.155 af, Atten= 01/q Lag= 0.0 min Primary = 3.15 cfs @ 12.01 hrs, Volume= 0.155 of Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev=1.08'@ 12.01 hrs Device Routing Invert Outlet Devices #1 Primary 1.00' 42.0' long LS Lip (6" X 6" Stacked Timber) 2 End Contraction(s) Primary OutFlow Max=3.07 cfs@ 12.01 hrs HW=1.08' (Free Discharge) t-1=LS Lip (6" X 6" Stacked Timber) (Weir Controls 3.07 cfs @ 0.92 fps) Summary for Pond 11 P: LS LIP-3 Inflow Area = 0.380 ar; 86.84%Impervious, Inflow Depth > 4.22" for 10-yr event Inflow = 2.41 cfs @ 12.00 hrs, Volume= 0.134 of Outflow = 2.41 cfs @ 12.00 hrs, Volume= 0.134 af, Atten= 0% Lag= 0.0 min Primary = 2.41 cfs @ 12.00 hrs, Volume= 0.134 of Routing by Stor-Ind method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Peak Elev=1.08'@ 12.00 hrs Device Routing Invert Outlet Devices #1 Primary 1.00' 32.0' long LS Lip (6" X 6" Stacked Timber) 2 End Contraction(s) Primary OutFlow Max=2.39 cfs@ 12.00 hrs HW=1.08' (Free Discharge) L1=LS Lip (6" X 6" Stacked Timber) (Weir Controls 2.39 cfs @ 0.93 fps) Independent Reports: Excerpt from NRCS Soils Report NOAA Precipitation Report USDA United States Department of Agriculture MRCS Natural Resources Conservation Service A product of the National Cooperative Soil Survey, a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local participants Custom Soil Resource Report for Albemarle County, Virginia April 14, 2020 3 N 74013D 74OZ!D 740310 D° 4N-N 4` W PSN 740130 79 740310 740,00 740,00 3 Map Scale: 1:3,610 (prkftd m A pD bat (8.5' z 11") diem Meters N 0 W 10D 200 3DD A r 0 7W 31D B00 90D Map proledim: Web Mertat0r Cmermordnz�:WGS84 Edge UTM Zme 17N WGS84 9 Custom Soil Resource Report Soil Map n 740580 8 429N 38 TN 740M 3 Fl MAPLEGEND Area of Interest (AOQ O Area of Interest (AOI) Solis Soil Map Unit Polygons N Soil Map Unit Lines Soil Map Unit Points Special Point Features V Blowout ® Borrow Pit Clay Spot O Closed Depression Gravel Pit Gravelly Spot O Landfill A. Lava Flow Marsh or swamp Mine or Quarry O Miscellaneous Water O Perennial Water y Rock Outcrop + Saline Spot Sandy Spot Severely Eroded Spot Q Sinkhole Slide or Slip J, Sodic Spot Custom Soil Resource Report MAP INFORMATION g Spoil Area The soil surveys that comprise your AOI were mapped at 1:15,800. o Stony Spot W Very Stony Spot Warning: Soil Map may not be valid at this scale. wet Spot Enlargement of maps beyond the scale of mapping can cause Other misunderstanding of the detail of mapping and accuracy of soil Special Line Features line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed Water Features scale. Streams and Canals Transportation Please rely on the bar scale on each map sheet for map �..ry Rails measurements. N Interstate Highways Source of Map: Natural Resources Conservation Service ti US Routes Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Major Roads Local Roads Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts Background distance and area. A projection that preserves area, such as the . Aerial Photography Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Albemarle County, Virginia Survey Area Data: Version 13, Sep 17, 2019 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Apr 22, 2015—Mar 10, 2017 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. 10 Custom Soil Resource Report Map Unit Legend Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 46B Grassland silt loam, 2 to 7 percent slopes 0.1 0.3% 51 D Bugley channery silt loam, 15 to 25 percent slopes 13.4 29.7% 53B Danripple loam, 2 to 7 percent slopes 8.1 18.1% 62B Buffstat silt loam, 2 to 7 percent slopes 3.6 8.0% 62C Buffstat silt loam, 7 to 15 percent slopes 13.3 29.4% 95 Hatboro silt loam, 0 to 2 percent slopes, occasionally flooded 6.6 14.6% Totals for Area of Interest 45.1 100.0% Map Unit Descriptions The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area. The map unit descriptions, along with the maps, can be used to determine the composition and properties of a unit. A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils. On the landscape, however, the soils are natural phenomena, and they have the characteristic variability of all natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous areas for which it is named and some minor components that belong to taxonomic classes other than those of the major soils. Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncentrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different management. These are called contrasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit descriptions along with some characteristics of each. A few areas of minor components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it 11 Custom Soil Resource Report Albemarle County, Virginia 4613—Grassland silt loam, 2 to 7 percent slopes Map Unit Setting National map unit symbol: 2v7j8 Elevation: 360 to 1,540 feet Mean annual precipitation: 25 to 65 inches Mean annual air temperature: 54 to 59 degrees F Frost -free period: 195 to 231 days Farmland classification: Farmland of statewide importance Map Unit Composition Grassland and similar soils: 85 percent Minor components: 5 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Grassland Setting Landform: Hillslopes Landform position (two-dimensional): Summit Landform position (three-dimensional): Interfluve Down -slope shape: Convex Across -slope shape: Convex Parent material: Residuum weathered from serecite schist Typical profile Ap - 0 to 9 inches: silt loam Bt - 9 to 38 inches: silty clay loam BC - 38 to 58 inches: channery silt loam Cr- 58 to 79 inches: bedrock Properties and qualities Slope: 2 to 7 percent Depth to restrictive feature: 40 to 60 inches to paralithic bedrock Natural drainage class: Moderately well drained Runoff class: High Capacity of the most limiting layer to transmit water (Ksat): Very low to moderately low (0.00 to 0.06 in/hr) Depth to water table: About 12 to 30 inches Frequency of flooding: None Frequency of ponding: None Available water storage in profile: Moderate (about 8.4 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 2e Hydrologic Soil Group: D Hydric soil rating: No Minor Components Delila Percent of map unit: 5 percent Landform: Drainageways 13 Custom Soil Resource Report Landform position (two-dimensional): Footslope Landform position (three-dimensional): Head slope, tread Down -slope shape: Concave Across -slope shape: Convex Hydric soil rating: Yes 51 D—Bugley channery silt loam, 15 to 25 percent slopes Map Unit Setting National map unit symbol: 2v7ji Elevation: 360 to 1,540 feet Mean annual precipitation: 25 to 65 inches Mean annual air temperature: 54 to 59 degrees F Frost -free period: 195 to 231 days Farmland classification: Not prime farmland Map Unit Composition Bugley and similar soils: 80 percent Estimates are based on observations, Description of Bugley descriptions, and transacts of the mapunit. Setting Landform: Interfluves Landform position (two-dimensional): Backslope Landform position (three-dimensional): Side slope Down -slope shape: Linear Across -slope shape: Convex Parent material: Residuum weathered from serecite schist Typical profile Ap - 0 to 6 inches: channery silt loam Bw- 6 to 18 inches: very channery silt loam R - 18 to 79 inches: bedrock Properties and qualities Slope: 15 to 25 percent Depth to restrictive feature: 10 to 20 inches to lithic bedrock Natural drainage class: Somewhat excessively drained Runoff class: Medium Capacity of the most limiting layer to transmit water (Ksat): Very low to high (0.00 to 5.95 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Available water storage in profile: Very low (about 2.1 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 7e Hydrologic Soil Group: D 14 Custom Soil Resource Report Hydric soil rating: No 53B—Danripple loam, 2 to 7 percent slopes Map Unit Setting National map unit symbol: 2v7jn Elevation: 360 to 1,540 feet Mean annual precipitation: 25 to 65 inches Mean annual air temperature: 54 to 59 degrees F Frost -free period: 195 to 231 days Farmland classification: All areas are prime farmland Map Unit Composition Danripple and similar soils: 80 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Danripple Setting Landform: Stream terraces Landform position (three-dimensional): Tread Down -slope shape: Convex Across -slope shape: Linear Parent material: Ancient alluvium derived from igneous rock Typical profile Ap - 0 to 7 inches: loam Btl - 7 to 33 inches: clay Bt2 - 33 to 79 inches: clay loam Properties and qualities Slope: 2 to 7 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: Medium Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.57 to 1.98 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Available water storage in profile: Moderate (about 8.4 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 2e Hydrologic Soil Group: B Hydric soil rating: No 15 Custom Soil Resource Report 6213—Buffstat silt loam, 2 to 7 percent slopes Map Unit Setting National map unit symbol: 2v7jt Elevation: 360 to 1,540 feet Mean annual precipitation: 25 to 65 inches Mean annual air temperature: 54 to 59 degrees F Frost -free period: 195 to 231 days Farmland classification: All areas are prime farmland Map Unit Composition Buffstat and similar soils: 80 percent Estimates are based on observations, Description of Buffstat descriptions, and transects of the mapunit. Setting Landform: Interfluves Landform position (two-dimensional): Summit Landform position (three-dimensional): Interfluve Down -slope shape: Convex Across -slope shape: Convex Parent material: Residuum weathered from serecite schist Typical profile Ap - 0 to 8 inches: silt loam Bt - 8 to 39 inches: silty clay loam C - 39 to 50 inches: channery silt loam R - 50 to 79 inches: bedrock Properties and qualities Slope: 2 to 7 percent Depth to restrictive feature: 40 to 60 inches to paralithic bedrock Natural drainage class: Well drained Runoff class: Medium Capacity of the most limiting layer to transmit water (Ksat): Very low to high (0.00 to 1.98 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Available water storage in profile: Moderate (about 8.3 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 2e Hydrologic Soil Group: B Hydric soil rating: No it. Custom Soil Resource Report 62C—Buffstat silt loam, 7 to 15 percent slopes Map Unit Setting National map unit symbol: 2v7jv Elevation: 360 to 1,540 feet Mean annual precipitation: 25 to 65 inches Mean annual air temperature: 54 to 59 degrees F Frost -free period: 195 to 231 days Farmland classification: Farmland of statewide importance Map Unit Composition Buffstat and similar soils: 80 percent Estimates are based on observations, Description of Buffstat descriptions, and transects of the mapunit. Setting Landform: Interfluves Landform position (two-dimensional): Backslope Landform position (three-dimensional): Interfluve Down -slope shape: Convex Across -slope shape: Convex Parent material: Residuum weathered from serecite schist Typical profile Ap - 0 to 8 inches: silt loam Bt - 8 to 39 inches: silty clay loam C - 39 to 50 inches: channery silt loam R - 50 to 79 inches: bedrock Properties and qualities Slope: 7 to 15 percent Depth to restrictive feature: 40 to 60 inches to paralithic bedrock Natural drainage class: Well drained Runoff class: Medium Capacity of the most limiting layer to transmit water (Ksat): Very low to high (0.00 to 1.98 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Available water storage in profile: Moderate (about 8.3 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 3e Hydrologic Soil Group: B Hydric soil rating: No IVA Custom Soil Resource Report 95—Hatboro silt loam, 0 to 2 percent slopes, occasionally flooded Map Unit Setting National map unit symbol: 2v7kb Elevation: 360 to 1,540 feet Mean annual precipitation: 25 to 65 inches Mean annual air temperature: 54 to 59 degrees F Frost -free period: 195 to 231 days Farmland classification: Not prime farmland Map Unit Composition Hatboro, occasionally flooded, and similar soils: 80 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Hatboro, Occasionally Flooded Setting Landform: Flood plains Down -slope shape: Linear Across -slope shape: Linear Parent material: Alluvium derived from igneous rock Typical profile A - 0 to 10 inches: silt loam Bg - 10 to 52 inches: silty clay loam Cg - 52 to 79 inches: sandy loam Properties and qualities Slope: 0 to 2 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Poorly drained Runoff class: Very high Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.57 to 1.98 in/hr) Depth to water table: About 0 to 30 inches Frequency of flooding: Occasional Frequency of ponding: None Available water storage in profile: High (about 11.0 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 4w Hydrologic Soil Group: B/D Hydric soil rating: Yes it 4/16/2020 Precipitation Frequency Data Server NOAA Atlas 14, Volume 2, Version 3 _ Location name: Gordonsville Virginia, USA. E ~, Latitude: 38.0715°, Longitude:-78.2597° ME t Elevation: 462.66 k'• � ' Source: ESRI Maps `vy ^ n "source: USGS POINT PRECIPITATION FREQUENCY ESTIMATES G.M. Bonnin, D. Martin, B. Lin, T. Pa2ybok, M.Yekta, and D. Riley NOAA, National Weather Service, 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 7 ������� 2 5 10 25 50 100 200 500 1000 0.350 0.415 0.486 0.549 0.619 0.674 0.725 0.773 0.831 0.878 5-min (g 315-0.387) (0.375-0.460) (0.438-0.537) (0.494-0.607) (0.554-0.682) (0.600-0.742) (0.643-0.798) (0.681-0.851) (0.724-0.917) (0.760-0.972) 0.558 0.664 0.778 0.878 0.986 1.07 1.15 1.23 1.31 1.38 10-min (0.504-0.619) (0.600-0.735) (0.702-0.861) (0.790-0.971) (0.883-1.09) (0.956-1.18) 1 (1.02-1.27) 1 (1.08-1.35) 1 (1.15-1.45) 1 (1.20-1.53) 0.984 1.-1. 1.25 1.36 1.46 1.55 1.65 1.74 15-min 29-0. (0.629-0.773) 54-0. (0.754-0.924) (0.888-1.09) (1.00-1.23) 1 (1.12-1.38) 1 (1.21-1.50) 1 (1.29-1.60) 1 (1.36-1.70) 1 (1.44-1.83) 1 (1.50-1.92) 0.957 1.15 1.40 1.61 1.85 2.05 2.23 2.41 2.63 2.81 30-min (0.863-1.06) 1 (1.04-1.28) 1 (1.26-1.55) 1 (1.45-1.78) 1 (1.66-2.04) 1 (1.82-2.25) 1 (1.98-2.46) 1 (2.12-2.65) 1 (2.30-2.91) 1 (2.43-3.11) 1.19 1.45 1.79 2.10 2.47 2.77 3.07 3.38 3.78 4. 60-min (1.08-1.32) (1.31-1.60) 1 (1.62-1.98) 1 (1.89-2.32) 1 (2.21-2.72) 1 (2.47-3.05) 1 (2.72-3.38) 1 (2.97-3.72) 1 (3.29-4.17) 1 (3.55-4.-4.54) 1.43 1.73 2.15 2.54 3.03 3.44 3.87 4.31 4.91 5.42 2-hr (1.27-1.61) (1.54-1.95) (1.92-2.42) (2.26-2.85) (2.67-3.39) (3.02-3.86) (3.37-4.32) 1 (3.72-4.81) 1 (4.20-5.49) 1 (4.59-6.08) 1.56 1.88 2 334 2 776 3 330 3 775 4 221 4 669 5 335 5 992 F3-hr (1.38-1.78) (1.66-2.14) 1 (2.07-2.67) 1 (2.43-3.14) 1 (2.88-3.73) 1 (3.26-4.24) 1 (3.64-4.76) 1 (4.02-5.31) 1 (4.53-6.06) 1 (4.96-6.71) 1.96 2.35 2.92 3.45 4.14 4.75 5.39 6.08 7.04 7.89 6-hr (1.73-2.24) 1 (2.08-2.70) 1 (2.56-3.34) (3.02-3.94) 1 (3.60-4.73) 1 (4.11-5.41) 1 (4.62-6.13) 1 (5.15-6.91) 1 (5.88-8.01) 1 (6.50-8.99) 2.44 2.93 3.63 4.32 5.25 F 6.09 6.99 F 7.98 F 9.41 F 10.7 12-hr (2.16-2.80) 1 (2.59-3.35) 1 (3.20-4.16) (3.79-4.94) 1 (4.57-5.98) 1 (5.25-6.92) 1 (5.95-T93) 1 (6.70-9.03) 1 (7.76-10.7) 1 (8.70-12.2) 2.85 3A5 4.41 5.22 6.42 7.45 8.58 9.83 17.7 13.3 24-hr (2.56-3.21) 1 (3.10-3.89) 1 (3.95-4.97) 1 (4.66-5.87) 1 (5.70-7.20) 1 (6.57-8.33) 1 (7.50-9.58) 1 (8.50-11.0) 1 (9.96-13.0) 1 (11.2-14.8) 3.35 4.06 5.16 6.07 7.38 S.49 9.68 11.0 12.9 14.4 2-day (3.03-3.74) (3.67d.53) (4.66-5.75) (5.46-6.76) (6.61-8.20) (7.54-9.41) (8.55-10.7) (9.62-12.2) (11.1-14.3) (12.4-16.1) 3.57 4.32 5.48 6.45 7.84 9.01 10.3 11.6 13.6 15.3 3-day (3.24-3.96) 1 (3.92-4.78) 1 (4.97-6.07) 1 (5.83-7.13) 1 (7.05-8.65) 1 (8.06-9.94) 1 (9.12-11.3) 1 (10.3-12.8) 1 (11.9-15.1) 1 (13.2-16.9) 357 11 F 4.57 5.81 1 F 6.82 8.29 9.52 10.9 12.3 14.4 16.1 4-day (3.44-4.17) 1 (4.17-5.04) 1 (5.29-6.40) 1 (6.20-7.51) 1 (7.50-9.11) 1 (8.57-10.5) 1 (9.69-11.9) 1 (10.9-13.5) 1 (12.6-15.8) 1 (14.0-17.8) 4.38 5.27 6.59 7.68 9.24 10.5 11.9 13.4 15.5 17.3 7-day P� (4.01-4.81) 1 (4.83-5.78) 1 (6.03-7.22) 1 (7.01-8.40) 1 (8.39-10.1) 1 (9.51-11.5) 1 (10.7-13.0) 1 (11.9-14.7) 1 (13.7-17.0) 1 (15.1-19.0) 4.98 5.97 7.37 8.51 10- 11.4 12.8 14.3 16.4 18.1 10rlay F� (4.58-5.41) 1 (5.50-6.49) 1 (6.78-8.01) 1 (7.81-9.24) 1 (9.25-11.0) 1 (10.4-12.4) 1 (11.6-13.9) 1 (12.8-15.5) 1 (14.6-17.8) 1 (15.9-19.7) 6.58 7.85 9.49 10.8 12.5 13.9 15.3 16.7 18.7 20.2 20i18y P� (6.14-7.08) 1 (7.33-8.43) 1 (8.84-10.2) 1 (10.0-11.6) 1 (11.6-13.4) 1 (12.8-14.9) 1 (14.1-16.4) 1 (15.3-18.0) 1 (16.9-20.1) 1 (18.2-21.8) 8.08 9.58 11.3 12.7 14.4 15.7 17.0 18.3 19.9 21.2 30-day (7.58-8.64) 1 (8.99-10.2) 1 (10.6-12.1) 1 (11.8-13.5) 1 (13.4-15.4) 1 (14.6-16.8) 1 (15.8-18.2) 1 (16.9-19.5) 1 (18.3-21.4) 1 (19.4-22.7) 45ilay (9.53-10.8) (11.3-12.7) (132-14.8) (14.6-16.4) (16.14- 8.5) (17.78- 0.0) (18?9-21.5) (2021' 2.9) (21?6-24.8) (22� 6.2) 11.9 14.0 16.2 17.8 19.9 27.4 22.8 24.2 25.9 27.2 60-day (11.3-12.6) (13.2-14.8) (15.3-17.1) (16.8-18.8) (18.7-21.0) (20.1-22.6) (21.4-24.1) (22.6-25.6) (24.2-27.5) (25.3-28.9) 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 (for a given duration and average recurrence interval) will be greater than the upper bound (or less than the lower bound) is 5%. Estimates at upper bounds are not checked against probable maximum precipitation (PMP) estimates and may be higher than currently valid PMP values. Please refer to NOAA Atlas 14 document for more information. Back to Top hftps://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=38.0715&Ion=-78.2597&data=depth&units=english&series=pds 1/4