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WPO202100043 Calculations 2023-03-14
SHIMP ENGINEERING, P.C. Design Fowsed Engineering March 13, 2023 Engineering Review Albemarle County Department of Community Development 401 McIntire Road Charlottesville, VA 22902 M. IIIMP y No. 45183 3it3�25�,w�1 Regarding: WPO 202100043 -Crozet Animal Wellness Center VSMP Amendment— SWM Calculation Packet Dear Reviewer, Enclosed is the stormwater calculation packet for the VSMP Amendment to Crozet Animal Wellness Center, WP0202100043. The development property has an area of 3.40 acres and a disturbed area of 0.85 acres. The project is a private development of a site. This amendment to the approved VSMP plan, dated 5/5/22 and approved on 5/20/22, proposes additional parking which requires a larger underground detention system. 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 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. SWM Quality is satisfied by reducing the total phosphorous load with stormwater BMPs and purchasing nutrient credits. The Stormtech underground storage system now treats a larger portion of the development with an isolator row, providing 0.22 Ib/yr of treatment. To meet the total treatment requirement of 0.55 lb/yr of phosphorous removal, phosphorous credits will be purchased. 0.19 Ib/yr nutrient credits were purchased as part of WP0202100043, leaving 0.14 Ib/yr left to be purchased as part of this VSMP amendment. Treatment Required WPO202100043 Nutrient Credits BMP Treatment Nutrient Credits Total Phos horous ( P ) Purchased (Total Phosphorous) Required 0.55lb/yr 0.19lb/yr 0.22lb/yr 0.14lb/yr SWM Quantity SWM Quantity is satisfied by analyzing concentrated runoff from the development at 1 Point Of Analysis (POA) downstream of the development property. 9VAC25-870-66-B(3) requires that concentrated runoff from the development at the 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 via a ditch, or as sheet flow to the existing channel. 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 22902 1 434.227.5140 1 shimp-engmeenng com Channel Protection: Energy- Balance Equation with Run-on for POA 1 Crozet Animal Wellness Center 1 Yr, 24 Hr Storm Comparison Q 11oa<Q 1Pta sus((RV 1P,a,—)A(RV i—sm)xiF.)+Q tpre, oau-n((RV 1P —)/(RV 1rog�roin)) IF. - 0.8 when LOD>_ 1 ac, I.F.-0.9 wben LOD < I ac, IF. -1.0 when predev site is fully forested PreDev Site Fully Forested? = an IF. = 0.9 Limits of Disturbance = 0.85 ac Onsite Offsite Pre Dev Am Onsite - 0.85 ac Pre Dev DA Offsite - 0.46 ac Post Dev Area Onsite - 0.85 ac Post Dev DA O$Site - 0.46 ac Q tare,sa. - 1.05 cfs Q 1psaomi, - 0.26 cfs RV 1 pre, so = 0.064 of RV 1 Pre, offie = 0.019 of RV 1 Piss. sre 0.118 of RV i p camr - 0.019 of Regulatory Maximum Postdev 1-yr Flow Rate \lax Q1pst < 0.77 rfs Achieved Design Postdev 1-yr Flow Rate Design Q1pa.t = 0.71 efs Energy Balance Equation Compliance Check: Achieved Votes: 1 The assumption in the caladaticn above is that the site equals the land-distu bing activity (LDA). The definition for "site" is not clearly defined m the regulations, but ]DAs are defined as regulated. The ureter quantity cdterie are applied to the sire as per the regulations_ - This site discharges to an a astivg cabinet. Since poradnelopment rmoffto this outfall meets the energy balance equation, Channel Protection Regiirecu nn per 9VAC25-870-WB 3 a are suet and channel protection requirements are satisfied. Flood Protection: Peak Flow Rate to Existing Channel for POA 1 Crozet Animal WeDness Center 10 Yr, 24 Hr Storm Comparison Regulatory Maximum 10-yr Flow Rate Q10pr. = Max Q10post = 4.64 its Achieved Design Postdev 10-yr Flow Rate Design Qiopos, = 4.64 efs Flood Protection Compliance Check: Achieved otes: 1. This site discharges into an existing channel. The 10-yr flow rate is reduced which meets the energy balance equation and the flood protection uirements in 9VAC25-870-66.0 If you have any questions about this calculation packet please do not hesitate to contact me at: chrisgshimp- 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 Predev HydroCAD Report Post-Dev POA Drainage Map Postdev HydroCAD Report Energy Balance Equation TOC Calculations VDOT LD-204 Independent Reports: NOAA Precipitation Report Excerpt from NRCS Soils Report CROZET ANIMAL WELLNESS CENTER PREDEV VRRM MAP Faso_ � � 1�111111 \ II� I II \ 1 \ \ \\ J III ( 1 • �' p �, ,�,; `.�.. = '.`.`. ...`.`. I M P E R VI 0 U S � 111 40 I I 0 Scale: FA ho DISTURBED AREA: 0.85 AC HSG B AREA: 0.85 AC TURF: 0.57 AC IMPERVIOUS: 0.28 AC 40 80 120 CROZET ANIMAL WELLNESS CENTER POSTDEV VRRM MAP IS MANA � TU / °E�l u E3E3 U = / RVIpUS /� � •� � / "� • 0' PUBLIC Nwia M I5 222IM)WO 0 PCSP PUWC I I UTUW EA9 INT,, I.Sm. ! 2022N0 MIS IF DISTURBED AREA: 0,85 AC \ HSG B AREA: 0.85 AC TURF: 0.30 AC \ I IMPERVIOUS: 0.55 AC 50 1 0 50 100 J x 150 Scale: 1 CfQ Yginio Ruirofj RetluN'an MCMotl Re-Oerelognenf Wnp'ianu SpreuasM1eef - verso.... D'Rm. w.smnm..mea�.r.mew oTma wat au.sanm,m anesaarcminm .mlevt Xearc CroM MYnal Wellnus Cents 3/13/INi Imeolove'.tearm Nair., No _ Site Information Post -Development Project (Treatment Volume and Loads) --.. Enter Total DrsWrlsea Area (acres) oas cheek: -_ u, RMPCes;yn Spen'f,e eml3a rts staa6 0 uneo.jawprem xo mnaeoe<eoeeo:mmen.ammexW J ------------------ fable Rur6ee area enttreei J ..Dr,velopmart land nreNoce oel�l-wmuma '.. w. r er—re moue, Brea '.., ggavl,�smarlasl w " Port-0avMopnmttlaM fn I j -aeurn ns 1�1- ore. n� ymuueem/gat-moned,g_aw m '.. aeryr enl�l-ameue, g.mmnv meroremoxgMreream gqueu�smnl>sl DE '. Ya4d a a%an,a% 685 fnuYKK - earn. Ceo fici de -- - --- aannilvevl al a5a& eSaY ca a aNa m1. 1 r..— ave a. om nvymv lrq eucl el nS manag.arun Oss n11 6II vym men euclmrM1l --- swaavTPmg(FoX � —smmww ewrer.e..ww ewowmnabties�e ..luw rtvwmaaw�w nown wr.ro..h.re.l m.e an,.�me.ay.,e. N From. n11 Ast ms ame a wvhvssl - mgpevssl[« - O30 h�+l wepwmem nID 4M weigmee a�lup nm wequepl^~I Xa�gmTug x eTg 4% xmaraaeiug 359( } ee�gag fug irr.rea.y.ul nID NH nious[mre.lxresl nE "°`u'u bewbn0o 0oW bW Mrmeu+4 ae4mce�N agggnwaq xep.ewu3 nE n9 reasxe y rousesue .el Ae.e ------__--- - are a. aE o9Xre—e-on. w eeoe. %,ee w Treatment Volume and Nutrient Load Treatment Volume and Nutrient lbJ ne OpIL a o ren> mm� renmeemvoi�ne 1. eaeil um oM)i IRm R.evo m 1� nwa. cue an wmeunhwaneul envne 13n v,nai nmmgvmo. 3,nv Merem eee o— ].f® nrel od.rtnlotaksey eq ��`mA�ove a9 —a %aaee�Ma+ ce n®e e�'llb/nIto w ` d.� ala opm�em5 L33 le/M m. 14rr IMrd .�H.ne.o,mr�,a,wm�..m wNm ceee d.ln[RE— oIP �m��roe=e v>ueM�e.ungu.'�� eer Ocee %re iml Post-DevelopmentX�a ew�.mm�eem,e o.nmvo«rer i TP foss Reiu[gion Repuirea llb/yrl 0.55 Investor Lcads (Informational Purposes Only) Xaeme�o=+an mgl�xM 6m R.p i ne e merv.., sso li MO o�000 a�000 a0000 00000 00000 00000 00000 00000 00000 00000 00000 o�000 00000 00000 00000 00000 00000 00000 00000 00000 00000 a0000 a0000 00000 00000 00000 0 Site Results (Water Quality Compliance) Area Checks O.A.A O.A.B O.A.0 A. D.A.E ARMEM FOREST/OVEN SPACE (a[) am O.M 0.M i0.00 O.W OK. I IMPEWnUSCOVERTRENTFDIa[ OA7 O.M 0.00�M. OWOK. MANAGEDMRFARENIa[) 0.19 O.M 0.00 00.W OK. MANAGED TURF AREA TREATED (a[) 0.19 O.M 0.00 O.W OK. AREA CHECK OK OK. OK. OK. Site Treatment VOIUMe (ffa) 2.11e Runoff Reduction Volume and TP By Drainage Area O.A. A D.AD O.A. E TOTALRUNOFF REDUMM VOLUME ACHIEVED pF) 0 0 0 TPLOADAVANIBLE FOR REMOVAL Qb/yrl 1.11 MM0 0.00 O.W 1.11 TPID MDUCTIONAGVEVED (b/yr) 0.22 0.000.22 TP LOAD REMAINING Ilb/yr) 0.88 0.00 O.W 0.88 NMOGEN MD REDUCTION ACHIEVED (lb/yr) am O.W 0.00 0.00 O.W 0.00 Total Phosphorus FINAL POST-OEVELOPMENTTPLOADQb/yr) 1.33 TP LOAD REDUCTION REQUIRED pb/yrl 0.55 TP WAD REDUCTION ACHIEVED pb/yrI 0.22 W LOAD REMAINING (lb/N): 1.11 REMAINING TP LOAD REDUCTION REQUIRED pbM: 0.33 Total Nitrogen (For Information Purposes( POST-DEVEMPMEM WAD (Ib/yr) 9.50 NMGGENLOADREDUCTIONACHIEVED)Ib/y0 0.00 REMAINING POST-DEV M MEM NRRWEH LOAD )Ib/yrl 9.50 m_.�. ,_�...m� �.�;a�;��,.� _ _ _ _ _ _ _ __ __ ��mm �000 �� o�00000 �s��00000 �00000 ®000a0 m00000 �®0000 ®®ooa0 m00000 ©0000 m00000 CROZET ANIMAL WELLNESS CENTER PREDEV DA MAP 1� s PREDEV DRAINAGE AREA 1: 1.31 AC ONSITE = 0.75 AC \ OFFSITE = 0.56 AC \ \OC TO POA 1: 11.8 MIN. RD 1 OIDA #1 b�j ?/ C E,7 m --PC' ACSA PUWC IIMJI EAY MT. NSM. d 202M WB \ I 01 1 40 fI Jir 120 Scale: 1 1S 2S DA 1 - O site DA - Offsite K POA 1 Subcat Reach on Link Drainage Diagram for PREDEV FHydroCACOepared by {enter your company name here}, Printed 3/13/2023 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 3/13/2023 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: DA 1 - Onsite Runoff Area=0.850 ac 32.94% Impervious Runoff Depth=0.90" Tc=11.8 min CN=73 Runoff=1.05 cfs 0.064 of Subcatchment2S: DA 1 - Offsite Runoff Area=0.460 ac 8.70% Impervious Runoff Depth=0.50" Tc=11.8 min CN=64 Runoff=0.26 cfs 0.019 of Link 3L: POA 1 Inflow=1.31 cfs 0.083 of Primary=1.31 cfs 0.083 of Total Runoff Area = 1.310 ac Runoff Volume = 0.083 of Average Runoff Depth = 0.76" 75.57% Pervious = 0.990 ac 24.43% Impervious = 0.320 ac Predev PREDEV Type/1 24-hr 1-YR Rainfall=3.07" Prepared by {enter your company name here} Printed 3/13/2023 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 3 Summary for Subcatchment 1 S: DA 1 - Orl Runoff = 1.05 cfs @ 12.05 hrs, Volume= 0.064 af, Depth= 0.90" 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=3.07" Area (ac) CN Description 0.570 61 >75% Grass cover, Good, HSG B 0.000 55 Woods, Good, HSG B 0.280 98 0.850 73 Weighted Average 0.570 67.06% Pervious Area 0.280 32.94% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.8 Direct Entry, Subcatchment 1S: DA 1 - Orl Hydrograph 1.05 CfS ❑Runoff Type II 24-hr 1-YID Rainfall=3.07" Runoff Area=0.850 ac Runoff Volume=0.064 of J I Runoff Depth=0.90i" �j Tc=11.8 min CN=73 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 Time (hours) Predev PREDEV Type/1 24-hr 1-YR Rainfall=3.07" Prepared by {enter your company name here} Printed 3/13/2023 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 4 Summary for Subcatchment 2S: DA 1 - Offsite Runoff = 0.26 cfs @ 12.06 hrs, Volume= 0.019 af, Depth= 0.50" 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=3.07" Area (ac) CN Description 0.420 61 >75% Grass cover, Good, HSG B 0.000 55 Woods, Good, HSG B ' 0.040 98 0.460 64 Weighted Average 0.420 91.30% Pervious Area 0.040 8.70% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.8 Direct Entry, 0.28 0.26 0.26 r__T__T_ 0.24 0.22 I 1 1 I 0.2 I I 1 0.18 0.16 ----------- c 014 I I I I I I I I 0.12 I I I I 0.08 i 1 0.04 I 1 1 I 0.02 Subcatchment 2S: DA 1 - Offsite Hydrograph 1 1 ---;--;--r-- r----; --;YRe K14yhr'l�Ylk- 1 1 1 1 /�/� 1 41_ __!I__1I__1_Jf1 _ RWni 4&0-� I 1 I I I I 1 I I I 1 I I I I 1 I I I I 1 1 I I I 1 I I I I 1 I I I I 1 1 I I I 1 -''-- --;-- -------'---- 1 1 I I I 1 1 I I I 1 1 1 I A I I 1 I I I I I I I I I I I I 1 I I I I - -- --;------- -- --; -------',---OW:64- ' I I I I 1 I I I 1 1 1 I 1 1 I I I I 1 I I I 1 1 1 I I 1 1 I I I I 1 I I I 1 1 1 I I 1 1 T--r--r--r- I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 1 I I I I 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 Time (hours) ■ Runoff Predev PREDEV Type/1 24-hr 1-YR Rainfall=3.07" Prepared by {enter your company name here} Printed 3/13/2023 HvdroCAD@ 9.10 s/n 07054 @ 2010 HvdroCAD Software Solutions LLC Paae 5 Summary for Link 3L: POA 1 Inflow Area = 1.310 ac, 24.43% Impervious, Inflow Depth = 0.76" for 1-YR event Inflow = 1.31 cfs @ 12.05 hrs, Volume= 0.083 of Primary = 1.31 cfs @ 12.05 hrs, Volume= 0.083 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Link 3L: POA 1 Hydrograph ■ Inflow 0 Primary i 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 Time (hours) Predev PREDEV Type/1 24-hr 10-YR Rainfall=5.58" Prepared by {enter your company name here} Printed 3/13/2023 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: DA 1 - Onsite Runoff Area=0.850 ac 32.94% Impervious Runoff Depth=2.74" Tc=11.8 min CN=73 Runoff=3.36 cfs 0.194 of Subcatchment2S: DA 1 - Offsite Runoff Area=0.460 ac 8.70% Impervious Runoff Depth=1.97" Tc=11.8 min CN=64 Runoff=1.28 cfs 0.075 of Link 3L: POA 1 Inflow=4.64 cfs 0.270 of Primary=4.64 cfs 0.270 of Total Runoff Area = 1.310 ac Runoff Volume = 0.270 of Average Runoff Depth = 2.47" 75.57% Pervious = 0.990 ac 24.43% Impervious = 0.320 ac Predev PREDEV Type/1 24-hr 10-YR Rainfall=5.58" Prepared by {enter your company name here} Printed 3/13/2023 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 7 Summary for Subcatchment 1 S: DA 1 - Orl Runoff = 3.36 cfs @ 12.04 hrs, Volume= 0.194 af, Depth= 2.74" 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=5.58" Area (ac) CN Description 0.570 61 >75% Grass cover, Good, HSG B 0.000 55 Woods, Good, HSG B 0.280 98 0.850 73 Weighted Average 0.570 67.06% Pervious Area 0.280 32.94% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.8 Direct Entry, Subcatchment 1S: DA 1 - Orl Hydrograph 3.36 cfs ❑ Runof Type II 24-hr 10-YR Rainfall=5.58" Runoff Area=0.850 ac Runoff Volume=0.194 of 2 Runoff Depth=2.74" LL Tc=11.8 min CN=73 1 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 Time (hours) Predev PREDEV Type/1 24-hr 10-YR Rainfall=5.58" Prepared by {enter your company name here} Printed 3/13/2023 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 8 Summary for Subcatchment 2S: DA 1 - Offsite Runoff = 1.28 cfs @ 12.04 hrs, Volume= 0.075 af, Depth= 1.97" 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=5.58" Area (ac) CN Description 0.420 61 >75% Grass cover, Good, HSG B 0.000 55 Woods, Good, HSG B 0.040 98 0.460 64 Weighted Average 0.420 91.30% Pervious Area 0.040 8.70% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.8 Direct Entry, Subcatchment 2S: DA 1 - Offsite Hydrograph 1.28 cfs Type II 24-hr 10-YR Rainfall=5.58" Runoff Area=0.460 ac Runoff Volume=0.075 of Runoff Depth=1.97r LL Tc=11.8 min CN=64 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 Time (hours) ❑ Runoff Predev PREDEV Type/1 24-hr 10-YR Rainfall=5.58" Prepared by {enter your company name here} Printed 3/13/2023 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 9 Summary for Link X: POA 1 Inflow Area = 1.310 ac, 24.43% Impervious, Inflow Depth = 2.47" for 10-YR event Inflow = 4.64 cfs @ 12.04 hrs, Volume= 0.270 of Primary = 4.64 cfs @ 12.04 hrs, Volume= 0.270 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Link X: POA 1 Hydrograph I I 6 4.64 Inflow Area=1.310 ac cfs I I I I I I I I I I I I I I I I I I I I I I I I I 4 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I _________ I_____I __I___I_____I___I__ I______ 3 I I I _ I _ _ I I I I I I I I I I I I I I I I I I I I I I I I I H I I I I I I I I I I I V I I I I I I I I I I I I I I I I I I I I I I I I I I I O .r__I__,__T__r__I _,__T__f__I__,__T__i I I LL I I I I I I I I I I I I 2 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 1 I I I I I I I I I I 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 Time (hours) ❑ Inflow ❑ Primary Predev PREDEV Type/1 24-hr 100-YR Rainfall=9.08" Prepared by {enter your company name here} Printed 3/13/2023 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 10 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: DA 1 - Onsite Runoff Area=0.850 ac 32.94% Impervious Runoff Depth=5.78" Tc=11.8 min CN=73 Runoff=6.99 cfs 0.409 of Subcatchment2S: DA 1 - Offsite Runoff Area=0.460 ac 8.70% Impervious Runoff Depth=4.66" Tc=11.8 min CN=64 Runoff=3.09 cfs 0.179 of Link 3L: POA 1 Inflow=10.07 cfs 0.588 of Primary=10.07 cfs 0.588 of Total Runoff Area = 1.310 ac Runoff Volume = 0.588 of Average Runoff Depth = 5.39" 75.57% Pervious = 0.990 ac 24.43% Impervious = 0.320 ac Predev PREDEV Type/1 24-hr 100-YR Rainfall=9.08" Prepared by {enter your company name here} Printed 3/13/2023 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 11 Summary for Subcatchment 1S: DA 1 - Onsite Runoff = 6.99 cfs @ 12.03 hrs, Volume= 0.409 af, Depth= 5.78" 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=9.08" Area (ac) CN Description 0.570 61 >75% Grass cover, Good, HSG B 0.000 55 Woods, Good, HSG B " 0.280 98 0.850 73 Weighted Average 0.570 67.06% Pervious Area 0.280 32.94% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (f /sec) (cfs) 11.8 Direct Entry, I I I I I I I I -- 9: 7 6 I I I I I 5 -------- - - - - -- 4 IL 3 I I I I I I I I I I 2 I I I I I 0 2 4 6 8 10 Subcatchment 1S: DA 1 - Onsite Hydrograph I I I I I I I I I I I I I I I I I I I I I I I I I ■ RunoH I I S--I---I--7--Y--T- Y--r--I---I--T--Y--Y--Y--r--I--- I- Type'III 24-'6hi^I 100-Nk I I I I I I I I I I I I I I I I I I I-----,-Rainfa11T9:O8"I I I I I I I I I I I I I I I I I I I I I I I I I RUnbff Are&0.850 alp __r__7__7__r__r__I___I__ 7__ 7__ r__ r__r__I__ r__ rkOn6f(Vg1Lpm6=;0.40$ elf --- ---kurtoff;D6 th45-.1 " I IT6=11.8 tnih - - r--r--I--,--,--r--r--r--r--r-,--,--r--r--r I I I I I I I I I I I I I I I I I N=7 I I I I I I I I I I I I I I I --r I I,--,--r --r - -r I I,--,--r - -r - -r I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 Time (hours) Predev PREDEV Type/1 24-hr 100-YR Rainfall=9.08" Prepared by {enter your company name here} Printed 3/13/2023 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 12 Summary for Subcatchment 2S: DA 1 - Offsite Runoff = 3.09 cfs @ 12.04 hrs, Volume= 0.179 af, Depth= 4.66" 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=9.08" Area (ac) CN Description 0.420 61 >75% Grass cover, Good, HSG B 0.000 55 Woods, Good, HSG B 0.040 98 0.460 64 Weighted Average 0.420 91.30% Pervious Area 0.040 8.70% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.8 Direct Entry, 2 Subcatchment 2S: DA 1 - Offsite Hydrograph 3.09 ❑ Runoff Type II 24-hr 100-YR Rainfall=9.08" Runoff Area=0.460 ac Runoff Volume=0.179 of Runoff Depth=4.66" Tc=11.8 min CN=64 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 Time (hours) Predev PREDEV Type/1 24-hr 100-YR Rainfall=9.08" Prepared by {enter your company name here} Printed 3/13/2023 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 13 Summary for Link 3L: POA 7 Inflow Area = 1.310 ac, 24.43% Impervious, Inflow Depth = 5.39" for 100-YR event Inflow = 10.07 cfs @ 12.03 hrs, Volume= 0.588 of Primary = 10.07 cfs @ 12.03 hrs, Volume= 0.588 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Link 3L: POA 1 Hydrograph --1--1--7--r I 1 r--r 1--T--r--i -l--T--r--1--1--i--r--r--1-- I I I I I I I I I I I I I I I I I ■ Inflow 11 --1--�-- --�__1--�__�__'__�_-1--�--'--�--1--�--+--r--�--1-- ■Primary 10.07 cfs I I I I I I I I I I I I I I I 1--J--1 i J IlLnfiloJw Areal ,3� 0 IAa ,O L I I I I I I I I I I I I I I I I I I I I I g i __I__ I I I I I -I -I __I__ -__ I __I I I I I I I I I I I I I I I I I I 6 � -I -y -Y -r I I I I I -y -Y -I -y -y -T -r -I -y -T -r -I -y -Y -r -r -I I I I I I I I I I I I I I I I I I ] i i I I I I I I I I I I I I I I I I I I I I I i I I I I I I I F I I I I I I I I 3 G 6 I 1 1 LL 11__7__1_ 1 I I I _7__r__7_1__1__7__r__1__1__1__r__1__1__7__r__r__1__ I I 1 I I I I 1 I I I 1 I I I I 1 q 1 __1__J__y__L_ 1 I I I 1 1 I 1 _J__J__1__J__J__y__L__1__J__y__L__1__J__1__ti__L__1__ I I I I I I I 1 I I I 1 I I I I 1 3 1 I I I I I I I I I 1 1 I I I 1 I I I I 1 2 1 I I I 1 __1__,__7__r. I I I I I I 1 1 I I I 1 I I I I 1 1 1 1 1 1 I I I ,__,__r__ r__�_,__ r__r__1__,__ 7__ 1__r__1. I I I I 1 1 I I 1 I I I 22 24 26 28 30 32 34 36 38 40 42 44 46 48 Time (hours) DRAINAGE AREA 1 TO POA 1 CROZET ANIMAL WELLNESS CENTER POSTDEV DA MAP RD ° ONSITE UNMANAGED = ONSITE AREA = 0.85 AC MANAGED = 0.64 AC UNMANAGED = 0.21 AC TOC = 5 MIN. (ASSUMED) OFFSITE AREA = 0.46 AC MANAGED = 0.23 AC \ UNMANAGED = 0.23 AC \ TOC = 11.8 MIN. �F SIT /AN AGED = 0.2 AC 21 A C OFFSITE UNMANAGED = 0.23 AC 120 DA 1 1S - Onsite ana DA 1 - Onsite Unmanaged DETENTION 1 \ POA 1 S4 Reach Aon Llnk SC-740 Managed (5S k 1 - Offsite managed Postdev POSTDEV Type 11 24-hr 1 YR Rainfall=3.07" Prepared by {enter your company name here} Printed 3/13/2023 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 SubcatchmentlS: DA 1 - Onsite Managed Runoff Area=0.640 ac 73.44% Impervious Runoff Depth=1.88" Tc=5.0 min CN=88 Runoff=2.17 cfs 0.100 of Subcatchment2S: DA 1 - Offsite Managed Runoff Area=0.230 ac 8.70% Impervious Runoff Depth=0.50" Tc=11.8 min CN=64 Runoff=0.13 cfs 0.010 of Pond 3P: DETENTION 1 SC-740 Peak Elev=655.97' Storage=0.050 of Inflow=2.23 cfs 0.110 of Outflow=0.40 cfs 0.095 of Subcatchment4S: DA 1 - Onsite Runoff Area=0.210 ac 38.10% Impervious Runoff Depth=1.01" Tc=5.0 min CN=75 Runoff=0.39 cfs 0.018 of Subcatchment5S: DA 1 - Offsite Unmanaged Runoff Area=0.230 ac 8.70% Impervious Runoff Depth=0.46" Tc=11.8 min UI Adjusted CN=63 Runoff=0.12 cfs 0.009 of Link 6L: PDA 1 Inflow=0.71 cfs 0.121 of Primary=0.71 cfs 0.121 of Total Runoff Area = 1.310 ac Runoff Volume = 0.136 of Average Runoff Depth = 1.25" 54.96% Pervious = 0.720 ac 45.04% Impervious = 0.590 ac Postdev POSTDEV Type 11 24-hr 1 YR Rainfall=3.07" Prepared by {enter your company name here} Printed 3/13/2023 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 3 Summary for Subcatchment 1 S: DA 1 - Onsite Managed Runoff = 2.17 cfs @ 11.96 hrs, Volume= 0.100 af, Depth= 1.88" 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=3.07" Area (ac) CN Description 0.170 61 >75% Grass cover, Good, HSG B 0.000 55 Woods, Good, HSG B 0.470 98 0.640 88 Weighted Average 0.170 26.56% Pervious Area 0.470 73.44% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 1S: DA 1 - Onsite Managed Hydrograph 2.17 cfs Type II 24-hr 1 YID 2 Rainfall=3.07" Runoff Area=0.640 ac Runoff Volume=0.100 of Runoff Depth=1.88" LL------------------------- Tc=5.0 mlh CN=80 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 Time (hours) ❑ Runoff Postdev POSTDEV Type 11 24-hr 1 YR Rainfall=3.07" Prepared by {enter your company name here} Printed 3/13/2023 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 4 Summary for Subcatchment 2S: DA 1 - Offsite Managed Runoff = 0.13 cfs @ 12.06 hrs, Volume= 0.010 af, Depth= 0.50" 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=3.07" Area (ac) CN Description 0.210 61 >75% Grass cover, Good, HSG B 0.000 55 Woods, Good, HSG B ' 0.020 98 0.230 64 Weighted Average 0.210 91.30% Pervious Area 0.020 8.70% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.8 Direct Entry, Subcatchment 2S: DA 1 - Offsite Managed 014 0.13 - -- 0.13 012 0.11 I I 1 I I 1 1 I °., I I I 0.09 '� 0.08 ----------- 1 1 O ° 07 I I I I LL °.06 I I I I 0.05 0.04 0.02 I 1 1 I 0.01 Hydrograph 1 1 -.•yOeA1U-6hll ,Ylk- --r-1--T--r--r--r--r-T- T- 444 1 1 1 1 /�/� 1 41 __! I __ 1I __ 1_ J_ RWnf1i43T-0-7 I 1 I I I I 1 I I I 1 I I I I 1 I I I I 1 1 I I I 1 --;-�,--;--;--; I I I I 1 I I I I 1 1 I I I 1 -'1----+--+----1---1-- - 0unof# 111Qepth�0-50, 1 1 I I I 1 1 I I I 1 1 1 I A I I 1 -T -T -T r I��T-�� I 1 1 I - ;--;--;--1,---1,-- -- ----L--1,---1,---Ih- CtN:44- 1 I I I I 1 I I I 1 1 1 I 1 1 I I I I 1 I I I 1 1 1 I I 1 1 I I I I 1 I I I 1 1 1 I I 1 1 T--r--r--r- I I I I 1 I I I I 1 1 I I 1 1 I I I I I I I I I I I I I I I I I I I I I I I I I I 1 I I I I 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 Time (hours) ■ Runoff Postdev POSTDEV Type 11 24-hr 1 YR Rainfall=3.07" Prepared by {enter your company name here) Printed 3/13/2023 HVdroCAD@ 9.10 s/n 07054 @ 2010 HVdroCAD Software Solutions LLC Paae 5 Summary for Pond 3P: DETENTION 1 SC-740 Inflow Area = 0.870 ac, 56.32% Impervious, Inflow Depth = 1.52" for 1 YR event Inflow = 2.23 cfs @ 11.96 hrs, Volume= 0.110 of Outflow = 0.40 cfs @ 12.17 hrs, Volume= 0.095 af, Atten= 82%, Lag= 12.4 min Primary = 0.40 cfs @ 12.17 hrs, Volume= 0.095 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Peak Elev= 655.97' @ 12.17 hrs Surf.Area= 0.046 ac Storage= 0.050 of Plug -Flow detention time= 165.4 min calculated for 0.095 of (86% of inflow) Center -of -Mass det. time= 99.3 min ( 920.4 - 821.0 ) Volume Invert Avail.Storage Storage Description #1 654.00' 0.064 of 20.00'W x 100.001 x 4.33'H STONE BEDDING 0.199 of Overall - 0.038 of Embedded = 0.161 of x 40.0% Voids #2 654.83' 0.038 of StormTech SC-740 x 36 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 0.102 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' 3.5" Vert. 1 YR ORIFICE C= 0.600 #3 Device 1 657.50' 5.0' long x 2.00' rise Sharp -Crested Rectangular Weir 2 End Contraction(s) 2.7' Crest Height #4 Device 1 655.83' 10.0" Vert. Orifice/Grate C= 0.600 Primary OutFlow Max=0.39 cfs @ 12.17 hrs HW=655.97' (Free Discharge) t1=PRIMARY 24" OUTLET (Passes 0.39 cfs of 6.55 cfs potential flow) 2=1 YR ORIFICE (Orifice Controls 0.32 cfs @ 4.79 fps) 3=Sharp-Crested Rectangular Weir( Controls 0.00 cfs) =Orifice/Grate (Orifice Controls 0.07 cfs @ 1.25 fps) POSTDEV Prepared by {enter your company name here} 659 658 a a 657 c 0 m v w 656 655 654 0.40 cfs Postdev Type 11 24-hr 1 YR Rainfall=3.07" Printed 3/13/2023 Pond 3P: DETENTION 1 SC-740 Hydrograph Irtf�o�vAi�e=0_$7!O a Poa;k J=-I0V=055.97? Storage:0L050, of 1 r 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 -r Time (hours) Pond 3P: DETENTION 1 SC-740 Stage -Discharge Discharge (cfs) ■ Inflow ■ Primary ❑ Primary POSTDEV Prepared by {enter your company name here} Postdev Type 11 24-hr 1 YR Rainfall=3.07" Printed 3/13/2023 Pond 3P: DETENTION 1 SC-740 i l i i l i i i i i i l i i T i i i i i i StcrmTech SC-740 STONE 654 .f+-. 0 0.005 0.01 0.015 Storage (acre-feet) ■ Storage Postdev POSTDEV Type 1124-hr 1 YR Rainfall=3.07" Prepared by {enter your company name here} Printed 3/13/2023 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 8 Summary for Subcatchment 4S: CIA 7 - Onsite Unmanaged Runoff = 0.39 cfs @ 11.97 hrs, Volume= 0.018 af, Depth= 1.01" 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=3.07" Area (acl CN Description 0.080 98 0.130 61 >75% Grass cover, Good, HSG B 0.210 75 Weighted Average 0.130 61.90% Pervious Area 0.080 38.10% Impervious Area Tc Length Description 5.0 Direct Entry, Subcatchment 4S: DA 1 - Onsite Unmanaged 0.42 0.3! 0.4 0.38 -------J--'--_ 0.38 0 32 I -r-y--T--T--- 0.3 0.28 0.26 0.24 --I---I--,I------ 0.22 r 1 1 02 I _ I__ 1- n I I 0.18 0.18 --L-�--J--. 0.14 0.12 0.1 0.08 --L-J--L-- 0.08 --L-�--J--'-- 0.04 __I__-__T__T__ I I I I I I I I I I I I I I I I i I I I I I I I I I I I I I I r- r-T--r-r--r--r-T--T-- I__I_---r--r---- --II---- --;--; -- - --l�4-hF'4-Y�2- __I__J__1__1__L__L__I__1__1__1__L__I____ --,Rai RainfaUlT'1I7-F3/S� .0A7 I "- I I I I I I I I I I I I I-7I - ,--;- ---- --Rdm6fi-Atea=0_21C1ad- ------------------- I I I I I I I I I I I I I I I I _J _1 _1 _L _I -----;--;--r-------;--OWn' of-DeptFt�1.01w- --I-1--T--T--r--I----T--T--T--I--I - T-T--T--I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I __I__-- II II__ II___I___III __I__ 1 --1-- J--1 --1--L--1---'--1--1__1--L--1---1--1--1--L--1-- I I I 1 1 1 I I I 1 1 I I I I 1 1 1 I I I 1 1 I I 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 Time (hours) ■ Runoff Postdev POSTDEV Type 11 24-hr 1 YR Rainfall=3.07" Prepared by {enter your company name here} Printed 3/13/2023 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 9 Summary for Subcatchment 5S: DA 1 - Offsite Unmanaged Runoff = 0.12 cfs @ 12.07 hrs, Volume= 0.009 af, Depth= 0.46" 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=3.07" Area (ac) CN Description 0.210 61 0.020 98 Unconnected pavement, HSG B 0.230 64 Weighted Average, UI Adjusted CN = 63 0.210 91.30% Pervious Area 0.020 8.70% Impervious Area 0.020 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.8 Direct Entry, Subcatchment 5S: DA 1 - Offsite Unmanaged 0.125 -'--�- 0.12 0.12 -----J1-- 0.115 --�r-rr--r 0.11 0.105 ._�__J1__ 7__ 7__r 0.1 0.095 r--1i----i--r 0.09-I___1__J__1__L 0.08 0.075 --r---i--T--r 0.07 0.065 -------;--1--r 0.06 -------J--1--L 0.055 -------7--r 0.05 0.045 ---;--;--T--� 0.04 0.035 —r--1--�--r-- 0.03 --L-J--J--1--- 0.025 0.02 0.015 I I 1 I --r--1--,--7--- 0.01-----J--' Hydrograph I I I I I I I I 1 I 1 I I I I Ii__i__1__L__I__J__i__1__L__I__ --,-_-,-_-r--r---1--11--r- 11tF 4=hr14yk _1 _L I 1 I I I I I I I I I I I I I I I --- Raj __t'IMTI MM_ I T 1 I 1 I I I I I I I I I I I I I I I 1 }yI �[J JIgpI jj l`,/IF �.11 Ip ,I/� SI —F lry �If - --l--T --r --r 1 1 l -- T--T/-�-r�-/--- _I _J _J _1 _L _L _I _JkU I4rrjj����/��� 1 1 nofFl©�YhV.ITVI-r- '__ ----J-- ----;--1--'1--;--;--;--1L--:TC1=- •.�mm- --1i-1--7--r--r 1 1 1--7--r--7 1 1 7--r--7--1- - _J__1__ 1__ L__L_L__J__1 L L_ L LKA r__r__1__ 1__ r _ r I I I I I I I I I I I I I I I I 1__L__L__1__ J__ 1__ 1__ L__L_ J__J__ 1__L__L_ 1 1 I 1 1 1 1 1 ________________________________________________ 1 I I I I 1 I I I I 1 1 I I 1 1 1 1 I 1 1 1 r 1 1 1 � r 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 Time (hours) ■ Runoff Postdev POSTDEV Type 1124-hr 1 YR Rainfall=3.07" Prepared by {enter your company name here} Printed 3/13/2023 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 10 Summary for Link 6L: POA 7 Inflow Area = 1.310 ac, 45.04% Impervious, Inflow Depth = 1.11" for 1 YR event Inflow = 0.71 cfs @ 11.99 hrs, Volume= 0.121 of Primary = 0.71 cfs @ 11.99 hrs, Volume= 0.121 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Link 6L: POA 1 Hydrograph I I I _7_r__r__ _ I I I I I I I I I I I I I I I I I __ __r__i__�__r__r_�__r__r__i__1__ r__r__i__1__r__i__ 1__ oinflM I I I I I I I I ■Primary 0.71 cfs --J--J L J i J L J L/ l - {` r` 1 ---i--}--i--i-In i*-A 1 1,13 J-1:a�- 0.7 1 1 1 0.65 _ ',y__r__, 1 1 1 1 __r__i__--__r__r_--__r__r__,__--__ r__ r__,__4__r__1__�__ 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 / -:--A --L- 1--J--1--L-J--1--L---J--L--L---J--L---J-- 0.8 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0.55 1 1 1 r__r__i_____r__i__ 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0.5 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1__L__I__J__L__L__I__J__L__I__J__ 0.45 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 04 - - 1_1 1 - �--r- -r --r- �--r--r--1--r--r--r- �--r--r--r- �--r--r- �-- 3 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 c------t--� ----'---------'--------'------------�-- LL 0.35 1 1 1 1 1 1 I 1 1 1 I 1 1 1 I 1 1 1 1 1 0.3 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 I 1 1 1 I 1 1 1 I 1 1 1 1 1 I 0.25 �r__r__r 1 1 1 I 1 1 1 I 1 1 1 I 1 1 1 1 1 0.21 i I I I I I I I I I I I I I I I I I I I 0.15 1 1 1 1 1 1 1 1 1 1 1 1 I 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0.1 11 1 1 11 1 1 - 11 11 1 - 11 11 1 22 24 26 28 30 32 34 36 38 40 42 44 Time thous) Postdev POSTDEV Type 1124-hr2 YR Rainfall=3.71" Prepared by {enter your company name here} Printed 3/13/2023 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 11 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 SubcatchmentlS: DA 1 - Onsite Managed Runoff Area=0.640 ac 73.44% Impervious Runoff Depth=2.46" Tc=5.0 min CN=88 Runoff=2.80 cfs 0.131 of Subcatchment2S: DA 1 - Offsite Managed Runoff Area=0.230 ac 8.70% Impervious Runoff Depth=0.81" Tc=11.8 min CN=64 Runoff=0.24 cfs 0.016 of Pond 3P: DETENTION 1 SC-740 Peak Elev=656.35' Storage=0.061 of Inflow=2.95 cfs 0.147 of Outflow=1.25 cfs 0.132 of Subcatchment4S: DA 1 - Onsite Runoff Area=0.210 ac 38.10% Impervious Runoff Depth=1.45" Tc=5.0 min CN=75 Runoff=0.56 cfs 0.025 of Subcatchment5S: DA 1 - Offsite Unmanaged Runoff Area=0.230 ac 8.70% Impervious Runoff Depth=0.76" Tc=11.8 min UI Adjusted CN=63 Runoff=0.22 cfs 0.015 of Link 6L: PDA 1 Inflow=1.73 cfs 0.172 of Primary=1.73 cfs 0.172 of Total Runoff Area = 1.310 ac Runoff Volume = 0.187 of Average Runoff Depth = 1.71" 54.96% Pervious = 0.720 ac 45.04% Impervious = 0.590 ac Postdev POSTDEV Type 1124-hr2 YR Rainfall=3.71" Prepared by {enter your company name here} Printed 3/13/2023 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 12 Summary for Subcatchment 1 S: DA 1 - Onsite Managed Runoff = 2.80 cfs @ 11.96 hrs, Volume= 0.131 af, Depth= 2.46" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Type II 24-hr 2 YR Rainfall=3.71" Area (ac) CN Description 0.170 61 >75% Grass cover, Good, HSG B 0.000 55 Woods, Good, HSG B 0.470 98 0.640 88 Weighted Average 0.170 26.56% Pervious Area 0.470 73.44% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 1S: DA 1 - Onsite Managed Hydrograph ❑ Runoff 1 2.80 cfs I Type II 24-hr 2 YID Rainfall=3.71E Runoff'Area=0.640 ad Runoff VOl u me=0.13 1 Of Runoff Depth=2.467 Tc=5.0 Min CN=88 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 Time (hours) Postdev POSTDEV Type 1124-hr2 YR Rainfall=3.71" Prepared by {enter your company name here} Printed 3/13/2023 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 13 Summary for Subcatchment 2S: DA 1 - Offsite Managed Runoff = 0.24 cfs @ 12.05 hrs, Volume= 0.016 af, Depth= 0.81" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Type II 24-hr 2 YR Rainfall=3.71" Area (ac) CN Description 0.210 61 >75% Grass cover, Good, HSG B 0.000 55 Woods, Good, HSG B 0.020 98 0.230 64 Weighted Average 0.210 91.30% Pervious Area 0.020 8.70% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.8 Direct Entry, Subcatchment 2S: DA 1 - Offsite Managed 0.26 0.24 0 24 I I I I 0 22 I I I 02 0.18 - I I I I ----------- 0.16 I I I I = 0.14 ° 0.12 0.1 I I I I 0.08 0.06 0.04 0.02 Hydrograph y{�e_'lL 4.602rY]t I I I I I I I I I I I QI rI�*(�111-I I I I I I I I I I I I _I f��IrlTiffT3i�11,r-I I I I I I I I I I I I I I I I I ---r----R-Un66 f'rA1fe&O-.23Q-ale- ft Ill WWI 016--b.-Oto-cif I I I I I I I I I I I I I I I I I kIunbff:DepiLi IT_d=11.8_ rh_i�_ I I I I I I I I I I I I 1 I I I I I I I I I I I I I I 1 I I I I i I I I I I I I I I I I 1 I I I I __1__T__T__r__I___I__T__T__T__I__ I I I I I I I I I I I I I I I 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 Time (hours) ■ RunoR Postdev POSTDEV Type 1124-hr2 YR Rainfall=3.71" Prepared by {enter your company name here) Printed 3/13/2023 HVdroCAD@ 9.10 s/n 07054 @ 2010 HVdroCAD Software Solutions LLC Paae 14 Summary for Pond 3P: DETENTION 1 SC-740 Inflow Area = 0.870 ac, 56.32% Impervious, Inflow Depth = 2.03" for 2 YR event Inflow = 2.95 cfs @ 11.96 hrs, Volume= 0.147 of Outflow = 1.25 cfs @ 12.07 hrs, Volume= 0.132 af, Atten= 58%, Lag= 6.4 min Primary = 1.25 cfs @ 12.07 hrs, Volume= 0.132 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Peak Elev= 656.35' @ 12.07 hrs Surf.Area= 0.046 ac Storage= 0.061 of Plug -Flow detention time= 137.0 min calculated for 0.132 of (90% of inflow) Center -of -Mass det. time= 84.8 min ( 898.7 - 813.9 ) Volume Invert Avail.Storage Storage Description #1 654.00' 0.064 of 20.00'W x 100.001 x 4.33'H STONE BEDDING 0.199 of Overall - 0.038 of Embedded = 0.161 of x 40.0% Voids #2 654.83' 0.038 of StormTech SC-740 x 36 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 0.102 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' 3.5" Vert. 1 YR ORIFICE C= 0.600 #3 Device 1 657.50' 5.0' long x 2.00' rise Sharp -Crested Rectangular Weir 2 End Contraction(s) 2.7' Crest Height #4 Device 1 655.83' 10.0" Vert. Orifice/Grate C= 0.600 Primary OutFlow Max=1.24 cfs @ 12.07 hrs HW=656.34' (Free Discharge) t1=PRIMARY 24" OUTLET (Passes 1.24 cfs of 10.37 cfs potential flow) 2=1 YR ORIFICE (Orifice Controls 0.38 cfs @ 5.63 fps) 3=Sharp-Crested Rectangular Weir( Controls 0.00 cfs) =Orifice/Grate (Orifice Controls 0.86 cfs @ 2.44 fps) Postdev POSTDEV Type// 24-hr 2 YR Rainfall=3.71" Prepared by {enter your company name here} Printed 3/13/2023 HydroCAD® 9.10 s/n 07054 ©2010 HydroCAD Software Solutions LLC Page 15 Pond 3P: DETENTION 1 SC-740 Hydrograph 29 /� 3 5cfs i--,`--',--i--i--ii 1�1�OaN /1■Inflow ---J,--�--i --'i-J,--�-- ■Primary rea=0 87!0 ',at Poa;k r=10V=656.�5,11 - ' 6 s1 --- - - -------- --------- - - - - Storage;* z 1.25 cfs I I I I I I I 659 658 a a 657 c 0 m v w 656 655 654 r 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 -r Time (hours) Pond 3P: DETENTION 1 SC-740 Stage -Discharge Discharge (cfs) ❑ Primary POSTDEV Prepared by {enter your company name here} Postdev Type/1 24-hr 2 YR Rainfall=3.71 " Printed 3/13/2023 Pond 3P: DETENTION 1 SC-740 i StcrmTech SC-740 STONE 654 .f+-. 0 0.005 0.01 0.015 Storage (acre-feet) ❑ Storage Postdev POSTDEV Type// 24-hr 2 YR Rainfall=3.71" Prepared by {enter your company name here} Printed 3/13/2023 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 17 Summary for Subcatchment 4S: DA 7 - Onsite Unmanaged Runoff = 0.56 cfs @ 11.97 hrs, Volume= 0.025 af, Depth= 1.45" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Type II 24-hr 2 YR Rainfall=3.71" Area (acl CN Description 0.080 98 0.130 61 >75% Grass cover, Good, HSG B 0.210 75 Weighted Average 0.130 61.90% Pervious Area 0.080 38.10% Impervious Area Tc Length Description 5.0 Direct Entry, Subcatchment 4S: DA 1 - Onsite Unmanaged o.0 0.5i 0.55 I 0.45 I I I I 04 I I I I .@ 0.35 3 0 0.3 I I I I LL 0.25 0.2 0.15 I I I I I I I I 0.1 I I I I n n5 I I I I I I I I I I I I I I I --r--T--r--r I I T--T--r--r I I T--r--r--r- �II -r -T -T -r -T -T r - T -T r _y_ pe_ 'III4Lhrl 2'IYI� RainfaIIT3.71 "' R_ yin_ dff_ 'IA_ i_�e_A=©_.21.0 _alp__ I- _i -+ _f _I _C ,I �tUpoff_IIIQepth - 45�'_ I I I I I I I I I I I I I I I Iym Iy^ I I I I I I I I I I I I Tcy5J0�i�t I I I I I I I I I I I I I I I I I I I I i I I i i I I I I I I I i I i I I I I I I I I I I II II II II I I I I I I I I I I I I I I I I I I I I I I I I I I I I 2 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 Time (hours) ■ Runoff Postdev POSTDEV Type 1124-hr2 YR Rainfall=3.71" Prepared by {enter your company name here} Printed 3/13/2023 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 18 Summary for Subcatchment 5S: DA 1 - Offsite Unmanaged Runoff = 0.22 cfs @ 12.06 hrs, Volume= 0.015 af, Depth= 0.76" Runoff by SCS TR-20 method, UH=SCS, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Type II 24-hr 2 YR Rainfall=3.71" Area (ac) CN Description 0.210 61 0.020 98 Unconnected pavement, HSG B 0.230 64 Weighted Average, UI Adjusted CN = 63 0.210 91.30% Pervious Area 0.020 8.70% Impervious Area 0.020 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.8 Direct Entry, Subcatchment 5S: DA 1 - Offsite Unmanaged 0.24 - - -- =__JI__ 0.22 0.23 0.22 --r-rrr--- 0.21 0.2 0.19 ---------1--- 0.18 6 17 0.15 0.14 ---Ji-- c0.12 ----J----L--- 01 _ 0.09 0.08 --;--;--;-- 0.07 --L-J--J--1--- 0.06 '-r-r--1--r- 0.05 0.03 0.02 ---- ------'--- Hydrograph I__�__r__�__i �__}__r__r__i__y__}__}__r__i__ -;--,--r--r--_-_- ,_i_Te:--r-1114=hr,2Y -1 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I __r_r__T__T__r__r_ ItiQf�T W_-I _ - J----;--; --; --1--J--1--1--L--1---I--,--1--1--L--1-��_pII-_-1--11)/��- L--I-- I--I-- __;__IjMOeO-qN=:6$- T--r--r--r- __I__J--1--1--L--L--I--J--1--1--L--I--J--1--1--L--L- .7__T__r__r__r__r_r__r__r__r__r_,__T__r__r__r_ ---- J-- I -- I--I--I---I-- I-- I -- I--I---I---I-- I -- I -- I --I-- I I I I I I I I I I I I I I I ----- --I_ I I ________________________------ _ 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 Time (hours) ■ Runoff Postdev POSTDEV Type 1124-hr2 YR Rainfall=3.71" Prepared by {enter your company name here} Printed 3/13/2023 HvdroCAD@ 9.10 s/n 07054 @ 2010 HvdroCAD Software Solutions LLC Paae 19 Summary for Link 6L: POA 1 Inflow Area = 1.310 ac, 45.04% Impervious, Inflow Depth = 1.57" for 2 YR event Inflow = 1.73 cfs @ 12.04 hrs, Volume= 0.172 of Primary = 1.73 cfs @ 12.04 hrs, Volume= 0.172 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Link 6L: POA 1 Hydrograph ■ Inflow 0 Primary 0 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 Time (hours) Postdev POSTDEV Type 11 24-hr 10 YR Rainfall=5.58" Prepared by {enter your company name here} Printed 3/13/2023 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 20 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 SubcatchmentlS: DA 1 - Onsite Managed Runoff Area=0.640 ac 73.44% Impervious Runoff Depth=4.22" Tc=5.0 min CN=88 Runoff=4.65 cfs 0.225 of Subcatchment2S: DA 1 - Offsite Managed Runoff Area=0.230 ac 8.70% Impervious Runoff Depth=1.97" Tc=11.8 min CN=64 Runoff=0.64 cfs 0.038 of Pond 3P: DETENTION 1 SC-740 Peak Elev=657.35' Storage=0.084 of Inflow=5.10 cfs 0.263 of Outflow=3.25 cfs 0.248 of Subcatchment4S: DA 1 - Onsite Runoff Area=0.210 ac 38.10% Impervious Runoff Depth=2.93" Tc=5.0 min CN=75 Runoff=1.13 cfs 0.051 of Subcatchment5S: DA 1 - Offsite Unmanaged Runoff Area=0.230 ac 8.70% Impervious Runoff Depth=1.89" Tc=11.8 min UI Adjusted CN=63 Runoff=0.61 cfs 0.036 of Link 6L: PDA 1 Inflow=4.64 cfs 0.335 of Primary=4.64 cfs 0.335 of Total Runoff Area = 1.310 ac Runoff Volume = 0.350 of Average Runoff Depth = 3.21" 54.96% Pervious = 0.720 ac 45.04% Impervious = 0.590 ac Postdev POSTDEV Type 11 24-hr 10 YR Rainfall=5.58" Prepared by {enter your company name here} Printed 3/13/2023 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 21 Summary for Subcatchment 1 S: DA 1 - Onsite Managed Runoff = 4.65 cfs @ 11.96 hrs, Volume= 0.225 af, Depth= 4.22" 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=5.58" Area (ac) CN Description 0.170 61 >75% Grass cover, Good, HSG B 0.000 55 Woods, Good, HSG B 0.470 98 0.640 88 Weighted Average 0.170 26.56% Pervious Area 0.470 73.44% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 1S: DA 1 - Onsite Managed Hydrograph _______ ■Runoff 4.65 cfs Type II 24-hr 10'YR Rainfall=5.56' Runoff Area=0.640 at - --- - Runoff Volume=0.225 of 3- Runoff Depth=4.22" Tc=5.0 min 2 CN=88 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 Time (hours) Postdev POSTDEV Type 11 24-hr 10 YR Rainfall=5.58" Prepared by {enter your company name here} Printed 3/13/2023 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 22 Summary for Subcatchment 2S: DA 1 - Offsite Managed Runoff = 0.64 cfs @ 12.04 hrs, Volume= 0.038 af, Depth= 1.97" 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=5.58" Area (ac) CN Description 0.210 61 >75% Grass cover, Good, HSG B 0.000 55 Woods, Good, HSG B ' 0.020 98 0.230 64 Weighted Average 0.210 91.30% Pervious Area 0.020 8.70% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.8 Direct Entry, Subcatchment 2S: DA 1 - Offsite Managed 07 ---'-- 0.64 O.65 I I I 0.6 I I I I I 0.55 I I I I I 0.5 I I I I I -L-L--L--1--L 0.45 I I I I I 04 I I I I I 0.35 LL 0.3 I I I I I 0.25 I I 0.2 0.15 0.1 I I I I I I -y -t 0.05 1 Hydrograph ___r--I--r-----r --r --r --i--r--r--r--r--r-7--r--r--r- I I I I I I I I I I I I I I I I I :fs I I I I I I I I I I I I I I I I I --'I,-- -- -- ; --; --I;--'I,-- -- ;T-Vpe-U-24- ' r 1-0-Y-k I I I I I I I I I I I I I I I --I, -,-- --T ----r---- -- ----rRainfiafw558` __________________________ RUndff'IAteA=0.230 alp --1--J--1--1--L--1-----1--1--1--L--1---I--1--1--L--1-- --I'I-- - - -----�dnoff:YQlumie=,'Q.O-3$_CIf_ --II--;--;-- ----IIr--III--;--hi IDet'- I I I I I I I I I I I I I I I I I --- ITd=14.8 hih- Y I I I I I I I I I I I I I I I I I I I I I I I I I I I I I -I-- -- -- --; -----I---- --;--L-----I---O+N=84- I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I y _t _♦ _F _I _I _y _� _f _I _I _I _- 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 Time (hours) ■ Runoff Postdev POSTDEV Type 11 24-hr 10 YR Rainfall=5.58" Prepared by {enter your company name here} Printed 3/13/2023 HVdroCAD@ 9.10 s/n 07054 @ 2010 HVdroCAD Software Solutions LLC Paae 23 Summary for Pond 3P: DETENTION 1 SC-740 Inflow Area = 0.870 ac, 56.32% Impervious, Inflow Depth = 3.63" for 10 YR event Inflow = 5.10 cfs @ 11.96 hrs, Volume= 0.263 of Outflow = 3.25 cfs @ 12.04 hrs, Volume= 0.248 af, Atten= 36%, Lag= 4.5 min Primary = 3.25 cfs @ 12.04 hrs, Volume= 0.248 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Peak Elev= 657.35' @ 12.04 hrs Surf.Area= 0.046 ac Storage= 0.084 of Plug -Flow detention time= 97.4 min calculated for 0.248 of (94% of inflow) Center -of -Mass det. time= 65.1 min ( 864.9 - 799.8 ) Volume Invert Avail.Storage Storage Description #1 654.00' 0.064 of 20.00'W x 100.001 x 4.33'H STONE BEDDING 0.199 of Overall - 0.038 of Embedded = 0.161 of x 40.0% Voids #2 654.83' 0.038 of StormTech SC-740 x 36 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 0.102 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' 3.5" Vert. 1 YR ORIFICE C= 0.600 #3 Device 1 657.50' 5.0' long x 2.00' rise Sharp -Crested Rectangular Weir 2 End Contraction(s) 2.7' Crest Height #4 Device 1 655.83' 10.0" Vert. Orifice/Grate C= 0.600 Primary OutFlow Max=3.23 cfs @ 12.04 hrs HW=657.33' (Free Discharge) t1=PRIMARY 24" OUTLET (Passes 3.23 cfs of 19.80 cfs potential flow) 2=1 YR ORIFICE (Orifice Controls 0.49 cfs @ 7.40 fps) 3=Sharp-Crested Rectangular Weir( Controls 0.00 cfs) =Orifice/Grate (Orifice Controls 2.74 cfs @ 5.02 fps) Postdev POSTDEV Type 11 24-hr 10 YR Rainfall=5.581r Prepared by {enter your company name here} Printed 3/13/2023 HydroCAD® 9.10 s/n 07054 ©2010 HydroCAD Software Solutions LLC Page 24 Pond 3P: DETENTION 1 SC-740 Hydrograph I I I I I I I I I I I I I I I I Inflow 5.10 cfs j Primary I'r1floW ;Area=0 87!0 'lac 5 P06rk_=I�eV= I I I I I I I I I I I I I I I I I I I I I I 4 I I I I I I I I I I I I I Storage:0L0841 of I I I I I I I I I I I I I I I 3.25 cfs -'---------' --'------' --'------'---------' -- --I-- I I I I I I I I I I I I I I I I I I 3 i I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 2 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I i I I I I I I I I I I I I I i I I I I I I I I I I I I I I I I I I I I I I I I 659 658 a a 657 c 0 m v w 656 655 654 r 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 Time (hours) Pond 3P: DETENTION 1 SC-740 Stage -Discharge Discharge (cfs) ❑ Primary POSTDEV Prepared by {enter your company name here} Postdev Type 11 24-hr 10 YR Rainfall=5.581r Printed 3/13/2023 Pond 3P: DETENTION 1 SC-740 i l i i l i i i i i i l i i T i i i i i i StcrmTech SC-740 STONE 654 .f+-. 0 0.005 0.01 0.015 Storage (acre-feet) 0 Storage Postdev POSTDEV Type 11 24-hr 10 YR Rainfall=5.58" Prepared by {enter your company name here} Printed 3/13/2023 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 26 Summary for Subcatchment 4S: DA 1 - Onsite Unmanaged Runoff = 1.13 cfs @ 11.96 hrs, Volume= 0.051 af, Depth= 2.93" 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=5.58" Area (ac) CN Description 0.080 98 0.130 61 >75% Grass cover, Good, HSG B 0.210 75 Weighted Average 0.130 61.90% Pervious Area 0.080 38.10% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 4S: DA 1 - Onsite Unmanaged Hydrograph 1.13 cfs ❑ Runaf Type II 24-hr 10 Yk 1 ____________i Rainfall=5.58" Runoff Area=0.210 ad Runoff Volume=0.051 of Runoff Depth=2.93" LL Tc=5.0 min CN=75 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 Time (hours) Postdev POSTDEV Type 11 24-hr 10 YR Rainfall=5.58" Prepared by {enter your company name here} Printed 3/13/2023 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 27 Summary for Subcatchment 5S: DA 7 - Mite Unmanaged Runoff = 0.61 cfs @ 12.04 hrs, Volume= 0.036 af, Depth= 1.89" 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=5.58" Area (ac) CN Description ` 0.210 61 0.020 98 Unconnected pavement, HSG B 0.230 64 Weighted Average, UI Adjusted CN = 63 0.210 91.30% Pervious Area 0.020 8.70% Impervious Area 0.020 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (f /sec) (cfs) 11.8 Direct Entry, Subcatchment 5S: DA 7 - Mite Unmanaged Hydrograph 1 --r-1--T-- 11--T--T--r I I T--T --T - -r I I T--T--T-T- 0.65 1 0.61 cfS = -TXP 1111124-hr '1011,Yt 0.8 --I-- �----I- --I-- �-- I- I- I- 1- I- I- 0.55 1 1 1 1 1 1i 1i r I�� -- J--J----- -1-- 1-- -- -1----1--1--�Rainfa[17* 581__ I 6.5 - -- --;--� --11-- --;-- -- --11---11--Rditff'At0A--0L.23aat- 1 1 1 1 1 1 1 1 1 1 0.45 __- __1 Off VQ1t4{hp#0.0- 0 fJ{ .-- ;--;------------ ------I�unOff 111Depth:;1.89, 035 35 1 1 1 � 1 1 1 1 1 1 1 1 1 --I---1-- �-- 1 --I-- I-- I-- I --I --I---1-- I-- I -- I --1---1 1 1 1 1 1- IT&J-f.8_f'f LL 0.3 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 -----1---- -- --I---- -- --I-----1---- ----1---1---1-- -- -- --1-- 0.25-J--;--i-------J--i-- -------11----iUCAOjJ;Stec�_C}N=6'$ 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0.2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 _J _1 _1 1 0.15 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 0.1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 --rr--T--r---r--r-'--r__r--1--r-'--r--r-r--1--�--r--r--1__ 0.05 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 Time (hove) ■ Runoff Postdev POSTDEV Type 11 24-hr 10 YR Rainfall=5.58" Prepared by {enter your company name here} Printed 3/13/2023 HvdroCAD@ 9.10 s/n 07054 @ 2010 HvdroCAD Software Solutions LLC Paae 28 Summary for Link 6L: POA 1 Inflow Area = 1.310 ac, 45.04% Impervious, Inflow Depth = 3.07" for 10 YR event Inflow = 4.64 cfs @ 12.01 hrs, Volume= 0.335 of Primary = 4.64 cfs @ 12.01 hrs, Volume= 0.335 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Link 6L: POA 1 Hydrograph ❑ Inflow ❑ Primary 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 Time (hours) Postdev POSTDEV Type 11 24-hr 100 YR Rainfall=9.08" Prepared by {enter your company name here} Printed 3/13/2023 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 29 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 SubcatchmentlS: DA 1 - Onsite Managed Runoff Area=0.640 ac 73.44% Impervious Runoff Depth=7.63" Tc=5.0 min CN=88 Runoff=8.07 cfs 0.407 of Subcatchment2S: DA 1 - Offsite Managed Runoff Area=0.230 ac 8.70% Impervious Runoff Depth=4.66" Tc=11.8 min CN=64 Runoff=1.54 cfs 0.089 of Pond 3P: DETENTION 1 SC-740 Peak Elev=657.96' Storage=0.096 of Inflow=9.24 cfs 0.496 of Outflow=9.11 cfs 0.481 of Subcatchment4S: DA 1 - Onsite Runoff Area=0.210 ac 38.10% Impervious Runoff Depth=6.03" Tc=5.0 min CN=75 Runoff=2.25 cfs 0.105 of Subcatchment5S: DA 1 - Offsite Unmanaged Runoff Area=0.230 ac 8.70% Impervious Runoff Depth=4.54" Tc=11.8 min UI Adjusted CN=63 Runoff=1.50 cfs 0.087 of Link 6L: PDA 1 Inflow=12.56 cfs 0.673 of Primary=12.56 cfs 0.673 of Total Runoff Area = 1.310 ac Runoff Volume = 0.688 of Average Runoff Depth = 6.31" 54.96% Pervious = 0.720 ac 45.04% Impervious = 0.590 ac Postdev POSTDEV Type 11 24-hr 100 YR Rainfall=9.08" Prepared by {enter your company name here} Printed 3/13/2023 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 30 Summary for Subcatchment 1 S: DA 1 - Onsite Managed Runoff = 8.07 cfs @ 11.96 hrs, Volume= 0.407 af, Depth= 7.63" 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=9.08" Area (ac) CN Description 0.170 61 >75% Grass cover, Good, HSG B 0.000 55 Woods, Good, HSG B ' 0.470 98 0.640 88 Weighted Average 0.170 26.56% Pervious Area 0.470 73.44% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 1S: DA 1 - Onsite Managed s I 8.07 _ 8 I I I I I I I I I I I I I I I I 6 I I I I I I I I 5 3 I I I I Q I I I I I LL I I I I I I I I I 3 I I I I I I I I I 2 I I I I I I I I I I I I I I I Hydrograph ]� _ _I_ _ �I _ ❑ Runoff I I I I I I I Type II 24-hr 100 YR Rainfall=9.08" I I I I I I I Runoff Area=0.640 ac I I I I I I I i__)Iunoff Volume=0.407 of I I I I I I I Runoff Depth=7.63" I I I I I I I I I I I Tc=5.0 min I I I I I I I I I I I CN=8 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 Time (hours) Postdev POSTDEV Type 11 24-hr 100 YR Rainfall=9.08" Prepared by {enter your company name here} Printed 3/13/2023 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 31 Summary for Subcatchment 2S: DA 1 - Offsite Managed Runoff = 1.54 cfs @ 12.04 hrs, Volume= 0.089 af, Depth= 4.66" 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=9.08" Area (ac) CN Description 0.210 61 >75% Grass cover, Good, HSG B 0.000 55 Woods, Good, HSG B ' 0.020 98 0.230 64 Weighted Average 0.210 91.30% Pervious Area 0.020 8.70% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.8 Direct Entry, Subcatchment 2S: DA 1 - Offsite Managed Hydrograph 1.54 cfs Type 'II 24-hr 100 Yk Rainfall=9.06' Runoff Area=0.230 at ---- Runoff Volume=0.089 of Runoff Depth=4.66" Tc=11.8 min CN=64 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 Time (hours) ❑ Runaff Postdev POSTDEV Type 11 24-hr 100 YR Rainfall=9.08" Prepared by {enter your company name here} Printed 3/13/2023 HvdroCAD@ 9.10 s/n 07054 @ 2010 HvdroCAD Software Solutions LLC Paae 32 Summary for Pond 3P: DETENTION 1 SC-740 Inflow Area = 0.870 ac, 56.32% Impervious, Inflow Depth = 6.84" for 100 YR event Inflow = 9.24 cfs @ 11.96 hrs, Volume= 0.496 of Outflow = 9.11 cfs @ 11.97 hrs, Volume= 0.481 af, Atten= 1 %, Lag= 0.7 min Primary = 9.11 cfs @ 11.97 hrs, Volume= 0.481 of Routing by Stor-Ind method, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Peak Elev= 657.96' @ 11.97 hrs Surf.Area= 0.046 ac Storage= 0.096 of Plug -Flow detention time= 70.2 min calculated for 0.481 of (97% of inflow) Center -of -Mass det. time= 51.2 min ( 835.8 - 784.6 ) Volume Invert Avail.Storage Storage Description #1 654.00' 0.064 of 20.00'W x 100.001 x 4.33'H STONE BEDDING 0.199 of Overall - 0.038 of Embedded = 0.161 of x 40.0% Voids #2 654.83' 0.038 of StormTech SC-740 x 36 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 0.102 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' 3.5" Vert. 1 YR ORIFICE C= 0.600 #3 Device 1 657.50' 5.0' long x 2.00' rise Sharp -Crested Rectangular Weir 2 End Contraction(s) 2.7' Crest Height #4 Device 1 655.83' 10.0" Vert. Orifice/Grate C= 0.600 Primary OutFlow Max=9.05 cfs @ 11.97 hrs HW=657.96' (Free Discharge) t1=PRIMARY 24" OUTLET (Passes 9.05 cfs of 23.76 cfs potential flow) 2=1 YR ORIFICE (Orifice Controls 0.56 cfs @ 8.31 fps) 3=Sharp-Crested Rectangular Weir(Weir Controls 5.06 cfs @ 2.26 fps) =Orifice/Grate (Orifice Controls 3.43 cfs @ 6.30 fps) Postdev POSTDEV Type 11 24-hr 100 YR Rainfall=9.08" Prepared by {enter your company name here} Printed 3/13/2023 HydroCAD® 9.10 s/n 07054 ©2010 HydroCAD Software Solutions LLC Page 33 Pond 3P: DETENTION 1 SC-740 Hydrograph �i�12C S--Ili l�r ___TI e� 10 ��O lay ■Inflow ip � I ■ Primary - --r-,-1--,-nlow;Aj ,--,-- r--I 9_P_J0I _a_1lI k__ FLrI _IeI�I VJyI =01yI 57I .9LrI _6__I�I ' a _4 _y _y _T _r __y__7 _ torage L086a ---=--:1-__ _ I I I I I I I I I I I I I I V , LL , 4- 3- 2- 659 658 u v 657 c 0 m m w 656 655 654 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 Time (hours) Pond 3P: DETENTION 1 SC-740 Stage -Discharge Discharge (cfs) ❑ Primary POSTDEV Prepared by {enter your company name here} Postdev Type 11 24-hr 100 YR Rainfall=9.08" Printed 3/13/2023 Pond 3P: DETENTION 1 SC-740 i l i i l i i i i i i l i i T i i i i i i StcrmTech SC-740 STONE 654 .f+-. 0 0.005 0.01 0.015 Storage (acre-feet) ■ Storage Postdev POSTDEV Type 11 24-hr 100 YR Rainfall=9.08" Prepared by {enter your company name here} Printed 3/13/2023 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 35 Summary for Subcatchment 4S: DA 1 - Onsite Unmanaged Runoff = 2.25 cfs @ 11.96 hrs, Volume= 0.105 af, Depth= 6.03" 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=9.08" Area (ac) CN Description 0.080 98 0.130 61 >75% Grass cover, Good, HSG B 0.210 75 Weighted Average 0.130 61.90% Pervious Area 0.080 38.10% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 4S: DA 1 - Onsite Unmanaged Hydrograph 2.25 CfS ❑ Runaf Type II 24-hr 100 Yk Rainfall=9.08" Runoff Area=0.210 ad Runoff Volume=0.105 of Runoff Depth=6.03" Tc=5.0 milk CN=75 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 Time (hours) Postdev POSTDEV Type 11 24-hr 100 YR Rainfall=9.08" Prepared by {enter your company name here} Printed 3/13/2023 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 36 Summary for Subcatchment 5S: DA 1 - Offsite Unmanaged Runoff = 1.50 cfs @ 12.04 hrs, Volume= 0.087 af, Depth= 4.54" 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=9.08" Area (ac) CN Description 0.210 61 0.020 98 Unconnected pavement, HSG B 0.230 64 Weighted Average, UI Adjusted CN = 63 0.210 91.30% Pervious Area 0.020 8.70% Impervious Area 0.020 100.00% Unconnected Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.8 Direct Entry, Subcatchment 5S: DA 1 - Offsite Unmanaged Hydrograph 1.50 cfs ❑ RunaH Type II 24-hr 100 Yk Rainfall=9.06' Runoff Area=0.230 ad 1 Runoff Volume=0.087 of Runoff Depth=4.54" LL Tc=11.8 min UI Adjusted CN=63 0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 Time (hours) Postdev POSTDEV Type 11 24-hr 100 YR Rainfall=9.08" Prepared by {enter your company name here} Printed 3/13/2023 HvdroCAD® 9.10 s/n 07054 ©2010 HvdroCAD Software Solutions LLC Paae 37 Summary for Link 6L: POA 1 Inflow Area = 1.310 ac, 45.04% Impervious, Inflow Depth = 6.17" for 100 YR event Inflow = 12.56 cfs @ 11.97 hrs, Volume= 0.673 of Primary = 12.56 cfs @ 11.97 hrs, Volume= 0.673 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-48.00 hrs, dt= 0.03 hrs Link 6L: POA 1 Hydrograph 1 1 1I 1 i i i 1 1 i 1 1 1 i ■ Inflow I I I I I I I I I I I I I ■ Pllmary J 1;nfilow1 reia= 3�;a I I I I I I I I I I I I I I I I I --------------------------------------------- I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I --J--L--1--J--J--1--L--1--J--1--L--1--J--1--L--L--I-- I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I --------------------------------------------- I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 1 __7__r__I__1__1__r__r__I__1__r__r__I__1__7__r__r__I__ 1 I 1 1 I 1 1 1 I I I I I I 1 1 I I 1 1 I I I 1 I I I I I I I 1 1 I I 1 1 I I I 1 I I I I I I I I I I I I I I I I I I I I I I I I 1 1 I I 1 1 I I I I I I I 1 I I I 1 1 I I 1 1 I I I 1 1 I I--� --1-- I-- I --I --I ------ I--j -'-- I-- I- --- 1 I 1 1 I 1 1 i 1 _ 22 24 26 28 30 32 34 36 38 40 42 44 46 48 Time (hours) Channel Protection: Energy Balance Equation with Run-on for POA 1 Crozet Animal Wellness Center 1 Yr, 24 Hr Storm Comparison Q Ipost < Q t Pre, site ((RV t Pre, site)/(RV 1 Post, soc))(I.F.) + Q 1 Pre, oosrte ((RV 1 Pre, offsrte)/(RV 1 Post, oosite)) I.F. = 0.8 when LOD > 1 ac, I.F.=0.9 when LOD < 1 ac, I.F. = 1.0 when predev site is fully forested PreDev Site Fully Forested? = no I.F. = 0.9 Limits of Disturbance = 0.85 ac Onsite Offsite Pre Dev Area Onsite = 0.85 ac Pre Dev DA Offsite = 0.46 ac Post Dev Area Onsite = 0.85 ac Post Dev DA OftSite = 0.46 ac Q t Pre, site = 1.05 cfs Q t Pre, otrt, = 0.26 cfs RV t Pre, site = 0.064 of RV t Pre, otnte = 0.019 of RV t Post. site = 0.118 of RV t Post, onite = 0.019 of Regulatory Maximum Postdev 1-yr Flow Rate Max Qtpost < 0.77 cfs Achieved Design Postdev 1-yr Flow Rate Design Qipost = 0.71 cts Energy Balance Equation Compliance Check: Achieved Notes: L The assumption in the calculation above is that the site equals the land -disturbing activity(LDA). The definition for "site" is not clearly defined in the regulations, but LDAs are defined as regulated. The water quantity criteria are applied to the site as per the regulations. 2. This site discharges to an existing cahnnet. Since postdevelopment runoff to this outfall meets the energy balance equation, Channel Protection Requirements per 9VAC25-870-66-B.3.a are met, and channel protection requirements are satisfied. Flood Protection: Peak Flow Rate to Existing Channel for POA 1 Crozet Animal Wellness Center 10 Yr, 24 Hr Storm Comparison Regulatory Maximum 10-yr Flow Rate Qropm = Max QroPost = 4.64 cfs Achieved Design Postdev 10-yr Flow Rate Design Qtopost = 4.64 cfs Flood Protection Compliance Check: Achieved ' Notes: 1. This site discharges into an existing channel. The 10-yr flow rate is reduced which meets the energy balance equation and the flood protection requirements in 9VAC25-870-66.0 Crozet Animal Wellness Center Time of Concentration Calculations - Predev 1 100 ft overland flow 10.0% slope 0.35 C-value 9.2 min Seelye Chart 230 ft s. c. flow 10.0% slope 1.5 fps velocity 2.6 min. NEH Figure 15-4 00 ft swale height min. Kirpich Chart 11.8 min. 100 ft overland flow 200 ft s. c. flow -field swale Crozet Animal Wellness Center Time of Concentration Calculations - Postdev 11.0% slope 11.5% slope 0.35 C-value 1.6 fps velocity height 9.7 min Seelye Chart 2.1 min. NEH Figure 15-4 min. Kirpich Chart 11.8 min. I 35 30 Roved V q z 25 c .e 300 or Bore W T o 20 N 200 Soil .. \ Poor W ~ z Grass s i F �Surfate Or i z 4 6 usgs ri • 0.5 W y 0 15 i 90 \ 20 `r)/ a. BO Dense Grass \ a O 70 e C = in 0 cc 50 20 a z 61) u U 40 c U S co 30 9 W 2 J B 20 7 10 6 I OVERLAND FLOW TIME i (Seelye Chan) Source: Data Book for Civil Eneineers. E.E. Seelye Plau 5-1 i Y m 1992 TRAVEL TIME FOR CHANNEL FLOW (Kirpich Chart) N (feet) GOO Tt (min.) 200 00 100 (feet) 10000 txe�p 50 )e — so 75000 Reis: o a (1) For use with natural chsnnels; Yse g lU (2) For {caved chemmis, mlti Ply d 1000 n 10 Tt by 0.2 9 g 5 ' Soo 5 too I I TIME OF CONCENTRATION OF SMALL DRAINAGE BASINS Source: VDOT V-13 Plate 5-3 Crozet Animal Wellnes Center LD-204 Stormwater Inlet Computations Inlets on Grade Only Sag Inlets Only `v r O E E _ m E y E y a y U H E .. a y a i a y z U U H m 0 elo o M❑ U 2 m 1 2 3 4 5 6 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 (ft) (so I..) (iNhr) (cfs) (cfs) (cfs) ('f) ('f) Cr) (ft) (ft) (cfs) (cfs) (ft) (ft) (ft) A4 DI-38 6 29,855 0.69 0.80 0.55 5.2 2.83 2.83 0.015 0.02 0.04 0.01 0.254 0.5 0.508 5.918 6.2 3.39 3.39 0.015 0.287 0.5 0.574 6.332 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