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WPO201900043 Calculations 2020-08-06
AutoZone COUNTY OF ALBEMARLE, VIRGINIA VSMP DESIGN CALCULATIONS & NARRATIVE JULY 16, 2019 REVISED: JULY 27, 2020 .•06000 s TIMMONS GROUP YOUR VISION ACHIEVED THROUGH OURS. Prepared by: Craig Kotarski, PE Timmons Group 608 Preston Ave, Suite 200 Charlottesville, VA 22903 434.327.1688 v Q U CRAIG W. J. KO'CAmsm Lie, No. 0402048507 7/27/2020 APPROVED by the Albemarle County Commun S/ 0 6/ 2 pDepartment Date File WP0201900043 Table of Contents Section Title Project Narrative 2 Pipe and Inlet Computations Virginia Runoff Reduction Method Worksheet Summary 4 Pre & Post -Developed HydroCAD Calculations Nutrient Credit Availability Letter Project Narrative: This project includes the construction of a new building, parking area, utilities, and associated site work. Limits of clearing and grading area is 1.33 acres. Water Quality Compliance: The disturbed area of 1.33 acres was used for the water quality analysis. In the proposed condition there will be 0.46 acres of managed turf and 0.87 acres of impervious cover. Ir the future development, there will be a total of 0.39 acres of managed turf and 0.94 acres of impervious cover. The 0.54 lb/yr of phosphorus removal required based on future development will be achieved through the purchase of nutrient credits. Water Quantity Compliance: Stormwater Quantity requirements for analysis point 1 will utilize a CMP detention system located within the parking area to meet all stormwater quantity requirements for this drainage area. Energy balance and channel protection for this analysis point are in compliance with all requirements. FORM lD 2M SHEET OF ROME PROJECT AUI 0Z DESIGNER: FF DATE 7a7=20 CHECKED: UNITS:NGUSH MLEi InNb "ly 202 DF3B 4 O.IW ow0095 tlRIGHT 0061 035 0022G 0.118 6 0] 00256 2.563 20110 0]]<3 00833 32539 0956 338 0.1410 01661 1012 60110 OW9 LW] O<T2 OCCO 2.1]8 2M DHB 4" 0220 081 01]62 PWGHT 0.179 6 0] 00195 <.148 2" 04822 00933 42718 09M 353 0.1471 0158C 4 4" 0.915 0952 06]8 0034 2.502 302 DIAC 6 W0 0 6 107U.offl�'. B UU 0"RIG 0250 074 0185 AM1nNW. 0.185 6 1 00218 8M6 2000 02486 00833 38211 3AB AM1nNW. 016 0A0A0172� OIA 001<5 12 32G6 l]63 T>BOfl 402 DI-3B 40'.p 0220 08] 0.191C0"RIGH 0.191 6 W 00208 1255 2000 Otl 00833 4W 8 0936 }50 0.1058 0.1569 5081 6000 0]8] 0936 0]I] INLETSOFT BY ENSOFTEC DATE: 727/2020 LD-229 PROJECT: AtAo.. STORM SEWER DESIGN COMPUTATIONS LOCATION: Chadotlesvllle COUNTY: ChadotlesNlle STORM FREQUENCY 10 NOAA STATION: Desigmd by: AF Checked by: UNITS ENGLISH PIPE NO. FROM POINT TOPOM GRAIN. AREA 'A' Acre 3 RUNOFF COEFF, C. 4 CA TOTAL INLET TIME MmWes ] RAIN FALL INHr 8 RUNOFF INVENTELEVATIONS LENGTH oflhe FL 12 SLOPE Ft/Ft 13 SIZE (Din Or SpW[dw) Irt 14 SHAPE Ninnber of Npes CeleciN CFS IS Friction NORMAL FLOW FLOW Slope Dep1Aof A of Hm V. En TIME Flow,dn Fl.,An REMARKS FtNt Ft SgFI Ft FN9ec Ft Sx. 16 17IS MCRE-ACCUM- MENT 5 UL = 6 "wnd CFS TWWQ CFS 9 UPPER END 10 LOWER END 11 REFERENCE 1 STA. REFERENCE 2 STA. 101 102 100 OW 0W 008 5.17 649 OW 687 45178 45144 62.81 OW541 21 O.W. 1 1165 O002W 0.97 136 047 SIA 136 1245 103 SWM IN O W 0 W O W 5 W O W 000 687 45210 451,88 36.98 O W598 18 Cimw. 1 8.80 0,W380 I W 125 044 551 147 668 201 202 SWM D.17 069 0.12 037 552 638 OW 268 45563 45542 2127 OW98] 12 Cl.w. 1 384 OW510 062 051 028 528 105 403 203 20d 2W OW OW 025 5.16 649 OW 1% 456W 45563 IW.0 001W] 12 Cimw. 1 387 00001 0.50 039 025 493 0.88 2153 205 206 20d D22 0.81 D.18 0.Is 5W 654 OW 116 45]50 456,80 36.10 001939 12 Cl.w. 1 538 OWIW 032 021 0.18 56] 0.98 6W 301 302 SWM D25 0]4 D.19 0.19 5W 654 O00 121 456 T2 454.83 15369 002531 ¢ CireWar I 6.14 OWIW 030 020 0.17 AN 0.88 2528 001 d02 SWM D22 0.87 D.19 0.19 5W 654 O00 125 45]25 456.16 24.14 004515 12 CireWar 1 S2D OWIIO 026 0.17 0.15 155 1.15 320 RDI RD 12W I D.16 0% D.14 0.14 5W 654 OW 094 1 45875 1 451.99 I W.SS 10018881 8 I CireWar I I I 1.SD 10 W50 0M 0.18 0.17 5M OA 975 LD-MT PROJECT: iIi twone DESIGNED BY: AF HYDRAULIC GRADE LINE ANALYSIS Checked: INCIDENCE PROBABILITY 10 Yea INIfT OR JUNCTION STA. INVERT EL. OUTFLOW PIPE DEPTH OF FLOW OIRFL1hV PIPE OUTLET WATER SURFACE ELEV. OIA PIPE D. .. DESIGN TISCH. Go CF=MS IENGTH PIPE Ln FNM FRICTION SLOPE,S (FTe� MM FRICTION LOW HI FRM JUNCTION LOW SURFACE FLOW AJL HI 13 HI FNA InW Inlet T, oI MH Sha qml .5 cp INN µN HI H Surta¢ E. YIN FVM (FM) EkvAi- APPRO%. Vo Cmtr. HoF FNA Mi , Hi (Expn) 0WIJM. SKEW A,Ia K Pad H FRM Sun HL FRM (1) 2 3 4) 5) 6) (n (8) 9) (10) (11) 12 13) 14) 15) 16) 18 17) (18) (19) 100 452.840 1w 451.440 1.75 452.840 21 6.870 62.81 0.00197 OA23 5.044 0.099 5.508 0.471 0.165 0.0 0.00 0.000 0.2M 0.000 0.264 YES 0.132 0.255 453.095 459.500 O.K. Sm 451.880 1.50 453.095 18 6.870 36.78 0.00381 0.140 5.W8 0.118 5.283 0.433 0.152 0.0 0.00 0.000 0.269 0.000 0.269 YES 0.135 0.275 453.370 461.800 O.K. 202 455.420 1.00 456.220 12 2.684 21.27 0.00506 DADS 5.283 0.108 4.934 0.378 0.132 0.0 0.00 0.000 0.241 0.748 0.313 YES 0.156 0.284 456.484 4 .790 O.K. 204 455.630 1.00 456.484 12 1.938 106.22 0.00284 0.280 4.934 0.095 5.466 0.464 0.162 0.0 0.00 0.000 0.257 0.000 0.259 YES 0.128 0.408 457.200 463.940 O.K. 206 4%.800 1.00 457.600 12 1.164 36.10 0.00095 0.034 5.466 0.116 0.000 0.000 0.000 0.0 0.00 0.000 0.116 1.164 0.151 YES 0.075 0.110 457.816 463.940 O.K. 302 454.830 1.00 455.630 12 1.210 153.69 0.00103 0.158 6.081 0.144e 0.000 0.0 0.00 0.000 0.144 1.210 0.189 YES 0.093 0.251 459.021 463.700 O.K. 402 456.160 1.00 456.960 12 1.250 24.14 0.00110 0.026 9.548 0.221 0.000 0.0 0.00 0.000 0.221 1.250 0.288 YES 0.144 0.17O 457.514 462.550 O.K. RD 457.790 0.67 458.323 8 0.942 5084 000541 0275 5.217 0.108 0.000 0.0 0.00 0.000 0.106 0000 OA06 YES 0.053 0.328 459.092 464100 O.K. Virginia Runoff Reduction Method Wofthest DEQ Virginia Runoff Reduction Method Re -Development Compliance Spreadsheet - Version 3.0 BMP Design Specifications List: 2011 Stds & Specs Site Summary Total Rainfall (in): 43 Total Disturbed Acreage: 1.33 Site Land Cover Summary Pre-ReDevelopment Land Cover (acres) Asoils BSolls [Soils DSoils Totals %of Total Forest/Open (acres) 0.00 0.00 0.00 0.00 0.00 0 Managed Turf(acres) 0.00 0.00 0.00 0.46 0.46 35 Impervious Cover (acres) 0.00 0.00 0.00 0.87 0.87 65 1.33 100 Post-ReDevelopment Land Cover (acres) Asoils BSoils CSGIls DSoils Totals %of Total Forest/Open (acres) 0.00 0.00 0.00 0.00 0.00 0 Managed Turf(acres) 1 0.00 0.00 0.00 0.39 0.39 29 Impervious Cover (acres) 1 0.00 0.00 0.00 0.94 0.94 71 1.33 100 Site Tv and Land Cover Nutrient Loads Final Port -Development Post- poff� Adjusted Pre- (Post-ReDevelopment ReDevelopment Development ReDevelopment w un rvious &Ne pe ) (New impervious) Site Rv 0.74 0.73 0.95 0.73 Treatment Volume(ft) 3,596 3,354 241 3,354 TP Load(lb/yr) 2.26 2.11 0.15 2.11 Total TP Load Reduction Required (lb/yr) 0.54 0.42 0.12 Final Post -Development Load (Post-ReDevelopment & New Impervious) Pre- ReDevelopment TN Load (Ib/yr) 16.16 15.36 Pre- ReDevelopment Final Post -Development Post-ReDevelopment TP TP Load per acre TP Load per acre Load per acre (lb/acre/yr) (lb/acre/yr) (lb/acre/yr) 1.67 1.70 1.67 Summary Print Virginia Runoff Reduction Method] Woftheet Site Compliance Summary Maximum% Reduction Required Below 20% Pre-ReDevelopment Load] Total Runoff Volume Reduction (k') 0 Total TP Load Reduction Achieved (lb/yr) 0.00 Total TN Load Reduction Achieved (lb/yr) 0.00 Remaining Post Development TP Load 2.26 (lb/yr) Remaining TP Load Reduction (lb/yr) 0.54 Required Summary Print Virginia Runoff Retlucfion Method Woftheet Drainage Area Summary D.A. A D.A. B D.A. C D.A. D D.A. E Total Forest/Open (acres) 0.00 0.00 0.00 0.00 0.00 0.00 Managed Turf(acros) 0.00 0.00 0.00 0.00 0.00 0.00 Impervious Corer(acres) 0.00 0.00 0.00 0.00 0.00 0.00 Total Area (acres) 0.00 0.00 0.00 0.00 0.00 0.00 Drainage Area Compliance Summary DA. A D.A. B DA. C D.A. D D.A. E Total TP Load Reduced (lb/yr) 1 0.00 0.00 1 0.00 1 0.00 0.00 0.00 TN Load Reduced (lb/yr) 1 0.00 0.00 1 0.00 1 0.00 0.00 0.00 Summary Print Virginia Runoff Reduction Method Worksheet ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ Runoff Volume and CN Calculations 1-year storm 2-year storm 10-year storm Target Rainfall Event (in) I 0.00 0.00 0.00 Drainage Areas RV & CN Drainage Area A Drainage Area R Drainage Area C Drainage Area D Drainage Area E CN 0 0 0 0 0 RR (fta) 0 0 0 0 0 I -year return period RV wa RR(wzin) 0.00 0.00 0.00 0.00 0.00 RV w RR(wiAn( 0.00 0.00 0.00 0.00 0.00 CN ad(urted 0 0 0 0 0 2-year return period RVwo RR (wzin) 0.00 0.00 0.00 0.00 0.00 RV w RR (wzin( 0.00 0.00 0.00 0.00 0.00 CN adjusted 0 0 0 0 0 10-year return period RV wo RR(Zin) 0.00 0.00 0.00 0.00 0.00 RV w RR(wzin( 0.00 0.00 0.00 0.00 0.00 CN adjusted 0 0 0 0 0 Summary Print PRE ONSITE POST AREA 1-D SWM A 2S ANALYSIS PT 1 POST AREA 1-U POST AREA 1-D SWM A � FUT (FUTURE) ANALYSIS PT 1 4S POST AREA 1-U (FUTURE) S4 Reach Aon Llnk AutoZone SWM Analysis Pre & Post Prepared by Timmons Group Area Listing (selected nodes) Area CN Description (acres) (subcatchment-numbers) 0.460 84 50-75% Grass cover, Fair, HSG D (1S) 0.870 80 >75% Grass cover, Good, HSG D (2S, 3S, 4S, 5S) 2.660 98 Paved parking, HSG D (1S, 2S, 3S, 4S, 5S) 3.990 92 TOTAL AREA Printed 11/12/2019 AutoZone SWM Analysis Pre & Post Prepared by Timmons Group Printed 11/12/2019 Soil Listing (selected nodes) Area Soil Subcatchment (acres) Group Numbers 0.000 HSG A 0.000 HSG B 0.000 HSG C 3.990 HSG D 0.000 Other 3.990 1S, 2S, 3S, 4S, 5S TOTAL AREA AutoZone SWM Analysis Pre & Post Prepared by Timmons Group Printed 11/12/2019 Ground Covers (selected nodes) HSG-A HSG-B HSG-C HSG-D Other Total Ground Subcatchment (acres) (acres) (acres) (acres) (acres) (acres) Cover Numbers 0.000 0.000 0.000 0.460 0.000 0.460 50-75% Grass cover, Fair 1S 0.000 0.000 0.000 0.870 0.000 0.870 >75% Grass cover, Good 2S, 3S, 4S, 5S 0.000 0.000 0.000 2.660 0.000 2.660 Paved parking 1S, 2S, 3S, 4S, 5S 0.000 0.000 0.000 3.990 0.000 3.990 TOTAL AREA AutoZone SWM Analysis Pre & Post Type 11 24-hr 1-YR Rainfall=3.03" Prepared by Timmons Group Printed 11/12/2019 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Paoe 5 Time span=0.00-30.00 hrs, dt=0.05 hrs, 601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment1S: PRE ONSITE Runoff Area=1.330 ac 65.41 % Impervious Runoff Depth=2.28" Tc=6.0 min CN=93 Runoff=4.94 cfs 0.253 of Subcatchment2S:POSTAREAI-U Runoff Area=0.400ac 17.50%Impervious Runoff Depth=1.47" Tc=6.0 min CN=83 Runoff=1.01 cfs 0.049 of Subcatchment3S:POSTAREAI-D Runoff Area=0.930ac 83.87%Impervious Runoff Depth=2.48" Tc=6.0 min CN=95 Runoff=3.65 cfs 0.192 of Subcatchment4S:POSTAREAI-U Runoff Area=0.370ac 18.92%Impervious Runoff Depth=1.47" Tc=6.0 min CN=83 Runoff=0.94 cfs 0.045 of Subcatchment5S:POSTAREAI-D Runoff Area=0.960ac 90.63%Impervious Runoff Depth=2.58" Tc=6.0 min CN=96 Runoff=3.86 cfs 0.207 of Pond 1 P: SWM A Peak Elev=454.78' Storage=0.017 of Inflow=3.65 cfs 0.192 of Outflow=2.70 cfs 0.192 of Pond 2P: SWM A Peak Elev=454.98' Storage=0.019 of Inflow=3.86 cfs 0.207 of Outflow=2.81 cfs 0.207 of Link 1: ANALYSISPT 1 Inflow=3.62 cfs 0.241 of Primary=3.62 cfs 0.241 of Link FLIT: ANALYSISPT 1 Inflow=3.66 cfs 0.252 of Primary=3.66 cfs 0.252 of Total Runoff Area = 3.990 ac Runoff Volume = 0.746 of Average Runoff Depth = 2.24" 33.33% Pervious = 1.330 ac 66.67% Impervious = 2.660 ac AutoZone SWM Analysis Pre & Post Type 11 24-hr 1-YR Rainfall=3.03" Prepared by Timmons Group Printed 11/12/2019 HydroCAD010.00-20 s/n 06538 @ 2017 HydroCAD Software Solutions LLC Page 6 Summary for Subcatchment 1S: PRE ONSITE Runoff = 4.94 cfs @ 11.96 hrs, Volume= 0.253 af, Depth= 2.28" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 1-YR Rainfall=3.03" Area (ac) CN Description 0.460 84 50-75% Grass cover, Fair, HSG D 0.870 98 Paved parking, HSG D 1.330 93 Weighted Average 0.460 34.59% Pervious Area 0.870 65.41% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 1S: PRE ONSITE 5 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 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 I I I I I I I I I N I I I I I I I I I ------------------ I I I I I I I I I v 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 LL 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 i I I I I I I I I ■ RunoH ---I-----I--I----I-----------I--I - 1I I I I - i I I I I I I Type 11 24yhr I I I I I I I I I I I I 1-YR RainfallT3.03'" I I I I I I I I I I I I Runbff ArdA=1.330 'ad I I I I I I I I I I I I I I : R.Ungffll: VOI:uine=110.-2$31'l a ---------------- III Fkunoff bu,pihF2.28'' I I I I I I I l l l l l l l Tq�&O:1 rhih I I I I I I I I I I I I I I IVY _Tfi I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 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 I I I I I I I I I I I I I I I I I I I 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) AutoZone SWM Analysis Pre & Post Type 11 24-hr 1-YR Rainfall=3.03" Prepared by Timmons Group Printed 11/12/2019 HydroCAD® 10.00-20 s/n 06538 @ 2017 HydroCAD Software Solutions LLC Page 7 Summary for Subcatchment 2S: POST AREA 1-U Runoff = 1.01 cfs @ 11.97 hrs, Volume= 0.049 af, Depth= 1.47" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 1-YR Rainfall=3.03" Area (ac) CN Description 0.330 80 >75% Grass cover, Good, HSG D 0.070 98 Paved parking, HSG D 0.400 83 Weighted Average 0.330 82.50% Pervious Area 0.070 17.50% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 2S: POST AREA 1-1.11 Hydrograph ❑ Runaff Type II 24-hr 1-YR Rainfall=3.03" Runoff Area=0.400 ac Runoff Volume=0.049 of Runoff Depth=1.47" Tc=6.0 min CN=83 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) AutoZone SWM Analysis Pre & Post Type 11 24-hr 1-YR Rainfall=3.03" Prepared by Timmons Group Printed 11/12/2019 HydroCAD010.00-20 s/n 06538 @ 2017 HydroCAD Software Solutions LLC Page 8 Summary for Subcatchment 3S: POST AREA 1-D Runoff = 3.65 cfs @ 11.96 hrs, Volume= 0.192 af, Depth= 2.48" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 1-YR Rainfall=3.03" Area (ac) CN Description 0.780 98 Paved parking, HSG D 0.150 80 >75% Grass cover, Good, HSG D 0.930 95 Weighted Average 0.150 16.13% Pervious Area 0.780 83.87% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 3S: POST AREA 1-D -7----- ----- ------ q I I I I I I I I I I I I I I I I I I C I I I I I I I I I I I I I I I I I I I I I I I I I 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 I I I I I I I I I I I I I I I I I I I I I I I I N I I I I I I I I I I 3 2 0 I I I I LL I I I I I I I I I I I I I I I I I I I I I 1 I 1 I I I I I I I I I I I I I I Hydrograph --------------- I I I I I I I I I I I I I � I � I � I � I I I I I I ■ Runoff I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I type II 24thr -1—YR RalnfaH;:3.0Y I I I I I I I I I I I I I I I Rdnbff Arhzl=0.930 ad I I I I I I I I I I I I I R.Ungff'11 V10l;uin041$2j of AinW-NP#11�4d �8'�- I I I I I Tc-6�0� nil I I I I I I tI 1 1 1 1 1 1 1 1 1 1 1 �YV 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 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 I I I I I I I I I I 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 I I I I I 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) AutoZone SWM Analysis Pre & Post Type 11 24-hr 1-YR Rainfall=3.03" Prepared by Timmons Group Printed 11/12/2019 HydroCAD® 10.00-20 s/n 06538 @ 2017 HydroCAD Software Solutions LLC Page 9 Summary for Subcatchment 4S: POST AREA 1-U (FUTURE) Runoff = 0.94 cfs @ 11.97 hrs, Volume= 0.045 af, Depth= 1.47" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 1-YR Rainfall=3.03" Area (ac) CN Description 0.300 80 >75% Grass cover, Good, HSG D 0.070 98 Paved parking, HSG D 0.370 83 Weighted Average 0.300 81.08% Pervious Area 0.070 18.92% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 4S: POST AREA 1-U (FUTURE) Hydrograph _I_ _I__i -r- i__r_i _-__I ---- r-i--r-i _ i __I ---- r--__r_-_ i _i--r-r- i__I__i -r- ❑Runoff 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 I I I I I I I I 0.91 Lib I I I I I I I I I I I I I Type II 24-hr I I I I 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-YR Rainfall=3.03" I I I I I I I I I I I I I I I I I I I I I I I I I I I I I Runoff Area=0.370 ac I I I I I I I I I I I I Runoff Volume=0.045 of I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I Runoff Depth=1.47" I I I I I I I I I I I I i LL I I I I I I I I I I I I I Tc=6.0 min I I I I I I I I I I I I I i CN=83I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I i I I I I I I I i i i i i i I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I ( I I I I I I I I I I I I I I I I I I 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 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) AutoZone SWM Analysis Pre & Post Type 11 24-hr 1-YR Rainfall=3.03" Prepared by Timmons Group Printed 11/12/2019 HydroCAD® 10.00-20 s/n 06538 @ 2017 HydroCAD Software Solutions LLC Page 10 Summary for Subcatchment 5S: POST AREA 1-D (FUTURE) Runoff = 3.86 cfs @ 11.96 hrs, Volume= 0.207 af, Depth= 2.58" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 1-YR Rainfall=3.03" Area (ac) CN Description 0.870 98 Paved parking, HSG D 0.090 80 >75% Grass cover, Good, HSG D 0.960 96 Weighted Average 0.090 9.37% Pervious Area 0.870 90.63% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 5S: POST AREA 1-D (FUTURE) 4 I I I I I I C I I I I I I I I I I I 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 I I I I I I I I I I I I I I I I I I I I I I I I I 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 - --- -F ---I--I -- ' I I I I I LL I I I I I I I Hydrograph _ ■Runoff Type II 24-Ihr 1-YR Rainfall=3.03" Runoff Area=0.960 ac Runoff Volume=0.207 of Runoff Depth=2.58"_ I I I I I I I I I I Tc=6.0 mini CN=96 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 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 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) AutoZone SWM Analysis Pre & Post Type 11 24-hr 1-YR Rainfall=3.03" Prepared by Timmons Group Printed 11/12/2019 HydroCAD® 10.00-20 s/n 06538 @ 2017 HydroCAD Software Solutions LLC Page 11 Summary for Pond 1 P: SWM A Inflow Area = 0.930 ac, 83.87% Impervious, Inflow Depth = 2.48" for 1-YR event Inflow = 3.65 cfs @ 11.96 hrs, Volume= 0.192 of Outflow = 2.70 cfs @ 12.03 hrs, Volume= 0.192 af, Atten= 26%, Lag= 3.9 min Primary = 2.70 cfs @ 12.03 hrs, Volume= 0.192 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Peak Elev= 454.78' @ 12.03 hrs Surf.Area= 0.009 ac Storage= 0.017 of Plug -Flow detention time=1.6 min calculated for 0.192 of (100% of inflow) Center -of -Mass det. time= 1.6 min ( 781.0 - 779.3 ) Volume Invert Avail.Storage Storage Description #1 452.10' 0.038 of 66.0" Round Pipe Storage L= 70.0' S= 0.0050 T Device Routing Invert Outlet Devices #1 Primary 452.10' 15.0" Round Culvert L= 75.0' CMP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 452.10' / 451.44' S= 0.0088 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.23 sf #2 Device 1 452.10' 8.2" Vert. Orifice/Grate C= 0.600 #3 Device 1 455.35' 24.0" W x 6.0" H Vert. Orifice/Grate C= 0.600 #4 Device 1 456.40' 4.7' long Sharp -Crested Vee/Trap Weir Cv= 2.62 (C= 3.28) Primary OutFlow Max=2.66 cfs @ 12.03 hrs HW=454.72' (Free Discharge) L1=Culvert (Passes 2.66 cfs of 6.59 cfs potential flow) 2=Orifice/Grate (Orifice Controls 2.66 cfs @ 7.26 fps) 3=Orifice/Grate ( Controls 0.00 cfs) =Sharp -Crested Vee/Trap Weir( Controls 0.00 cfs) AutoZone SWM Analysis Pre & Post Type 1124-hr 1-YR Rainfall=3.03" Prepared by Timmons Group Printed 11/12/2019 Pond 1 P: SWM A Hydrograph I I I I I I 1 � I I I I I I 1 � I 1 ■ Inflow 4 s.as as ■ Primary Inflo' 'W' Are6=01.19$0 aG Okr 1111111111171, 3- 270c Stbragq=0'�; 017 of 11 1 1 11 11 11111111 11 1 2 E 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 I I I I I I I I I I I I 1 1 1 I 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 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) AutoZone SWM Analysis Pre & Post Type 11 24-hr 1-YR Rainfall=3.03" Prepared by Timmons Group Printed 11/12/2019 HydroCAD® 10.00-20 s/n 06538 @ 2017 HydroCAD Software Solutions LLC Page 13 Summary for Pond 2P: SWM A Inflow Area = 0.960 ac, 90.63% Impervious, Inflow Depth = 2.58" for 1-YR event Inflow = 3.86 cfs @ 11.96 hrs, Volume= 0.207 of Outflow = 2.81 cfs @ 12.03 hrs, Volume= 0.207 af, Atten= 27%, Lag= 4.0 min Primary = 2.81 cfs @ 12.03 hrs, Volume= 0.207 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Peak Elev= 454.98' @ 12.03 hrs Surf.Area= 0.009 ac Storage= 0.019 of Plug -Flow detention time=1.7 min calculated for 0.206 of (100% of inflow) Center -of -Mass det. time= 1.7 min ( 773.9 - 772.1 ) Volume Invert Avail.Storage Storage Description #1 452.10' 0.038 of 66.0" Round Pipe Storage L= 70.0' S= 0.0050 T Device Routing Invert Outlet Devices #1 Primary 452.10' 15.0" Round Culvert L= 75.0' CMP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 452.10' / 451.44' S= 0.0088 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.23 sf #2 Device 1 452.10' 8.2" Vert. Orifice/Grate C= 0.600 #3 Device 1 455.35' 24.0" W x 6.0" H Vert. Orifice/Grate C= 0.600 #4 Device 1 456.40' 4.7' long Sharp -Crested Vee/Trap Weir Cv= 2.62 (C= 3.28) Primary OutFlow Max=2.78 cfs @ 12.03 hrs HW=454.92' (Free Discharge) L1=Culvert (Passes 2.78 cfs of 6.91 cfs potential flow) 2=Orifice/Grate (Orifice Controls 2.78 cfs @ 7.58 fps) 3=Orifice/Grate ( Controls 0.00 cfs) =Sharp -Crested Vee/Trap Weir( Controls 0.00 cfs) AutoZone SWM Analysis Pre & Post Prepared by Timmons Group Pond 212: SWM A Type 1124-hr 1-YR Rainfall=3.03" Printed 11/12/2019 Hydrograph I I I I I I I I i I _____ ___ _____ I I � I I I � I ■ow a ■ Prima I I I I I I .ea a. I I I- � i I I -I--�- �I ; ; �____� Infl�, Inflpvlv'IlArea=0.'11960 aG IIIIIIII II III IIIIII P k lev=454'1.98' 3 e, ,_ Stbragq=0'I; 019 of i 2 LL 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 I I I I I I I I I I I I I I I I I I I 1 2 3 4 5 6 7 8 0 10 11 12 13 14 15 16 ' Time (hours) AutoZone SWM Analysis Pre & Post Type 11 24-hr 1-YR Rainfall=3.03" Prepared by Timmons Group Printed 11/12/2019 HydroCAD® 10.00-20 s/n 06538 @ 2017 HydroCAD Software Solutions LLC Page 15 Summary for Link 1: ANALYSIS PT 1 Inflow Area = 1.330 ac, 63.91 % Impervious, Inflow Depth = 2.18" for 1-YR event Inflow = 3.62 cfs @ 12.00 hrs, Volume= 0.241 of Primary = 3.62 cfs @ 12.00 hrs, Volume= 0.241 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Link 1: ANALYSIS PT 1 Hydrograph FE ]—I n—fl.—. ❑ Primary Time (hours) AutoZone SWM Analysis Pre & Post Type 11 24-hr 1-YR Rainfall=3.03" Prepared by Timmons Group Printed 11/12/2019 HydroCAD® 10.00-20 s/n 06538 @ 2017 HydroCAD Software Solutions LLC Page 16 Summary for Link FUT: ANALYSIS PT 1 Inflow Area = 1.330 ac, 70.68% Impervious, Inflow Depth = 2.27" for 1-YR event Inflow = 3.66 cfs @ 12.00 hrs, Volume= 0.252 of Primary = 3.66 cfs @ 12.00 hrs, Volume= 0.252 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Link FUT: ANALYSIS PT 1 Hydrograph ❑ Inflow ❑ Primary Time (hours) AutoZone SWM Analysis Pre & Post Type 11 24-hr 2-YR Rainfall=3.66" Prepared by Timmons Group Printed 11/12/2019 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Paae 17 Time span=0.00-30.00 hrs, dt=0.05 hrs, 601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment1S: PRE ONSITE Runoff Area=1.330 ac 65.41 % Impervious Runoff Depth=2.89" Tc=6.0 min CN=93 Runoff=6.17 cfs 0.320 of Subcatchment2S:POSTAREAI-U Runoff Area=0.400ac 17.50%Impervious Runoff Depth=1.99" Tc=6.0 min CN=83 Runoff=1.37 cfs 0.066 of Subcatchment3S:POSTAREAI-D Runoff Area=0.930ac 83.87%Impervious Runoff Depth=3.10" Tc=6.0 min CN=95 Runoff=4.50 cfs 0.240 of Subcatchment4S:POSTAREAI-U Runoff Area=0.370ac 18.92%Impervious Runoff Depth=1.99" Tc=6.0 min CN=83 Runoff=1.26 cfs 0.061 of Subcatchment5S:POSTAREAI-D Runoff Area=0.960ac 90.63%Impervious Runoff Depth=3.20" Tc=6.0 min CN=96 Runoff=4.72 cfs 0.256 of Pond 1 P: SWM A Peak Elev=455.53' Storage=0.024 of Inflow=4.50 cfs 0.240 of Outflow=3.40 cfs 0.240 of Pond 2P: SWM A Peak Elev=455.62' Storage=0.024 of Inflow=4.72 cfs 0.256 of Outflow=3.81 cfs 0.256 of Link 1: ANALYSISPT 1 Inflow=4.52 cfs 0.306 of Primary=4.52 cfs 0.306 of Link FLIT: ANALYSISPT 1 Inflow=4.97 cfs 0.318 of Primary=4.97 cfs 0.318 of Total Runoff Area = 3.990 ac Runoff Volume = 0.944 of Average Runoff Depth = 2.84" 33.33% Pervious = 1.330 ac 66.67% Impervious = 2.660 ac AutoZone SWM Analysis Pre & Post Type 11 24-hr 2-YR Rainfall=3.66" Prepared by Timmons Group Printed 11/12/2019 HydroCAD010.00-20 s/n 06538 @ 2017 HydroCAD Software Solutions LLC Page 18 Summary for Subcatchment 1S: PRE ONSITE Runoff = 6.17 cfs @ 11.96 hrs, Volume= 0.320 af, Depth= 2.89" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 2-YR Rainfall=3.66" Area (ac) CN Description 0.460 84 50-75% Grass cover, Fair, HSG D 0.870 98 Paved parking, HSG D 1.330 93 Weighted Average 0.460 34.59% Pervious Area 0.870 65.41% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 1S: PRE ONSITE I I I I I I I I I 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 I I I I I I I I I I I I I I I I I I I I I I --------------- I I I I I I I I 5 I I I I I I I I I I N 4 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 M 3 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 1 I I I I I I I I I I II I I I Hydrograph I I I I I I I I I I I � I � I � I � I I I I I I ■ Runoff 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 l l l l -' - r Type I 4-hr 2-YR Rainfall=3.66" J I I I I I I Runoff Area=1.330 ac 'lRunoff Volume=0.320 of Runoff Depth=2.89" 1 -, T ;T'c=6.0 min I CN=93 L L_1_J__ I I I I I I I__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 II I I I I I 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) AutoZone SWM Analysis Pre & Post Type 11 24-hr 2-YR Rainfall=3.66" Prepared by Timmons Group Printed 11/12/2019 HydroCAD® 10.00-20 s/n 06538 @ 2017 HydroCAD Software Solutions LLC Page 19 Summary for Subcatchment 2S: POST AREA 1-U Runoff = 1.37 cfs @ 11.97 hrs, Volume= 0.066 af, Depth= 1.99" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 2-YR Rainfall=3.66" Area (ac) CN Description 0.330 80 >75% Grass cover, Good, HSG D 0.070 98 Paved parking, HSG D 0.400 83 Weighted Average 0.330 82.50% Pervious Area 0.070 17.50% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 2S: POST AREA 1-1.11 Hydrograph I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 1.37ck I I I I I I I I I I I I I Type II 24-hr I I I I I I I I I I I I I I I I I I I I I 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-YR Rainfall=3.66" I I I I I I I I I I I I I I I Runoff Area=0.400 ac Runoff Volume=0.066 of I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I Runoff Depth=1.99" I I I I I I I I I I I I i LL I I I I I I I I I I I I I Tc=6.0 min I I I I I I I i I I I I I I i CN=83I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I i i i i i i I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 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 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) ❑ Runaff AutoZone SWM Analysis Pre & Post Type 11 24-hr 2-YR Rainfall=3.66" Prepared by Timmons Group Printed 11/12/2019 HydroCAD010.00-20 s/n 06538 @ 2017 HydroCAD Software Solutions LLC Page 20 Summary for Subcatchment 3S: POST AREA 1-D Runoff = 4.50 cfs @ 11.96 hrs, Volume= 0.240 af, Depth= 3.10" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 2-YR Rainfall=3.66" Area (ac) CN Description 0.780 98 Paved parking, HSG D 0.150 80 >75% Grass cover, Good, HSG D 0.930 95 Weighted Average 0.150 16.13% Pervious Area 0.780 83.87% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 3S: POST AREA 1-D 5 I I I I I I I I I I I I I I I 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 3 I I I I I I I I I I I I I I I I I I I I II 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 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 Hydrograph I I I I I I I I I I I I I I I ❑ Runaff a.w c�a I I I I I I I I I I I I I Type II 24ihr I IIIIII 2-YR RaiinfallT3.66" I I I I I I I I I I I I I I I I Runbff Aral=0.930 'ad RunQff'Il V;oflUm-0=O.�24-01'I-af Fkunoff bu,pihr-3.11'10'' I I I I I I I I I I I T{Ft61�' i11iri I I I I I I I I I I I hI I I tI I I I I I I I I I I I I -IVY I I I I I I I I I I I I I I I I I I I I I I I 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-T-T--I--Y-Y--I--Y-T-Y--I--Y-Y-T--Y-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 I I I I I I I I I I I I 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 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) AutoZone SWM Analysis Pre & Post Type 11 24-hr 2-YR Rainfall=3.66" Prepared by Timmons Group Printed 11/12/2019 HydroCAD010.00-20 s/n 06538 @ 2017 HydroCAD Software Solutions LLC Page 21 Summary for Subcatchment 4S: POST AREA 1-U (FUTURE) Runoff = 1.26 cfs @ 11.97 hrs, Volume= 0.061 af, Depth= 1.99" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 2-YR Rainfall=3.66" Area (ac) CN Description 0.300 80 >75% Grass cover, Good, HSG D 0.070 98 Paved parking, HSG D 0.370 83 Weighted Average 0.300 81.08% Pervious Area 0.070 18.92% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 4S: POST AREA 1-U (FUTURE) I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 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 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I LL I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I III IIIII�III�III�III Hydrograph IN Type II 24-hr 2-YR Rainfall=3.66" Runoff Area=0.370 ac Runoff Volume=0.061 of Runoff Depth=1.99" Tc=6.0 min CN=83 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) ❑ Runoff AutoZone SWM Analysis Pre & Post Type 11 24-hr 2-YR Rainfall=3.66" Prepared by Timmons Group Printed 11/12/2019 HydroCAD010.00-20 s/n 06538 @ 2017 HydroCAD Software Solutions LLC Page 22 Summary for Subcatchment 5S: POST AREA 1-D (FUTURE) Runoff = 4.72 cfs @ 11.96 hrs, Volume= 0.256 af, Depth= 3.20" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 2-YR Rainfall=3.66" Area (ac) CN Description 0.870 98 Paved parking, HSG D 0.090 80 >75% Grass cover, Good, HSG D 0.960 96 Weighted Average 0.090 9.37% Pervious Area 0.870 90.63% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 5S: POST AREA 1-D (FUTURE) 5 I I I I I I I I I I I I I I I I I I I I I I I I I I I 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 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 LL 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 III I I I I I I I I I IIIII�III�III�III I I I I I I I I I I I I , Hydrograph _I__,_,__I__r_r_y__I__r_,_y__r_,_ ■RUnOff Type II 24-Ihr r L-2-YR Rainfall=3.66" Runoff Area=0.960 ac Runoff Volume=0.256 of Runoff Depth=3.20" Tc_ =6.0 min I I I I I I I I I I I I I I I I I I I I I I I CN=96 I I I I I I I I I I I I I i I I I I I I I I I I I I I I I I I I I I I I I I I I I 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--1-J--1--L-1- �--L-1-J--1--L-1-J--L-L- I I I I I I I I I I I I I I I I I I I I I I II II I I I I I I I I I I I I I I I I I 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) AutoZone SWM Analysis Pre & Post Type 11 24-hr 2-YR Rainfall=3.66" Prepared by Timmons Group Printed 11/12/2019 HydroCAD® 10.00-20 s/n 06538 @ 2017 HydroCAD Software Solutions LLC Page 23 Summary for Pond 1 P: SWM A Inflow Area = 0.930 ac, 83.87% Impervious, Inflow Depth = 3.10" for 2-YR event Inflow = 4.50 cfs @ 11.96 hrs, Volume= 0.240 of Outflow = 3.40 cfs @ 12.04 hrs, Volume= 0.240 af, Atten= 24%, Lag= 4.4 min Primary = 3.40 cfs @ 12.04 hrs, Volume= 0.240 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Peak Elev= 455.53' @ 12.03 hrs Surf.Area= 0.009 ac Storage= 0.024 of Plug -Flow detention time=1.9 min calculated for 0.240 of (100% of inflow) Center -of -Mass det. time= 1.9 min ( 775.4 - 773.5 ) Volume Invert Avail.Storage Storage Description #1 452.10' 0.038 of 66.0" Round Pipe Storage L= 70.0' S= 0.0050 T Device Routing Invert Outlet Devices #1 Primary 452.10' 15.0" Round Culvert L= 75.0' CMP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 452.10' / 451.44' S= 0.0088 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.23 sf #2 Device 1 452.10' 8.2" Vert. Orifice/Grate C= 0.600 #3 Device 1 455.35' 24.0" W x 6.0" H Vert. Orifice/Grate C= 0.600 #4 Device 1 456.40' 4.7' long Sharp -Crested Vee/Trap Weir Cv= 2.62 (C= 3.28) Primary OutFlow Max=3.32 cfs @ 12.04 hrs HW=455.46' (Free Discharge) L1=Culvert (Passes 3.32 cfs of 7.72 cfs potential flow) 2=Orifice/Grate (Orifice Controls 3.07 cfs @ 8.37 fps) 3=Orifice/Grate (Orifice Controls 0.25 cfs @ 1.09 fps) =Sharp -Crested Vee/Trap Weir( Controls 0.00 cfs) AutoZone SWM Analysis Pre & Post Prepared by Timmons Group Pond 1 P: SWM A Type 11 24-hr 2-YR Rainfall=3.66" Printed 11/12/2019 Hydrograph -+-� -I _i-r-t-y-y _i -r-+-y -I -I-r-t-+-y -I _♦ y -y -I 5 ■Inflow a50 qs I I I I I � I � ■Pnmary _L_IniflA__vnrArOa=0.'930 aG 4 P0Ak; rII0v =456 53' 340 ofi Stbraaa=0.024 of _ 3 I I I I I I I I I — I LL 2- 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) AutoZone SWM Analysis Pre & Post Type 11 24-hr 2-YR Rainfall=3.66" Prepared by Timmons Group Printed 11/12/2019 HydroCAD® 10.00-20 s/n 06538 @ 2017 HydroCAD Software Solutions LLC Page 25 Summary for Pond 2P: SWM A Inflow Area = 0.960 ac, 90.63% Impervious, Inflow Depth = 3.20" for 2-YR event Inflow = 4.72 cfs @ 11.96 hrs, Volume= 0.256 of Outflow = 3.81 cfs @ 12.02 hrs, Volume= 0.256 af, Atten= 19%, Lag= 3.2 min Primary = 3.81 cfs @ 12.02 hrs, Volume= 0.256 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Peak Elev= 455.62' @ 12.02 hrs Surf.Area= 0.009 ac Storage= 0.024 of Plug -Flow detention time=1.9 min calculated for 0.256 of (100% of inflow) Center -of -Mass det. time= 1.9 min ( 768.6 - 766.7 ) Volume Invert Avail.Storage Storage Description #1 452.10' 0.038 of 66.0" Round Pipe Storage L= 70.0' S= 0.0050 T Device Routing Invert Outlet Devices #1 Primary 452.10' 15.0" Round Culvert L= 75.0' CMP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 452.10' / 451.44' S= 0.0088 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.23 sf #2 Device 1 452.10' 8.2" Vert. Orifice/Grate C= 0.600 #3 Device 1 455.35' 24.0" W x 6.0" H Vert. Orifice/Grate C= 0.600 #4 Device 1 456.40' 4.7' long Sharp -Crested Vee/Trap Weir Cv= 2.62 (C= 3.28) Primary OutFlow Max=3.68 cfs @ 12.02 hrs HW=455.55' (Free Discharge) L1=Culvert (Passes 3.68 cfs of 7.84 cfs potential flow) 2=Orifice/Grate (Orifice Controls 3.11 cfs @ 8.49 fps) 3=Orifice/Grate (Orifice Controls 0.57 cfs @ 1.43 fps) =Sharp -Crested Vee/Trap Weir( Controls 0.00 cfs) AutoZone SWM Analysis Pre & Post Type 11 24-hr 2-YR Rainfall=3.66" Prepared by Timmons Group Printed 11/12/2019 HydroCAD010.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Page 26 Pond 2P: SWM A Hydrograph I I, ;I 'Illr4. IlraflpvlvlArea=D0inflow -, ,FE II II ■Primary 5 .1960 aG I I I I I I I I I I I I I __I I __ (y6�� T ell Ifev=456.6Z 4 i i i i i 3 81 cts i I I I I I I I I Stbragq=0; 024 of 3 ------------ LL 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 1 I I I I I I I I I I I I I I 4 5 6 7 8 0 10 11 12 13 14 15 16 ' Time (houm) AutoZone SWM Analysis Pre & Post Type 11 24-hr 2-YR Rainfall=3.66" Prepared by Timmons Group Printed 11/12/2019 HydroCAD® 10.00-20 s/n 06538 @ 2017 HydroCAD Software Solutions LLC Page 27 Summary for Link 1: ANALYSIS PT 1 Inflow Area = 1.330 ac, 63.91 % Impervious, Inflow Depth = 2.76" for 2-YR event Inflow = 4.52 cfs @ 12.01 hrs, Volume= 0.306 of Primary = 4.52 cfs @ 12.01 hrs, Volume= 0.306 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Link 1: ANALYSIS PT 1 Hydrograph ❑ Inflow ❑ Primary Time (hours) AutoZone SWM Analysis Pre & Post Type 11 24-hr 2-YR Rainfall=3.66" Prepared by Timmons Group Printed 11/12/2019 HydroCAD® 10.00-20 s/n 06538 @ 2017 HydroCAD Software Solutions LLC Page 28 Summary for Link FUT: ANALYSIS PT 1 Inflow Area = 1.330 ac, 70.68% Impervious, Inflow Depth = 2.87" for 2-YR event Inflow = 4.97 cfs @ 12.00 hrs, Volume= 0.318 of Primary = 4.97 cfs @ 12.00 hrs, Volume= 0.318 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Link FUT: ANALYSIS PT 1 Hydrograph FE ]—I n—fl.—. ❑ Primary Time (hours) AutoZone SWM Analysis Pre & Post Type II 24-hr 10-YR Rainfall=5.53" Prepared by Timmons Group Printed 11/12/2019 HydroCAD® 10.00-20 s/n 06538 ©2017 HydroCAD Software Solutions LLC Paae 29 Time span=0.00-30.00 hrs, dt=0.05 hrs, 601 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment1S: PRE ONSITE Runoff Area=1.330 ac 65.41 % Impervious Runoff Depth=4.72" Tc=6.0 min CN=93 Runoff=9.76 cfs 0.523 of Subcatchment2S:POSTAREAI-U Runoff Area=0.400ac 17.50%Impervious Runoff Depth=3.66" Tc=6.0 min CN=83 Runoff=2.45 cfs 0.122 of Subcatchment3S:POSTAREAI-D Runoff Area=0.930ac 83.87%Impervious Runoff Depth=4.94" Tc=6.0 min CN=95 Runoff=6.98 cfs 0.383 of Subcatchment4S:POSTAREAI-U Runoff Area=0.370ac 18.92%Impervious Runoff Depth=3.66" Tc=6.0 min CN=83 Runoff=2.27 cfs 0.113 of Subcatchment5S:POSTAREAI-D Runoff Area=0.960ac 90.63%Impervious Runoff Depth=5.06" Tc=6.0 min CN=96 Runoff=7.26 cfs 0.405 of Pond 1 P: SWM A Peak Elev=456.12' Storage=0.028 of Inflow=6.98 cfs 0.383 of Outflow=6.87 cfs 0.383 of Pond 2P: SWM A Peak Elev=456.19' Storage=0.029 of Inflow=7.26 cfs 0.405 of Outflow=7.15 cfs 0.405 of Link 1: ANALYSISPT 1 Inflow=9.52 cfs 0.505 of Primary=9.52 cfs 0.505 of Link FLIT: ANALYSISPT 1 Inflow=9.60 cfs 0.518 of Primary=9.60 cfs 0.518 of Total Runoff Area = 3.990 ac Runoff Volume = 1.546 of Average Runoff Depth = 4.65" 33.33% Pervious = 1.330 ac 66.67% Impervious = 2.660 ac AutoZone SWM Analysis Pre & Post Type // 24-hr 10-YR Rainfall=5.53" Prepared by Timmons Group Printed 11/12/2019 HydroCAD010.00-20 s/n 06538 @ 2017 HydroCAD Software Solutions LLC Page 30 Summary for Subcatchment 1S: PRE ONSITE Runoff = 9.76 cfs @ 11.96 hrs, Volume= 0.523 af, Depth= 4.72" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 10-YR Rainfall=5.53" Area (ac) CN Description 0.460 84 50-75% Grass cover, Fair, HSG D 0.870 98 Paved parking, HSG D 1.330 93 Weighted Average 0.460 34.59% Pervious Area 0.870 65.41% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 1S: PRE ONSITE I I I I I I I I I I I I I I I I I 10 9.]Bc I I I I I I I 9 ---------------------- 1I I I I I I I I I I I I I I I I I I I a I I I I I I I I I I I T_T__I _T_T__I__r_ 7 I I I I I I I -1-J--L-1-,--I--L-1- N 6 I I I I I I I I v I I I I I I 5 I I I I I I I I LL } I I I I I I I I 3 I I I I I I I I I I I I 't I I I I I I 1 II II II II I, Hydrograph I i I I I I I I I I I I y I I I I I I I I I I ■ Runoff I I I I I I I I I I I I I - III Type-�;4yhi-- IO-I YR Rainfallr5.5IIIIIII I - Runbff Al��='I _r_ 30 'ad_ _ -T __ _ T -r-T-T Kull14ffll,Vioju_q_=,'0:,53 a I Ikunoff bupih4J2" . ------------------ T_T__1__ r_T_1__ Ic__ �'h -7__L_1_I-- -- - __I ___1 __1 __1 __1___1 __I __1 ___I __I __I __I___1 __I __ I 1 I 1 1 1 1 1 I 1 I I I I 1 I 11 I 1 1 1 1 1 I 1 I I I I 1 I 1 I 1 1 1 1 1 1 1 1 I 1 1 1 I II II II II II II II II II II II i Time (houm) AutoZone SWM Analysis Pre & Post Type // 24-hr 10-YR Rainfall=5.53" Prepared by Timmons Group Printed 11/12/2019 HydroCAD010.00-20 s/n 06538 @ 2017 HydroCAD Software Solutions LLC Page 31 Summary for Subcatchment 2S: POST AREA 1-U Runoff = 2.45 cfs @ 11.97 hrs, Volume= 0.122 af, Depth= 3.66" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 10-YR Rainfall=5.53" Area (ac) CN Description 0.330 80 >75% Grass cover, Good, HSG D 0.070 98 Paved parking, HSG D 0.400 83 Weighted Average 0.330 82.50% Pervious Area 0.070 17.50% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 2S: POST AREA 1-1.11 Hydrograph Type II 24-hr 10-YR Rainfall=5.53" Runoff Area=0.400 ac Runoff Volume=0.122 of Runoff Depth=3.66" T'c=6.0 mini I � CN=83 I I I I I I I I I I I I I i I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 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 I I I I I I I I I I I I I I I I I I I I 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) AutoZone SWM Analysis Pre & Post Type // 24-hr 10-YR Rainfall=5.53" Prepared by Timmons Group Printed 11/12/2019 HydroCAD010.00-20 s/n 06538 @ 2017 HydroCAD Software Solutions LLC Page 32 Summary for Subcatchment 3S: POST AREA 1-D Runoff = 6.98 cfs @ 11.96 hrs, Volume= 0.383 af, Depth= 4.94" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 10-YR Rainfall=5.53" Area (ac) CN Description 0.780 98 Paved parking, HSG D 0.150 80 >75% Grass cover, Good, HSG D 0.930 95 Weighted Average 0.150 16.13% Pervious Area 0.780 83.87% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 3S: POST AREA 1-D 7 6 4 3 2 Hydrograph i i i i i i i i i i i i i i i i i ■ Runoff Type II 24yhr 10=YFtl�ainf�f1T8:5f3�'- Runbff ArL%6=0.930 'ad Runoff', V.ol',urne=',0.',3$3', at f tiffoff-DeO:F4-94M 11,11 Tc=6,0': rhih 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) AutoZone SWM Analysis Pre & Post Type // 24-hr 10-YR Rainfall=5.53" Prepared by Timmons Group Printed 11/12/2019 HydroCAD010.00-20 s/n 06538 @ 2017 HydroCAD Software Solutions LLC Page 33 Summary for Subcatchment 4S: POST AREA 1-U (FUTURE) Runoff = 2.27 cfs @ 11.97 hrs, Volume= 0.113 af, Depth= 3.66" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 10-YR Rainfall=5.53" Area (ac) CN Description 0.300 80 >75% Grass cover, Good, HSG D 0.070 98 Paved parking, HSG D 0.370 83 Weighted Average 0.300 81.08% Pervious Area 0.070 18.92% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 4S: POST AREA 1-U (FUTURE) I I I I I I I I I I I I I I I I I I I I I I I I I I I I ill 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 LL _1_J__L_L_J_J__L_ I I I I 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 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I Hydrograph 1 I I I I I I I I I I I I I I I I I I I Type II 24-hr I I I I I I I I I I I 10-YR Rainfall=5.53" Runoff Area=0.370 ac Runoff Volume=0.113 of Runoff Depth=3.66" Tc=6.0 min CN=83 0 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) ❑ Runoff AutoZone SWM Analysis Pre & Post Type // 24-hr 10-YR Rainfall=5.53" Prepared by Timmons Group Printed 11/12/2019 HydroCAD® 10.00-20 s/n 06538 @ 2017 HydroCAD Software Solutions LLC Page 34 Summary for Subcatchment 5S: POST AREA 1-D (FUTURE) Runoff = 7.26 cfs @ 11.96 hrs, Volume= 0.405 af, Depth= 5.06" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Type II 24-hr 10-YR Rainfall=5.53" Area (ac) CN Description 0.870 98 Paved parking, HSG D 0.090 80 >75% Grass cover, Good, HSG D 0.960 96 Weighted Average 0.090 9.37% Pervious Area 0.870 90.63% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 6.0 Direct Entry, Subcatchment 5S: POST AREA 1-D (FUTURE) g ( I I I I I I I I I I I I Ir7. 7 IIIIIIIII 6 I I I I I I I I I I I I I I I I I I I I I 5 I I I I I I I I I N I I I I I I I I I 3 4 0 ( I I I LL 3 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 -T-1 Hydrograph I I I I I I I I I I I I I Pe r I I I I I I I I I I I I I I I I I -,10-XR-itinfaH;:5.5.3" IIIIIIIIIIIIIIII RLOOff Arlea1 610 '10 Run' gff: V^ib_lLume=11r0J40 /5:4f II II I I �Mn�l i�i}Tii�S:gVrlr I I I I I I I I I I I I I I I I I TC=610:rrlih - 1--1--1-J--1--L-1- �--L-1-J--1--L-1-J--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__r_T_1__I__r_T_T__r_T_ I I I I I I I I I I I I I I I I 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) AutoZone SWM Analysis Pre & Post Type/1 24-hr 10-YR Rainfall=5.53" Prepared by Timmons Group Printed 11/12/2019 HydroCAD® 10.00-20 s/n 06538 @ 2017 HydroCAD Software Solutions LLC Page 35 Summary for Pond 1 P: SWM A Inflow Area = 0.930 ac, 83.87% Impervious, Inflow Depth = 4.94" for 10-YR event Inflow = 6.98 cfs @ 11.96 hrs, Volume= 0.383 of Outflow = 6.87 cfs @ 11.98 hrs, Volume= 0.383 af, Atten= 1%, Lag= 0.9 min Primary = 6.87 cfs @ 11.98 hrs, Volume= 0.383 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Peak Elev= 456.12' @ 11.98 hrs Surf.Area= 0.008 ac Storage= 0.028 of Plug -Flow detention time=1.9 min calculated for 0.383 of (100% of inflow) Center -of -Mass det. time= 1.9 min ( 763.8 - 762.0 ) Volume Invert Avail.Storage Storage Description #1 452.10' 0.038 of 66.0" Round Pipe Storage L= 70.0' S= 0.0050 T Device Routing Invert Outlet Devices #1 Primary 452.10' 15.0" Round Culvert L= 75.0' CMP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 452.10' / 451.44' S= 0.0088 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.23 sf #2 Device 1 452.10' 8.2" Vert. Orifice/Grate C= 0.600 #3 Device 1 455.35' 24.0" W x 6.0" H Vert. Orifice/Grate C= 0.600 #4 Device 1 456.40' 4.7' long Sharp -Crested Vee/Trap Weir Cv= 2.62 (C= 3.28) Primary OutFlow Max=6.66 cfs @ 11.98 hrs HW=456.08' (Free Discharge) L1=Culvert (Passes 6.66 cfs of 8.54 cfs potential flow) 2=Orifice/Grate (Orifice Controls 3.37 cfs @ 9.18 fps) 3=Orifice/Grate (Orifice Controls 3.29 cfs @ 3.29 fps) =Sharp -Crested Vee/Trap Weir( Controls 0.00 cfs) AutoZone SWM Analysis Pre & Post Prepared by Timmons Group c 7 5 li li II II II I I I q I I I -T-7 -i r-T T LL 3- 2- Pond 1 P: SWM A Hydrograph Type II 24-hr 10-YR Rainfall=5.53" Printed 11/12/2019 II II II II � li � II II � II � II ■Inflow - ■ Pnma InfIO1 w' ,IArea=0.'ll930 aG ry POAk:FII0vkI:456';12' _ JI _StOrsga-0:028 of - 1I I I I i I I I I i I i I I i I i I I I I i I I I I i I i I I i I i I _T_T_7_1__I -F-T-7 -i -I _r_T_7__i__I 1 2 3 4 5 6 7 8 0 10 11 12 13 14 15 16 ' Time (hours) AutoZone SWM Analysis Pre & Post Type/1 24-hr 10-YR Rainfall=5.53" Prepared by Timmons Group Printed 11/12/2019 HydroCAD® 10.00-20 s/n 06538 @ 2017 HydroCAD Software Solutions LLC Page 37 Summary for Pond 2P: SWM A Inflow Area = 0.960 ac, 90.63% Impervious, Inflow Depth = 5.06" for 10-YR event Inflow = 7.26 cfs @ 11.96 hrs, Volume= 0.405 of Outflow = 7.15 cfs @ 11.98 hrs, Volume= 0.405 af, Atten= 2%, Lag= 0.9 min Primary = 7.15 cfs @ 11.98 hrs, Volume= 0.405 of Routing by Stor-Ind method, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Peak Elev= 456.19' @ 11.98 hrs Surf.Area= 0.008 ac Storage= 0.029 of Plug -Flow detention time=1.9 min calculated for 0.404 of (100% of inflow) Center -of -Mass det. time= 1.9 min ( 758.1 - 756.2 ) Volume Invert Avail.Storage Storage Description #1 452.10' 0.038 of 66.0" Round Pipe Storage L= 70.0' S= 0.0050 T Device Routing Invert Outlet Devices #1 Primary 452.10' 15.0" Round Culvert L= 75.0' CMP, projecting, no headwall, Ke= 0.900 Inlet / Outlet Invert= 452.10' / 451.44' S= 0.0088 '/' Cc= 0.900 n= 0.013 Corrugated PE, smooth interior, Flow Area= 1.23 sf #2 Device 1 452.10' 8.2" Vert. Orifice/Grate C= 0.600 #3 Device 1 455.35' 24.0" W x 6.0" H Vert. Orifice/Grate C= 0.600 #4 Device 1 456.40' 4.7' long Sharp -Crested Vee/Trap Weir Cv= 2.62 (C= 3.28) Primary OutFlow Max=6.94 cfs @ 11.98 hrs HW=456.15' (Free Discharge) L1=Culvert (Passes 6.94 cfs of 8.63 cfs potential flow) 2=Orifice/Grate (Orifice Controls 3.40 cfs @ 9.27 fps) 3=Orifice/Grate (Orifice Controls 3.54 cfs @ 3.54 fps) =Sharp -Crested Vee/Trap Weir( Controls 0.00 cfs) AutoZone SWM Analysis Pre & Post Prepared by Timmons Group ond 212: SWM A P Hydrograph Type 1124-hr 10-YR Rainfall=5.53" Printed 11/12/2019 ---,---I--i---;--i -P -� - ■Inflow zee ■Pnmary I6frpw ' rea--4-960 aG PoAk l �[Ov�45slIIIII; 19' - IIIIIIIF Sta=4429-a# - I l l i l l l l i l i l l i l i l I l l i l l l l i l i l l i l i l l i l I I I I I I I I I l i l I I I I I I I I I l i 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 4 5 6 7 8 0 10 11 12 13 14 15 16 ' Time (hours) AutoZone SWM Analysis Pre & Post Prepared by Timmons Group Type // 24-hr 10-YR Rainfall=5.53" Printed 11/12/2019 Summary for Link 1: ANALYSIS PT 1 Inflow Area = 1.330 ac, 63.91 % Impervious, Inflow Depth = 4.56" for 10-YR event Inflow = 9.52 cfs @ 11.97 hrs, Volume= 0.505 of Primary = 9.52 cfs @ 11.97 hrs, Volume= 0.505 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Link 1: ANALYSIS PT 1 Hydrograph ❑Inflow - 1 asz m. I I I [I Primary ° s sz�s Inflow Area=1.330 ac (IIIIIIIIII III 8- IIIIIIIIII IIIIIIIIII (IIII IIIIIIIIII 1 I I 1 7 ,111 (IIIIIIIIIIIIIII (IIIIIIIIIII I I _ 6 III 1 IIIIIIIIII I I ... � I IIIIII I I I I 1 IIIIIIIIIIIIIII LL 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 1 1 1 1 I I I I I I I I I 1 1 2 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 I I I I D 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) AutoZone SWM Analysis Pre & Post Prepared by Timmons Group Type // 24-hr 10-YR Rainfall=5.53" Printed 11/12/2019 Summary for Link FUT: ANALYSIS PT 1 Inflow Area = 1.330 ac, 70.68% Impervious, Inflow Depth = 4.67" for 10-YR event Inflow = 9.60 cfs @ 11.97 hrs, Volume= 0.518 of Primary = 9.60 cfs @ 11.97 hrs, Volume= 0.518 af, Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span= 0.00-30.00 hrs, dt= 0.05 hrs Link FUT: ANALYSIS PT 1 Hydrograph 10 I i - EI I � I I l i l 8 I i I i 7 I i i I I i i I LL I I 4 ' -r-7 -I -I-r-r-l--I--r_ i 3 I I I I 2 i 1 InflloW Area=fit 330aa- TI nIIIII11111 L_J_L__I__ L_ 1_ J_J__L_ L_ 1_ J__'__ L_ L_ I--r-r_1__I__I__r_r_1__I__I__r_r_r -r - 1 I l l l l l l l l l l L_L_J_J__'__L_J_J_L__'__L_J_J__'__L_L_ r-rrr- 1 l i l l i l i l l l l i l i l l i l i l l i l i l l l l i l i l l i l i l l i l i l l l l i l i l I--r-T-�--I-T-r-T-�--I--I-r-r-1--I--r-T- I l i l i l l i l i l l l l i l i l 1 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 Time (hours) ❑ Inflow ❑ Primary "Tomorrow's Natural Resources Today" &BA11 Chesapeake Bay Nutrient Land Trust, LLC. November 8, 2019 Timmons Group ATTN: Anna Fontaine 608 Preston Avenue, Suite 200 Charlottesville, VA 22903 RE: CBNLT / Oak Grove — Nutrient Credit Availability Project Reference: Autozone — Charlottesville Store #6464, Albemarle County Attention: Ms. Fontaine: This letter is to confirm the availability of authorized Nutrient Credits sufficient to meet your project requirements at our Oak Grove nutrient facility, which is registered with the Virginia Department of Environmental Quality (DEQ). These Nutrient Credits are generated and managed under the terms of the Oak Grove Nutrient Reduction Implementation Plan dated May 11, 2017 which was authorized by the DEQ on August 31, 2017. The Oak Grove project has been authorized to provide Nutrient Credits for use in the James River watershed. These Credits are transferable to those entities regulated under DEQ's Stormwater Management Program in accordance with VA Code § 62.1-44.15:35. Currently our Oak Grove facility has 8.80 pounds of Phosphorus Credits available. If we can provide further assistance please feel free to contact our office. Sincerely, Chesapeake Bay Nutrient Land Trust, LLC By Its Manager EarthSource Solutions, Inc. Scott A. Reed Vice President Chesapeake Bay Nutrient Land Trust, LLC. • 5735 S. Laburnum Avenue • Richmond, VA 23231 • P: 804.222.5114 9 www.cbnit.com