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HomeMy WebLinkAboutWPO202100043 Calculations 2021-10-22 (2),, SHIMP ENGINEERING, P.C. LTFI0F'�. Design Focused Engineering O� l October 20, 2021 �Cra' v M. Engineering Review Albemarle County Department of Community Development 401 McIntire Road Charlottesville, VA 22902 i. No. 45183 101.01st Regarding: WPO 202100043Crozet Animal Wellness Center VSMP— SWM Calculation Packet Dear John, Enclosed is the stormwater calculation packet for Crozet Animal Wellness Center. The development property has an area of 3.40 acres and a disturbed area of 0.66 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, a Stormtech underground storage system will be provided which treats 0.28 Ibs/yr of phosphorous. To meet the total treatmenl requirement of 0.77 lbs/yr of phosphorous removal, phosphorous credits will be purchased. This amount totals 0.48 Ibs/yr phosphorous credits and satisfies the nutrient treatment requirement. Treatment Required Total Phosphorous) Treatment Provided (Total Phosphorous) 0.77lb/yr 0.77lb/yr SWM Quantity SWM Quantity is satisfied by analyzing concentrated runoff from the development at 2 Points Of Analysis (POAs) downstream of the development property. 9VAC25-870-66-B(3) requires that concentrated runoff from the development at each POA meet the energy balance equation. To achieve this, most concentrated runoff from the site will be routed to a Stormtech underground storage system which then discharges to POA 1. The remaining runoff is minimal and flows to POA 2 as sheet flow. The runoff to both POAs meets 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 Charlortesvdle. VA 22902 1 434 227 5140 1 shimp-engineering com POA1&2 Pre-dev Peak Runoff Max. Allowed Peak Runoff Post-dev Peak Runoff 1-Yr 1.53 cfs 0.84 cfs 0.76 cfs 10-Yr 5.06 cfs 5.06 cfs 4.74 cfs If you have any questions about this calculation packet please do not hesitate to contact me at: chris ashimp- engineering com or by phone at 434-227-5140. 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 POA Drainage Map Post-Dev POA Drainage Map Energy Balance Equation TOC Calculations Predev HydroCAD Report Postdev HydroCAD Report VDOT LD-268 Ditch Design Independent Reports: NOAA Precipitation Report Excerpt from NRCS Soils Report CROZET ANIMAL WELLNESS CENTER PREDEV VRRM MAP 000 III oory rvova ♦ NAOED J I I� ��� ♦ TURF -,rvzoro �,� �.. �':.. ♦ � I ,o \ III �� °�°�°�°�°�, . ' . ' � � '��,'��,'��,'��,'��,'��,'� ' . : ♦ ♦ ♦ ♦ ♦� �j � 0000 IMPERVIOUS � aaaaaaaa ��r�v � 2av�x� / eoo � �\ � ♦ aaaaaaaa ♦ �c��� ����cx� a ���=�`♦w♦ .�. \•:� � � III / lIIG TMP 56-II GWNtt OF ALBEMARIE OB 3930 PG "a OB 1671 PG 603 PLAT OB 367 PG 155 PLAT ZONE: R2 RESIOENIIAL USE: FOREST 51 AC FA TMP 56A2-01-6 R. PARTNERS, LLC BB OB2O PG 56J OS 6079 PG 391 PLAT OE 3G9 PC 155 PLAT BB z55 PG 175 BEST. ZONE: R2 RESIOENPAL USE: SINGLE FAMILY RESIOENIIAL B.. AG N DISTURBED AREA: 0.66 AC HSG B AREA: 0.66 AC TURF: 0.38 AC IMPERVIOUS: 0.28 AC 40 I I 0 Scale: 40 80 120 CROZET ANIMAL WELLNESS CENTER POSTDEV VRRM MAP LSVtf r o..� ttt4\e stilts ,," te�t �� as ita ♦a��tti...p�. r.t C• t t t'\ t t t t t t t jam\ V I t I t rT• .tt�`' tt ,,,tsse flt.ertt . ♦ tr=tom ttt I slit r [_t ♦ iJr� ! •- tQ tftt ♦ tl trtt �t?` Itt'tt�+t���♦ttttt�tttt�r 1 Ott i I tt I t tt t Ittr 'iX Ii•�'tlttt II';�r9ttlj tt �y^� L." t�,�1ts ±+i tlL1 ss1 t rE� tti t\� ra tlMiRctsls .tt" trf.ttt�.t`. e ttt t tt1 a•�s1 es4s1 t I�s�s3cn_. t t t i� t-it :.tttr t0. tit. I t r 1 tt �r ttt Yt.'ty�i Ty L tlltt t�iiti tots .ti i . ♦ r ttt`t�.t..c�t.` ��+� i $�A`�� [ssstl tr :?Rttt. tt.tt���.syr s i t t t t t tra i i 0yy t t t t t t t\ t to ttotttl�t Rtt t. rf•t .�tta~t .� t£itti tit.ti ;tq t/�tit�t �rtttttttt is �',ttl tatty •=., Ott ttttt t� .r 9 ttt1: *iv tst=sit Rtte�sr ,•It r o t t e r ris.. \.its sss ttattttatser t t t tit t t t t t t t ttttttttsss t t t t p t t t t i t 1>1 �- Gitnetit {�i 1� t t t t t t t t I t i r r•� t � t ♦ rat ♦ t,�. t +[ 'ry TAP 56-I1 COUNTY OF AUDEMARLE GO 3830 PG 168 UP 1671 PG 603 PLAT DO 387 PG 155 PIAT ZONE: R2 RESIDENTAL USE FOREST 5.51 AC t.. R t t t t t7t t t t II Nt t l� t 3.. . ttttat tt:•-\1 tttitt t ♦ / t t 4 t t t 6ttt ltttt� t7744t t rtti.. \tt' iJ t�tttt t t Ft.. sift Att t t tptr't u.. 1��t�ttttttttt�Y �� I 50 Scale: 1 RIP 56A2-01-6 RRH PARTNERS. LLC DID 4024 PG 567 DO 0079 PG 391 PLAT DO 367 PG 155 PLAT DID 255 PG 175 DESC. ZONE: R2 RESIDENTAL USE: SINGLE FAMILY RESIDENTAL PON AC DISTURBED AREA: 0.66 AC HSG B AREA: 0.66 AC TURF: 0.23 AC IMPERVIOUS: 0.43 AC Jir 50 100 150 DM WMIWQNumfJRMURbn MCMde DevelopmentmWftnm3genESM1eM- C 2011 BMP SaM a 3pilllotlms 02013 Dra OMP3 dar&aM 3Pedfl lms PJf Name: Crozet Animal Wellness Center Date: 10/19/2021 BMPOesign Spe[ifirmiam Lis[ 2013 MA SWS & Spe. On5 dnla aamralinm'na.l 43 awan E.minmC 1.m TM I �m m+IlmclmW 1.M is rgetm Wea 114/eve/yri OA] vl lvrme::m�m.eem.l o.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[) 0.32 0.00 0.00 0.00 0.00 OK. IMPERV��GED TUEAAREA (a[) 0.00 0.00 000 0.00 0.00 OK. MANAGED TURF AREA TREATED (a[) 0.00 0.00 000 0.00 O.00 OK. AREA CHECK OK OK. OK. OK OK. Site Treatment Volume (ks) 1,635 Runoff Reduction Volume and TP By Drainage Area D.A. A D.A. B___j D.A. C D.A. D O.A. E TOTAL RUNOFFI.OADAUOION VOLUME 0 0 0 0 . OV L (Ib/ ) TP LOADAVAINBLE FOR REMOVAL Qb/yFI 0.71 O.W 0.00 � 0.00 O.M 0.71 TPIDADREDUCnONACHIEVED)Ib/yr) 0.28 0.00 DOD 0.00 O.W 0.28 TPLOAD REMAINING llb/yr) 0.43 DCO 0.00 0.00 O.W a." NnROGEN IDAD REDUCION ACHIEVED pb/yil 0.CU O.W 0.00 0.00 O.W D.00 Total Phosphorus FINAL POST -DEVELOPMENT TP LOAD (11b/yr) 1.33 TP LOAD REDUCTION REQUIRED (Ib/yr)jj 0.77 TP WAD REDUCTION AOIIEVED pb/yrl 0.28 W WAO REMAINING Qb/N):F 0.74 REMAINING TP LOAD REDUCTION REQUIRED (Ib/yr): 0.48 Total Nitrogen (For Information Purposes) POST -DEVELOPMENT LOAD jib/yr)ll 7.35 NITROGEN LOAD REDUCION ACHIEVED (Ib/yr) 0 00 000 . REMAINING POST -DEVELOPMENT NITRWEN LOAD Pb/yrl -- �o o �o �o �© ��mm��e �000000 �000000 �m0000o �000000 ��mm��� �m0000o �000000 ��� ��®o m������ o�a0000 000ao ®�®ooao m000aa ®®000ao 0000aa ®®000ao 0000aa ki ,I CROZET ANIMAL WELLNESS CENTER PREDEV DA MAP h 7-77 G 1.28 �A #i = aC i J / Oeoo TMP 56-11 COUNTY OF ALBEMARLE I DB 3830 PG 168 DB 1671 PG 603 PLAT DB 367 PG 155 PLAT ZONE: R2 RESIDENTIAL G1� USE: FOREST 5.51 AC Scale: 1" A-40' PREDEV DRAINAGE AREA 1: 1.28 AC HSG B AREA: 1.28 AC TURF: 0.88 AC IMPERVIOUS: 0.40 AC TOC TO POA 1: 11.8 MIN. II TMP 56A2 01 6 R&H PARTNERS, LLC DB 4024 PG 567 DB 4079 PG 391 PLAT DB 367 PG 155 PLAT DB 255 PG 175 DESC. ZONE: R2 RESIDENTIAL USE: SINGLE FAMILY RESIDENTIAL 8.08 AC N 120 CROZET ANIMAL WELLNESS CENTER POSTDEV DA MAP POSTDEV DRAINAGE AREA 1: 0.46 AC HSG B AREA: 0.46 AC TURF: 0.46 AC IMPERVIOUS: 0.00 AC TOC TO POA 2: 12.2 MIN. POSTDEV DRAINAGE AREA 2: 0.36 AC HSG B AREA: 0.36 AC \ TURF: 0.00 AC \ IMPERVIOUS: 0.36 AC \ TOC TO POA 2: 5 MIN. POSTDEV DRAINAGE AREA 3: 0.10 AC HSG B AREA: 0.10 AC TURF: 0.00 AC IMPERVIOUS: 0.10 AC TOC TO POA 2: 5 MIN. POSTDEV DRAINAGE AREA 4: 0.40 AC ° a z HSG B AREA: 0.40 AC 1I TURF: 0.40 AC a IMPERVIOUS: 0.00 AC TOC TO POA 1: 11.1 MIN. N 0 O B DA #2 = 0.357 AC m DA #1 = 0.459 AC II � ' ell F I II •� I 'I ; I 64 p � Po cgs POA 2 POA 1 TMP 56-11 COUNTY OF ALBEMARLE DB 3830 PG 168 DB 1671 PG 603 PLAT DB 367 PG 155 PLAT ZONE: R2 RESIDENTIAL USE: FOREST 5.51 AC W z W �OfF ¢N� T4ivr� TMP 56A2-01--6 RDB PARTNERS, 7DB 4024 PG 567DB 4079 PG 397 PLAT DB 367 PG 175 PLAT DESC ZO E: PG SI NTIALZONE: R2 RESIDENTIALUSE: SINGLE FAMILY 3 = 0.095 AC REe08"AC` 40 1 0 40 80 N 120 1 Balance Eauation Crozet Animal Wellness (POA 1 & 2) 1 Qdeveloped� I.F. *(Qpre-developed*RVPre-Developed)/Redeveloped Qdeveloped� (Qforestedx RVforested) Redeveloped Predev Postdev Drainage Area 1.32 ac 1.32 ac Qpre-developer 1.53 RVPre-Develoi = 0.094 MaX Qdevek = RVDeveloped = 0.137 I 0.84 cfs Maximum QIoyr= 5.06 cfs (predev) Achieved Q10yr = 4.74 cfs Crozet Animal Wellness Center Time of Concentration Calculations - Predev 1 100 ft overland flow 10.0% slope 0.35 C-value 9.2 min 5eelye Chart 201 ft s. c. flow 6.5% slope 1.3 fps velocity 2.6 min. NEH Figure 15-4 00ft swale height min. Kirpich Chart 11.8 min. 100 ft overland flow 10.0% slope 0.35 C-value 9.2 min 5eelye Chart s. c. flow -field slope velocity min. NEH Figure 15-4 140 ft swale 2 ft height 1.7 min. Kirpich Chart 10.9 min. Crozet Animal Wellness Center Time of Concentration Calculations - Postdev 1 100 ft overland flow 10.0% slope 0.35 C-value 9.2 min Seelye Chart 256 ft s. c. flow -field 7.5% slope 1.4 fps velocity 3.0 min. NEH Figure 15-4 swale height min. Kirpich Chart 12.2 min. 100 ft overland flow 11.0% slope 0.35 C-value 9.5 min Seelye Chart 143 ft s. c. flow -field 9.1% slope 1.5 fps velocity 1.6 min. NEH Figure 15-4 swale height min. Kirpich Chart 11.1 min. 1S DA 1 1L POA 1 Subcat Reach on Link Drainage Diagram for PREDEV FprHydroCADO epared by {enter your company name here}, Printed 10/19/2021 9.10 s/n 07054 0 2010 HydroCAD Software Solutions LLC PreDev PREDEV Type/1 24-hr 1-YR Rainfall=3.07" Prepared by {enter your company name here} Printed 10/19/2021 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 2 Time span=0.00-48.00 hrs, dt=0.02 hrs, 2401 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Link 1 L: POA 1 Inflow=1.53 cfs 0.094 of Primary=1.53 cfs 0.094 of Subcatchment 1 S: DA 1 Runoff Area=1.320 ac 30.30% Impervious Runoff Depth=0.85" Tc=11.8 min CN=72 Runoff=1.53 cfs 0.094 of Total Runoff Area = 1.320 ac Runoff Volume = 0.094 of Average Runoff Depth = 0.85" 69.70% Pervious = 0.920 ac 30.30% Impervious = 0.400 ac PreDev PREDEV Type/1 24-hr 1-YR Rainfall=3.07" Prepared by {enter your company name here} Printed 10/19/2021 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 3 Summary for Link 1 L: POA 1 Inflow Area = 1.320 ac, 30.30% Impervious, Inflow Depth = 0.85" for 1-YR event Inflow = 1.53 cfs @ 12.05 hrs, Volume= 0.094 of Primary = 1.53 cfs @ 12.05 hrs, Volume= 0.094 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.02 hrs Summary for Subcatchment 1S: DA 1 Runoff = 1.53 cfs @ 12.05 hrs, Volume= 0.094 af, Depth= 0.85" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.02 hrs Type II 24-hr 1-YR Rainfall=3.07" Area (ac) CN Description 0.920 61 >75% Grass cover, Good, HSG B 0.000 55 Woods, Good, HSG B 0.400 98 1.320 72 Weighted Average 0.920 69.70% Pervious Area 0.400 30.30% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.8 Direct Entry, PreDev PREDEV Type/1 24-hr 10-YR Rainfall=5.58" Prepared by {enter your company name here} Printed 10/19/2021 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 4 Time span=0.00-48.00 hrs, dt=0.02 hrs, 2401 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Link 1 L: POA 1 Inflow=5.06 cfs 0.292 of Primary=5.06 cfs 0.292 of Subcatchment 1 S: DA 1 Runoff Area=1.320 ac 30.30% Impervious Runoff Depth=2.65" Tc=11.8 min CN=72 Runoff=5.06 cfs 0.292 of Total Runoff Area = 1.320 ac Runoff Volume = 0.292 of Average Runoff Depth = 2.65" 69.70% Pervious = 0.920 ac 30.30% Impervious = 0.400 ac PreDev PREDEV Type/1 24-hr 10-YR Rainfall=5.58" Prepared by {enter your company name here} Printed 10/19/2021 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 5 Summary for Link 1 L: POA 1 Inflow Area = 1.320 ac, 30.30% Impervious, Inflow Depth = 2.65" for 10-YR event Inflow = 5.06 cfs @ 12.04 hrs, Volume= 0.292 of Primary = 5.06 cfs @ 12.04 hrs, Volume= 0.292 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.02 hrs Summary for Subcatchment 1S: DA 1 Runoff = 5.06 cfs @ 12.04 hrs, Volume= 0.292 af, Depth= 2.65" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.02 hrs Type II 24-hr 10-YR Rainfall=5.58" Area (ac) CN Description 0.920 61 >75% Grass cover, Good, HSG B 0.000 55 Woods, Good, HSG B 0.400 98 1.320 72 Weighted Average 0.920 69.70% Pervious Area 0.400 30.30% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.8 Direct Entry, PreDev PREDEV Type/1 24-hr 100-YR Rainfall=9.08" Prepared by {enter your company name here} Printed 10/19/2021 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 6 Time span=0.00-48.00 hrs, dt=0.02 hrs, 2401 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Link 1 L: POA 1 Inflow=10.67 cfs 0.622 of Primary=10.67 cfs 0.622 of Subcatchment 1 S: DA 1 Runoff Area=1.320 ac 30.30% Impervious Runoff Depth=5.65" Tc=11.8 min CN=72 Runoff=10.67 cfs 0.622 of Total Runoff Area = 1.320 ac Runoff Volume = 0.622 of Average Runoff Depth = 5.65" 69.70% Pervious = 0.920 ac 30.30% Impervious = 0.400 ac PreDev PREDEV Type/1 24-hr 100-YR Rainfall=9.08" Prepared by {enter your company name here} Printed 10/19/2021 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 7 Summary for Link 1 L: POA 1 Inflow Area = 1.320 ac, 30.30% Impervious, Inflow Depth = 5.65" for 100-YR event Inflow = 10.67 cfs @ 12.03 hrs, Volume= 0.622 of Primary = 10.67 cfs @ 12.03 hrs, Volume= 0.622 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.02 hrs Summary for Subcatchment 1S: DA 1 Runoff = 10.67 cfs @ 12.03 hrs, Volume= 0.622 af, Depth= 5.65" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.02 hrs Type II 24-hr 100-YR Rainfall=9.08" Area (ac) CN Description 0.920 61 >75% Grass cover, Good, HSG B 0.000 55 Woods, Good, HSG B 0.400 98 1.320 72 Weighted Average 0.920 69.70% Pervious Area 0.400 30.30% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.8 Direct Entry, 3S 1S A DA 5S 4P DA 4 to offsite) 4S DETENTI N 1 SC-740 CIA 3 11L 2L POA 2 POA 1 Subcat Reach on Link Drainage Diagram for POSTDEV FprHydroCADO epared by {enter your company name here}, Printed 10/19/2021 9.10 s/n 07054 0 2010 HydroCAD Software Solutions LLC PostDev POSTDEV Type 11 24-hr 1 YR Rainfall=3.07" Prepared by {enter your company name here} Printed 10/19/2021 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 2 Time span=0.00-48.00 hrs, dt=0.02 hrs, 2401 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Link 1 L: PDA 2 Inflow=0.69 cfs 0.113 of Primary=0.69 cfs 0.113 of Subcatchment 1 S: DA 1 Runoff Area=0.460 ac 0.00% Impervious Runoff Depth=0.39" Tc=12.2 min CN=61 Runoff=0.17 cfs 0.015 of Link 2L: PDA 1 Inflow=0.16 cfs 0.013 of Primary=0.16 cfs 0.013 of Subcatchment3S: DA 2 Runoff Area=0.360 ac 100.00% Impervious Runoff Depth=2.84" Tc=5.0 min CN=98 Runoff=1.61 cfs 0.085 of Pond 4P: DETENTION 1 SC-740 Peak Elev=656.51' Storage=0.045 of Inflow=1.66 cfs 0.100 of Outflow=0.29 cfs 0.089 of Subcatchment4S: DA 3 Runoff Area=0.100 ac 100.00% Impervious Runoff Depth=2.84" Tc=5.0 min CN=98 Runoff=0.45 cfs 0.024 of Subcatchment5S: DA 4 (to offsite) Runoff Area=0.400 ac 0.00% Impervious Runoff Depth=0.39" Tc=11.1 min CN=61 Runoff=0.16 cfs 0.013 of Total Runoff Area = 1.320 ac Runoff Volume = 0.137 of Average Runoff Depth = 1.24" 65.15% Pervious = 0.860 ac 34.85% Impervious = 0.460 ac PostDev POSTDEV Type 11 24-hr 1 YR Rainfall=3.07" Prepared by {enter your company name here} Printed 10/19/2021 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 3 Summary for Link 1 L: POA 2 Inflow Area = 0.920 ac, 50.00% Impervious, Inflow Depth = 1.48" for 1 YR event Inflow = 0.69 cfs @ 11.96 hrs, Volume= 0.113 of Primary = 0.69 cfs @ 11.96 hrs, Volume= 0.113 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.02 hrs Summary for Subcatchment 1S: DA 1 Runoff = 0.17 cfs @ 12.08 hrs, Volume= 0.015 af, Depth= 0.39" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.02 hrs Type II 24-hr 1 YR Rainfall=3.07" Area (ac) CN Description 0.460 61 >75% Grass cover, Good, HSG B 0.000 55 Woods, Good, HSG B 0.000 98 0.460 61 Weighted Average 0.460 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 12.2 Direct Entry, Summary for Link 2L: POA 1 Inflow Area = 0.400 ac, 0.00% Impervious, Inflow Depth = 0.39" for 1 YR event Inflow = 0.16 cfs @ 12.06 hrs, Volume= 0.013 of Primary = 0.16 cfs @ 12.06 hrs, Volume= 0.013 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.02 hrs Summary for Subcatchment 3S: DA 2 Runoff = 1.61 cfs @ 11.96 hrs, Volume= 0.085 af, Depth= 2.84" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.02 hrs Type II 24-hr 1 YR Rainfall=3.07" Area (ac) CN Description 0.360 98 0.360 100.00% Impervious Area PostDev POSTDEV Type 11 24-hr 1 YR Rainfall=3.07" Prepared by {enter your company name here) Printed 10/19/2021 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 4 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Pond 4P: DETENTION 1 SC-740 Inflow Area = 0.820 ac, 43.90% Impervious, Inflow Depth = 1.47" for 1 YR event Inflow = 1.66 cfs @ 11.96 hrs, Volume= 0.100 of Outflow = 0.29 cfs @ 12.20 hrs, Volume= 0.089 af, Atten= 82%, Lag= 14.5 min Primary = 0.29 cfs @ 12.20 hrs, Volume= 0.089 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.02 hrs Peak Elev= 656.51' @ 12.20 hrs Surf.Area= 0.032 ac Storage= 0.045 of Plug -Flow detention time= 166.6 min calculated for 0.089 of (89% of inflow) Center -of -Mass det. time= 109.9 min ( 888.2 - 778.4 ) Volume Invert Avail.Storage Storage Description #1 654.00' 0.054 of 14.00'W x 100.001 x 5.00'H STONE BEDDING 0.161 of Overall - 0.025 of Embedded = 0.135 of x 40.0% Voids #2 654.83' 0.025 of StormTech SC-740 x 24 Inside #1 Effective Size= 44.6"W x 30.0"H => 6.45 sf x 7.121 = 45.9 cf Overall Size= 51.0"W x 30.0"H x 7.561 with 0.44' Overlap 0.079 of Total Available Storage Device Routing Invert Outlet Devices #1 Primary 654.83' 24.0" Round PRIMARY 24" OUTLET L= 50.0' Ke= 0.300 Inlet / Outlet Invert= 654.83' / 654.33' S= 0.0100 T Cc= 0.900 n= 0.012 #2 Device 1 654.83' 3.0" Vert. 1 YR ORIFICE C= 0.600 #3 Device 1 658.00' 5.0' long x 1.50' rise Sharp -Crested Rectangular Weir 2 End Contraction(s) 2.0' Crest Height Primary OutFlow Max=0.29 cfs @ 12.20 hrs HW=656.51' (Free Discharge) tTPRIMARY 24" OUTLET (Passes 0.29 cfs of 12.13 cfs potential flow) 2=1 YR ORIFICE (Orifice Controls 0.29 cfs @ 6.00 fps) 3=Sharp-Crested Rectangular Weir( Controls 0.00 cfs) Summary for Subcatchment 4S: DA 3 Runoff = 0.45 cfs @ 11.96 hrs, Volume= 0.024 af, Depth= 2.84" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.02 hrs Type II 24-hr 1 YR Rainfall=3.07" Area (ac) CN Descri 0.100 98 0.100 100.00% Impervious Area PostDev POSTDEV Type 11 24-hr 1 YR Rainfall=3.07" Prepared by {enter your company name here) Printed 10/19/2021 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 5 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 5S: DA 4 (to offsite) Runoff = 0.16 cfs @ 12.06 hrs, Volume= 0.013 af, Depth= 0.39" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.02 hrs Type II 24-hr 1 YR Rainfall=3.07" Area (ac) CN Description 0.400 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.1 Direct Entry, PostDev POSTDEV Type 11 24-hr 10 YR Rainfall=5.58" Prepared by {enter your company name here} Printed 10/19/2021 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 6 Time span=0.00-48.00 hrs, dt=0.02 hrs, 2401 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Link 1 L: PDA 2 Inflow=3.78 cfs 0.260 of Primary=3.78 cfs 0.260 of Subcatchment 1 S: DA 1 Runoff Area=0.460 ac 0.00% Impervious Runoff Depth=1.73" Tc=12.2 min CN=61 Runoff=1.09 cfs 0.066 of Link 2L: PDA 1 Inflow=0.99 cfs 0.058 of Primary=0.99 cfs 0.058 of Subcatchment3S: DA 2 Runoff Area=0.360 ac 100.00% Impervious Runoff Depth=5.34" Tc=5.0 min CN=98 Runoff=2.95 cfs 0.160 of Pond 4P: DETENTION 1 SC-740 Peak Elev=658.30' Storage=0.071 of Inflow=3.67 cfs 0.227 of Outflow=3.20 cfs 0.216 of Subcatchment4S: DA 3 Runoff Area=0.100 ac 100.00% Impervious Runoff Depth=5.34" Tc=5.0 min CN=98 Runoff=0.82 cfs 0.045 of Subcatchment5S: DA 4 (to offsite) Runoff Area=0.400 ac 0.00% Impervious Runoff Depth=1.73" Tc=11.1 min CN=61 Runoff=0.99 cfs 0.058 of Total Runoff Area = 1.320 ac Runoff Volume = 0.329 of Average Runoff Depth = 2.99" 65.15% Pervious = 0.860 ac 34.85% Impervious = 0.460 ac PostDev POSTDEV Type 11 24-hr 10 YR Rainfall=5.58" Prepared by {enter your company name here} Printed 10/19/2021 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 7 Summary for Link 1 L: POA 2 Inflow Area = 0.920 ac, 50.00% Impervious, Inflow Depth = 3.40" for 10 YR event Inflow = 3.78 cfs @ 12.01 hrs, Volume= 0.260 of Primary = 3.78 cfs @ 12.01 hrs, Volume= 0.260 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.02 hrs Summary for Subcatchment 1S: DA 1 Runoff = 1.09 cfs @ 12.05 hrs, Volume= 0.066 af, Depth= 1.73" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.02 hrs Type II 24-hr 10 YR Rainfall=5.58" Area (ac) CN Description 0.460 61 >75% Grass cover, Good, HSG B 0.000 55 Woods, Good, HSG B 0.000 98 0.460 61 Weighted Average 0.460 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 12.2 Direct Entry, Summary for Link 2L: POA 1 Inflow Area = 0.400 ac, 0.00% Impervious, Inflow Depth = 1.73" for 10 YR event Inflow = 0.99 cfs @ 12.04 hrs, Volume= 0.058 of Primary = 0.99 cfs @ 12.04 hrs, Volume= 0.058 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.02 hrs Summary for Subcatchment 3S: DA 2 Runoff = 2.95 cfs @ 11.96 hrs, Volume= 0.160 af, Depth= 5.34" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.02 hrs Type II 24-hr 10 YR Rainfall=5.58" Area (ac) CN Description 0.360 98 0.360 100.00% Impervious Area PostDev POSTDEV Type 11 24-hr 10 YR Rainfall=5.58" Prepared by {enter your company name here) Printed 10/19/2021 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Pond 4P: DETENTION 1 SC-740 Inflow Area = 0.820 ac, 43.90% Impervious, Inflow Depth = 3.32" for 10 YR event Inflow = 3.67 cfs @ 11.97 hrs, Volume= 0.227 of Outflow = 3.20 cfs @ 12.02 hrs, Volume= 0.216 af, Atten= 13%, Lag= 3.0 min Primary = 3.20 cfs @ 12.02 hrs, Volume= 0.216 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.02 hrs Peak Elev= 658.30' @ 12.02 hrs Surf.Area= 0.032 ac Storage= 0.071 of Plug -Flow detention time= 115.7 min calculated for 0.216 of (95% of inflow) Center -of -Mass det. time= 87.5 min ( 865.6 - 778.1 ) Volume Invert Avail.Storage Storage Description #1 654.00' 0.054 of 14.00'W x 100.001 x 5.00'H STONE BEDDING 0.161 of Overall - 0.025 of Embedded = 0.135 of x 40.0% Voids #2 654.83' 0.025 of StormTech SC-740 x 24 Inside #1 Effective Size= 44.6"W x 30.0"H => 6.45 sf x 7.121 = 45.9 cf Overall Size= 51.0"W x 30.0"H x 7.561 with 0.44' Overlap 0.079 of Total Available Storage Device Routing Invert Outlet Devices #1 Primary 654.83' 24.0" Round PRIMARY 24" OUTLET L= 50.0' Ke= 0.300 Inlet / Outlet Invert= 654.83' / 654.33' S= 0.0100 T Cc= 0.900 n= 0.012 #2 Device 1 654.83' 3.0" Vert. 1 YR ORIFICE C= 0.600 #3 Device 1 658.00' 5.0' long x 1.50' rise Sharp -Crested Rectangular Weir 2 End Contraction(s) 2.0' Crest Height Primary OutFlow Max=3.15 cfs @ 12.02 hrs HW=658.30' (Free Discharge) tTPRIMARY 24" OUTLET (Passes 3.15 cfs of 26.16 cfs potential flow) 2=1 YR ORIFICE (Orifice Controls 0.43 cfs @ 8.81 fps) 3=Sharp-Crested Rectangular Weir(Weir Controls 2.72 cfs @ 1.83 fps) Summary for Subcatchment 4S: DA 3 Runoff = 0.82 cfs @ 11.96 hrs, Volume= 0.045 af, Depth= 5.34" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.02 hrs Type II 24-hr 10 YR Rainfall=5.58" Area (ac) CN Descri 0.100 98 0.100 100.00% Impervious Area PostDev POSTDEV Type 11 24-hr 10 YR Rainfall=5.58" Prepared by {enter your company name here) Printed 10/19/2021 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 5S: DA 4 (to offsite) Runoff = 0.99 cfs @ 12.04 hrs, Volume= 0.058 af, Depth= 1.73" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.02 hrs Type II 24-hr 10 YR Rainfall=5.58" Area (ac) CN Description 0.400 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.1 Direct Entry, PostDev POSTDEV Type 11 24-hr 100 YR Rainfall=9.08" Prepared by {enter your company name here} Printed 10/19/2021 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 10 Time span=0.00-48.00 hrs, dt=0.02 hrs, 2401 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Link 1 L: PDA 2 Inflow=8.15 cfs 0.493 of Primary=8.15 cfs 0.493 of Subcatchment 1 S: DA 1 Runoff Area=0.460 ac 0.00% Impervious Runoff Depth=4.29" Tc=12.2 min CN=61 Runoff=2.81 cfs 0.164 of Link 2L: PDA 1 Inflow=2.54 cfs 0.143 of Primary=2.54 cfs 0.143 of Subcatchment3S: DA 2 Runoff Area=0.360 ac 100.00% Impervious Runoff Depth=8.84" Tc=5.0 min CN=98 Runoff=4.81 cfs 0.265 of Pond 4P: DETENTION 1 SC-740 Peak Elev=658.53' Storage=0.073 of Inflow=6.90 cfs 0.430 of Outflow=6.87 cfs 0.419 of Subcatchment4S: DA 3 Runoff Area=0.100 ac 100.00% Impervious Runoff Depth=8.84" Tc=5.0 min CN=98 Runoff=1.34 cfs 0.074 of Subcatchment5S: DA 4 (to offsite) Runoff Area=0.400 ac 0.00% Impervious Runoff Depth=4.29" Tc=11.1 min CN=61 Runoff=2.54 cfs 0.143 of Total Runoff Area = 1.320 ac Runoff Volume = 0.646 of Average Runoff Depth = 5.87" 65.15% Pervious = 0.860 ac 34.85% Impervious = 0.460 ac PostDev POSTDEV Type 11 24-hr 100 YR Rainfall=9.08" Prepared by {enter your company name here} Printed 10/19/2021 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 11 Summary for Link 1 L: POA 2 Inflow Area = 0.920 ac, 50.00% Impervious, Inflow Depth = 6.42" for 100 YR event Inflow = 8.15 cfs @ 11.97 hrs, Volume= 0.493 of Primary = 8.15 cfs @ 11.97 hrs, Volume= 0.493 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.02 hrs Summary for Subcatchment 1S: DA 1 Runoff = 2.81 cfs @ 12.04 hrs, Volume= 0.164 af, Depth= 4.29" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.02 hrs Type II 24-hr 100 YR Rainfall=9.08" Area (ac) CN Description 0.460 61 >75% Grass cover, Good, HSG B 0.000 55 Woods, Good, HSG B 0.000 98 0.460 61 Weighted Average 0.460 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 12.2 Direct Entry, Summary for Link 2L: POA 1 Inflow Area = 0.400 ac, 0.00% Impervious, Inflow Depth = 4.29" for 100 YR event Inflow = 2.54 cfs @ 12.03 hrs, Volume= 0.143 of Primary = 2.54 cfs @ 12.03 hrs, Volume= 0.143 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.02 hrs Summary for Subcatchment 3S: DA 2 Runoff = 4.81 cfs @ 11.96 hrs, Volume= 0.265 af, Depth= 8.84" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.02 hrs Type II 24-hr 100 YR Rainfall=9.08" Area (ac) CN Description 0.360 98 0.360 100.00% Impervious Area PostDev POSTDEV Type 11 24-hr 100 YR Rainfall=9.08" Prepared by {enter your company name here) Printed 10/19/2021 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Pond 4P: DETENTION 1 SC-740 Inflow Area = 0.820 ac, 43.90% Impervious, Inflow Depth = 6.29" for 100 YR event Inflow = 6.90 cfs @ 11.97 hrs, Volume= 0.430 of Outflow = 6.87 cfs @ 11.98 hrs, Volume= 0.419 af, Atten= 0%, Lag= 0.5 min Primary = 6.87 cfs @ 11.98 hrs, Volume= 0.419 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.02 hrs Peak Elev= 658.53' @ 11.98 hrs Surf.Area= 0.032 ac Storage= 0.073 of Plug -Flow detention time= 80.0 min calculated for 0.419 of (97% of inflow) Center -of -Mass det. time= 64.4 min (839.3 - 774.9) Volume Invert Avail.Storage Storage Description #1 654.00' 0.054 of 14.00'W x 100.001 x 5.00'H STONE BEDDING 0.161 of Overall - 0.025 of Embedded = 0.135 of x 40.0% Voids #2 654.83' 0.025 of StormTech SC-740 x 24 Inside #1 Effective Size= 44.6"W x 30.0"H => 6.45 sf x 7.121 = 45.9 cf Overall Size= 51.0"W x 30.0"H x 7.561 with 0.44' Overlap 0.079 of Total Available Storage Device Routing Invert Outlet Devices #1 Primary 654.83' 24.0" Round PRIMARY 24" OUTLET L= 50.0' Ke= 0.300 Inlet / Outlet Invert= 654.83' / 654.33' S= 0.0100 T Cc= 0.900 n= 0.012 #2 Device 1 654.83' 3.0" Vert. 1 YR ORIFICE C= 0.600 #3 Device 1 658.00' 5.0' long x 1.50' rise Sharp -Crested Rectangular Weir 2 End Contraction(s) 2.0' Crest Height Primary OutFlow Max=6.86 cfs @ 11.98 hrs HW=658.53' (Free Discharge) tTPRIMARY 24" OUTLET (Passes 6.86 cfs of 27.65 cfs potential flow) 2=1 YR ORIFICE (Orifice Controls 0.45 cfs @ 9.11 fps) 3=Sharp-Crested Rectangular Weir(Weir Controls 6.42 cfs @ 2.46 fps) Summary for Subcatchment 4S: DA 3 Runoff = 1.34 cfs @ 11.96 hrs, Volume= 0.074 af, Depth= 8.84" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.02 hrs Type II 24-hr 100 YR Rainfall=9.08" Area (ac) CN Descri 0.100 98 0.100 100.00% Impervious Area PostDev POSTDEV Type 11 24-hr 100 YR Rainfall=9.08" Prepared by {enter your company name here) Printed 10/19/2021 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 5S: DA 4 (to offsite) Runoff = 2.54 cfs @ 12.03 hrs, Volume= 0.143 af, Depth= 4.29" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.02 hrs Type II 24-hr 100 YR Rainfall=9.08" Area (ac) CN Description 0.400 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.1 Direct Entry, Channel Lining Type EARTH LD-268 Crozet Animal Wellness Roadside and Median Ditch Design Form Side Slope No Lining Protective Lining Design Intensity Allowable Ditch C A CA TOC L R Min Slope Max Slope 0 (cfs) Velocity _:1 _:1 (Rift) (ft/ft) Storm (in/hr) (fps) n=.03 EC-2 or EC-3: n=.05 Paved: n=.015 INCR ACC Vel' on Velocity' Depth" on Depth 1 0.90 0.10 0.09 0.09 5.0 4 4 0.033 0.033 2-Yr 5.17 0.47 1.5 0.03 0.02 1.27 10-Yr 6.81 0.61 1.5 0.03 0.07 'Velocity calculations performed using maximum slope for this application "Depth calculations performed using minimum slope for this application Note: Max. velocity for unlined ditch = 1.5 fps, for EC-2 matting = 4 fps, for EC-3 matting = 7 fps NOAA Atlas 14, Volume 2, Version 3r„,„" Location name: Crozet, Virginia, USA* ,.. Latitude: 36, Longitude:-76.7038° Elevation: 660.23 ft" " source: ESRI Maps° A "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)1 Average recurrence interval (years) Duretion 1 2 5 10 25 60 1 100 00 200 500 1000 5-min 0 (0.306-0374) (0.366-0.447) (0.43 -0527) (0.485-0 594) (0.545-0 669) (0.590 729) (06 3 0 787) (0.669-0.842) (0.7012-0 912) (0.746-0 970) 1.30 10-min (0.488-0 597) (0.585-0-0..715) (0.69 0.844) (0.7760.949) (0.869-1 w) (0.940-5.16) (1.0- .25) (1.06-21.34) : (13-t.44) 1 (1.17-31753) 0.812 16-min (0.6110-0.78) (0.736-0899) (0.8744-11.07) (0.982-11.20) (110-21335) (119-3147) (1.274358) (1.34-d268) (1. 2-6L82) (1.a71292) 30-min (0. 36- 02) 1 (1.021224) 1 (1.24-1.52) 1 (1.42-1.74) 1 (1.63-2?00) (1.9221) (1.942.42) (2.08-2762) (2.6-22..89) (2.393.11) 1.15 60-min A756) 4 2 (1.07) (1.2 (1.59 1694) (1.85-2.27) (2.?7-2? 67) (2. 3 3.00) (2.663.33) (2.92-3.68) (3: 4-4.14) (3.484.53) 2.96 6.28 2-hr (1.23-1.55) (1.50-61888) (1.88-236) (2.21�77) (2.62-3.30) (2.95 3575) (3.294.21) (3. 3-4.69) (4.05837) (4.46-5.96) 4.14 6.85 3-hr (1.35-1.71) (1.642408) (266261) (2.40-3.05) (2.85-3.64) (3.2�14) (3.604.66) (3. 865.21) (4.85a98) (4.90-6.64) 6-hr (17 5-2.20) (2. 2-2767) (2.62 3531) (3.07 3790) 17 (3.47-4.68) (4. � 5837) (46 9-6.10) (5. 3-6.90) (5.98-8.0) (6.62 9.10) 3.00 11.1 12-hr (2.222983) (26 83.41) (3.32�56) (3.91�03) (4.7236.11) (540-27508) (6: 3-8.14) (6. 09.32) (8. 011.1) (8.97- 2.7) 207 4-hr (27 63.43) 71 (3.34-4.15) 73 (42 4-5.29) 58 (4.90.6.23) (6.068360) (6.96--08..78) (7: 3- 0.1) (8.9611.5) (10.613.7) (1114 15.6) 2-0ey (32 6-4.03) (3: 5-4.88) (5. 0-6.19) (5.84- .25) (7.04-8.79) (8.02--010.1) (9.06-131.5) (102- 3.0) (11 73 5.3) (13.0.17.3) 3-day (34 9427) (42 35.17) (5.35-6.55) (62 673.67) (7.5�29) (8. 9--610.6) (97 0. 2.1) (10.9- 3.7) (12.6-16.1) (13.9- 8.1) 4-day 7 3 (34.51) (4.515.45) (5.761-6.91) (6.67 8 08) (8.04 9979) (916-1112) (10.3- 2.8) (11.6-14A) (13.4-16.9) (14.9- 9.0) 7-day (4.345.18) (523-6.24) (65 3-73.80) (7.57 990) (9. 3- 0.9) (102- 2A) (11 4214.0) (12 7d5.7) (14.6- 8.2) (16.0. 0.3) 10-dey (4.965.84) (5.95-7.00) (7.32118.3) (8.41 9.93) (9.91--- 1.7) (111-132) (12.3-14.8) (13.6-16.4) (15.3- 8.8) (167- 0.8) 20-dey (65 9-7..59) (7.8 9204) (9A70- 0.9) (107- 2.4) (124314.3) (1374 5.9) (15.0-137.5) (16.3- 9.1) (18.0-21A) (19.3- 3.2) 30 dey (813-9.25) (9.64-131.0) (11412.9) (127--14.5) (144-116.4) (15.6-167.9) (16.9 9.4) (18?0- 0.9) (19672.8) (2027224.3) 45-day (102-$.5) 1 (12.0- 3.6) 1 (14.0- 5.8) 1 (15.5-17.5) 1 (174$ 9.7) 1 (1821.3) 1 (2021' 2.8) (21.3-24.4) (2?9-6.4) (24.0.27.9) 60-day (12.0. 3.4) (14145.8) (162- 8.1) (176 9.9) (_ 22.1) (212? 3.8) (2266.4) (23826.9) (254?6.8) (26.5- 0.2) 1 Precipitation frequency (PF) estimates in this table are based on frequency analysis of partial duration series (PDS). Numbers in parenthesis are PF estimates at lower and upper bounds of the 90% confidence interval. The probability that precipitation frequency estimates (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 A9as 14 document for more information. Back to Top PF graphical W 4'YN 3 XWN 3 Hydrologic Soil Group —Albemarle County, Virginia 3 N (Crozet Animal Wellness Center) H 701280 701340 H 430 7eIMD TYI53] 3 R Map Sde: 1:3,150(priltd on A ppbait(8.5' z 11")sheet. Mates NN 0 45 90 180Feet Z70 //k, \ 0 150 300 am 900 Mappmjemm:Web Madnr Camermadiratm:WG584 Edge86:UrMZone17NWGSB4 USDA Natural Resources Web Soil Survey Conservation Service National Cooperative Soil Survey @ 3 4'WN L`t 7/12/2021 Page 1 of 4 3 3' V N MAPLEGEND Area of Interest (AOI) 0 Area of Interest (AOI) Solis 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 (Crozet Animal Wellness Center) 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 AC I 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 14, Jun 3, 2020 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: May 20, 2019—Aug 1, 2019 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 7/12/2021 Conservation Service National Cooperative Soil Survey Page 2 of 4 Hydrologic Soil Group—Albemade County, Virginia Crozet Animal Wellness Center Hydrologic Soil Group Map unit symbol Map unit name Rating Acres in AOI Percent of AOI 4D Ashe loam, 15 to 25 B 1.6 3.4% percent slopes 7B Braddock loam, 2 to 7 B 12.6 26.4% percent slopes 17 Craigsville loam, 0 to 2 A 12.7 26.6% percent slopes, frequently Flooded 25B Dyke silt loam, 2 to 7 B 4.4 9.3% percent slopes 26D3 Dyke day loam, 15 to 25 B 4.1 8.5% percent slopes, severely eroded 36C Hayesville loam, 7 to 15 B 12.3 25.8% percent slopes Totals for Area of Interest 47.6 100.0% Natural Resources Web Soil Survey 7/12/2021 Conservation Service National Cooperative Soil Survey Page 3 of 4 Hydrologic Soil Group —Albemarle County, Virginia Crozet Animal Wellness Center 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 7/12/2021 Conservation Service National Cooperative Soil Survey Page 4 of 4