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HomeMy WebLinkAboutWPO202200036 Calculations 2022-08-12SHIMP ENGINEERING, P.C. Design Focused Engineering August 12, 2022 p Z U y Engineering Review Li . No 45183 °7+ Albemarle County Q'12122 Department of Community Development SStONALG 401 McIntire Road Charlottesville, VA 22902 Regarding: WPO 2022xxxxx Overlook Hotel VSMP — SWM Calculation Packet Dear Reviewer, Enclosed is the stormwater calculation packet for the VSMP plan for Overlook Hotel. The development property has an area of 2.69 acres and a disturbed area of 2.87 acres. The project is a private development 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. SWM Quality SWM Quality is satisfied by providing required nutrient treatment for the development. 9VAC25-870-65 requires that the total phosphorous (TP) nutrient load created by the site development be treated in accordance with the VRRM Redevelopment Spreadsheet reduction requirements. To achieve nutrient treatment, an underground tank storage system will be implemented which provides 0.71 Ib/yr of treatment. To meet the total treatment requirement of 2.97 lbs/yr of phosphorous removal, 2.26 Ibs/yr phosphorous credits will be purchased. This amount totals 2.97 Ibs/yr of phosphorous treatment and satisfies the nutrient treatment requirement. Treatment Required Total Phosphorous) Treatment Provided Total Phosphorous) 2.97lb/yr 2.97lb/yr SWM Quantity SWM Quantity is satisfied by analyzing concentrated runoff from the development at 1 Point Of Analysis (POA) at an existing storm structure adjacent to the property. 9VAC25-870-66-B(3) requires that concentrated runoff from the development at each POA meets the energy balance equation. To achieve this, the runoff at the POA was analyzed and the runoff to POA Imeets the energy balance equation. 9VAC25-870-66-C requires that the post-dev 10-year runoff at the POAs not exceed the pre-dev 10-yr runoff. This condition has also been satisfied. See table below for summary. 912 E. High St. Charlottesville, VA 229021434.227.5140 1 shimp-engmeering.com Energ}, Balance Equation and Run-on Summary for Site Outfall 1 Overlook Hotel 1 Tr. 24 Hr Storm Comparison Q 1%sQ IP.> ((nVr IMs. )'(AV I Pe.S)xB'j+Q 1Pe,a ((RV�1Pc. �)(RV, Iert., )) IF=04whw LAD11ttc, 1F-siwhen WDa lac, IF= 1 when site it forested PneDer Site Fully Forested? - w IF = 0.6 Derelopmentl.imits = _'.89 ac On Site OH Site Pre Dn� DA Site = 2 61 ac the Dec' DA OHsire = 0 ac Ibu Dec-DA Sine (Mamged) = 3 63 ac you Da' DA 085ite = 0 a< Pon Der DA site (UD-DfaDaFad) = 0.11 ac Q tts s. = 4.33 cfs QIRe One= OOO ti> &V t Pc sw = 0219 a< &V I wsDme = 0-000 of &V t twa se = 0.612 of RV I ao4 (» = 0.000 of QIp�IMU AWwdI 5 t.4L Po'. tde, nomate'. 9 tcrm d; 0.87 Eoere_v Balance Egwbw Compluacr. a; aatl Preder newatK Storm I cis 10 cT Pouter nmrates stern cts l OaT As part of the stormwater analysis for this site, the future development of the adjacent parcel, TMP 78-13, was included. The proposed detention pond is designed for 62.3% impervious area on 1.01 ac of developable space following construction of the Overlook Hotel site. Should the post -development conditions not exceed this amount of impervious area and all impervious area be treated by the detention pond, no further stormwater quantity treatment is necessary. This site was analyzed for stormwater quantity treatment only and does not address stormwater quality requirements. If you have any questions about this calculation packet please do not hesitate to contact me at: chris(-,shimp- enQineering con or by phone at 434-299-9843. Regards, Chris Marshall, EIT Shimp Engineering, PC Contents: Water Quality Calculations: Pre-Dev VRRM Land Cover Map Post-Dev VRRM Land Cover Map VRRM Redevelopment Spreadsheet Water Quantity Calculations: Pre-Dev Drainage Area Map Predev HydroCAD Report Post-Dev Drainage Area Map Postdev HydroCAD Report Energy Balance Equation TOC Calculations Outlet Drainage Protection Spreadsheet LD-204 LD-226 Independent Reports: NOAA Precipitation Report Excerpt from NRCS Soils Report OVERLOOK HOTEL PREDEV VRRM MAP \ \II \ I A \I 1 � � � � art_' �� .(. • `I � \ / � \ \ _� Via"` "•��� /f% •: -�•�/!� �-- jt IIII � \ \ � !/ //f11• ••.•1•••�//:�. /�r' //r ( I/� � I \ \ \ ( � �\.j• �/y /� /y�/j.� // '� •.ram^• � �l III �I \ \ \ l M� • ////�i <• • �r�� ��i,;� /� \ `� ` i //' �j I / II IIII � \ \ \ ( /�j/� {•.� �.% /// � \ ///� jllj�ll \ \ \ \ I 11�1•I$%�i//���if�i'i�// \ \ �//�/ IIII I( \ ,., ,� �/llt • /' �•i .ii � / �IIIIIIII I I l j it It�FFlllll�lj�lt1., l�llll III ' I I I II I[Itll•li'i��jf // \ �\` � / /�� I III I IIII � I I l Itl I�IfIFII�:/ / f IIII II \< ( I ( I t I // .N /��� /pll�II INN DISTURBED AREA TOTAL = 2.87 AC WOODS = AC TURF = AC IMPERVIOUS = 0.00 AC 300 I III .� ✓ ( I f , ::•.•.'' •, OVERLOOK HOTEL POSTDEV VRRM MAP DISTURBED AREA TOTAL = 2.87 AC WOODS = 0.00 AC TURF = 1.28 AC IMPERVIOUS = 1.59 AC 6 CZ 100 0 100 200 300 Scale: 1 "=100' DM WMIWQBurwABeduRbn MC dxew DevelopmentmmptianmBgendsM1eee- C2011BNBsfaMaNeatlSptlllodme OMUDm BM19staMardeaMSWdnodms nJj Dame: ovedoo4 Hotel Da@: 8/12/2M BWDein Speeip ram Lisf: 2013 Mah Std5&SpB6 Ona dnta x.inrminm'ne:l 43 .wan E 1.m TM I JTPJE RVIFmCM nxB �m. m m+IEmcImW Ia.BG is rgetm Wen 114/eve/yrl OA] vl lvrmesm�mneem.l B.m 3.0 0. ommmm ommmm ommmm ommmm oommm oommm oommm 0ommm ommmm omomm ®momo ®�000 ®momo ®mmmo ®mmmo ®mmmo ®mmmo ©mmmo 0mmmo ®mmmo ®mmmo 0mmmo 0mmmo ommmm ommmm ommmm 0 ®mmmo ®mmmo 0mmmo ®mmmo ®mmmo ®mmmo ©mmmm ©ommm MEN Site Results (Water Quality Compliance) Area Checks FOREST/OPEN SPACE (a[) D.A.A am D.A.B 0.00 D.A.0 0.00 DA.D 0.DO O.F.E O.W A.-CHEM OK. IMPERVIOUS COVER(a[) IAJ 0.00 0.00 0.00 0.00 OK. IMPERV��GED TUEAAREA (a[) 0.69 0.00 DOD 0.00 0.00 OK. MANAGED TURF AREA TREATED (a[) 0.69 O.00 000 0.00 O.co OK. AREA CHECK OK OK. OK. OK OK. Site Treatment Volume (ffs) 6,6m Runoff Reduction Volume and TP By Drainage Area D.A. A D.A. B D.A. C D.A. D O.A. E TOTAL RUNOFF RFDUOION VOLUME ACHIEVEDIW) 0 0 0 0 0 TP LOADAVAINBLE FOR REMOVAL Qb/yrI 3.56 O.W 0.00 0.00 O.M 3.56 TP IDAD REDUCTION ACHIEVED)Ib/yrl 0.71 O.W 0.00 0.00 O.W 0.71 TP LOAD REMAINING IIb/yr) 2.85 DOD 0.00 0.00 0.00 2.85 NnROGEN IDAD REDUCTION ACHIEVED pb/yrl 0.00 O.W 0.00 0.00 O.W 0.00 Total Phosphorus FINAL POST-DEVELOPMENTTP LOAD Qb/yr) 4.15 TP LOAD REDUCTION REQUIRED pb/yrl 2.97 TP WAD REDUCTION AOIIFVED lb/yrl 0.71 W WAD REMAINING Qb/yr): 3A4 REMAINING TP LOAD REDUCTION REQUIRED pb/yr): 2.26 Total Nitrogen (For Information Purposes) POST -DEVELOPMENT LOAD IIb/yr) 29.69 NITROGEN LOAD REDUCTION ACHIEVED Pb/yrl a m REMAINING POST -DEVELOPMENT NITRWEN LOAD Pb/yrl 29.69 �o m �o �© �o ��mm��e �000000 �000000 ®000a® �m000a© ��mm��e �0000a� �000000 ��� ��®o m������ 0�00000 �000ao ®�®ooao m0ooaa ®®®ooao o0ooaa ®®000ao o0ooaa OVERLOOK HOTEL PREDEV DRAINAGE AREA MAP Drainage Area 1: Total Area = 2.61 ac Woods = 0.05 AC (HSG B), 1.39 AC (HSG D) Turf = 1.17 AC (HSG D) Impervious = 0.00 AC Time of Concentration = 11.3 iDU�I�b�I�bl 0is Drainage Ar a 1 Onsite 2L POA 1 $Ubcat Reach on Link Drainage Diagram for PREDEV Prepared by {enter your company name here}, Printed 8/11/2022 HydroCAD® 9.10 s/n 07054 0 2010 HydroCAD Software Solutions LLC Predev PREDEV Type/1 24-hr 1-YR Rainfall=3.02" Prepared by {enter your company name here} Printed 8/11/2022 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 2 Time span=0.00-48.00 hrs, dt=0.03 hrs, 1601 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1 S: Drainage Areal Onsite Runoff Area=2.610ac 0.00%Impervious Runoff Depth=1.14" Tc=11.3 min CN=78 Runoff=4.33 cfs 0.249 of Link 2L: POA 1 Inflow=4.33 cfs 0.249 of Primary=4.33 cfs 0.249 of Total Runoff Area = 2.610 ac Runoff Volume = 0.249 of Average Runoff Depth = 1.14' 100.00% Pervious = 2.610 ac 0.00% Impervious = 0.000 ac Predev PREDEV Type/1 24-hr 1-YR Rainfall=3.02" Prepared by {enter your company name here} Printed 8/11/2022 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 3 Summary for Subcatchment 1S: Drainage Areal Onsite Runoff = 4.33 cfs @ 12.04 hrs, Volume= 0.249 af, Depth= 1.14" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Type II 24-hr 1-YR Rainfall=3.02" Area (ac) CN Description 1.390 77 Woods, Good, HSG D 0.050 55 Woods, Good, HSG B 1.170 80 >75% Grass cover, Good, HSG D 2.610 78 Weighted Average 2.610 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.3 Direct Entry, Summary for Link 2L: POA 1 Inflow Area = 2.610 ac, 0.00% Impervious, Inflow Depth = 1.14" for 1-YR event Inflow = 4.33 cfs @ 12.04 hrs, Volume= 0.249 of Primary = 4.33 cfs @ 12.04 hrs, Volume= 0.249 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Predev PREDEV Type/1 24-hr 10-YR Rainfall=5.53" Prepared by {enter your company name here} Printed 8/11/2022 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 4 Time span=0.00-48.00 hrs, dt=0.03 hrs, 1601 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1 S: Drainage Areal Onsite Runoff Area=2.610ac 0.00%Impervious Runoff Depth=3.17" Tc=11.3 min CN=78 Runoff=12.07 cfs 0.689 of Link 2L: POA 1 Inflow=12.07 cfs 0.689 of Primary=12.07 cfs 0.689 of Total Runoff Area = 2.610 ac Runoff Volume = 0.689 of Average Runoff Depth = 3.17" 100.00% Pervious = 2.610 ac 0.00% Impervious = 0.000 ac Predev PREDEV Type/1 24-hr 10-YR Rainfall=5.53" Prepared by {enter your company name here} Printed 8/11/2022 HVdroCAD® 9.10 s/n 07054 ©2010 HVdroCAD Software Solutions LLC Paoe 5 Summary for Subcatchment 1S: Drainage Areal Onsite Runoff = 12.07 cfs @ 12.03 hrs, Volume= 0.689 af, Depth= 3.17" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Type II 24-hr 10-YR Rainfall=5.53" Area (ac) CN Description 1.390 77 Woods, Good, HSG D 0.050 55 Woods, Good, HSG B 1.170 80 >75% Grass cover, Good, HSG D 2.610 78 Weighted Average 2.610 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.3 Direct Entry, Summary for Link 2L: POA 1 Inflow Area = 2.610 ac, 0.00% Impervious, Inflow Depth = 3.17" for 10-YR event Inflow = 12.07 cfs @ 12.03 hrs, Volume= 0.689 of Primary = 12.07 cfs @ 12.03 hrs, Volume= 0.689 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Predev PREDEV Type/1 24-hr 100-YR Rainfall=9.09" Prepared by {enter your company name here} Printed 8/11/2022 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 6 Time span=0.00-48.00 hrs, dt=0.03 hrs, 1601 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1 S: Drainage Areal Onsite Runoff Area=2.610ac 0.00%Impervious Runoff Depth=6.41" Tc=11.3 min CN=78 Runoff=23.83 cfs 1.393 of Link 2L: POA 1 Inflow=23.83 cfs 1.393 of Primary=23.83 cfs 1.393 of Total Runoff Area = 2.610 ac Runoff Volume = 1.393 of Average Runoff Depth = 6.41" 100.00% Pervious = 2.610 ac 0.00% Impervious = 0.000 ac Predev PREDEV Type/1 24-hr 100-YR Rainfall=9.09" Prepared by {enter your company name here} Printed 8/11/2022 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 7 Summary for Subcatchment 1S: Drainage Areal Onsite Runoff = 23.83 cfs @ 12.03 hrs, Volume= 1.393 af, Depth= 6.41" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Type II 24-hr 100-YR Rainfall=9.09" Area (ac) CN Description 1.390 77 Woods, Good, HSG D 0.050 55 Woods, Good, HSG B 1.170 80 >75% Grass cover, Good, HSG D 2.610 78 Weighted Average 2.610 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.3 Direct Entry, Summary for Link 2L: POA 1 Inflow Area = 2.610 ac, 0.00% Impervious, Inflow Depth = 6.41" for 100-YR event Inflow = 23.83 cfs @ 12.03 hrs, Volume= 1.393 of Primary = 23.83 cfs @ 12.03 hrs, Volume= 1.393 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs OVERLOOK HOTEL POSTDEV DRAINAGE AREA MAP IT Q--::D Q---::D Drainage Area 1: Total Area = 3.75 ac Woods = 0.63 ac Managed Turf = 0.89 ac Impervious = 1.18 ac Drainage Area 1 to Detention Pond #1 (Overlook Hotel Site): Total Area = 0.47 ac Woods = 0.00 ac Managed Turf = 0.43 ac (HSG D) Impervious = 0.04 ac (HSG D) Time of Concentration = 5.0 Drainage Area 1 to Detention Pond #1 (Assumed Future Development of Adj. Parcel): Total Area = 1.01 ac Woods = 0.00 ac Managed Turf = 0.38 ac (HSG D) Impervious = 0.63 ac (HSG D) Time of Concentration = 5.0 Drainage Area 1 to Underground Grid Storage: Total Area = 2.16 ac Woods = 0.00 ac Managed Turf = 0.17 ac (HSG B), 0.52 ac (HSG D) Impervious = 0.43 ac (HSG B), 1.04 ac (HSG D) Time of Concentration = 5.0 Drainage Area 1 Untreated: Total Area = 0.11 ac Woods = 0.00 ac Managed Turf = 0.05 ac (HSG B), 0.05 ac (HSG D) Impervious = 0.01 ac (HSG B) Time of Concentration = 5.0 (7S Drainage Area 1 Onsit to Underground Storage (i, Adjacent Parcel to Detention Pond Onsite Pond Detenti n Pond 11S rainage Area 1 Onsite Untreated Underground Grid Storage 2L POA 1 S4 Reach X 4on Llnk Postdev POSTDEV Type/1 24-hr 1-YR Rainfall=3.02" Prepared by {enter your company name here} Printed 8/11/2022 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 2 Time span=0.00-48.00 hrs, dt=0.03 hrs, 1601 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Link 2L: POA 1 Inflow=0.87 cfs 0.611 of Primary=0.87 cfs 0.611 of Subcatchment3S: Adjacent Parcel to Runoff Area=1.010 ac 62.38% Impervious Runoff Depth=2.09" Tc=5.0 min CN=91 Runoff=3.72 cfs 0.176 of Pond 4P: Underground Grid Storage Peak Elev=475.69' Storage=0.181 of Inflow=7.96 cfs 0.376 of Outflow=0.38 cfs 0.376 of Pond 5P: Detention Pond Peak Elev=461.60' Storage=4,864 cf Inflow=4.87 cfs 0.228 of Outflow=0.48 cfs 0.227 of Subcatchment5S: DrainageArea 1 Onsiteto Runoff Area=0.470 ac 8.51%Impervious Runoff Depth=1.33" Tc=5.0 min UI Adjusted CN=81 Runoff=1.15 cfs 0.052 of Subcatchment7S: Drainage Area 1 Onsite Runoff Area=2.160 ac 68.06% Impervious Runoff Depth=2.09" Tc=5.0 min CN=91 Runoff=7.96 cfs 0.376 of Subcatchment1IS: DrainageArea1Onsite-Runoff Area=0.110ac 9.09%Impervious Runoff Depth=0.82" Tc=5.0 min UI Adjusted CN=72 Runoff=0.16 cfs 0.008 of Total Runoff Area = 3.750 ac Runoff Volume = 0.612 of Average Runoff Depth = 1.96" 42.67% Pervious = 1.600 ac 57.33% Impervious = 2.150 ac Postdev POSTDEV Type/1 24-hr 1-YR Rainfall=3.02" Prepared by {enter your company name here) Printed 8/11/2022 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 3 Summary for Link 2L: POA 1 Inflow Area = 3.750 ac, 57.33% Impervious, Inflow Depth > 1.96" for 1-YR event Inflow = 0.87 cfs @ 12.04 hrs, Volume= 0.611 of Primary = 0.87 cfs @ 12.04 hrs, Volume= 0.611 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Summary for Subcatchment 3S: Adjacent Parcel to Detention Pond Runoff = 3.72 cfs @ 11.96 hrs, Volume= 0.176 af, Depth= 2.09" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Type II 24-hr 1-YR Rainfall=3.02" Area (ac) CN Description 0.630 98 Unconnected roofs, HSG D 0.380 80 >75% Grass cover, Good, HSG D 1.010 91 Weighted Average 0.380 37.62% Pervious Area 0.630 62.38% Impervious Area 0.630 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Pond 4P: Underground Grid Storage Inflow Area = 2.160 ac, 68.06% Impervious, Inflow Depth = 2.09" for 1-YR event Inflow = 7.96 cfs @ 11.96 hrs, Volume= 0.376 of Outflow = 0.38 cfs @ 13.02 hrs, Volume= 0.376 af, Atten= 95%, Lag= 63.6 min Primary = 0.38 cfs @ 13.02 hrs, Volume= 0.376 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Peak Elev= 475.69' @ 13.02 hrs Surf.Area= 0.107 ac Storage= 0.181 of Plug -Flow detention time= 209.5 min calculated for 0.376 of (100% of inflow) Center -of -Mass det. time= 209.4 min ( 1,010.1 - 800.6 ) Volume Invert Avail.Storage Storage Description #1 473.00' 0.795 of RCP Box 10x 8 x 58 Inside= 120.0"W x 96.0"H => 78.61 sf x 8.001 = 628.9 cf Outside= 140.0"W x 116.0"H => 112.78 sf x 8.001 = 902.2 cf 1.201 of Overall x 95.0% Voids Postdev POSTDEV Type/1 24-hr 1-YR Rainfall=3.02" Prepared by {enter your company name here) Printed 8/11/2022 HvdroCAD@ 9.10 s/n 07054 @ 2010 HvdroCAD Software Solutions LLC Paae 4 Device Routing Invert Outlet Devices #1 Primary 473.00' 15.0" Round Culvert L= 36.0' CMP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 473.00' / 471.00' S= 0.0556 T Cc= 0.900 n= 0.013 Corrugated PE, smooth interior #2 Device 1 478.00' 6.0' long x 7.00' rise Sharp -Crested Rectangular Weir 2 End Contraction(s) 5.0' Crest Height #3 Device 1 473.00' 3.0" Vert. Orifice/Grate C= 0.600 #4 Device 2 473.00' 15.0" Round Culvert L= 5.0' Ke= 0.900 Inlet / Outlet Invert= 473.00' / 473.00' S= 0.0000 T Cc= 0.900 n= 0.012 Primary OutFlow Max=0.38 cfs @ 13.02 hrs HW=475.69' (Free Discharge) t1=Culvert (Passes 0.38 cfs of 6.71 cfs potential flow) � 3=O2=Sharp-Crested Rectangular Weir( Controls 0.00 cfs) t4=Culvert ( Controls 0.00 cfs) rifice/Grate (Orifice Controls 0.38 cfs @ 7.72 fps) Summary for Pond 5P: Detention Pond Inflow Area = 1.480 ac, 45.27% Impervious, Inflow Depth = 1.85" for 1-YR event Inflow = 4.87 cfs @ 11.96 hrs, Volume= 0.228 of Outflow = 0.48 cfs @ 12.39 hrs, Volume= 0.227 af, Atten= 90%, Lag= 25.8 min Primary = 0.48 cfs @ 12.39 hrs, Volume= 0.227 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Peak Elev= 461.60' @ 12.39 hrs Surf.Area= 3,454 sf Storage= 4,864 cf Plug -Flow detention time= 226.3 min calculated for 0.227 of (100% of inflow) Center -of -Mass det. time= 225.5 min ( 1,034.7 - 809.2 ) Volume Invert Avail.Storage Storage Description #1 460.00' 14,670 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic -feet) (cubic -feet) 460.00 2,630 0 0 462.00 3,660 6,290 6,290 464.00 4,720 8,380 14,670 Device Routing Invert Outlet Devices #1 Primary 460.00' 15.0" Round Culvert L= 60.0' CMP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 460.00' / 456.00' S= 0.0667 T Cc= 0.900 n= 0.012 #2 Device 1 462.00' 36.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 1 460.00' 2.5" Vert. Orifice/Grate C= 0.600 #4 Device 1 461.00' 4.0" Vert. Orifice/Grate C= 0.600 #5 Primary 462.50' 12.0' long x 20.0' breadth Broad -Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Postdev POSTDEV Type/1 24-hr 1-YR Rainfall=3.02" Prepared by {enter your company name here) Printed 8/11/2022 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 5 Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63 Primary OutFlow Max=0.48 cfs @ 12.39 hrs HW=461.60' (Free Discharge) Culvert (Passes 0.48 cfs of 4.60 cfs potential flow) 2=Orifice/Grate ( Controls 0.00 cfs) 3=Orifice/Grate (Orifice Controls 0.20 cfs @ 5.89 fps) =Orifice/Grate (Orifice Controls 0.28 cfs @ 3.17 fps) S=Broad-Crested Rectangular Weir( Controls 0.00 cfs) Summary for Subcatchment 5S: Drainage Area 1 Onsite to Detention Pond Runoff = 1.15 cfs @ 11.96 hrs, Volume= 0.052 af, Depth= 1.33" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Type II 24-hr 1-YR Rainfall=3.02" Area (ac) CN Description 0.040 98 Unconnected pavement, HSG D 0.430 80 >75% Grass cover, Good, HSG D 0.470 82 Weighted Average, UI Adjusted CN = 81 0.430 91.49% Pervious Area 0.040 8.51% Impervious Area 0.040 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 7S: Drainage Area 1 Onsite to Underground Storage Runoff = 7.96 cfs @ 11.96 hrs, Volume= 0.376 af, Depth= 2.09" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Type II 24-hr 1-YR Rainfall=3.02" Area (ac) CN Descri 0.170 61 >75% Grass cover, Good, HSG B 0.520 80 >75% Grass cover, Good, HSG D 0.430 98 Unconnected pavement, HSG B 1.040 98 Unconnected pavement, HSG D 2.160 91 Weighted Average 0.690 31.94% Pervious Area 1.470 68.06% Impervious Area 1.470 100.00% Unconnected Tc Length Slope Velocity Capacity Description 5.0 Direct Entry, Postdev POSTDEV Type/1 24-hr 1-YR Rainfall=3.02" Prepared by {enter your company name here} Printed 8/11/2022 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 6 Summary for Subcatchment 11S: Drainage Areal Onsite -Untreated Runoff = 0.16 cfs @ 11.97 hrs, Volume= 0.008 af, Depth= 0.82" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Type II 24-hr 1-YR Rainfall=3.02" Area (ac) CN Description 0.050 61 >75% Grass cover, Good, HSG B 0.050 80 >75% Grass cover, Good, HSG D 0.010 98 Unconnected pavement, HSG B 0.000 98 Unconnected pavement. HSG D 0.110 73 Weighted Average, UI Adjusted CN = 72 0.100 90.91 % Pervious Area 0.010 9.09% Impervious Area 0.010 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Postdev POSTDEV Type/1 24-hr 10-YR Rainfall=5.53" Prepared by {enter your company name here} Printed 8/11/2022 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 7 Time span=0.00-48.00 hrs, dt=0.03 hrs, 1601 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Link 2L: POA 1 Inflow=7.35 cfs 1.347 of Primary=7.35 cfs 1.347 of Subcatchment3S: Adjacent Parcel to Runoff Area=1.010 ac 62.38% Impervious Runoff Depth=4.50" Tc=5.0 min CN=91 Runoff=7.62 cfs 0.379 of Pond 4P: Underground Grid Storage Peak EIev=478.08' Storage=0.423 of Inflow=16.30 cfs 0.810 of Outflow=1.07 cfs 0.810 of Pond 5P: Detention Pond Peak EIev=462.52' Storage=8,261 cf Inflow=10.54 cfs 0.514 of Outflow=6.51 cfs 0.513 of Subcatchment5S: DrainageArea 1 Onsiteto Runoff Area=0.470 ac 8.51%Impervious Runoff Depth=3.46" Tc=5.0 min UI Adjusted CN=81 Runoff=2.92 cfs 0.135 of Subcatchment7S: Drainage Area 1 Onsite Runoff Area=2.160 ac 68.06% Impervious Runoff Depth=4.50" Tc=5.0 min CN=91 Runoff=16.30 cfs 0.810 of Subcatchment1IS: DrainageArea1Onsite-Runoff Area=0.110ac 9.09%Impervious Runoff Depth=2.61" Tc=5.0 min UI Adjusted CN=72 Runoff=0.53 cfs 0.024 of Total Runoff Area = 3.750 ac Runoff Volume = 1.348 of Average Runoff Depth = 4.31" 42.67% Pervious = 1.600 ac 57.33% Impervious = 2.150 ac Postdev POSTDEV Type/1 24-hr 10-YR Rainfall=5.53" Prepared by {enter your company name here) Printed 8/11/2022 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 8 Summary for Link 2L: POA 1 Inflow Area = 3.750 ac, 57.33% Impervious, Inflow Depth > 4.31" for 10-YR event Inflow = 7.35 cfs @ 12.02 hrs, Volume= 1.347 of Primary = 7.35 cfs @ 12.02 hrs, Volume= 1.347 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Summary for Subcatchment 3S: Adjacent Parcel to Detention Pond Runoff = 7.62 cfs @ 11.96 hrs, Volume= 0.379 af, Depth= 4.50" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Type II 24-hr 10-YR Rainfall=5.53" Area (ac) CN Description 0.630 98 Unconnected roofs, HSG D 0.380 80 >75% Grass cover, Good, HSG D 1.010 91 Weighted Average 0.380 37.62% Pervious Area 0.630 62.38% Impervious Area 0.630 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Pond 4P: Underground Grid Storage Inflow Area = 2.160 ac, 68.06% Impervious, Inflow Depth = 4.50" for 10-YR event Inflow = 16.30 cfs @ 11.96 hrs, Volume= 0.810 of Outflow = 1.07 cfs @ 12.56 hrs, Volume= 0.810 af, Atten= 93%, Lag= 36.1 min Primary = 1.07 cfs @ 12.56 hrs, Volume= 0.810 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Peak Elev= 478.08' @ 12.56 hrs Surf.Area= 0.107 ac Storage= 0.423 of Plug -Flow detention time= 361.2 min calculated for 0.809 of (100% of inflow) Center -of -Mass det. time= 361.4 min ( 1,140.8 - 779.3 ) Volume Invert Avail.Storage Storage Description #1 473.00' 0.795 of RCP Box 10x 8 x 58 Inside= 120.0"W x 96.0"H => 78.61 sf x 8.001 = 628.9 cf Outside= 140.0"W x 116.0"H => 112.78 sf x 8.001 = 902.2 cf 1.201 of Overall x 95.0% Voids Postdev POSTDEV Type/1 24-hr 10-YR Rainfall=5.53" Prepared by {enter your company name here) Printed 8/11/2022 HvdroCAD@ 9.10 s/n 07054 @ 2010 HvdroCAD Software Solutions LLC Paae 9 Device Routing Invert Outlet Devices #1 Primary 473.00' 15.0" Round Culvert L= 36.0' CMP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 473.00' / 471.00' S= 0.0556 T Cc= 0.900 n= 0.013 Corrugated PE, smooth interior #2 Device 1 478.00' 6.0' long x 7.00' rise Sharp -Crested Rectangular Weir 2 End Contraction(s) 5.0' Crest Height #3 Device 1 473.00' 3.0" Vert. Orifice/Grate C= 0.600 #4 Device 2 473.00' 15.0" Round Culvert L= 5.0' Ke= 0.900 Inlet / Outlet Invert= 473.00' / 473.00' S= 0.0000 T Cc= 0.900 n= 0.012 Primary OutFlow Max=0.99 cfs @ 12.56 hrs HW=478.08' (Free Discharge) t1=Culvert (Passes 0.99 cfs of 9.85 cfs potential flow) � 3=O2=Sharp-Crested Rectangular Weir (Weir Controls 0.46 cfs @ 0.94 fps) t4=Culvert (Passes 0.46 cfs of 1.34 cfs potential flow) rifice/Grate (Orifice Controls 0.53 cfs @ 10.72 fps) Summary for Pond 5P: Detention Pond Inflow Area = 1.480 ac, 45.27% Impervious, Inflow Depth = 4.17" for 10-YR event Inflow = 10.54 cfs @ 11.96 hrs, Volume= 0.514 of Outflow = 6.51 cfs @ 12.03 hrs, Volume= 0.513 af, Atten= 38%, Lag= 4.3 min Primary = 6.51 cfs @ 12.03 hrs, Volume= 0.513 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Peak Elev= 462.52' @ 12.03 hrs Surf.Area= 3,935 sf Storage= 8,261 cf Plug -Flow detention time= 159.2 min calculated for 0.513 of (100% of inflow) Center -of -Mass det. time= 158.3 min ( 945.9 - 787.6 ) Volume Invert Avail.Storage Storage Description #1 460.00' 14,670 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic -feet) (cubic -feet) 460.00 2,630 0 0 462.00 3,660 6,290 6,290 464.00 4,720 8,380 14,670 Device Routing Invert Outlet Devices #1 Primary 460.00' 15.0" Round Culvert L= 60.0' CMP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 460.00' / 456.00' S= 0.0667 T Cc= 0.900 n= 0.012 #2 Device 1 462.00' 36.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 1 460.00' 2.5" Vert. Orifice/Grate C= 0.600 #4 Device 1 461.00' 4.0" Vert. Orifice/Grate C= 0.600 #5 Primary 462.50' 12.0' long x 20.0' breadth Broad -Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Postdev POSTDEV Type/1 24-hr 10-YR Rainfall=5.53" Prepared by {enter your company name here) Printed 8/11/2022 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 10 Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63 Primary OutFlow Max=6.50 cfs @ 12.03 hrs HW=462.52' (Free Discharge) Culvert (Inlet Controls 6.42 cfs @ 5.23 fps) 2=Orifice/Grate (Passes < 11.51 cfs potential flow) 3=Orifice/Grate (Passes < 0.26 cfs potential flow) =Orifice/Grate (Passes < 0.49 cfs potential flow) S=Broad-Crested Rectangular Weir(Weir Controls 0.08 cfs @ 0.37 fps) Summary for Subcatchment 5S: Drainage Area 1 Onsite to Detention Pond Runoff = 2.92 cfs @ 11.96 hrs, Volume= 0.135 af, Depth= 3.46" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Type II 24-hr 10-YR Rainfall=5.53" Area (ac) CN Description 0.040 98 Unconnected pavement, HSG D 0.430 80 >75% Grass cover, Good, HSG D 0.470 82 Weighted Average, UI Adjusted CN = 81 0.430 91.49% Pervious Area 0.040 8.51% Impervious Area 0.040 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 7S: Drainage Area 1 Onsite to Underground Storage Runoff = 16.30 cfs @ 11.96 hrs, Volume= 0.810 af, Depth= 4.50" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Type II 24-hr 10-YR Rainfall=5.53" Area (ac) CN Descri 0.170 61 >75% Grass cover, Good, HSG B 0.520 80 >75% Grass cover, Good, HSG D 0.430 98 Unconnected pavement, HSG B 1.040 98 Unconnected pavement, HSG D 2.160 91 Weighted Average 0.690 31.94% Pervious Area 1.470 68.06% Impervious Area 1.470 100.00% Unconnected Tc Length Slope Velocity Capacity Description 5.0 Direct Entry, Postdev POSTDEV Type/1 24-hr 10-YR Rainfall=5.53" Prepared by {enter your company name here} Printed 8/11/2022 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 11 Summary for Subcatchment 11S: Drainage Areal Onsite -Untreated Runoff = 0.53 cfs @ 11.96 hrs, Volume= 0.024 af, Depth= 2.61" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Type II 24-hr 10-YR Rainfall=5.53" Area (ac) CN Description 0.050 61 >75% Grass cover, Good, HSG B 0.050 80 >75% Grass cover, Good, HSG D 0.010 98 Unconnected pavement, HSG B 0.000 98 Unconnected pavement. HSG D 0.110 73 Weighted Average, UI Adjusted CN = 72 0.100 90.91 % Pervious Area 0.010 9.09% Impervious Area 0.010 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Postdev POSTDEV Type 1124-hr 25-YR Rainfall=6.80" Prepared by {enter your company name here} Printed 8/11/2022 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 12 Time span=0.00-48.00 hrs, dt=0.03 hrs, 1601 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Link 2L: POA 1 Inflow=14.28 cfs 1.731 of Primary=14.28 cfs 1.731 of Subcatchment3S: Adjacent Parcel to Runoff Area=1.010 ac 62.38% Impervious Runoff Depth=5.74" Tc=5.0 min CN=91 Runoff=9.57 cfs 0.483 of Pond 4P: Underground Grid Storage Peak Elev=478.63' Storage=0.479 of Inflow=20.46 cfs 1.034 of Outflow=4.26 cfs 1.034 of Pond 5P: Detention Pond Peak Elev=462.75' Storage=9,189 cf Inflow=13.41 cfs 0.664 of Outflow=10.86 cfs 0.663 of Subcatchment5S: DrainageArea 1 Onsiteto Runoff Area=0.470 ac 8.51%Impervious Runoff Depth=4.62" Tc=5.0 min UI Adjusted CN=81 Runoff=3.84 cfs 0.181 of Subcatchment7S: Drainage Area 1 Onsite Runoff Area=2.160 ac 68.06% Impervious Runoff Depth=5.74" Tc=5.0 min CN=91 Runoff=20.46 cfs 1.034 of Subcatchment1IS: DrainageArea1Onsite-Runoff Area=0.110ac 9.09%Impervious Runoff Depth=3.66" Tc=5.0 min UI Adjusted CN=72 Runoff=0.74 cfs 0.034 of Total Runoff Area = 3.750 ac Runoff Volume = 1.731 of Average Runoff Depth = 5.54" 42.67% Pervious = 1.600 ac 57.33% Impervious = 2.150 ac Postdev POSTDEV Type 1124-hr 25-YR Rainfall=6.80" Prepared by {enter your company name here) Printed 8/11/2022 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 13 Summary for Link 2L: POA 1 Inflow Area = 3.750 ac, 57.33% Impervious, Inflow Depth = 5.54" for 25-YR event Inflow = 14.28 cfs @ 12.03 hrs, Volume= 1.731 of Primary = 14.28 cfs @ 12.03 hrs, Volume= 1.731 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Summary for Subcatchment 3S: Adjacent Parcel to Detention Pond Runoff = 9.57 cfs @ 11.96 hrs, Volume= 0.483 af, Depth= 5.74" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Type II 24-hr 25-YR Rainfall=6.80" Area (ac) CN Description 0.630 98 Unconnected roofs, HSG D 0.380 80 >75% Grass cover, Good, HSG D 1.010 91 Weighted Average 0.380 37.62% Pervious Area 0.630 62.38% Impervious Area 0.630 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Pond 4P: Underground Grid Storage Inflow Area = 2.160 ac, 68.06% Impervious, Inflow Depth = 5.74" for 25-YR event Inflow = 20.46 cfs @ 11.96 hrs, Volume= 1.034 of Outflow = 4.26 cfs @ 12.10 hrs, Volume= 1.034 af, Atten= 79%, Lag= 8.8 min Primary = 4.26 cfs @ 12.10 hrs, Volume= 1.034 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Peak Elev= 478.63' @ 12.10 hrs Surf.Area= 0.107 ac Storage= 0.479 of Plug -Flow detention time= 313.7 min calculated for 1.033 of (100% of inflow) Center -of -Mass det. time= 313.9 min ( 1,086.8 - 772.9 ) Volume Invert Avail.Storage Storage Description #1 473.00' 0.795 of RCP Box 10x 8 x 58 Inside= 120.0"W x 96.0"H => 78.61 sf x 8.001 = 628.9 cf Outside= 140.0"W x 116.0"H => 112.78 sf x 8.001 = 902.2 cf 1.201 of Overall x 95.0% Voids Postdev POSTDEV Type 1124-hr 25-YR Rainfall=6.80" Prepared by {enter your company name here) Printed 8/11/2022 HvdroCAD@ 9.10 s/n 07054 @ 2010 HvdroCAD Software Solutions LLC Paae 14 Device Routing Invert Outlet Devices #1 Primary 473.00' 15.0" Round Culvert L= 36.0' CMP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 473.00' / 471.00' S= 0.0556 T Cc= 0.900 n= 0.013 Corrugated PE, smooth interior #2 Device 1 478.00' 6.0' long x 7.00' rise Sharp -Crested Rectangular Weir 2 End Contraction(s) 5.0' Crest Height #3 Device 1 473.00' 3.0" Vert. Orifice/Grate C= 0.600 #4 Device 2 473.00' 15.0" Round Culvert L= 5.0' Ke= 0.900 Inlet / Outlet Invert= 473.00' / 473.00' S= 0.0000 T Cc= 0.900 n= 0.012 Primary OutFlow Max=4.25 cfs @ 12.10 hrs HW=478.63' (Free Discharge) t1=Culvert (Passes 4.25 cfs of 10.43 cfs potential flow) � 3=O2=Sharp-Crested Rectangular Weir (Passes 3.69 cfs of 9.66 cfs potential flow) t4=Culvert (Inlet Controls 3.69 cfs @ 3.01 fps) rifice/Grate (Orifice Controls 0.55 cfs @ 11.29 fps) Summary for Pond 5P: Detention Pond Inflow Area = 1.480 ac, 45.27% Impervious, Inflow Depth = 5.39" for 25-YR event Inflow = 13.41 cfs @ 11.96 hrs, Volume= 0.664 of Outflow = 10.86 cfs @ 12.01 hrs, Volume= 0.663 af, Atten= 19%, Lag= 2.9 min Primary = 10.86 cfs @ 12.01 hrs, Volume= 0.663 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Peak Elev= 462.75' @ 12.01 hrs Surf.Area= 4,058 sf Storage= 9,189 cf Plug -Flow detention time= 139.7 min calculated for 0.663 of (100% of inflow) Center -of -Mass det. time= 138.9 min ( 919.9 - 781.0 ) Volume Invert Avail.Storage Storage Description #1 460.00' 14,670 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic -feet) (cubic -feet) 460.00 2,630 0 0 462.00 3,660 6,290 6,290 464.00 4,720 8,380 14,670 Device Routing Invert Outlet Devices #1 Primary 460.00' 15.0" Round Culvert L= 60.0' CMP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 460.00' / 456.00' S= 0.0667 T Cc= 0.900 n= 0.012 #2 Device 1 462.00' 36.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 1 460.00' 2.5" Vert. Orifice/Grate C= 0.600 #4 Device 1 461.00' 4.0" Vert. Orifice/Grate C= 0.600 #5 Primary 462.50' 12.0' long x 20.0' breadth Broad -Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Postdev POSTDEV Type 1124-hr 25-YR Rainfall=6.80" Prepared by {enter your company name here) Printed 8/11/2022 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 15 Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63 Primary OutFlow Max=10.70 cfs @ 12.01 hrs HW=462.75' (Free Discharge) Culvert (Inlet Controls 6.79 cfs @ 5.53 fps) 2=Orifice/Grate (Passes < 19.82 cfs potential flow) 3=Orifice/Grate (Passes < 0.27 cfs potential flow) =Orifice/Grate (Passes < 0.53 cfs potential flow) S=Broad-Crested Rectangular Weir (Weir Controls 3.91 cfs @ 1.33 fps) Summary for Subcatchment 5S: Drainage Area 1 Onsite to Detention Pond Runoff = 3.84 cfs @ 11.96 hrs, Volume= 0.181 af, Depth= 4.62" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Type II 24-hr 25-YR Rainfall=6.80" Area (ac) CN Description 0.040 98 Unconnected pavement, HSG D 0.430 80 >75% Grass cover, Good, HSG D 0.470 82 Weighted Average, UI Adjusted CN = 81 0.430 91.49% Pervious Area 0.040 8.51% Impervious Area 0.040 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 7S: Drainage Area 1 Onsite to Underground Storage Runoff = 20.46 cfs @ 11.96 hrs, Volume= 1.034 af, Depth= 5.74" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Type II 24-hr 25-YR Rainfall=6.80" Area (ac) CN Descri 0.170 61 >75% Grass cover, Good, HSG B 0.520 80 >75% Grass cover, Good, HSG D 0.430 98 Unconnected pavement, HSG B 1.040 98 Unconnected pavement, HSG D 2.160 91 Weighted Average 0.690 31.94% Pervious Area 1.470 68.06% Impervious Area 1.470 100.00% Unconnected Tc Length Slope Velocity Capacity Description 5.0 Direct Entry, Postdev POSTDEV Type 1124-hr 25-YR Rainfall=6.80" Prepared by {enter your company name here} Printed 8/11/2022 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 16 Summary for Subcatchment 11S: Drainage Areal Onsite -Untreated Runoff = 0.74 cfs @ 11.96 hrs, Volume= 0.034 af, Depth= 3.66" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Type II 24-hr 25-YR Rainfall=6.80" Area (ac) CN Description 0.050 61 >75% Grass cover, Good, HSG B 0.050 80 >75% Grass cover, Good, HSG D 0.010 98 Unconnected pavement, HSG B 0.000 98 Unconnected pavement. HSG D 0.110 73 Weighted Average, UI Adjusted CN = 72 0.100 90.91 % Pervious Area 0.010 9.09% Impervious Area 0.010 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Postdev POSTDEV Type/1 24-hr 100-YR Rainfall=9.09" Prepared by {enter your company name here} Printed 8/11/2022 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 17 Time span=0.00-48.00 hrs, dt=0.03 hrs, 1601 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Link 2L: POA 1 Inflow=24.58 cfs 2.430 of Primary=24.58 cfs 2.430 of Subcatchment3S: Adjacent Parcel to Runoff Area=1.010 ac 62.38% Impervious Runoff Depth=8.00" Tc=5.0 min CN=91 Runoff=13.05 cfs 0.674 of Pond 4P: Underground Grid Storage Peak EIev=480.25' Storage=0.643 of Inflow=27.90 cfs 1.440 of Outflow=7.63 cfs 1.440 of Pond 5P: Detention Pond Peak EIev=462.95' Storage=10,015 cf Inflow=18.55 cfs 0.939 of Outflow=16.96 cfs 0.938 of Subcatchment5S: DrainageArea 1 Onsiteto Runoff Area=0.470 ac 8.51%Impervious Runoff Depth=6.78" Tc=5.0 min UI Adjusted CN=81 Runoff=5.51 cfs 0.265 of Subcatchment7S: Drainage Area 1 Onsite Runoff Area=2.160 ac 68.06% Impervious Runoff Depth=8.00" Tc=5.0 min CN=91 Runoff=27.90 cfs 1.440 of Subcatchment1IS: DrainageArea1Onsite-Runoff Area=0.110ac 9.09%Impervious Runoff Depth=5.66" Tc=5.0 min UI Adjusted CN=72 Runoff=1.12 cfs 0.052 of Total Runoff Area = 3.750 ac Runoff Volume = 2.431 of Average Runoff Depth = 7.78" 42.67% Pervious = 1.600 ac 57.33% Impervious = 2.150 ac Postdev POSTDEV Type/1 24-hr 100-YR Rainfall=9.09" Prepared by {enter your company name here) Printed 8/11/2022 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 18 Summary for Link 2L: POA 1 Inflow Area = 3.750 ac, 57.33% Impervious, Inflow Depth = 7.78" for 100-YR event Inflow = 24.58 cfs @ 11.99 hrs, Volume= 2.430 of Primary = 24.58 cfs @ 11.99 hrs, Volume= 2.430 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Summary for Subcatchment 3S: Adjacent Parcel to Detention Pond Runoff = 13.05 cfs @ 11.96 hrs, Volume= 0.674 af, Depth= 8.00" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Type II 24-hr 100-YR Rainfall=9.09" Area (ac) CN Description 0.630 98 Unconnected roofs, HSG D 0.380 80 >75% Grass cover, Good, HSG D 1.010 91 Weighted Average 0.380 37.62% Pervious Area 0.630 62.38% Impervious Area 0.630 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Pond 4P: Underground Grid Storage Inflow Area = 2.160 ac, 68.06% Impervious, Inflow Depth = 8.00" for 100-YR event Inflow = 27.90 cfs @ 11.96 hrs, Volume= 1.440 of Outflow = 7.63 cfs @ 12.08 hrs, Volume= 1.440 af, Atten= 73%, Lag= 7.6 min Primary = 7.63 cfs @ 12.08 hrs, Volume= 1.440 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Peak Elev= 480.25' @ 12.08 hrs Surf.Area= 0.107 ac Storage= 0.643 of Plug -Flow detention time= 262.6 min calculated for 1.440 of (100% of inflow) Center -of -Mass det. time= 262.9 min ( 1,027.5 - 764.6 ) Volume Invert Avail.Storage Storage Description #1 473.00' 0.795 of RCP Box 10x 8 x 58 Inside= 120.0"W x 96.0"H => 78.61 sf x 8.001 = 628.9 cf Outside= 140.0"W x 116.0"H => 112.78 sf x 8.001 = 902.2 cf 1.201 of Overall x 95.0% Voids Postdev POSTDEV Type/1 24-hr 100-YR Rainfall=9.09" Prepared by {enter your company name here) Printed 8/11/2022 HvdroCAD@ 9.10 s/n 07054 @ 2010 HvdroCAD Software Solutions LLC Paae 19 Device Routing Invert Outlet Devices #1 Primary 473.00' 15.0" Round Culvert L= 36.0' CMP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 473.00' / 471.00' S= 0.0556 T Cc= 0.900 n= 0.013 Corrugated PE, smooth interior #2 Device 1 478.00' 6.0' long x 7.00' rise Sharp -Crested Rectangular Weir 2 End Contraction(s) 5.0' Crest Height #3 Device 1 473.00' 3.0" Vert. Orifice/Grate C= 0.600 #4 Device 2 473.00' 15.0" Round Culvert L= 5.0' Ke= 0.900 Inlet / Outlet Invert= 473.00' / 473.00' S= 0.0000 T Cc= 0.900 n= 0.012 Primary OutFlow Max=7.62 cfs @ 12.08 hrs HW=480.25' (Free Discharge) t1=Culvert (Passes 7.62 cfs of 12.01 cfs potential flow) 2=Sharp-Crested Rectangular Weir (Passes 6.99 cfs of 64.54 cfs potential flow) 3=O t4=Culvert (Inlet Controls 6.99 cfs @ 5.70 fps) rifice/Grate (Orifice Controls 0.63 cfs @ 12.85 fps) Summary for Pond 5P: Detention Pond Inflow Area = 1.480 ac, 45.27% Impervious, Inflow Depth = 7.61" for 100-YR event Inflow = 18.55 cfs @ 11.96 hrs, Volume= 0.939 of Outflow = 16.96 cfs @ 11.99 hrs, Volume= 0.938 af, Atten= 9%, Lag= 1.8 min Primary = 16.96 cfs @ 11.99 hrs, Volume= 0.938 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Peak Elev= 462.95' @ 11.99 hrs Surf.Area= 4,165 sf Storage= 10,015 cf Plug -Flow detention time= 116.9 min calculated for 0.938 of (100% of inflow) Center -of -Mass det. time= 116.2 min ( 888.5 - 772.3 ) Volume Invert Avail.Storage Storage Description #1 460.00' 14,670 cf Custom Stage Data (Prismatic)Listed below (Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic -feet) (cubic -feet) 460.00 2,630 0 0 462.00 3,660 6,290 6,290 464.00 4,720 8,380 14,670 Device Routing Invert Outlet Devices #1 Primary 460.00' 15.0" Round Culvert L= 60.0' CMP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 460.00' / 456.00' S= 0.0667 T Cc= 0.900 n= 0.012 #2 Device 1 462.00' 36.0" Horiz. Orifice/Grate C= 0.600 Limited to weir flow at low heads #3 Device 1 460.00' 2.5" Vert. Orifice/Grate C= 0.600 #4 Device 1 461.00' 4.0" Vert. Orifice/Grate C= 0.600 #5 Primary 462.50' 12.0' long x 20.0' breadth Broad -Crested Rectangular Weir Head (feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 Postdev POSTDEV Type/1 24-hr 100-YR Rainfall=9.09" Prepared by {enter your company name here) Printed 8/11/2022 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 20 Coef. (English) 2.68 2.70 2.70 2.64 2.63 2.64 2.64 2.63 Primary OutFlow Max=16.68 cfs @ 11.99 hrs HW=462.94' (Free Discharge) Culvert (Inlet Controls 7.10 cfs @ 5.79 fps) 2=Orifice/Grate (Passes < 28.25 cfs potential flow) 3=Orifice/Grate (Passes < 0.28 cfs potential flow) =Orifice/Grate (Passes < 0.56 cfs potential flow) S=Broad-Crested Rectangular Weir(Weir Controls 9.57 cfs @ 1.80 fps) Summary for Subcatchment 5S: Drainage Area 1 Onsite to Detention Pond Runoff = 5.51 cfs @ 11.96 hrs, Volume= 0.265 af, Depth= 6.78" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Type II 24-hr 100-YR Rainfall=9.09" Area (ac) CN Description 0.040 98 Unconnected pavement, HSG D 0.430 80 >75% Grass cover, Good, HSG D 0.470 82 Weighted Average, UI Adjusted CN = 81 0.430 91.49% Pervious Area 0.040 8.51% Impervious Area 0.040 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 7S: Drainage Area 1 Onsite to Underground Storage Runoff = 27.90 cfs @ 11.96 hrs, Volume= 1.440 af, Depth= 8.00" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Type II 24-hr 100-YR Rainfall=9.09" Area (ac) CN Descri 0.170 61 >75% Grass cover, Good, HSG B 0.520 80 >75% Grass cover, Good, HSG D 0.430 98 Unconnected pavement, HSG B 1.040 98 Unconnected pavement, HSG D 2.160 91 Weighted Average 0.690 31.94% Pervious Area 1.470 68.06% Impervious Area 1.470 100.00% Unconnected Tc Length Slope Velocity Capacity Description 5.0 Direct Entry, Postdev POSTDEV Type/1 24-hr 100-YR Rainfall=9.09" Prepared by {enter your company name here} Printed 8/11/2022 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 21 Summary for Subcatchment 11S: Drainage Areal Onsite -Untreated Runoff = 1.12 cfs @ 11.96 hrs, Volume= 0.052 af, Depth= 5.66" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Type II 24-hr 100-YR Rainfall=9.09" Area (ac) CN Description 0.050 61 >75% Grass cover, Good, HSG B 0.050 80 >75% Grass cover, Good, HSG D 0.010 98 Unconnected pavement, HSG B 0.000 98 Unconnected pavement. HSG D 0.110 73 Weighted Average, UI Adjusted CN = 72 0.100 90.91 % Pervious Area 0.010 9.09% Impervious Area 0.010 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Energy Balance Equation and Run-on Summary for Site Outfall 1 Overlook Hotel 1 Yr, 24 Hr Storm Comparison Q 1 post <_ Q 1 Pre, site ((RV i Pre, site)/(RV 1 Pre, sae))(IF) + Q I Pre, offsite ((RV t Pre, offsite)/(RV t Pre, offsae)) IF = 0.8 when LOD >_ 1 ac, IF=0.9 when LOD < 1 ac, IF = 1 when site if forested PreDev Site Fully Forested? = no IF Development Limits = 2.89 ac On Site Off Site Pre Dev DA Site = 2.61 ac Pre Dev DA Offsite = 0 ac Post Dev DA Site (Managed) = 3.64 ac Post Dev DA Offsite = 0 ac Post Dev DA Site (Un-Managed) = 0.11 ac Q I Pre, site = 4.33 cfs Q t Pre, oftite = 0.00 cfs RV i Pre, site = 0.249 of RV i Pre, orate = 0.000 of RV i Post, site = 0.612 of RV i Post, orate = 0.000 of Qlpost (Max Allowed) <_ 1.41 Postdev Flowrates Storm cfs I-cr 0.87 Energy Balance Equation Compliance: Achieved Predev Flowrates Storm cfs 10-yr Postdev Flowrates Storm cfs 10-yr Overlook Hotel Time of Concentration Calculations - Predev 100 ft overland flow 20.0% slope 0.35 C-value 8.3 min Seelye Chart 35 ft s. c. flow 51.4% slope 3.4 fps velocity 0.2 min. NEH Figure 15-4 392 ft swale 14 ft height 2.8 min. Kirpich Chart 11.3 min. 35 i 30 V Paved a i 25 c .e 500 Bare T o 20 W 200 Sal . r 1 Groosss W ~ 's a� ~_ -gurfaoe z W Grow u 0.5 W W z 1.0 0 15 2.0 a. HO Dense Grua a z O 70 t 5.0 z (n 60 'Y \ \ / U C9 F 0 50 g 20 La a lzi N U J 40 1p zz S U 0 30 W z J i J 9 20 7 10 6 OVERLAND FLOW TIME 3cclye Chen) Source: Data Hook for Cwi Lancers. EE Seelye Plate 5-1 Velocity (tw) 1992 TRAVEL TIME FOR CHANNEL FLOW (I(Irpich Chan) H (feet) 500 Tt (Nin.) 200 too I00 L (feet) t0000 fxF,�Ie 50 50 cao u 8 (1) ier we eith nearel Memsls; a5a € t0 (21 Far V ceserels, -Itlpiy taco ° to MF 0.z 5 jj 500 5 100 I I TIME OF CONCENTMTION OF SHALL OAAINME MSINS Source: VDOT Plate 5-3 V-13 PREDEV POA 1: Outlet Protection Calculations - Reference Nomograph 3.18-3 Pi a Outfall # La ft W ft Do in Do ft 3Do ft d50 ft d50 in Depth in AO 12 14 24 2 6 0.5 6 9 Overlook Hotel LD-204 Slomrwater Inlet Computations Inlets on Glade Goy Sag Inlets Only 2` E ~ 4L34 v y` ci '� r c i a S d w s m y i s ?nni ¢` rc ci o o 1 c3 18�' o o s1 d a sy 1 z s s a s 9 m n iz 1a 14 1s 1s n 1 is 1s z0 zi(ac) (iNM1O Icfs) Icfs) (cfs) ('f) rr) V) (fl) (fl) (cw (cfs) (fl) Ifl) (fl) MA DI-] 10,827 0.25 0.70 0.17 5.2 0.90 0.90 0.015 0.02 0.05 0.02 3.34 2.41 100.0% 1.05 0.00 0.124 0.5 0.248 2.069 6.8 1.18 1.18 0.015 0.02 0.05 0.02 3.57 2.57 100.0% 1.18 0.07 0.139 0.5 0.278 2.324 A5 DI-38 8 11,984 0.28 0.90 0.25 5.2 1.28 1.28 0.015 0.02 0.05 0.02 2.37 1.42 100.0% 0.31 0.00 0.055 0.5 0.11 1.101 6.8 1.69 1.69 0.015 0.02 0.05 0,02 2.53 1.52 100.0% 1.69 0.00 0.062 0.5 0,124 1.239 A7 DI-313 8 10,674 0.25 0.90 0.22 5.2 1.14 1.14 0.015 0.02 0.05 0.02 4.40 2.64 100.0% 1.61 0.00 0.142 0.5 0.284 3.557 6.8 1.50 1.50 0.015 0.02 0.05 0,02 470 2.82 100.0% 1.92 -0.42 0,16 0.5 0.32 4 A9 DI-] 17,153 0.39 0.70 0.28 5.2 1.42 1.42 0.015 0.02 0.05 0.02 7.00 2.52 100.0% 2.37 0.00 0.214 0.5 0.428 7.121 6.8 1.88 1.88 0.015 0.02 0.05 0.02 7.49 2.10 100.0% 2.84 -0.96 0.241 0.5 0.482 8.034 Overlook Hotel LD-229 Storm Drain Design Computations From To Catch. Runoff Increment Accum. Total 10-yr 1"r Up Down Pipe Invert Pipe Pipe Velocity Flow time Structure Structure Area Caef AC AC TOC Intensity Flow Invert Invert Length Slope Diameter Capacity Increment (ac) (min) in/hr) (cfs) Elev. Elev. (ff) % (in) cfs Ns) (min) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 A9 A8 0.39 0.70 028 028 5.00 8.18 1.10 496.00 492.00 81.00 4.94% 15 1.3 3.6 0.38 M A7 000 0.00 0.00 0.28 5.00 6.18 1.]0 491.80 489D0 ]400 379% 15 2.2 4.1 030 A7 As 0.25 0.90 022 0.50 6.00 6.18 3.07 488.80 487.00 65.00 2.77% 15 1.6 5.2 0.21 M A5 028 0.90 0.25 0.74 5.00 6.18 4.60 486.80 482 00 118.00 4.07% 15 4.6 5.1 039 M M 0.30 0.90 027 027 5.00 6.18 1.67 "1.80 480.00 65.00 2.77% 8 7.5 5.0 0.22 M UGS 0.00 0.00 0.00 1.01 5.00 6.18 6.27 479.80 479D0 1600 5.00% 18 10.4 4.9 005 MA UGS 0.25 0.70 0.17 0.17 5.00 6.18 1.08 479.00 478.00 24.50 4.08% 12 5.3 5.4 0.08 A45 UGS 070 0.80 0.56 0.56 5.00 6.18 3.47 482.00 479.00 5] 00 5.26% 8 2.8 4.8 020 A3 A2 0.00 0.00 0.00 1.75 5.00 6.18 10.81 472.80 470.00 35.80 7.82% 15 18.9 10.9 0.05 A2 Al 000 0.00 0.00 1.75 5.00 6.18 10.81 466.00 46000 4660 12.88% 15 18.9 10.9 007 At AO 0.00 0.00 0.00 1.75 5.00 6.18 10.81 455.00 454.50 32.00 1.56% 24 1&0 7.6 0.07 NOAA Atlas 14, Volume 2, Version 3 Location name: Charlottesville, Virginia, USA*`r Latitude: 38.0319°, Longitude:-78.4472' Elevation: 496.5 ft** �A 'source: ESRI Maps -- source: USGS POINT PRECIPITATION FREQUENCY ESTIMATES G.M. Bonin, D. Martin, B. Lin, T. Parzybok, 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)t Average recurrence interval (years) Duretion 7 2 5 70 25 50 1 100 00 200 500 7000 -m 5in (0.3118-0392) (0.30 79-0.466) (0.443-0.545) (0.497--0 612) (0.557-0687) (0.603-0 746) (0.6450.802) (0.682-0854) (0.724-0 919) (0.758-0 974) 70-min (0.508-0626) (0.605-0745) (0.709-0872) (0.7950979) (0.888-1310) (0.96-1.19) 1 (1.02127) 1 (1.08-21335) 1 (1. 5-3145) : (19-16.53) 0.704 0.844 737) 1.12 2 3 1.46 5 75-min (0.761-09 (0. 97-1610) (1.00.?24) (1: 3-1639) (1.22-1751) (1.29-1..61) (1.36-15.71) (1.4411..83) (1.50.�93) 30-min (0.8704607) 1 (1.051.29) 1 (1.274257) 1 (1.46- .80) 1 (1.67-2606) (1. 3-2..27) (1.98-2.47) (2. 2-2.66) (2.30-22..91) (2: 33.12) 4.11 60-min (1.9-1.34) (1.3�62) (1.63201) (1.90.2.34) (2.2�74) (2. 83907) (27 33.40) (2. 8-3.73) (3. 9�818) (3.54-4.55) 3.07 3.91 6.47 2-hr 3894) (1.27-1 65) (1.54-2.9) (19 32.49) (2.27�92) (2. 8-3.47) (3. 3 (3.384.41) (3. 3-4591) (4. 0---5.60) (45 9-6.20) 3-hr (1.39-1..82) (1.68-2.20) (2.9-2.75) (2.453.22) (2.91-3.83) (3.94734) (3.67-4.87) (4.05-5.43) (4.578.20) (4.99-6.86) 6-hr (17 8-2.29) (2: 52376) (2.66-3.42) (3.1244..03) (3.724.83) (4.24---5..53) (4.77827) (5.32-7708) (6.08 8a21) (67 39.23) 11.2 72-hr (22 32.90) (2. 9-3.49) (3.34-4.35) (3.945.14) (4.7".23) (5.46--321) :75 (69-8.26) (6.989?42) (8. 9-11.2) (9.07- 2.7) 24-hr (2.731 3?40) (3.294.6 3. 94611) (4. 9-05..25) (4.936.19) (6. 3-67059) (6.94 8978) (79 3- 0.1) (8.99-11.6) (10.5- 3.8) (11.8-15.6) 2-0ey (32 0-3.99) (38 84.83) (49 36.14) (6. 8-721) (6.98-8.76) (7.97--010.1) (9.03-131.5) (102- 3.0) (11.8- 5.4) (13.1-1 3) 3-day (3.444.21) (4.478.10) (5. 98.48) (6.21-8.60) (7.51 923) (8.57--610.6) (97 0. 2.1) (10.9- 3.7) (12.6- 6.1) (14.0. 8.2) 4-day 6 9 (34.43) (4.478.36) (5.66-681) (6.64899) (8. 39570) (9.17--111.1) (10.4-2.7) (11.73--14A) (13.5- 6.9) 1 (15.0. 9.1) 18.6 7-day (4.30-5.11) (5. 8-6.15) (6.46- .69) (7.51 8?95) (8. 8-610.8) (102- 2.3) (11.5-13.9) (128415.7) (14.70- 8.2) 1 (162- 0.4) 10 dey (4.90.5.74) (5. 8-6.90) (72 58.51) (8.36-9.82) (9.89-161.7) (11.1213.2) (12.414.8) (137--16.5) (15.6-19.0) (17.1---21.1) 20-dey (6.52--7.46) (77 88.90) (9.39- 0.8) (10.6- 2.2) (12.3-14.2) (13.6- 5.7) (14.9-127.3) (16.3- 9.0) (18.0-21.3) (19.4-3.1) 30-dey (8.04-9.10) (9.54-10.8) (11.3-2.8) (12.6-14.3) (14.3-16.2) (185-107.7) (16.8- 9.2) (18?0- 0.6) (195722.6) (20.6-24.0) as -day (101U 1.3) 1 (11.9-13.4) 1 (13.9- 5.6) 1 (15.4137.3) 1 (173- 9.4) 1 (187021.1) 1 (20.0.22.6) (21.3-24.2) (22?8-5.2) (24.0.27.7) 60-day (11.9--13.2) (14.0-1-5.6) (16'1- 8.0) (17'76- 9.7) (19z70--22.0) (212? 3.7) I (22.6- 5.4) (239-26.9) I 5--2-89 (252 (267830.4) 1 Precipitation frequency (PF) estmates 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 Atias 14 document for more information. Back to Top PF graphical 38° 1M-N R R_ 38' 1' 47' N 72MM 72MW 7490 723M 724= 3 Map Scale: 1:1,800 (priled m A portrait (8.5' z 11") sheet. � Meters N 0 75 50 100Feet ,51 A 0 e Mappmerbm:WebM�mr Cmlamordnatm:WGSB4 Edge86:UrMZore17NW(SB4 ISDA Natural Resources Web Soil Survey Conservation Service National Cooperative Soil Survey Hydrologic Soil Group —Albemarle County, Virginia (Overlook Hotel Soils Map) 3 M1 p 3S°TWN I q — 1'4TN R4100 3 4/18/2022 Page 1 of 4 MAPLEGEND Area of Interest (A01) 0 Area of Interest A01) Soils Soil Rating Polygons 0 A Q AID o B Q BID o C 0 CID 0 D 0 Not rated or not available Soil Rating Lines . r A ,y AID rV B ram/ BID N C N CID i D . . Not rated or not available Soil Rating Points A Q AID O B 0 BID Hydrologic Soil Group —Albemarle County, Virginia (Overlook Hotel Soils Map) 0 C CID D 13 Not rated or not available Water Features Streams and Canals Transportation µ� Rails N Interstate Highways �y US Routes Major Roads Local Roads Background . Aerial Photography MAP INFORMATION The soil surveys that comprise your AOI were mapped at 1:15,800. Warning: Soil Map may not be valid at this scale. Enlargement of maps beyond the scale of mapping can cause misunderstanding of the detail of mapping and accuracy of soil line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed scale. Please rely on the bar scale on each map sheet for map measurements. Source of Map: Natural Resources Conservation Service Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts distance and area. A projection that preserves area, such as the 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 15, Sep 13, 2021 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Jun 8, 2020---Sep 23, 2020 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. USDA Natural Resources Web Soil Survey 4/18/2022 Conservation Service National Cooperative Soil Survey Page 2 of 4 Hydrologic Soil Group —Albemarle County, Virginia Overlook Hotel Soils Map Hydrologic Soil Group Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 13E Catoctin silt loam, 25 to 45 percent slopes, very stony B 0.6 10.0% 23B Yadkin day loam, 2 to 7 percent slopes B 0.1 1.9% 71B Rabun clay loam, 2 to 7 percent slopes B 0.4 7.4% 71E Rabun clay loam, 25 to 45 percent slopes B 0.8 13.8% 88 Udorthents, loamy, 2 to 25 percent slopes 4.0 66.9% Totals for Area of Interest 6.0 100.0% Natural Resources Web Soil Survey 4/18/2022 Conservation Service National Cooperative Soil Survey Page 3 of 4 Hydrologic Soil Group —Albemarle County, Virginia Overlook Hotel Soils Map Description Hydrologic soil groups are based on estimates of runoff potential. Soils are assigned to one of four groups according to the rate of water infiltration when the soils are not protected by vegetation, are thoroughly wet, and receive precipitation from long -duration storms. The soils in the United States are assigned to four groups (A, B, C, and D) and three dual classes (A/D, B/D, and C/D). The groups are defined as follows: Group A. Soils having a high infiltration rate (low runoff potential) when thoroughly wet. These consist mainly of deep, well drained to excessively drained sands or gravelly sands. These soils have a high rate of water transmission. Group B. Soils having a moderate infiltration rate when thoroughly wet. These consist chiefly of moderately deep or deep, moderately well drained or well drained soils that have moderately fine texture to moderately coarse texture. These soils have a moderate rate of water transmission. Group C. Soils having a slow infiltration rate when thoroughly wet. These consist chiefly of soils having a layer that impedes the downward movement of water or soils of moderately fine texture or fine texture. These soils have a slow rate of water transmission. Group D. Soils having a very slow infiltration rate (high runoff potential) when thoroughly wet. These consist chiefly of clays that have a high shrink -swell potential, soils that have a high water table, soils that have a claypan or clay layer at or near the surface, and soils that are shallow over nearly impervious material. These soils have a very slow rate of water transmission. If a soil is assigned to a dual hydrologic group (A/D, B/D, or C/D), the first letter is for drained areas and the second is for undrained areas. Only the soils that in their natural condition are in group D are assigned to dual classes. Rating Options Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Tie -break Rule: Higher Natural Resources Web Soil Survey 411a2022 Conservation Service National Cooperative Soil Survey Page 4 of 4