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WPO202200017 Calculations 2023-03-16
SHIMP ENGINEERING, P.C. Design Focused Engineering Stormwater Management Plan Calculation Packet WP02022-00017 Tax Map 45, Parcel 100 Tax Map 45, Parcel 100A Tax Map 45, Parcel 10013 Tax Map 45, Parcel 101 Tax Map 45, Parcel 10113 Project Name: 664 West Rio Prepared by: Shimp Engineering P.C. Date: March 15, 2023 Revised: March 16, 2023 APPROVED by the Albemarle County Community Development Department Date 03/16/2023 File WP0202200017 ***TREE REMOVAL ONLY*** A��o,aV 314115 4r ti'�slbav�. B�� 912 E. High Sr. Charlottesville, VA 22902 1434.227.5140 1 shimp-engineering.com SHIMP ENGINEERING, P.C. Design Focused Engineering March 16, 2023 John Anderson Albemarle County Department of Community Development 401 McIntire Road Charlottesville, VA 22902 Regarding: WPO 2022-00017 664 West Rio (Tree Removal Only) — VSMP Plan SWM Calculation Packet Dear John, Enclosed is the stormwater calculation packet for 664 Rio Road VSMP Plan. The development property has an area of 4.07 acres and a disturbed area of 1.48 acres. The purpose of this VSMP Plan is to clear the trees from the site so that future development can occur at a later date for a residential building, a self -storage building and a linear park. The site is naturally divided by a stream located to the north of the property, and the site outfall is located to the northeast of the property. To analyze the water quantity, the site is divided into two drainage areas based on the stream on site. The drainage area to the south of the stream (Drainage Area 1) is partially converted from wooded/turf conditions to mulch condition. This creates a lower weighted curve number (CN) in the post development conditions to meet water quantity requirements in 9VAC25-870-66-B(3) and 9VAC25-870-66-C. While the drainage area to the North of the Stream (Drainage Area 2) is considered to have a sheet flow conditions to meet the requirements in 9VAC25-870-66-D. The site also meets the water quantity requirements set forth in 9VAC25-870-65. Runoff Quality Narrative: To address runoff quality requirements set forth in 9VAC25-870-65, the site land cover information was entered into the VRRM Re -development Spreadsheet. This included pre -development and post - development land areas. The VRRM spreadsheet, attached in this packet, showed that the project required a total phosphorous (TP) reduction of 0.19 lb/yr. A purchase of 0.19 Ib/yr phosphorous credit shall be made to achieve required TP reduction for this site. Treatment Required Total Phosphorous) Treatment Provided (Total Phosphorous) 0.19 lb/yr 0.19 lb/yr Runoff Quantity Narrative: SWM Quantity is satisfied by analyzing concentrated runoff from the development at the site outfall at the northeast comer of the development property. The site drainage area is divided into two drainage areas based on a stream north of the property, the drainage area to the south of the stream (drainage area 1) and the drainage area to the north of the stream (drainage area 2). Both drainage area 1 & 2 flow to the site outfall but the analysis for them differs as follow: SHIMP ENGINEERING, P.C. Design Focused Engineering Drainage Area 1: 9VAC25-870-66-B(3) requires that concentrated runoff from development at the site outfall meet the energy balance equation. To achieve this, portions of this area are converted from wooded/turf surface area to mulch surface area. This results in a reduction in the weighted curve number in the post development conditions. This causes the site runoff to be reduced from drainage area 1 to site outfall 1 which therefore meets the energy balance equation requirements set forth in 9VAC25-870-66-B(3). The pre development conditions for drainage area 1 are as follow: CN 0.178 ac impervious 98 2.852 ac turf 61 0.59 ac woods 55 Weighted CN 62 The post development conditions for drainage area 1 are as follow: CN 0.178 ac impervious 98 2.179 ac turf 61 1.263 ac mulch 48 Weighted CN 58 9VAC25-870-66-C(2).b requires that the concentrated stormwater flow to stormwater conveyance systems that currently experience localized flooding during the 10-year 24-hour storm event and Releases a post -development peak flow rate for the 10-year 24-how storm event that is less than the predevelopment peak flow rate from the 10-year 24-how storm event. This condition has also been satisfied as the peak flow for the 10-year 24-hour storm event for the post development is less than the pre -development flow for the 10-year 24-hour storm event. Eoe BJleure E ueliou S..,:ouoSite OuHJII 24 Hr 1 year Storm Com risoo: Q cLe YQ �RVMu.. YRveae IF.=LLtl 0121 Mu Q[..eyn -111 ARV�e 0121 LTC RVq�..gy= ACN6reJ PR1-ON Mn Pwtll£OIYe-O.]5 c4.9Ye aanph wM 9VAC25H'16F6R(3) MWmon QlOye=9.15 [61peMr]AchieveJ 1110yr=]3H [h. SN compleswN 9VAC258]6f6L(2) Flw Prttler Fbmfl[5 Poeltler Flownlee R[Jurlw f'h[rk o s� UP 0H PORLOA-IAC UP 09 FOR LOA< AC LTC M NOIe: LTC 6aneVLeveli'n fm LioUOf TRe Ckuig 664 West Rio Tree Removal Only) SHIMP ENGINEERING, P.C. Design Focused Engineering Drainage Area 2: Drainage area 2 lies north of the stream and has 0.398 acres of potential runoff in a stormwater runoff through turf area which flow to the stream and then reaches the site outfall. This area is designed to have sheet flow runoff and meets the requirements in 9VAC25-870-66-D. 9VAC25-870-66-D requires evaluating for potential impacts on down -gradient resources for increased volumes of sheet flow that will cause or contribute to erosion, sedimentation, or flooding. The pre development drainage area 1 has 1.52 cfs Q, and 9.15 cfs Qio while pre development drainage area 2 has 0.21 cfs Q, and 1.23 cfs Qio. Since drainage area 1 and drainage are 2 both flow to the same site outfall that is being analyzed, adding the two pre development flows together results in the following: Q pr d, for 1-year = 1.52 cfs + 0.21 cfs = 1.73 cfs Q pr d, for 10-year = 9.15 cfs + 1.23 cfs = 10.38 cfs The post development drainage area 1 has 0.75 cfs Q, and 7.34 cfs Qio while pre development drainage area 2 has 0.21 cfs Qi and 1.23 cfs Qio. Since drainage area 1 and drainage are 2 both flow to the same site outfall that is being analyzed, adding the two post development flows together results in the following: Q p�j-a, for 1-year = 0.75 cfs + 0.21 cfs = 0.96 cfs Q pot -dam for 10-year = 7.34 cfs + 1.23 cfs = 8.57 cfs When comparing the pre and post development flows, the results show that the post development flow is reduced by 44.5% for the 1-year storm and by 17.4% for the 10-year storm. Since the runoff to the site outfall for the post -development has been decreased from the runoff for the pre -development, there will be no runoff that contributes to erosion, sedimentation, or flooding of down gradient resources which therefore meets the requirements in 9VAC25-870-66-D. Detention system modeHnr notes: 1. The stormwater quantity calculations include the total drainage area to site outfall which would account for a total limits of disturbance of 4.02 ac though the limits of tree clearing proposed in this VSMP plan = 1.48 ac. If you have any questions about this calculation packet please do not hesitate to contact me at: steohanie@shimp-en ing eering com or justin@shimp-engineering.com or by phone at 434-299-9843. Regards, Stephanie Paul Shimp Engineering, PC SHIMP ENGINEERING, P.C. Design Focused Engineering Contents: Water Quantity Calculations: Pre -Development Drainage Area Map Pre -Development HydroCAD Report Post -Development Drainage Area Maps Post -Development HydroCAD Report Energy Balance Equations TOC Calculations & Nomographs Water Quality Calculations: Pre -Development VRRM Land -use Map Post -Development VRRM Land -use Map VRRM Redevelopment Spreadsheet - 1 VRRM Redevelopment Spreadsheet - 2 VRRM Redevelopment Spreadsheet - 3 Independent Reports: Excerpt from NRCS Soils Report NOAA Precipitation Report SHIMP ENGINEERING, P.C. Design Focused Engineering Water Quantity Calculations: Pre -Development Drainage Area Map Pre -Development HydroCAD Report Post -Development Drainage Area Maps Post -Development HydroCAD Report Energy Balance Equations TOC Calculations & Nomographs Post -Development Inlets Drainage Area Maps LEGEND ®PRE DEV DA 1 TO SITE OUTFALL IMP. PRE DEV DA 1 TO SITE OUTFALL TURF. ®PRE DEV DA 1 TO SITE OUTFALL WOODS. PRE DEV DA 2 TO SITE OUTFALL TURF. -------SOILS — DA —PRE DEVELOPMENT DRAINAGE AREA 1 — DA —PRE DEVELOPMENT DRAINAGE AREA 2 NOTE: ALL SOILS ON SITE ARE HSG B Pre-Dev Drainage Area 2 to Site Outfall CN 61 SF AC % Turf 17,333 0.398 100.0 Total Drainage Area 17,333 0.398 100.0 Wei htedCN61 TOC=5.0 SI NPENGINEERING, P.C. MOMEUNG-MADPLANMNG-PRQIELT AMNAGENBNT R o Es LLE.. „Me= �srNPHONE�HINa_(434) 227-5140 TM. 45-1000 i I 134 01i-' d 4.4 ,ram, d I 1 �,y �,A d \ Il��ll��i'//Il--ll��"" ./• MMM_ SPIV d 4A d \ y e/ M y y ° ••JJ�� I +- S )7 �1I�^S "II 1 7—^)y��� y TYLEPImNE }'i� I 1 II 1 d dddda \9 _ ° rt M yy y My yy ss I 1i >� II I I i �r/'L'rS /M 4p,/ i > I ''aa4a[�aa >i �a /iI t i /a Hi> aI I� lIi>> P >>>iII'I i >i II > >at l >♦11 I >JI >>> i>\i >> >i) •ja>; I}`1 \\\t\.,,l° °pd \\ \\ ` \ \\ PRE DI / dQ\IP °dQad `0. DRAIN))\da d\\p I ;A4$1 °d°\ c Q° ° P Q \`\ \\ r i > >i> ;ii iIl�KLiK Ii i� i; ii )i 444 db4idddQ It 9d _03mdd9 `\RCci\ i \4 i/i 14 ji > i\\i \, dd6d d°d \ iF`\` i \i °ddp -d D�ILE> i V 1d\ \ ddd ` ddd d \\° °d d \d \ \\ � \ \ \ `\\ \ \\ `\ i�IdddC i I >_ i�PTEOEx. DTINtlia\ \O411 °ddQ°d CVA. ii w�it li Ii \i\/ERLA d°-°dFLOii i1 i\ P '+d l\dx f ew - w%i ��' i l� i i i i i �I it it lii Ili it �1 Id I i i�'1�1 •{ ° w33 :Ili j'i M� �> iyi/ i1I�i ili �>Ii Ii Ili 11 it it 11I lill i)ill it>M`'•i� �$i o^ i s i' i - 9 i i fiIDLO3 ii it it i i I i 1 i t s )i 1� i'1 i i) ad PRE—DEV DAl I I I I ! i i d INwm.es F O y i' i' i i t/ i i i / > I> 1 i 1 >l I IN"4TT.T0 TIME OF i it i11 '> 'ii Iii l i i i i ,> ,i i INw477.70 CONCENTRATION '\.-� 1 s•C RIP -RAP DITCH i FLON�i ZI, $C 1 Y�\ > pi>� i ii i i Bt%t r' i i i ;.'i� i� i/t/it j� c; \ 1 m/ SITE PRIVATE SIGN li 1 i / i i/' ; i i i i i�.� ,,// /i / i /i /i \ '� Ex. ,O• `bt}u �> I i111 i i; i t /I i 3� i r' i CHACNNI6L! i/,i ' R i r i\ \�A ?i/i OUTFACE -2.]e Nil\ ] 1i 1 i /4 i BENCHMARK: I ;V\.. i \ i i\, i �Y--jam i `�\ i i i i / i i. > f(9/�• �� i \ i �i > �� j I i/ / TOP IN \ EIEVATON v.7a \\ 52 \I i �i��i �.� ,i �,; i `\i Sj i i((npn>p`5* o` io i �i, I / STEEP SLOPES L('p i > d. (MANAGED) lU'.pINT ACCE55 ESMT. D.B. 107-527 D.B. ,OM-4R5 PLAT TM. 45-105 60 0 60 664 West -Rio -(Tree Removal Only) Pre Development Drainage Area Map Sale: 1 "=60` W. 45-948 ti 120 180 1S Pre Development Drainage Area 1 2L Site Outfall Subcat Reach Aon L4 3S Pre Development Drainge Area 2 [4L Site Outfall Pre Dev DA Pre Dev DA Prepared by Shimp Engineering, P.C. Printed 3/14/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 2 Area Listing (all nodes) Area CN Description (acres) (subcatchment-numbers) 0.590 55 Woods, Good, HSG B (1S) 3.250 61 >75% Grass cover, Good, HSG B (1S, 3S) 0.178 98 Paved parking, HSG B (1S) 4.018 62 TOTAL AREA Pre Dev DA Pre Dev DA Prepared by Shimp Engineering, P.C. Printed 3/14/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 3 Soil Listing (all nodes) Area Soil Subcatchment (acres) Group Numbers 0.000 HSG A 4.018 HSGB 1S,3S 0.000 HSG C 0.000 HSG D 0.000 Other 4.018 TOTAL AREA Pre Dev DA Pre Dev DA Type H 24-hr I yr; 24 hr Rainfall=3.01 " Prepared by Shimp Engineering, P.C. Printed 3/14/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 4 Time span=0.00-72.00 hrs, dt=0.01 hrs, 7201 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1S: Pre Development Drainage Area 1 Subcatchment3S: Pre Development Drainge Area 2 Link 2L: Site Outfall Link 4L: Site Outfall Runoff Area=3.620 ac 4.92% Impervious Runoff Depth=0.40" Tc=11.2 min CN=62 Runoff=1.52 cfs 0.121 of Runoff Area=0.398 ac 0.00% Impervious Runoff Depth=0.37" Tc=5.0 min CN=61 Runoff=0.21 cfs 0.012 of Inflow=1.52 cfs 0.121 of Primary=1.52 cfs 0.121 of Inflow=0.21 cfs 0.012 of Primary=0.21 cfs 0.012 of Total Runoff Area = 4.018 ac Runoff Volume = 0.134 of Average Runoff Depth = 0.40" 95.57% Pervious = 3.840 ac 4.43% Impervious = 0.178 ac Pre Dev DA Pre Dev DA Type H 24-hr I yr; 24 hr Rainfall=3.01 " Prepared by Shimp Engineering, P.C. Printed 3/14/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 5 Summary for Subcatchment 1S: Pre Development Drainage Area 1 Runoff = 1.52 cfs @ 12.06 hrs, Volume= 0.121 A Depth= 0.40" Runoff by SCS TR-20 method, UH=SCS, Time Span-- 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 1 yr, 24 hr Rainfall=3.01" Area (ac) CN Description 0.178 98 Paved parking, HSG B 2.852 61 >75% Grass cover, Good, HSG B 0.590 55 Woods_ Good_ HSG B 3.620 62 Weighted Average 3.442 95.08% Pervious Area 0.178 4.92% Impervious Area Tc Length Description 11.2 Direct Entry, Time of Concentration Subcatchment 1S: Pre Development Drainage Area 1 ❑ Runoff 1.52 cfs :Type II 24-hr 1 yr Rainfall^3.01"RUr1off,Vo'IUrri6,01121 of Runoff bep#h=b.i4b'� Tic=11�.2 htiri a 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 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Pre Dev DA Pre Dev DA Type H 24-hr I yr; 24 hr Rainfall=3.01 " Prepared by Shimp Engineering, P.C. Printed 3/14/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 6 Summary for Subcatchment 3S: Pre Development Drainge Area 2 Runoff = 0.21 cfs @ 11.99 hrs, Volume= 0.012 A Depth= 0.37" Runoff by SCS TR-20 method, UH=SCS, Time Span-- 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 1 yr, 24 hr Rainfall=3.01" Area (ac) CN Description 0.398 61 >75% Grass cover, Good, HSG B 0.398 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Time of Concentration Subcatchment 3S: Pre Development Drainge Area 2 Hydrograph 0.22 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 'r 0---_-.TrLY''I 2 0.2, _ _- _JfTIIII _n 0.2 F Z_JIlI Y `_Ttl�I 0.19 -Ir-r-Ir-r- - VV 017 O_16 0.15 0.14 rea,= 0.13 -r-r-r-T- -r-r-r-r-r-r-r-r-r-r-r-r-r TT_��_ 0.12 -- LL O., w„xff LII�L4JaaVVVIl . OOJ ALIl rl -Y-Y-Y-Y-Y- 0.08 TTrrTrTTTTTTTTTTT-T-T-7-T� T 0.07 _I---I-I- ---------------------I-I-I I_■}�_ I_ T 006 _L_L_L_L_ _L_L_L_L_L_L_1_L_1_L_1_1_L_1_1_1_1_1_ J_ J_ J_ J_ J_J_ Y 0.05 -`-`-`-L- !, U.04 4 0.03 -r-r-r -r- 1 1 r-r-r-r-r-r-r-r-r-r-r-r-r-r-T-r-�-T-7-�-T-7-�-7-7-�-7-r- 0.02 I I I I _I I I I I I I I I I I I I I I I I I I I I I I 0.01 Time (hours) ■ Runoff Pre Dev DA Pre Dev DA Type H 24-hr I yr; 24 hr Rainfall=3.01 " Prepared by Shimp Engineering, P.C. Printed 3/14/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 7 Summary for Link 2L: Site Outfall Inflow Area = 3.620 ac, 4.92% Impervious, Inflow Depth = 0.40" for 1 yr, 24 hr event Inflow = 1.52 cfs @ 12.06 hrs, Volume= 0.121 of Primary = 1.52 cfs @ 12.06 hrs, Volume= 0.121 at Atten= 01/o, Lag= 0.0 min Primary outflow = Inflow, Time Span-- 0.00-72.00 hrs, dt= 0.01 hrs 1 52 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 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I Link 2L: Site Outfall 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 1416v f IAir6ea- .,620laic I I I I I I I I I I I I I I I I I I I I I I i I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 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 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) ■ Inflow ■ Primary Pre Dev DA Pre Dev DA Type H 24-hr I yr; 24 hr Rainfall=3.01 " Prepared by Shimp Engineering, P.C. Printed 3/14/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 8 Summary for Link 4L: Site Outfall Inflow Area = 0.398 ac, 0.00% Impervious, Inflow Depth = 0.37" for 1 yr, 24 hr event Inflow = 0.21 cfs @ 11.99 hrs, Volume= 0.012 of Primary = 0.21 cfs @ 11.99 hrs, Volume= 0.012 at Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span-- 0.00-72.00 hrs, dt= 0.01 hrs O.T. 0.1' 0.1 0.11 0.1', OA 0.1', at e 0.1 u 0. 0.01 Link 4L: Site Outfall Hydrograph _L_L J_J_1_1_1_1_1_ L_ L_L 0.2� i r r r r-- nflow Area-93W_ r-�-�-r-r-T-r-r-r-r-r-r- I I I I I I I I I I I I I I I I --I- _L_L__ _L_4_{_;_y_y_L_L_L_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 1 1 -r-I-7-1-I-T-T-T-T-T-r-r-r I I I I I- I- l- l- l- l- T- T- r- r -r -r -r _L_L__J_J_J_1_1_L_L_L_L_L_L_1_J_J_J_J_L_J_J_J_J_1_1_1_ L_L_LJ_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 L_L-IL_L_L_L_L -r-r- Y_T- 4- -r I ,' -r-r-- ��-�-�-�-r-r-r-r-r-r-r-r-r-r-I--1--rr--I--1-�- r-T-r-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 1 1 1 1 1 1 1 1 1 1 1 1 I I i I I I 1 I I _______I _I _I__1__I__I__I_ I__________________ 1 J1 _J1 _1_1_L_L_L_L_L_L_I__I__I_J_J_J_J_J_J_J_J_1_L_L_L_L_L_L 1 1 I _r_r__1_1_4_4_T_T_T_T_T_r_r_I__I__I__I__I__I_-I_1_Y_l_4_Y_T_r_r_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 y -+- { -f- f 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 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) ■ Inflow ■ Primary Pre Dev DA Pre Dev DA Type 1124-hr 10 yr; 24 hr Rainfall=5.51 " Prepared by Shimp Engineering, P.C. Printed 3/14/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 9 Time span=0.00-72.00 hrs, dt=0.01 hrs, 7201 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1S: Pre Development Drainage Area 1 Subcatchment3S: Pre Development Drainge Area 2 Link 2L: Site Outfall Link 4L: Site Outfall Runoff Area=3.620 ac 4.92% Impervious Runoff Depth=1.76" Tc=11.2 min CN=62 Runoff=9.15 cfs 0.532 of Runoff Area=0.398 ac 0.00% Impervious Runoff Depth=1.69" Tc=5.0 min CN=61 Runoff--1.23 cfs 0.056 of Inflow=9.15 cfs 0.532 of Primary=9.15 cfs 0.532 of Inflow=1.23 cfs 0.056 of Primary=1.23 cfs 0.056 of Total Runoff Area = 4.018 ac Runoff Volume = 0.588 of Average Runoff Depth = 1.75" 95.57% Pervious = 3.840 ac 4.43% Impervious = 0.178 ac Pre Dev DA Pre Dev DA Type 1124-hr 10 yr; 24 hr Rainfall=5.51 " Prepared by Shimp Engineering, P.C. Printed 3/14/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paize 10 Summary for Subcatchment 1S: Pre Development Drainage Area 1 Runoff = 9.15 cfs @ 12.04 hrs, Volume= 0.532 A Depth= 1.76" Runoff by SCS TR-20 method, UH=SCS, Time Span-- 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 10 yr, 24 hr Rainfall=5.51 " Area (ac) CN Description 0.178 98 Paved parking, HSG B 2.852 61 >75% Grass cover, Good, HSG B 0.590 55 Woods_ Good_ HSG B 3.620 62 Weighted Average 3.442 95.08% Pervious Area 0.178 4.92% Impervious Area Tc Length Description 11.2 Direct Entry, Time of Concentration Subcatchment 1S: Pre Development Drainage Area 1 10 II 9.15 r-r--T-T-T-T-I-7-r-1--I-1 I cfs 9 Type ;II'12,4�h',r ,10 yr r-r-r- _r_r_r_r_T_r_r_y_���� I 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 r-r-r-+ T-r-+aainfall^5.547 7 I I I I I I I I I I I I I 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 � 1 _J_J_J IR1.rriof#'alol�rtl�--0�532# 5 I I I I I#unio f;dep#h=1.',7.6'!_ _ _ _ _I _I _I _I _L 4 __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 IN �T�L 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 _L_L_L_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 12 34 36 38 40 42 44 46 48 50 52 54 Time (hours) ■ Runoff Pre Dev DA Pre Dev DA Type 1124-hr 10 yr; 24 hr Rainfall=5.51 " Prepared by Shimp Engineering, P.C. Printed 3/14/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paize 11 Summary for Subcatchment 3S: Pre Development Drainge Area 2 Runoff = 1.23 cfs @ 11.97 hrs, Volume= 0.056 A Depth= 1.69" Runoff by SCS TR-20 method, UH=SCS, Time Span-- 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 10 yr, 24 hr Rainfall=5.51 " Area (ac) CN Description 0.398 61 >75% Grass cover, Good, HSG B 0.398 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Time of Concentration Subcatchment 3S: Pre Development Drainge Area 2 Hydrograph I � � I � I � I I � I � � � � � I � I I � I I � I � I I ❑Runoff 1.2 cfs I�I�II�I�II�I�II� Ty,pe;II,24,h,r ,10 yr I�I�II�I�II�I�II�I 1�1�11�1�11�1�11�1�11�11����1F I�I�II�I�II�I�II�I�II�II� Rainfall^5.51 1 I�II�I�II�I�I � II�II�I�II :Runoff AFna=p-M 46 I�I�II�I�II�I�I I�II�I�II�I�I I�II�I�II RUlloff.VolUnIO,01056 9f I�II�I�II� �I � I�II�I�II RunofF,:bep#h=1.60" I� I�I�II I! ! I! II T0,5-Qinio �II�I�II�I�II�I�II�II I�II�I�II�I�II�I�II�II�I�II Time (hours) Pre Dev DA Pre Dev DA Type 1124-hr 10 yr; 24 hr Rainfall=5.51 " Prepared by Shimp Engineering, P.C. Printed 3/14/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paye 12 Summary for Link 2L: Site Outfall Inflow Area = 3.620 ac, 4.92% Impervious, Inflow Depth = 1.76" for 10 yr, 24 hr event Inflow = 9.15 cfs @ 12.04 hrs, Volume= 0.532 of Primary = 9.15 cfs @ 12.04 hrs, Volume= 0.532 A Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span-- 0.00-72.00 hrs, dt= 0.01 hrs Link 2L: Site Outfall Hydrograph -I--I -i - r -I -i -i - --,-7-T-,-7-,-T-T-T-T-1- FE Inflow 10 9.15 -,7-T,T--6T--fIoW'Araa:g l ■ Primary cfs nac 9 III III III III II IIII 8 -III -III -II -III --III --III --III --III --III --III --III --III --III --III - --1III1 -II - 1 7 I I I 1 I I I 1 I I I I I I I I 1 I I 1 I I I 1 I 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 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 5- 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 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 1 1 1 1 1 1 1 11 I I 1 I I I 1 I I 1 I I I I I 1 1 I I 1 I I I 1 I 1 2f I I I I I 1 I 1 I I I I I 1 1 I I 1 I I 1 I 1 -T-T-T-T-T- I 1 1 1 1 1 1 1 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 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Pre Dev DA Pre Dev DA Type 1124-hr 10 yr; 24 hr Rainfall=5.51 " Prepared by Shimp Engineering, P.C. Printed 3/14/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paye 13 Summary for Link 4L: Site Outfall Inflow Area = 0.398 ac, 0.00% Impervious, Inflow Depth = 1.69" for 10 yr, 24 hr event Inflow = 1.23 cfs @ 11.97 hrs, Volume= 0.056 of Primary = 1.23 cfs @ 11.97 hrs, Volume= 0.056 A Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span-- 0.00-72.00 hrs, dt= 0.01 hrs Link 4L: Site Outfall Hydrograph I I I I I I I I I I I I I I I I I I I I I I I ■ Inflow ■ Primary 1.23 cfs II II ' 1416v f Ilar6e—T6.i39$ laic: I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 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 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 o 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 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 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 50 52 54 56 58 60 62 64 66 68 70 72 Time (hour:) Pre Dev DA Pre Dev DA Type H 24-hr 100 yr, 24 hr Rainfall=9.04" Prepared by Shimp Engineering, P.C. Printed 3/14/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paize 14 Time span=0.00-72.00 hrs, dt=0.01 hrs, 7201 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1S: Pre Development Drainage Area 1 Subcatchment3S: Pre Development Drainge Area 2 Link 2L: Site Outfall Link 4L: Site Outfall Runoff Area=3.620 ac 4.92% Impervious Runoff Depth=4.38" Tc=11.2 min CN=62 Runoff=23.43 cfs 1.321 of Runoff Area=0.398 ac 0.00% Impervious Runoff Depth=4.26" Tc=5.0 min CN=61 Runoff--3.15 cfs 0.141 of Inflow=23.43 cfs 1.321 of Primary=23.43 cfs 1.321 of Inflow=3.15 cfs 0.141 of Primary=3.15 cfs 0.141 of Total Runoff Area = 4.018 ac Runoff Volume = 1.462 of Average Runoff Depth = 4.37" 95.57% Pervious = 3.840 ac 4.43% Impervious = 0.178 ac Pre Dev DA Pre Dev DA Type 1124-hr 100 yr, 24 hr Rainfall=9.04" Prepared by Shimp Engineering, P.C. Printed 3/14/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paize 15 Summary for Subcatchment 1S: Pre Development Drainage Area 1 Runoff = 23.43 cfs @ 12.03 hrs, Volume= 1.321 A Depth= 4.38" Runoff by SCS TR-20 method, UH=SCS, Time Span-- 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 100 yr, 24 hr Rainfall=9.04" Area (ac) CN Description 0.178 98 Paved parking, HSG B 2.852 61 >75% Grass cover, Good, HSG B 0.590 55 Woods_ Good_ HSG B 3.620 62 Weighted Average 3.442 95.08% Pervious Area 0.178 4.92% Impervious Area Tc Length Description 11.2 Direct Entry, Time of Concentration Subcatchment 1S: Pre Development Drainage Area 1 26 25 ; -r-r-r-T-r-T- -L-L 23.43 1 1 1 ---1-Tr-1r-r-r-r-r-r-r-r-r-T-r-T-T-T-T-�--1I--I--r-r cfs _ JI---J-J-J--'-J--'--L-1--L-L-L-L-L-1-L-1-J-1-J-J-J-�- - -J- 24 23 -Y-r -'I 'I - �- �I - ,_._.__i-�__1--i--I--1--r-1--r-r-r-r-Y-T-T-T-T-*-T-.--i--- J J - 1 1 L Twee IF 2"r-'19{00yr_ I 1 I I I I 1 I I 1 I 1 1 1 I I 22 21 - - - - - T -I -I -I -I -I -I - -24 fir- 20 I_ 19 / _r_r_r_T_ I I I I 11 I I I I 1 I I 1 I 1 I 1 I I I I I rI _r_r_T-T-TRajnfall^2.®4F� 16 I I 1 I I I I 1 I I 1 I 1 I 1 I I I I I 'C 4II_ I I_I_ Yq 15 14 _LI _LI _L1 J1 _a_II_416 _1I_ -T-T-T- 1321 c 13 _L_L_L_1. 12 i _Y_r_T_T_ `- J w j _1_y_y_y__I_y__1__I__I__1__r_1__r_F_r-r �r'io D�Q^ih�.'3$r1 LL 11 / I I I I I I I I I I I I I I I I I I I I I I I MV�/ I ivv I I I I I I I I I I I I I I I I I I I I I I I I I I I 10 T_T_T_T__I_r__I__I- I- I rT-r-r-r-r-T-T-T-T-T l_J_J_J_J_J_J__I_J__I__ L _I__ L_ L_ L_ L_ L_ 1_ L_ 1_J_ J_J_ J_ I _ i -Y-T-t-T- -T-1-1-1--I--I--I--I--I--I--Y-I--r-r-T-T-T-1-T-1-7-Y-Y-Y- r 6 --I -I_I ___I_I_I_I_I__I_I__I__I__I__I__I_I 5 -1 -I -I -1 -L-1 4 1 1 -r-r-r- T - 1 I I I I 1 I I I I I I I I I I --I-T-T -1 -1 -1 3 _ __J_J___J__________L___L_L_L_L_L_1_L_1_J_1_J_J__I_J__I__I__I_ 1 2 i _T_r_r __r_I__r_r_T_r_T_T_T_T_l_T_T_1__I_l__I__I__I_ 12 34 36 38 40 42 44 Time (hours) ■ Runoff Pre Dev DA Pre Dev DA Type H 24-hr 100 yr, 24 hr Rainfall=9.04" Prepared by Shimp Engineering, P.C. Printed 3/14/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paize 16 Summary for Subcatchment 3S: Pre Development Drainge Area 2 Runoff = 3.15 cfs @ 11.96 hrs, Volume= 0.141 A Depth= 4.26" Runoff by SCS TR-20 method, UH=SCS, Time Span-- 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 100 yr, 24 hr Rainfall=9.04" Area (ac) CN Description 0.398 61 >75% Grass cover, Good, HSG B 0.398 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Time of Concentration Subcatchment 3S: Pre Development Drainge Area 2 Hydrograph I I I I I I I I I I I I I I II I I I I I I I 1 I � 1 I I 1 I I 1 I I I 1 I I I I ❑Runoff 3.15 cfs 3 'll TYp;e 11 24*rII,1Q0-yr- I � I I I I i i i i I I I I I I I I jr� F I I I I i i I i I i i I I i I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I Rainfall^9.04" I I I I I I I I I I I I I I I I I I I I I I I I I -i------------------------�--I- Ruofa=pa - nA" 2 I 11 I 1 1 I 1 I 1 1 RUriof:V01Un16,0141 9f 1 I 1 I 1 1 I 1 I 1 1 I 1 I 1 11 I I 1 I 1 1 I 1 I 1 1 LL I I I I I I I I I I I I I I kunloff DGOih=4.126'1 I I I I I I I I I I I I I I I I I I I I I I I T =S.QiN 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Il��icNr61 11 I 1 1 I 1 1 1 1 I 1 I 1 1 I 1 1 1 1 I 1 1 I 1 I 1 1 11 I 1 1 I 1 1 1 1 I 1 I 1 1 I 1 1 1 1 I 1 1 I 1 I 1 11 I 1 1 I 1 1 1 1 I 1 I 1 1 I 1 1 1 1 I 1 1 I I I I 11 I 1 1 I 1 1 1 1 I 1 I 1 1 I 1 1 1 1 I 1 1 I I I I I 11 I 1 1 I 1 1 1 1 I 1 1 1 1 I 1 1 1 1 I 1 1 I I I 11 I 1 1 I 1 1 1 1 I 1 1 I 1 1 I I I I Time (hours) Pre Dev DA Pre Dev DA Type H 24-hr 100 yr, 24 hr Rainfall=9.04" Prepared by Shimp Engineering, P.C. Printed 3/14/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Pale 17 Summary for Link 2L: Site Outfall Inflow Area = 3.620 ac, 4.92% Impervious, Inflow Depth = 4.38" for 100 yr, 24 hr event Inflow = 23.43 cfs @ 12.03 hrs, Volume= 1.321 of Primary = 23.43 cfs @ 12.03 hrs, Volume= 1.321 at Atten= 0"1 Lag= 0.0 min Primary outflow = Inflow, Time Span-- 0.00-72.00 hrs, dt= 0.01 hrs Link 2L: Site Outfall Hydrograph 1 I I I I I I I I I I 1 I I 1 I I I 1 I I 1 I I I I I I I 1 1 1 ■ Inflow 26. ■ Primary cfs 24 23.43 JI 11 f f� I1ir,,6GV I 22 I 1 I I I I ------J-J---J-J- J- I I 1 I I I 1 I I I I I I I I I I I I I I I I I 20 I I 1 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 I I I I I I I I I I I I I I I I I I I I I I IsJ I I 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_J_J_J_J_J_J_J_J_J_1_1_L_1_1_L_L_L_L_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 16 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 ._. 14 I I I 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 I I I I I I I I I I I I I I I I I I I I I I I I 12 I I I 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 10- I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 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 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-I-I-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 4 , 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 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Pre Dev DA Pre Dev DA Type H 24-hr 100 yr, 24 hr Rainfall=9.04" Prepared by Shimp Engineering, P.C. Printed 3/14/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paye 18 Summary for Link 4L: Site Outfall Inflow Area = 0.398 ac, 0.00% Impervious, Inflow Depth = 4.26" for 100 yr, 24 hr event Inflow = 3.15 cfs @ 11.96 hrs, Volume= 0.141 of Primary = 3.15 cfs @ 11.96 hrs, Volume= 0.141 A Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span-- 0.00-72.00 hrs, dt= 0.01 hrs Link 4L: Site Outfall 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 ■ Inflow �-.�I I I I I I ICI, I I 1� I � � ■ Primary 3.15cfs I I inflo%iirAP6i—V.'3go'a:c 3- 2- 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 50 52 54 56 58 60 62 64 66 68 70 72 Time (hour:) 1S Post Development Drainage Area 1 2L Site Outfall Sub4 Reach Aon L4 3S Post Development Drainge Area 2 4L Site Outfall Post Dev DA Post Dev DA Prepared by Shimp Engineering, P.C. Printed 3/14/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 2 Area Listing (all nodes) Area CN Description (acres) (subcatchment-numbers) 1.263 48 Mulch (1S) 2.577 61 >75% Grass cover, Good, HSG B (1S, 3S) 0.178 98 Paved parking, HSG B (1S) 4.018 59 TOTAL AREA Post Dev DA Post Dev DA Prepared by Shimp Engineering, P.C. Printed 3/14/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 3 Soil Listing (all nodes) Area (acres) Soil Group Subcatchment Numbers 0.000 HSG A 2.755 HSGB 1S,3S 0.000 HSG C 0.000 HSG D 1.263 Other is 4.018 TOTAL AREA Post Dev DA Post Dev DA Type H 24-hr I yr; 24 hr Rainfall=3.01 " Prepared by Shimp Engineering, P.C. Printed 3/14/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 4 Time span=0.00-72.00 hrs, dt=0.01 hrs, 7201 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1S: Post Development Drainage Area 1 Subcatchment3S: Post Development Drainge Area 2 Link 2L: Site Outfall Link 4L: Site Outfall Runoff Area=3.620 ac 4.92% Impervious Runoff Depth=0.28" Tc=11.2 min CN=58 Runoff=0.75 cfs 0.084 of Runoff Area=0.398 ac 0.00% Impervious Runoff Depth=0.37" Tc=5.0 min CN=61 Runoff=0.21 cfs 0.012 of Inflow=0.75 cfs 0.084 of Primary=0.75 cfs 0.084 of Inflow=0.21 cfs 0.012 of Primary=0.21 cfs 0.012 of Total Runoff Area = 4.018 ac Runoff Volume = 0.096 of Average Runoff Depth = 0.29" 95.57% Pervious = 3.840 ac 4.43% Impervious = 0.178 ac Post Dev DA Post Dev DA Type H 24-hr I yr; 24 hr Rainfall=3.01 " Prepared by Shimp Engineering, P.C. Printed 3/14/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 5 Summary for Subcatchment 1S: Post Development Drainage Area 1 Runoff = 0.75 cfs @ 12.08 hrs, Volume= 0.084 A Depth= 0.28" Runoff by SCS TR-20 method, UH=SCS, Time Span-- 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 1 yr, 24 hr Rainfall=3.01" Area (ac) CN Description 0.178 98 Paved parking, HSG B 2.179 61 >75% Grass cover, Good, HSG B + 1.263 48 Mulch 3.620 58 Weighted Average 3.442 95.08% Pervious Area 0.178 4.92% Impervious Area Tc Length Slope Velocity Capacity Description 11.2 Direct Entry, Time of Concentration Subcatchment 1S: Post Development Drainage Area 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 -r-r-r-r-r-r-r-r-r-r-r-r-r-r-rr-r rr-r r,-r,-,-,-,-,-,-�---�-,-,-r- 08 - - 0.75J-J-J- 075 / I/J� I� ii- "r- I- �- -r-r-r-r--r-r-r-r-r-r-r-r-rr-r rr-rr-,-r-, 0 7 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I jjrrJJ 0-65 1 -r-r-r-r--r-r-r-r-r-r-r-r-r-r-r-r-r-r-r-T-r-r-,-,-r-r-,-,-�-,-,-,-r- 0-6iafali�8.0�"- _L_L_L_Y 0-55 -r-r-r-r--r-r-r-r-r-r-r-T-r-T-T-r-r- 0.5 0.45 RUrfbff Vo1UrtWF'0j'084 Af_ -r-r-r-r- r r r r r r r-r-T-r-r-r-r 0.4 0.35 1 _ r -r- r - r -r- r -r-,- r -,- r -i- IC.�1 4.2- ib]nl- 0.3-r-r-r-r-r-r-r-r- -L-Y-'-Y- -~-*-f-~-*-f--*-'--'-'-L-'-'-'-'-4-4-4-'-'-J-'-J-J-Y-J-L- 0.25 I I I I 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 0-2 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 0-15 ----------------------- ----------------- 0 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 0-05 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 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) ■ Runoff Post Dev DA Post Dev DA Type H 24-hr I yr; 24 hr Rainfall=3.01 " Prepared by Shimp Engineering, P.C. Printed 3/14/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 6 Summary for Subcatchment 3S: Post Development Drainge Area 2 Runoff = 0.21 cfs @ 11.99 hrs, Volume= 0.012 A Depth= 0.37" Runoff by SCS TR-20 method, UH=SCS, Time Span-- 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 1 yr, 24 hr Rainfall=3.01" Area (ac) CN Description 0.398 61 >75% Grass cover, Good, HSG B 0.398 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Time of Concentration Subcatchment 3S: Post Development Drainge Area 2 Hydrograph 0.22 I I I I I I I I I I I I I I I I I I 1 II 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 I I I I I I I I I I I 'r 0.21 cfs 0.21 -L_L 0.2 -F-Y-F-h- -h-t-t-Y-t-t-t-t-i-t-i-Y-Y-Y-Y-Y-i-Y `F ZY���i !f O.,J I I -r-r-r-r- -r-T-r-r-T-r-T-T-T-T-T-T-T-T-T-T-T-T-T-T-T-T-Y-T-I- l- 018 V -- 1 1 1 I I I I 1 1-207 -T-r-r-r-r-r-r-r-r-r-r-r-r-r-r-�-r-�-�-�-�-T-1-I-1 017 1 1 1 1 1 1 1 1 1 1 1 1 1 1 O_1(�` 0.15 1 1 1 1 1 1 1 1 1 1 1 rea,= 0.14 -r-r-r-r- --r-r-r-r-r-r-r-rr-r-r-r-r T el^ + - 0.13....... 1 1 -r-r-r-T- 1 1 1 1 1 1 1 1 1 1 1 1 1 1 -r-r-r-r-r-r-r-r-r-r-r-r-r 0.12 - r 00.1 _L_L_L_L_ 1 1 _L_L_L_L_L_L_1_L_1_1_1_1_1_1_1_1 ��1„_1^_ 1 1 1 1 1 1 1 1 1 1 LL O., -L_L_L_L_ _L_1_L_L_1_L_1_1_1_1_1_1_1_1_1_1"wJx 1, LIIVVV// wJxff !f O.OJ -r-r-r-Y- -Y-Y-T-r-T-T-T-T-T-T-T-T-T-t-T-Y-Y-Y-Y-Y-Y- � Anr- 0.08 -r-r-r-T- -T-T-r-r-T-r-T-T-T-T-T-T-T-T-T-T-T-T-T-7-T-T 0.07 _I---I-I- ---------------------I-I-I I_■}�_ I_ T 006 _L_L_L_L_ _L_L_L_L_L_L_1_L_1_L_1_1_L_1_1_1_1_1_ J_ J_ J_ J_ J_J_ Y 0.05 -`-`-`-L- !� U.04 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 4 0.03 -r-r-r -r- 1 1 r-r-r-r-r-r-r-r-r-r-r-r-r-r-T-r-�-T-7-�-T-7-�-7-7-�-7-r- 0.02 I 11 I 1 I I I I I I I 1 1 I I 1 I I 1 I 1 1 I 1 I 0.01 Time (hours) ■ Runoff Post Dev DA Post Dev DA Type H 24-hr I yr; 24 hr Rainfall=3.01 " Prepared by Shimp Engineering, P.C. Printed 3/14/2023 HydrOCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 7 Summary for Link 2L: Site Outfall Inflow Area = 3.620 ac, 4.92% Impervious, Inflow Depth = 0.28" for 1 yr, 24 hr event Inflow = 0.75 cfs @ 12.08 hrs, Volume= 0.084 of Primary = 0.75 cfs @ 12.08 hrs, Volume= 0.084 A Atten= 01/o, Lag= 0.0 min Primary outflow = Inflow, Time Span-- 0.00-72.00 hrs, dt= 0.01 hrs Link 2L: Site Outfall Hydrograph I -r-r-------- I I I I I I I I I I I I I I I I I -�-�-7-7-r-r-r-r-r-r-I- r-r-r -r-r-r 0-8 o 7C JJ I I I I I I I I I I I I I I I I I I I I I I I I I rLc y _y I y1J Ira;�,- � I '�'M"s'�.w�w.� ,- �- �- I I � 1 1 1 1 1 �� Area 61 0.75 1I I I I I I I I I I I I I I I I I I I �*-r-r-r-r-r 0.7 / _L _L 0.65 I I 1 1 1 0.6 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 1 1 I 1 1 1 1 I 1 1 1 I 1 1 1 I 1 1 1 1 I 1 1 1 L__ 0.5 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 N _r_r �-i_i_ 0.45 I_i_i_i_i_r_I 3 0.4 O 035 1 1 1 1 I 1 1 I 1 1 1 I I 1 1 1 I 1 1 I 1 1 I 1 I 1 1 I 1 1 0.3 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 / 0.25 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 1 1 1 1 02 -Ir-i-I� -I-1-r-r-r-r-r-r-r-r 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 , _L_L__ _1_L_L_L_1__I_J_J_J_J_J_J_J_J_1_1_1_L_L_L_L _L 0.1 0.1 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 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) ■ Inflow ■ Primary Post Dev DA Post Dev DA Type H 24-hr I yr; 24 hr Rainfall=3.01 " Prepared by Shimp Engineering, P.C. Printed 3/14/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 8 Summary for Link 4L: Site Outfall Inflow Area = 0.398 ac, 0.00% Impervious, Inflow Depth = 0.37" for 1 yr, 24 hr event Inflow = 0.21 cfs @ 11.99 hrs, Volume= 0.012 of Primary = 0.21 cfs @ 11.99 hrs, Volume= 0.012 at Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span-- 0.00-72.00 hrs, dt= 0.01 hrs O.T. 0.1' 0.1 0.11 0.1', OA 0.1', at e 0.1 u 0. 0.01 Link 4L: Site Outfall Hydrograph _L_L J_J_1_1_1_1_1_ L_ L_L 0.2� i r r r r-- nflow Area-93W_ r-�-�-r-r-T-r-r-r-r-r-r- I I I I I I I I I I I I I I I I --I- _L_L__ _L_4_{_;_y_y_L_L_L_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 1 1 -r-I-7-1-I-T-T-T-T-T-r-r-r I I I I I- I- l- l- l- l- T- T- r- r -r -r -r _L_L__J_J_J_1_1_L_L_L_L_L_L_1_J_J_J_J_L_J_J_J_J_1_1_1_ L_L_LJ_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 L_L-IL_L_L_L_L -r-r- Y_T- 4- -r I ,' -r-r-- ��-�-�-�-r-r-r-r-r-r-r-r-r-r-I--1--rr--I--1-�- r-T-r-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 1 1 1 1 1 1 1 1 1 1 1 1 I I i I I I 1 I I _______I _I _I__1__I__I__I_ I__________________ 1 J1 _J1 _1_1_L_L_L_L_L_L_I__I__I_J_J_J_J_J_J_J_J_1_L_L_L_L_L_L 1 1 I _r_r__1_1_4_4_T_T_T_T_T_r_r_I__I__I__I__I__I_-I_1_Y_l_4_Y_T_r_r_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 y -+- { -f- f 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 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) ■ Inflow ■ Primary Post Dev DA Post Dev DA Type 1124-hr 10 yr; 24 hr Rainfall=5.51 " Prepared by Shimp Engineering, P.C. Printed 3/14/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 9 Time span=0.00-72.00 hrs, dt=0.01 hrs, 7201 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1S: Post Development Drainage Area 1 Subcatchment3S: Post Development Drainge Area 2 Link 2L: Site Outfall Link 4L: Site Outfall Runoff Area=3.620 ac 4.92% Impervious Runoff Depth=1.46" Tc=11.2 min CN=58 Runoff=7.34 cfs 0.440 of Runoff Area=0.398 ac 0.00% Impervious Runoff Depth=1.69" Tc=5.0 min CN=61 Runoff=1.23 cfs 0.056 of Inflow=7.34 cfs 0.440 of Primary=7.34 cfs 0.440 of Inflow=1.23 cfs 0.056 of Primary=1.23 cfs 0.056 of Total Runoff Area = 4.018 ac Runoff Volume = 0.496 of Average Runoff Depth = 1.48" 95.57% Pervious = 3.840 ac 4.43% Impervious = 0.178 ac Post Dev DA Post Dev DA Type 1124-hr 10 yr; 24 hr Rainfall=5.51 " Prepared by Shimp Engineering, P.C. Printed 3/14/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paize 10 Summary for Subcatchment 1S: Post Development Drainage Area 1 Runoff = 7.34 cfs @ 12.04 hrs, Volume= 0.440 A Depth= 1.46" Runoff by SCS TR-20 method, UH=SCS, Time Span-- 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 10 yr, 24 hr Rainfall=5.51 " Area (ac) CN Description 0.178 98 Paved parking, HSG B 2.179 61 >75% Grass cover, Good, HSG B + 1.263 48 Mulch 3.620 58 Weighted Average 3.442 95.08% Pervious Area 0.178 4.92% Impervious Area Tc Length Slope Velocity Capacity Description 11.2 Direct Entry, Time of Concentration Subcatchment 1S: Post Development Drainage Area 1 -r-r __I_ 1__I__I__I__�__I__I__ r -- -. r_t_ 8 i t I I p I I i I II i I i I i i I i I II I I I I I I 7.34 ctJ -I ----------- Type II 24-hr 10 r- 7 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I -I -I -I -I -24 he 1 I I I IRainfall^5.151 I I I I I I I I I I I I I I I I I I I I I I I " 5 IR unoif Area=3.I 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 p I I I I I I I I I I I I I I I I R I I I I I I A l l Q�iol'ffL�oJ�rri�,(1t44��f- I 4� I I I I I I I I I I I I I I I I I I I I Un�offiDlle� fhl=l. �/yw " LL iii 3- T& 11'1.2 Mirl I I I I I I I I 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--1-1-,-1-J-,-J-J-J- I-J- �--I- I--I--I--I--L-L-L-L-L-L-L- r 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 L-L-L-L-L_L-L-1-1-1-�- 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 III I�III�III 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 Time (hours) ■ Runoff Post Dev DA Post Dev DA Type 1124-hr 10 yr; 24 hr Rainfall=5.51 " Prepared by Shimp Engineering, P.C. Printed 3/14/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paize 11 Summary for Subcatchment 3S: Post Development Drainge Area 2 Runoff = 1.23 cfs @ 11.97 hrs, Volume= 0.056 A Depth= 1.69" Runoff by SCS TR-20 method, UH=SCS, Time Span-- 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 10 yr, 24 hr Rainfall=5.51 " Area (ac) CN Description 0.398 61 >75% Grass cover, Good, HSG B 0.398 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Time of Concentration Subcatchment 3S: Post Development Drainge Area 2 Hydrograph I � � I � I � I I � I � � � � � I � I I I I � � I ❑Runoff 1.2 cfs �I�II�I�II� �I �IIII I I�I�II�I�II�I�II� Ty�pe'II'24-hr 10 yr I�I�II�I�II�I�II�I 24 nF_ I�I�II�I�II�I�II�I� _ irl aainfall`^5.511 I�II�I�II�I�I � II�II� I :Runoff AFna=p-398 as I�I�II�I�II�I�I I�II�I�II�I�I I�II� I RUlloff.Vo'IUr lidl=* 56 9f I�II�I�II� �I � I�II� I Runoff beOih=1.60'4 I� I� I ! TO=5-Q injo �II�I�II�I�II�I�II�II I�II�I�II�I�II�I�II�II�I�II Time (hours) Post Dev DA Post Dev DA Type 1124-hr 10 yr; 24 Air Rainfall=5.51 " Prepared by Shimp Engineering, P.C. Printed 3/14/2023 HydrOCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paye 12 Summary for Link 2L: Site Outfall Inflow Area = 3.620 ac, 4.92% Impervious, Inflow Depth = 1.46" for 10 yr, 24 hr event Inflow = 7.34 cfs @ 12.04 hrs, Volume= 0.440 of Primary = 7.34 cfs @ 12.04 hrs, Volume= 0.440 A Atten= 01/o, Lag= 0.0 min Primary outflow = Inflow, Time Span-- 0.00-72.00 hrs, dt= 0.01 hrs Link 2L: Site Outfall Hydrograph -r-r-.-r-r-r- ■ Inflow 8 ■ Primary 7.34 cfs InflovN 7Atr6a#I- 3� :i626 'laic: I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I i I I I I I I I I I I I I I I I I I s I I J_J_J_J_J_1_J_J_1_1_1_L_1_L_L_L_L_L 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 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 ,E -----'--'--'-J-J-J-�-J-J-1-J-1-1-1-1-L-L-L-L-L-L-L-L-L-L-L-'--'-- O I I 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 4 O 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 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 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 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 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) Post Dev DA Post Dev DA Type 1124-hr 10 yr; 24 hr Rainfall=5.51 " Prepared by Shimp Engineering, P.C. Printed 3/14/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paye 13 Summary for Link 4L: Site Outfall Inflow Area = 0.398 ac, 0.00% Impervious, Inflow Depth = 1.69" for 10 yr, 24 hr event Inflow = 1.23 cfs @ 11.97 hrs, Volume= 0.056 of Primary = 1.23 cfs @ 11.97 hrs, Volume= 0.056 A Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span-- 0.00-72.00 hrs, dt= 0.01 hrs Link 4L: Site Outfall Hydrograph I I I I I I I I I I I I I I I I I I I I I I I ■ Inflow ■ Primary 1.23 cfs II II ' 1416v f Ilar6e—T6.i39$ laic: I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 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 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 o 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 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 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 50 52 54 56 58 60 62 64 66 68 70 72 Time (hour:) Post Dev DA Post Dev DA Type H 24-hr 100 yr, 24 hr Rainfall=9.04" Prepared by Shimp Engineering, P.C. Printed 3/14/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 14 Time span=0.00-72.00 hrs, dt=0.01 hrs, 7201 points Runoff by SCS TR-20 method, UH=SCS Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Subcatchment 1S: Post Development Drainage Area 1 Subcatchment3S: Post Development Drainge Area 2 Link 2L: Site Outfall Link 4L: Site Outfall Runoff Area=3.620 ac 4.92% Impervious Runoff Depth=3.89" Tc=11.2 min CN=58 Runoff 20.73 cfs 1.172 of Runoff Area=0.398 ac 0.00% Impervious Runoff Depth=4.26" Tc=5.0 min CN=61 Runoff3.15 cfs 0.141 of Inflow=20.73 cfs 1.172 of Primary=20.73 cfs 1.172 of Inflow=3.15 cfs 0.141 of Primary=3.15 cfs 0.141 of Total Runoff Area = 4.018 ac Runoff Volume = 1.313 of Average Runoff Depth = 3.92" 95.57% Pervious = 3.840 ac 4.43% Impervious = 0.178 ac Post Dev DA Post Dev DA Type 1124-hr 100 yr, 24 hr Rainfall=9.04" Prepared by Shimp Engineering, P.C. Printed 3/14/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paize 15 Summary for Subcatchment 1S: Post Development Drainage Area 1 Runoff = 20.73 cfs @ 12.03 hrs, Volume= 1.172 A Depth= 3.89" Runoff by SCS TR-20 method, UH=SCS, Time Span-- 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 100 yr, 24 hr Rainfall=9.04" Area (ac) CN Description 0.178 98 Paved parking, HSG B 2.179 61 >75% Grass cover, Good, HSG B + 1.263 48 Mulch 3.620 58 Weighted Average 3.442 95.08% Pervious Area 0.178 4.92% Impervious Area Tc Length Slope Velocity Capacity Description 11.2 Direct Entry, Time of Concentration Subcatchment 1S: Post Development Drainage Area 1 22 21113 .--.-7 -_-___--rrLrLrIIIIII rrrLrFLrIII -_-___--- �ri;FLr-II'IIII2 -_-___---0 � s r*FTLFTIIIIIr --f-----3rLI'III_IFrILFr �I1Jy�IIIII ----- _�-_-_-�v- ---- 3-c*f----__- 0 28551 - O 1------^^ O7 T.FT1F*'IIIII T-_-�--_-• ! 17 -r-r-T- _Ir_r_r_r_r_r_'_.I_Y_Y_.I_ 1-1- r-rrTI -rI -T '� 16 - 90IIII'II L_i-^ uln �^-lJ--_-• 14 - ,3 t1------�1+yY'��IIIII �r------1-1-�-_-IlllIIIIIIIIIIII 12 -r-r-r-T j_1_1 LL0 10 L-L_L unnRO__C • _- 96 T2&-----���YJ��IIIIII �II1I`II -T-T-T-T- 7 _r_r_r_T -1-1-1-1--I- -r-r-r-r-r-r-r-r-1-1-1- - 6 I I I I - 4 _I _I _I _F _I - 32- - 12 34 36 38 40 42 44 Time (hours) ■ Runoff Post Dev DA Post Dev DA Type H 24-hr 100 yr, 24 hr Rainfall=9.04" Prepared by Shimp Engineering, P.C. Printed 3/14/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paize 16 Summary for Subcatchment 3S: Post Development Drainge Area 2 Runoff = 3.15 cfs @ 11.96 hrs, Volume= 0.141 A Depth= 4.26" Runoff by SCS TR-20 method, UH=SCS, Time Span-- 0.00-72.00 hrs, dt= 0.01 hrs Type II 24-hr 100 yr, 24 hr Rainfall=9.04" Area (ac) CN Description 0.398 61 >75% Grass cover, Good, HSG B 0.398 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Time of Concentration Subcatchment 3S: Post Development Drainge Area 2 Hydrograph I I I I I I I I I I I I I I I I II II I I I I 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 ❑ Runoff 3,15 cfs l I I I I I I I I I I I I I I I I I II I 3 Type 11 24rhr11Q®-yr I I I I I I I I I I I I I I I I . I I I I I I I I I I I I I I I I I I I I I I jr� F I I I I I I I I I I I I I I 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; II ( I I I I I I I I. Vainfall^9.04" I I I I I I I I I I I I I I I I I I I I I I I I I I I I I ( I I I I I I I I I I I I I I -i------------------------�--I- Ruofa=pa - nA" 2 I 11 I 1 1 I 1 I 1 1 RUF1of:V01Un16=*A41 9f 1 I 1 I 1 1 I 1 I 1 1 I 1 I 1 11 I I 1 I 1 1 I 1 I 1 1 LL I I I I I I I I I I I I I I kunloff DGOih=4.126'1 I I I I I I I I I I I I I I I I I I I I I I I T =S.QiN 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Il��icNr61 11 I 1 1 I 1 1 1 1 I 1 I 1 1 I 1 1 1 1 I 1 1 I 1 I 1 1 11 I 1 1 I 1 1 1 1 I 1 I 1 1 I 1 1 1 1 I 1 1 I 1 I 1 11 I 1 1 I 1 1 1 1 I 1 I 1 1 I 1 1 1 1 I 1 1 I I I I 11 I 1 1 I 1 1 1 1 I 1 I 1 1 I 1 1 1 1 I 1 1 I I I I I 11 I 1 1 I 1 1 1 1 I 1 1 1 1 I 1 1 1 1 I 1 1 I I I 11 I 1 1 I 1 1 1 1 I 1 1 I 1 1 I I I I Time (hours) Post Dev DA Post Dev DA Type H 24-hr 100 yr, 24 hr Rainfall=9.04" Prepared by Shimp Engineering, P.C. Printed 3/14/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Pale 17 Summary for Link 2L: Site Outfall Inflow Area = 3.620 ac, 4.92% Impervious, Inflow Depth = 3.89" for 100 yr, 24 hr event Inflow = 20.73 cfs @ 12.03 hrs, Volume= 1.172 of Primary = 20.73 cfs @ 12.03 hrs, Volume= 1.172 at Atten= 0"1 Lag= 0.0 min Primary outflow = Inflow, Time Span-- 0.00-72.00 hrs, dt= 0.01 hrs Link 2L: Site Outfall Hydrograph -' - I - ' -I- I I I I I I I I I I I I I I I I I I I --- IIII 23 / - Ir - II- - I- -i- -I-- T 22 20.73cfs IT'��}� I r J J �i�� 2� _r _i____ ___i_ -I -I -I -I ---I-y---I-y-y �F��AW =.9EV1G- 26 .19 I 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-J--I-J-J-J-J-J-J-J-J-1-1-1-1-1-1-1-L-L-i_L- i 17 16 - ----------I- T- T-T- T- T-T-T-T-T-T-T I I I �--'--'--'--'--'-J-J--'-J-J-J-J-J-J-J-J-J-L-L-J-L-L-L-L-J-L-L- I I I I I I 14 .� 13--I--r-I--r-I-1-1--I-1-1-1-1-1-�-l-I-T-T-T-T-T-T-r-r-T-r-r- V 11 ' , ______ ____� _i _I__I_7 l__I_j j 7_7_i _T_T_i _T O LL 10 9 I 8 7 6-I - -I -I -I -I -I ---I-7----7-7-7-7-7-7--+-+-r-+-+-r-r-r-r-r-r _I I I I 4 ' -L-'- '--'--'-J-J--'-J-J--'-J-J-J-J-J-J-J-J-1-1-1-J-1-1-L-L-1-L-L- I 2 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 50 52 54 56 58 60 62 64 66 68 70 72 Time (hours) ■ Inflow ■ Primary Post Dev DA Post Dev DA Type H 24-hr 100 yr, 24 hr Rainfall=9.04" Prepared by Shimp Engineering, P.C. Printed 3/14/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paye 18 Summary for Link 4L: Site Outfall Inflow Area = 0.398 ac, 0.00% Impervious, Inflow Depth = 4.26" for 100 yr, 24 hr event Inflow = 3.15 cfs @ 11.96 hrs, Volume= 0.141 of Primary = 3.15 cfs @ 11.96 hrs, Volume= 0.141 A Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span-- 0.00-72.00 hrs, dt= 0.01 hrs Link 4L: Site Outfall 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 ■ Inflow �-.�I I I I I I ICI, I I 1� I � � ■ Primary 3.15cfs I I inflo%iirAP6i—V.'3go'a:c 3- 2- 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 50 52 54 56 58 60 62 64 66 68 70 72 Time (hour:) Floor Predev Flowrates Postdev Flowrates Reduction Check Storm cfa Storm cf 1-yr 1-yr 0 5 Achieved 10-yr 10-yr 7.34 Predev Reduced 664 West Rio Energy Balance Equation Summary: Site Outfall 24 Hr 1 year Storm Comparison: Q�dopmj� I.F.'(Qy,ed„vw,d RVP-oo.a VdryI�d Qd,oi,ed<MQ .„ 'RVf.,,,,,d)/Rv�,u w LF. = 0.8 1. Limits of Disturbance 4.02 ac Qn.rd., e,mm — 52 RVn,-o,.emped = 0.121 DA 11 DA 21 Total I I I DA 11 DA 21 Total 1.52 1 0.21 1 1.73 1 1 1-yr 1 0.75 1 0.21 1 0.96 9.15 1 1.23 110.381 1 10-vr 1 7.34 1 1.23 1 8.57 664 West Rio (Tree Removal Only) Time of Concentration Calcdations Pre Dev DA 1 to Siteoutfall 1 TOC (Onsite) 100ft Overland Flow 1 10.20% slope 0.35 C-value 7.9 min Seelye Chart 241.5 ft S.C. Flow 1 8.28% slope 1.9fps velocity 2.1 min. NEH Figure 15-4 205.Oft Channel 25.Oft height 1 1.2 min. Kirpich Chart T0C=j 11.2 min. Appendix 6D-1 Overland Flow Time - Seelye 42 -1.0 S-D.19 O Tc= 0.225 L0 = Ov,WrM Flow T1. mn•Aes I =r nglh or Sol, real 35 S •.Slope er~ C = Rehanel'C V.I. lor Gro.m Ch»Gee Boo 30 Soo Paved 0.9 400 0.8 25 - 0.7 300 0.6 n Bare 20 ' 200 Soli 0.5 z \\\� tu Poor 0 LL fa59 Su J 0.5 -eeeelrGrass\ 0 0.3 Q °- 100 1.0 0 \ �5�' O ¢ 90 Surface in��� BO Dense,\\ .0 \ v old l- 70 \ 5. ull 0.2 Z W � 60 i�� 10 w i \ / L~7 50 20 U U 40 t� u 30 0 9 ¢ z F 8 20 O Aoticrial "C' voiue 4v Seleoleo Orourio CRoroceer 07ae Oroaa 0.215 Fvaa1 0.25 7 51Graze Surface 0.2e oen 0.]0 voor Graee Suripce 0.36 Ppeture 0.40 B 10 5Qe Sol 0.49 Pa.ro 0.90 OVERLAND FLOW TIME REPRINTED WITH PERMISSION FROM "DATA BOON FOR CIVIL ENGINEERS" vOL. I - DESIGN 2n0 EDITION 119511 BY E. E. SEI SI NVENGINEERING, P.C. EAMI ELUyG-MADPLANMNG-PRQIEL7MANA6EAFM 112 40 .1-.r�o ES LLE. V. a,1e= . w.a Ma_E < eEr . oM 1.00 0.90 0.80 0.70 0.60 0.50 0.40 0.30 0.20 0.10 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0.005 0 4V O b O [- W WO GV CJ W 0 [- of w o b 0 O CS O O O O O Ori N Velocity (fr/B) 664 West Rio (Tree Removal Only) Pre Development Drainage Area 1 Time of Concentration TRAVEL TIME FOR CHANNEL FLOW (Kirpich Chart) H (feet] 500 Tc (min.) 200 100 100 L (feet) 10000 a Ex8OF1e 50 'o 50 GOOD 0 6 Note: o u no (1) For use with natural channels; a 0 10 ( or paved channels, m0ltiply Tt 0.2 1000 10 E £ 5 a 500 5 100 1 1 TIME OF CONCENTRATION OF SMALL DRAINAGE BASINS Source: VDOT V-13 Plate 5-3 I I 664 West Rio(Tree Removal Only) Time of Concentration Calculations Post Dev DA 1 to Siteoutfall 1 TOC (Onsite) 100k Overland Flow 30.20h/a slope 0.35 C-value 7.9 min Seelye Chart 241.5 ft S.C. Flow 8.28% slope 1.9 fps velocity 2.1 min. NEH Figure 15-4 205.0ft Channel 25.0ft height 1.2 min. Kirpich Chart TOC= 11.2 min. Appendix 6D-1 Overland Flow Time - Seelye 42 -1.0 Tc= 0.225 Lo S-D.19 O Te = OMrIaM Flow Thee, mnrAe4 I =r nglh or Sol, real 35 G -.S" er~ C = Rahanel'C V.I. br Gro.m Ch»Gee Boo 30 Soo Paved 0.9 400 0.8 25 - 0.7 300 0.6 n Bare 20' 200 Soil 0.5 z \\\� tu Poor 0 LL fa59 Su J 1- 0.5 Grass\ 0 0.3 Q 15�' °- 100 1.0 0 \ O ¢ 90 Surface in��� BO Dense,\\ .0 \ l�. v 01155 W Z 70 \ 5. 0.2 W � 60 i�� 10 w i \ / L~7 50 20 U U 40 c0 u 30 0 9 ¢ � z F 8 20 O Aa11mal "C' vowe far Sweated Grauno Cnorocrer oor- Oroaa 0.215 Fvaat 0.25 7 /,110 Graze Surface 0.2e nen O.]O Poor Graze Surioce 0.36 ,"lure 0.40 B 10 Bore Soli 0.4e Pa.ro 0.90 OVERLAND FLOW TIME REPRINTED WITH PERMISSION FROM "DATA BOON FOR CIVIL ENGINEERS" vOL. I - DESIGN 2n0 EDITION 119511 BY E. E. SEELYE SI NVENGINEERING, P.C. EAMWEUNG-MADPLANMNG-FRQIEL7MANA6EAFM 112 40 .1-.RLo ES LLE. V. a,1e= �ar..a Ma_E < eEr . oM 1.00 0.90 0.80 0.70 0.60 0.50 0.40 0.30 0.20 0.10 0.09 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 0.005 0 IN O 0 O CS O O O O O Ori N Velocity (fr/B) 664 West Rio (Tree Removal Only) Post Development Drainage Area 1 Time of Concentration TRAVEL TIME FOR CHANNEL FLOW (Kirpich Chart) H (feet] 500 Tc (min.) 200 100 100 L (feet) 10000 a Ex8OF1e 50 'o 50 GOOD 0 6 Note: o u no (1) For uae with natural channels; a 0 10 ( or peveE channels, multiply Tt 0.2 1000 10 � E £ 5 a 500 5 100 1 1 TIME OF CONCENTRATION OF SMALL DRAINAGE BASINS Source: VDOT V-13 Plate 5-3 I I SHIMP ENGINEERING, P.C. Design Focused Engineering Water Quality Calculations: Pre -Development VRRM Land -use Map Post -Development VRRM Land -use Map VRRM Redevelopment Spreadsheet - 1 VRRM Redevelopment Spreadsheet - 2 VRRM Redevelopment Spreadsheet - 3 ® PRE DEV IMP. PRE DEV TURF. ® PRE DEV WOODS. - LTC - LIMITS OF TREE CLEARING ------- SOILS NOTE: ALL SOILS IN i LIMITS OF TREE 7 CLEARING ARE HSG B ------------------ - BoX W W WW. 45-100A W , .y UNITS a ,rSc (Lm)a I.mn / 7E;_ 1- W. 45-1000 lJ v y W W CWI. W W W W/ C TM. 45-1J3 7G TIN. 45-100 W rH G B f S W O W LTC 00 W W I`W FO '0 W. 45-948 W W W ��Yur �jG I W. 45-101411. 41, W ' W W W l�C t W W l` 27B, W HSG B` 4CW W ♦ ti ` SGN B o WI1508 TREE , W / CLEAAMO (LTC}LbAC W /A i0P C£Bg MCHARK pIINLET '• ELEVATION-527.78 ,, W ny A i /t W W - - - - • _. 1 _. _ swMPENGINMRING, P.C. 30MINT AID= ESNT. D.B. 107 127 D.B. I0M_b5 B,T 60 0 60 120 180 664 West Rio (Tree Removal Only) EA'6BffM7,,6.L4AD,MfflN6_pR0ffaAMNA6E, .„.„�0T7ItS—E. VA „>02 �. N.„I„a-E <„EER °oM Pre Development VRRM Map sale: 1 „=60' ® POST DEV IMP. POST DEV TURF. LTC — LIMITS OF TREE CLEARING ------- SOILS NOTE: ALL SOILS IN LIMITS OF TREE CLEARING ARE HSG B SNIMPENGINEERING, P.C. EAM ELUNG-LANDPLANMNG-PRaffb7MANA6EAFM 40 .HARLOTTES—E. VA „Pe= .I..sHINa-E <PH�EENN . OM W. 45-1000 5 � W W W W W W W W W W W O x _ ------------- i i a x\ W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W TAk 45i0013 W W W W W W W W W W W 1M. 45-1 J3 Q W W W" W W W W W W W W W W W W W W W W W W \ W W N W W W W W W W W W W W W W W W W W W W W W W W W W W W W \ Box r W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W CW.' 1.1 L 1/ , W. 45-100A t7 'Y 'Y W W W W W . H- W W W W �SW. J# It 1 y W W W W W W W W W W W'L/ W I1M118 Cf W W W W W n l'Y I arrmc (LTCJ�1.18AC � �1 W W W_E�rx W W W rH G B W LTc W� -i MOO W W W W �WWWWW�WWWWW wLTC FFO �W W yl p W W W W W W� LTC W W W LTC 001IIIIIIIIII' LiC yr� 27B � HSG B + BENCHMARK: t TOP C£ INLET ELEVATONON- �S2].]B -'- + , ,�.LTC TM. 45-100 1 y r �11 rrjj� W W. 45-101 ' 4A W W n't4C i SGB P WI15 Of W CLEARMO (LTC}1.bAC , W W n n W W ny W LTC ETC LJ LTC 0 30MINT ACCESS ESMi. D.B. 107 127 D.B. 10�5-bs PLAT 664 West Rio (Tree Removal Only) Post Development VRRM Map _5rc 60 0 Scale: 1 W. 45-94B ti 120 180 DEQ Virginia Runoff Reduction Method Re -Development Compliance Spreadsheet - Version 3.0 L:2011 B M P Standards and SpecificationO 2013 Draft B M P Standards and Specifications Project Name: 664 West Rio (Tree Removal Only) data input cells Date: 3/16/2023 constant Values Linear Development Project? No calculation cells Site Information Post -Development Project (Treatment Volume and Loads) Enter Total Disturbed Area (acres) 4 1.a6 Check., BMP Design Specifications List. 2013 Draft Stds & Specs Linear project? No '0 Land cover areas entered correctly? ✓ a Total disturbed area entered? ✓ Pre-ReDevelopment Land Cover (acres) A Soils BSoils CSoils DSoils Totals Forest/Open Space (acres) -- undisturbed forest/open space 0.59 0.59 Managed Tuff (aue) -- disturbed, graded for yards or other tuff to be w moed/managed 0.82 0.82 Impervious Cover (acres) 0.07 0.07 1.48 Post -Development Land Cover (acres) A soils BSoils CSoils DSoils Totals Forest/Open Space (acres) -- undisturbed, protected forest/open spare or reforested land 0.00 Managed Tuff (aue) -- disturbed, graded for yards or other tuff to be mowed/managed 1.41 1.41 Impervious Caver(acres) 0.07 0.07 Area Check OK. OK. OK. OK. 1.48 Constants Runoff Coefficients Rv Annual Rainfall (inch.) 43 ASoils BSoils cSoils DSoils Target Rainfall Event(inchesl 1.00 Forest/Open Space 0.02 0.03 0.04 0.05 Total Phosphorus (TP) EMC (mgi 0.26 Managed Turf 0.15 0.20 0.22 0.25 Total Nitrogen (TN) EMC(mg/L) 1.86 Impervious Cover 0.95 0.95 0.95 0.95 Target TP Load(lb/acre/W) 0.41 Pj (u nitless correction factor( aw L • • •' • COVER SUMMARY POSTDEVELOPMENT Land Cover Summary -Pre Land Cover Summary-Post(Final) Land Cover Summo195% Land Cover Summary -Post Pre-ReDevelopment Listed Adjusted' Post ReDev. & New Impervious Pna[-ReDevelopPost-Develo t New Im omen pervious Forest/Open Space Forest/Open Space Forest/Open Space Cover (acres) 0.59 0.59 000 Cover (acres) Cover(acresl Weighted Rv(forest) 0.03 0.03 Weighted Rv(Wrest) 0.00 Weighted Rv(forest) %Forest 40% 40% %Forest 0% %Forest Managed Tuff Cover (acres) 0.82 0.82 Managed Tuff Cover 141 Managed Tuff Cover (acres) (acres) Weighted RvWi 0.20 0.20 Weighted Rv (tuff) 0.20 Weighted Rv (tur0 %Managed Tuff 55% 55% %Managed Tuff 95% %Managed Tuff Impervious Cover (acres) 0.07 0.07 Impervious Cover (acres) 0.07 ReDev. Impervious 0.07 Impervious Cover 0.00 cover(acresl (acres) (acres) Rvjmpervious) 0.95 0.95 Rv(impervious) 0.95 Rv(im,xmious) 0.95 Rv(impervious) - %Impervious 5% 5% %Impervious 5% %Impervious 5% Total Site Area (acres) 1.48 1.48 Final She Area (acres) 1.48 Total R4Dev. Site Area 1.48 (aim) Site Rv 0.17 0.17 Final Post Dev She Rv 0.24 ReDev Site Rv 07A Treatment Volume and Nutrient Load Treatment Volume and Nutrient Load Pont-DmmI.Pn em Pre-ReDevelopment Treatment Volume Final Post -Development Post-ReDevebpment (acre-ft) 0.0207 0.0207 Treatment Volume (acre-hl 0.0290 Treatmem Volume (aue-ftl 0A290 Treatment Volume -- tacre-R) Pre-ReDevelopment Treatment Volume Final Post -Development Post-ReDevelopment Post-0evelopment (Dnbic feat) 901 901 Treatment Volume 1,265 Treatmem Volume 1,265 Treatment Volume (cubic - (cubicfeet) (cubicfeet) feet) Pm-ReDevelopment TP Load Final Port- Port-ReaevM ekipme Por eve t-Dlopment TP Load (Ib/yr) 0.57 0.57 * Development TP Load 0.79 * Load (TP) 0.79 (Ib/yr) IIb/yr) (lb/yr)• hPRenevelapmen[TP toad pera[re * Final Post -Development TP POSCRenevelopmei (IbnentTPr) O.Ba O.ae toad peraore 0i toad cram, 0.54 pb/../Vl Ilb/acrei Baseline TP Load jb/yr) Max. Reduction Required (OAS Ibs/acre/yr applied to are -redevelopment area excluding pervious 0.61 (Below Pre- Zoe IaM proposed for new Impervious cover) ReDevelopment Load) ' Adjusted Land Cover Summary: TP Load Reduction TP Load Reduction Pre ReDevelopment land rover minus pervious land cver(/oresVopeo space or managed * Required for 0.19 Required for New 0 turf) acreage proposed for newimormious rover. Redeveloped Area Impervious Area (Ib/yr) IIb/yr) Adjusted tom( acreage is consistent with Post-ReDevelopment acreage (minus acreage of *Reduction below new development land newimperviouscover). limitation not required Column Isirows land reduction requdement for new impervious rover (bored on new development load limit, 0.4116s/acre/year). Post -Development Requirement for TP Load Reduction Required (Ib/yr) 0.19 Nitrogen Loads (Informational Purposes Only) Final Post -Development TN Load Pre-ReDevelopment TN Wad(Ib/yr) 4.05 (Port-ReDevelopment&New Impervious) 5.69 (Ib/yr) Site Results (Water Quality Compliance) Area Checks D.A. A D.A. B D.A. C D.A. D D.A. E AREA CHECK FOREST/OPEN SPACE (ac) 0.00 0.00 0.00 0.00 0.00 OK. IMPERVIOUS COVER(ac) 0.00 0.00 0.00 0.00 0.00 OK. IMPERVIOUS COVER TREATED(ac) 0.00 0.00 0.00 0.00 0.00 OK. MANAGED TURF AREA (ac) 0.00 0.00 0.00 0.00 0.00 OK. MANAGED TURF AREA TREATED (ac) 0.00 0.00 0.00 0.00 0.00 OK. AREA CHECK Site Treatment Volume (ft3) 1,z6s Runoff Reduction Volume and TP By Drainage Area D.A. A D.A. B D.A. C D.A. D D.A. E TOTAL RUNOFF REDUCTION VOLUME ACHIEVED (R) 0 0 0 0 0 0 TP LOAD AVAILABLE FOR REMOVAL (Ib/yr) 0.00 0.00 0.00 0.00 11 0.00 0.00 TP LOAD REDUCTION ACHIEVED (Ib/yr) 0.00 0.00 0.00 0.00 0.00 0.00 TP LOAD REMAINING (Ib/yr) 0.00 0.00 0.00 0.00 0.00 0.00 NITROGEN LOAD REDUCTION ACHIEVED (Ib/yr) 0.00 0.00 0.00 0.00 0.00 0.00 Total Phosphorus FINAL POST-DEVELOPMENTTP LOAD (Ib/yr) 0.79 TP LOAD REDUCTION REQUIRED (Ib/yr) 0.19 TP LOAD REDUCTION ACHIEVED (Ib/yr) 0.00 TP LOAD REMAINING (Ib/yr): 0.79 REMAINING TP LOAD REDUCTION REQUIRED (Ib/yr): 0.19 Total Nitrogen (For Information Purposes) POST -DEVELOPMENT LOAD (Ib/yr) 5.69 NITROGEN LOAD REDUCTION ACHIEVED (Ib/yr) 0.00 REMAINING POST -DEVELOPMENT NITROGEN LOAD (Ib/yr) 5.69 Ngne RUM.- ene. Wonan¢I OEQ Virginia Runoff Reduction MCNotl RedOevelopment Compliance Spreadsheet -Version 3.0 RMP Oe5on 5pe[Iflmrbns strt 2013.. sell. Spe¢ Site Summary Project Title: 660 Wert Rio (Tres, Feel Only) Date: OSNl Total RalMall(in): 43 Total mounted Acreye: I Lars Site Land Cover Summary Pre-Renevelopment Land Cover (acres) Asolls 1 Becas 1 Csah DSMS Tandy %a1TWl reteit/Opm (al 1 D. 1 SS i Dan i Dm D.Ss ao Managed Turf (sal Den Del DDD Don D. SS Impervloua Cnwr(avm) DEC OaT DDD Den 0.07 S 1.48 ]Ip Land Cover (acres) Asolls BSog[ Csah DSMS Toad. %aLToxl Forest/Open (a[ra[I Don DDO DO] DN O.N 0 Managed Tud(ave[) D. I tA1 DO] DN Lo1 95 Impernan Cow[(aves)I D00 1 oaT DaD Door 0.07 S 1.. ]N Site Tv and land Cover Nutrient Loads Final ever DevelopmentPost- em4 Aalumd Rc IPNXPeleprem Reonvempmen Development ReornloPnm ew m wil Ixrx m meuil sltt Rv D.za Dza Dn Trea4rem Volume ha 1.265 L265 501 re med lnMl D.zs Dn 0.11 Bewne TP load nal l: D.6MR• Total n mad Reduction Required! (al DIa DL9 D Final Pon-Developmentu ld Per IPoY-RaoeMopmem& New Imryrvlwn) ae "'I'le .m Tx mad Dial I s 6s a.os Pre Mal Port-0—mein[ Port-ReOeuelapmem TP ReoeMognem Vmad per a[re Wad per ace, TP iota perame m r pb/acreMl Ilb/arre/yrl o.3e o.sd o.sd Site Compliance Summary Novel ra.mm uirea amm, zm: •rrore:xaeenmm� MrrednreposEevekpmem nmoerokss [inn a•esu°ImemegnemmgDfid roM(aa1 cM1 laeuu�reeadu�m�fureoonen•.=vanneor.rvmue-mwmemeyacasewMl, msuremue=5mureu, asl lyuµ. Total RunoHVOYme Reduttlon(hal 0 To. TP mad Reduction A[Meved(lb/yr) ODD Tom Tx mad Reduction Achieved jim/yr) ODD Remained Post Development TP mad Ola m/yrl Final TP mad Reduc mn(Ib/yrl 0.19 Required Drainage Area Summary DlA oAB DAC DAO DlC Totl Forest/Open la[ra[I 0.00 D.N O.OD D00 DO] D.DO Managed Our iscro) Cl3D D.N D. D00 om D.DO ImpervlwaCm) a.00 D.ao O.OD D00 DO] O.DO Ironed Area lacereloal B.ao p.ao o.oD D.00 Dm B.ao Drainage Area Compliance Summary OAA DAB DAC DAD DAE Trust TP mad Reduced llb/yrj DO] O.N O.Oo DOD om DO] TR mad Reduced llial Dm O.N D. I OM OM DO] Runoff Volume and CN Calculations I.yearnmm 2-yearrtorm 10-parLoma Ironies Fall Event pnl I ODD DOD DDT am"eAmx Rvacx Dramye AmaA Damage Areall Drainage AmaC Drainage one Drainage Area ON RN lhi) m 1jear rum period —s(—) eelwslq Von a vu 2jear rmum perlad wrely nl vlwslnl Von on aayvu 10.year rmm armed wre lananl evaal Von ne aryve Summery Dar SHIMP ENGINEERING, P.C. Design Focused Engineering Independent Reports: Excerpt from NRCS Soils Report NOAA Precipitation Report USDA United States Department of Agriculture MRCS Natural Resources Conservation Service A product of the National Cooperative Soil Survey, a joint effort of the United States Department of Agriculture and other Federal agencies, State agencies including the Agricultural Experiment Stations, and local participants Custom Soil Resource Report for Albemarle County, Virginia March 19, 2019 Soil Map The soil map section includes the soil map for the defined area of interest, a list of soil map units on the map and extent of each map unit, and cartographic symbols displayed on the map. Also presented are various metadata about data used to produce the map, and a description of each soil map unit. • .fL�r .J lii�il '� I • j • - ♦� �.,rJJ Ji 1f, . •� lJ f � a• ) 7ChM34C q► H@o b(M mood m¢ ¢hag wmh.- MAPLEGEND Area of Interest (AOO O Area of Interest (AOI) Solis Soil Map Unit Polygons N Soil Map Unit Lines Soil Map Unit Points Special Point Features V Blowout ® Borrow Pit Clay Spot O Closed Depression Gravel Pit Gravelly Spot O Landfill A. Lava Flow Marsh or swamp Mine or Quarry O Miscellaneous Water O Perennial Water y Rock Outcrop + Saline Spot Sandy Spot Severely Eroded Spot Q Sinkhole Slide or Slip J, Sodic Spot Custom Soil Resource Report MAP INFORMATION g Spoil Area The soil surveys that comprise your AOI were mapped at 1:15,800. o Stony Spot W Very Stony Spot Warning: Soil Map may not be valid at this scale. wet Spot Enlargement of maps beyond the scale of mapping can cause Other misunderstanding of the detail of mapping and accuracy of soil Special Line Features line placement. The maps do not show the small areas of contrasting soils that could have been shown at a more detailed Water Features scale. Streams and Canals Transportation Please rely on the bar scale on each map sheet for map �..ry Rails measurements. N Interstate Highways Source of Map: Natural Resources Conservation Service ti US Routes Web Soil Survey URL: Coordinate System: Web Mercator (EPSG:3857) Major Roads Local Roads Maps from the Web Soil Survey are based on the Web Mercator projection, which preserves direction and shape but distorts Background distance and area. A projection that preserves area, such as the . Aerial Photography Albers equal-area conic projection, should be used if more accurate calculations of distance or area are required. This product is generated from the USDA-NRCS certified data as of the version date(s) listed below. Soil Survey Area: Albemarle County, Virginia Survey Area Data: Version 12, Aug 29, 2018 Soil map units are labeled (as space allows) for map scales 1:50,000 or larger. Date(s) aerial images were photographed: Apr 22, 2015—Mar 10, 2017 The orthophoto or other base map on which the soil lines were compiled and digitized probably differs from the background imagery displayed on these maps. As a result, some minor shifting of map unit boundaries may be evident. 10 Custom Soil Resource Report Map Unit Legend Map Unit Symbol Map Unit Name Acres in AOI Percent of AOI 27B Elioak loam, 2 to 7 percent slopes 1.3 25.6% 27C Elioak loam, 7 to 15 percent slopes 3.4 67.5% 34C Glenelg loam, 7 to 15 percent slopes 0.3 6.9% Totals for Area of Interest 5.1 100.0% Map Unit Descriptions The map units delineated on the detailed soil maps in a soil survey represent the soils or miscellaneous areas in the survey area. The map unit descriptions, along with the maps, can be used to determine the composition and properties of a unit. A map unit delineation on a soil map represents an area dominated by one or more major kinds of soil or miscellaneous areas. A map unit is identified and named according to the taxonomic classification of the dominant soils. Within a taxonomic class there are precisely defined limits for the properties of the soils. On the landscape, however, the soils are natural phenomena, and they have the characteristic variability of all natural phenomena. Thus, the range of some observed properties may extend beyond the limits defined for a taxonomic class. Areas of soils of a single taxonomic class rarely, if ever, can be mapped without including areas of other taxonomic classes. Consequently, every map unit is made up of the soils or miscellaneous areas for which it is named and some minor components that belong to taxonomic classes other than those of the major soils. Most minor soils have properties similar to those of the dominant soil or soils in the map unit, and thus they do not affect use and management. These are called noncontrasting, or similar, components. They may or may not be mentioned in a particular map unit description. Other minor components, however, have properties and behavioral characteristics divergent enough to affect use or to require different management. These are called contrasting, or dissimilar, components. They generally are in small areas and could not be mapped separately because of the scale used. Some small areas of strongly contrasting soils or miscellaneous areas are identified by a special symbol on the maps. If included in the database for a given area, the contrasting minor components are identified in the map unit descriptions along with some characteristics of each. A few areas of minor components may not have been observed, and consequently they are not mentioned in the descriptions, especially where the pattern was so complex that it was impractical to make enough observations to identify all the soils and miscellaneous areas on the landscape. The presence of minor components in a map unit in no way diminishes the usefulness or accuracy of the data. The objective of mapping is not to delineate pure taxonomic classes but rather to separate the landscape into landforms or 11 Custom Soil Resource Report landform segments that have similar use and management requirements. The delineation of such segments on the map provides sufficient information for the development of resource plans. If intensive use of small areas is planned, however, onsite investigation is needed to define and locate the soils and miscellaneous areas. An identifying symbol precedes the map unit name in the map unit descriptions. Each description includes general facts about the unit and gives important soil properties and qualities. Soils that have profiles that are almost alike make up a soil series. Except for differences in texture of the surface layer, all the soils of a series have major horizons that are similar in composition, thickness, and arrangement. Soils of one series can differ in texture of the surface layer, slope, stoniness, salinity, degree of erosion, and other characteristics that affect their use. On the basis of such differences, a soil series is divided into soil phases. Most of the areas shown on the detailed soil maps are phases of soil series. The name of a soil phase commonly indicates a feature that affects use or management. For example, Alpha silt loam, 0 to 2 percent slopes, is a phase of the Alpha series. Some map units are made up of two or more major soils or miscellaneous areas. These map units are complexes, associations, or undifferentiated groups. A complex consists of two or more soils or miscellaneous areas in such an intricate pattern or in such small areas that they cannot be shown separately on the maps. The pattern and proportion of the soils or miscellaneous areas are somewhat similar in all areas. Alpha -Beta complex, 0 to 6 percent slopes, is an example. An association is made up of two or more geographically associated soils or miscellaneous areas that are shown as one unit on the maps. Because of present or anticipated uses of the map units in the survey area, it was not considered practical or necessary to map the soils or miscellaneous areas separately. The pattern and relative proportion of the soils or miscellaneous areas are somewhat similar. Alpha -Beta association, 0 to 2 percent slopes, is an example. An undifferentiated group is made up of two or more soils or miscellaneous areas that could be mapped individually but are mapped as one unit because similar interpretations can be made for use and management. The pattern and proportion of the soils or miscellaneous areas in a mapped area are not uniform. An area can be made up of only one of the major soils or miscellaneous areas, or it can be made up of all of them. Alpha and Beta soils, 0 to 2 percent slopes, is an example. Some surveys include miscellaneous areas. Such areas have little or no soil material and support little or no vegetation. Rock outcrop is an example. iv Custom Soil Resource Report Albemarle County, Virginia 2713—Elioak loam, 2 to 7 percent slopes Map Unit Setting National map unit symbol: kb8y Mean annual precipitation: 25 to 65 inches Mean annual air temperature: 54 to 59 degrees F Frost -free period: 195 to 231 days Farmland classification: All areas are prime farmland Map Unit Composition Elioak and similar soils: 80 percent Estimates are based on observations, descriptions, and transects of the mapunit. Description of Elioak Setting Landform: Hillslopes Landform position (two-dimensional): Summit Landform position (three-dimensional): Interfluve Down -slope shape: Convex Across -slope shape: Convex Parent material: Residuum weathered from mica schist Typical profile H1 - 0 to 8 inches: loam H2 - 8 to 39 inches: silty clay H3 - 39 to 79 inches: silt loam Properties and qualities Slope: 2 to 7 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: Medium Capacity of the most limiting layer to transmit water (Ksat): Moderately high to high (0.20 to 1.98 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Available water storage in profile: Moderate (about 6.6 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 2e Hydrologic Soil Group: B Hydric soil rating: No 13 Custom Soil Resource Report 27C—Elioak loam, 7 to 15 percent slopes Map Unit Setting National map unit symbol: kb8z Mean annual precipitation: 25 to 65 inches Mean annual air temperature: 54 to 59 degrees F Frost -free period: 195 to 231 days Farmland classification: Farmland of statewide importance Map Unit Composition Elioak and similar soils: 80 percent Estimates are based on observations, Description of Elioak descriptions, and transects of the mapunit. Setting Landform: Hillslopes Landform position (two-dimensional): Summit Landform position (three-dimensional): Interfluve Down -slope shape: Convex Across -slope shape: Convex Parent material: Residuum weathered from mica schist Typical profile H1 - 0 to 8 inches: loam H2 - 8 to 39 inches: silty clay H3 - 39 to 79 inches: silt loam Properties and qualities Slope: 7 to 15 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: Medium Capacity of the most limiting layer to transmit water (Ksat) high (0.20 to 1.98 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Moderately high to Available water storage in profile: Moderate (about 6.6 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 3e Hydrologic Soil Group: B Hydric soil rating: No 14 Custom Soil Resource Report 34C—Glenelg loam, 7 to 15 percent slopes Map Unit Setting National map unit symbol: kb9l Mean annual precipitation: 25 to 65 inches Mean annual air temperature: 54 to 59 degrees F Frost -free period: 195 to 231 days Farmland classification: Farmland of statewide importance Map Unit Composition Glenelg and similar soils: 85 percent Estimates are based on observations, Description of Glenelg descriptions, and transects of the mapunit. Setting Landform: Hillslopes Landform position (two-dimensional): Summit Landform position (three-dimensional): Interfluve Down -slope shape: Convex Across -slope shape: Convex Parent material: Residuum weathered from mica schist Typical profile H1 - 0 to 8 inches: loam H2 - 8 to 28 inches: silty clay loam H3 - 28 to 80 inches: loam Properties and qualities Slope: 7 to 15 percent Depth to restrictive feature: More than 80 inches Natural drainage class: Well drained Runoff class: Medium Capacity of the most limiting layer to transmit water (Ksat) high (0.57 to 1.98 in/hr) Depth to water table: More than 80 inches Frequency of flooding: None Frequency of ponding: None Available water storage in profile: High (about 9.7 inches) Interpretive groups Land capability classification (irrigated): None specified Land capability classification (nonirrigated): 3e Hydrologic Soil Group: B Hydric soil rating: No Moderately high to 15 2124122, 8:53 AM Precipitation Frequency Data Server NOAA Atlas 14, Volume 2, Version 3 Location name: Charlottesville Virginia, USA* E Latitude: 38.0844°, Longitude:-78.4763° Elevation: 529.69 ft" ' source: ESRI Maps "source: USGS POINT PRECIPITATION FREQUENCY ESTIMATES G.M. Bonnin, D. Martin, B. Lin, T. Pa2ybok, M.Yekta, and D. Riley NOAA, National Weather Service, Silver Spring, Maryland PF tabular I PF graphical I Maps & aerials PF tabular PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches)1 Average recurrence interval (years) Duration 7 ������� 2 5 10 25 50 100 200 500 1000 0.352 0.419 0.492 0.553 0.623 0.678 0.729 0.778 0.837 0.884 5-min (g 317-0.390) (0.379-0.465) (0.443-0.545) (0.497-0.612) (0.558-0.688) (0.604-0.747) (0.645-0.803) (0.684-0.857) (0.728-0.924) (0.762-0.981) 0.562 0.671 0.789 0.885 0.994 1.08 1.16 1.23 1.32 1.39 10-min F� (0.506-0.623) (0.605-0.744) (0.710-0.873) (0.795-0.979) (0.889-1.10) (0.961-1.19) 1 (1.03-1.28) 1 (1.08-1.36) 1 (1.15-1A6) 1 (1.20-1.54) O. 0.843 0.998 1.12 1.26 1.37 1.46 1.56 1.67 1.75 15-min (0.633-0.779) (0.761-0.935) (0.898-1.11) 1 (1.01-1.24) 1 (1.13-1.39) 1 (1.22-1.51) 1 (1.30-1.61) 1 (1.37-1.71) 1 (1.45-1.84) 1 (1.51-1.94) 0.962 1.16 1.42 1.62 1.87 2.06 2.24 2.42 2.65 2.83 30-min (0.868-1.07) 1 (1.05-1.29) 1 (1.28-1.57) 1 (1.46-1.79) 1 (1.67-2.06) 1 (1.83-2.27) 1 (1.99-2.47) 1 (2.13-2.67) 1 (2.31-2.93) 1 (2.44-3.14) 1.20 1.46 1.82 2.11 2.48 2.79 3.09 3.40 3.80 4.13 60-min (1.08-1.33) 1 (1.32-1.62) 1 (1.64-2.01) 1 (1.90-2.34) 1 (2.22-2.74) 1 (2.48-3.07) 1 (2.74-3.40) 1 (2.99-3.74) 1 (3.31-4.20) 1 (3.56-4.58) 1.44 1.75 2.19 2.58 3.07 3.48 3.91 4.35 4.97 5.50 2-hr (1.27-1.64) 1 (1.54-1.99) 1 (1.93-2.49) 1 (2.27-2.92) 1 (2.68-3.47) 1 (3.03-3.94) 1 (3.38-4.41) 1 (3.73-4.91) 1 (4.22-5.62) 1 (4.61-6.23) 1.58 1.92 2.40 2.81 3.35 3.81 4.28 4.77 5.45 6.04 3-hr (1.39-1.81) 1 (1.68-2.20) 1 (2.10-2.75) 1 (2.45-3.21) 1 (2.91-3.83) 1 (3.29-4.34) 1 (3.67-4.87) 1 (4.06-5.44) 1 (4.58-6.22) 1 (5.02-6.90) 2.01 2.43 3.02 3.56 4.27 4.90 5.56 6.28 7.30 8.19 6-hr (1.78-2.28) 1 (2.15-2.76) 1 (2.66-3.42) 1 (3.12-4.02) 1 (3.73-4.83) 1 (4.24-5.52) 1 (4.77-6.27) (5.32-7.08) 1 (6.10-8.23) 1 (6.75-9.26) 2.53 3.05 3.80 4.50 5.48 6.34 7.29 8.32 9.86 11.2 12-hr (2.23-2.89) 1 (2.69-3.49) 1 (3.35-4.35) 1 (3.94-5.13) 1 (4.76-6.23) 1 (5.46-7.20) 1 (6.19-8.26) (6.98-9.43) 1 (8.11-11.2) 1 (9.09-12.8) 3.01 3.65 4.66 5.51 6.77 7.84 9.04 10.4 12.3 14.0 24-hr (2.71-3.38) (3.28-4.10) (4.17-5.23) (4.92-6.16) (6.00-7.55) (6.91-8.73) (7.89-10.0) (8.94-11.5) (10.5-13.6) (11.7-15.5) 3.55 4.31 5.48 6.44 7.84 9.01 10.3 11.7 13.7 15.4 2-day (3.19-3.97) (3.87,4.82) (4.91-6.12) (5.76-7.18) (6.95-8.71) (7.93-9.99) (8.96-11.4) (10.1-13.0) (11.7-15.3) (13.0-17.1) 3.78 4.59 5.83 6.85 8.32 9.56 10.9 12.4 14.5 16.3 3-day (3.44-4.20) 1 (4.16-5.08) 1 (5.28-6.45) 1 (6.18-7.57) 1 (7.48-9.19) 1 (8.53-10.5) 1 (9.65-12.0) 1 (10.9-13.6) 1 (12.6-16.0) 1 (13.9-18.0) 4.01 4.87 6.18 7.25 8.81 10.1 11.5 13.1 15.3 17.1 4-day (3.68-4.42) 1 (4.45-5.35) 1 (5.65-6.79) 1 (6.61-7.96) 1 (8.00-9.66) 1 (9.13-11.1) 1 (10.3-12.6) 1 (11.6-14.3) 1 (13.4-16.8) 1 (14.9-18.9) 4.67 5.62 7.02 8.18 9.83 11.2 12.7 14.3 16.5 18.4 7-day P� (4.29-5.10) 1 (5.16-6.14) 1 (6.44-7.67) 1 (7.48-8.93) 1 (8.94-10.7) 1 (10.1-12.2) 1 (11.4-13.8) 1 (12.7-15.6) 1 (14.6-18.1) 1 (16.1-20.3) 5.30 6.35 7.85 9.05 10.8 12.2 13.6 15.2 17.4 19.2 10day F� (4.88-5.73) 1 (5.87-6.88) 1 (7.23-8.49) 1 (8.33-9.79) 1 (9.85-11.6) 1 (11.1-13.1) 1 (12.3-14.7) 1 (13.7-16.4) 1 (15.5-18.9) 1 (16.9-20.9) 6.95 8.29 10.0 11.4 13.2 14.7 16.1 17.6 19.7 21.3 20i18y P� (6.51-7.45) 1 (7.76-8.89) 1 (9.36-10.7) 1 (10.6-12.2) 1 (12.3-14.1) 1 (13.6-15.7) 1 (14.9-17.3) 1 (16.2-18.9) 1 (17.9-21.2) 1 (19.3-23.0) 8.53 10.1 12.0 13.4 15.2 16.6 17.9 19.3 21.0 22.4 30-day (8.03-9.09) 1 (9.52-10.8) 1 (11.2-12.7) 1 (12.5-14.2) 1 (14.2-16.2) 1 (15.5-17.7) 1 (16.7-19.1) 1 (17.9-20.6) 1 (19.4-22.5) 1 (20.5-24.0) 10.6 12.B 14.7 16.3 18.3 19.8 21.3 22.7 24.5 25.8 45ilay (10.1-11.3) 1 (11.9-13.3) 1 (13.9-15.6) 1 (15.4-17.2) 1 (17.2-19.4) 1 (18.6-21.0) 1 (19.9-22.6) 1 (21.2-24.1) 1 (22.7-26.1) (23.9-27.5) 12.5 14.7 17.0 16.7 20.8 22.4 23.9 25.4 27.2 28.5 60-day (11.8-13.2) (13.9-15.5) (16.1-17.9) (17.6-19.7) (19.7-22.0) (21.1-23.6) (22.5-25.3) (23.8-26.8) (25.4-28.8) (26.5-30.2) 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 Atlas 14 document for more information. Back to Top hftps://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=38.0844&Ion=-78.4763&data=depth&units=english&series=pds#maps 1/4