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HomeMy WebLinkAboutWPO202200017 Calculations 2023-02-13SHIMP ENGINEERING, P.C. Design Focused Engineering Stormwater Management Plan Calculation Packet WPO2022-00017 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: April 12, 2022 Revision date: February 9, 2023 TiI sHfmp > 0. 45183 ZIT '0� 912 E. High Sr. Charlottesville, VA 22902 1434.227.5140 1 shimp-engineering.com SHIMP ENGINEERING, P.C. Design Focused Engineering February 9, 2023 John Anderson Albemarle County Department of Community Development 401 McIntire Road Charlottesville, VA 22902 Regarding: WPO 2022-00017 664 West Rio — 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 4.02 acres. The project is a private redevelopment of a site to create 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 routed to two detention systems 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 4.44 lb/yr. A purchase of 4.44 Ib/yr phosphorous credit shall be made to achieve required TP reduction for this site. Treatment Required (Total Phosphorous) Treatment Provided (Total Phosphorous) 4.44 lb/yr 4.44 lb/yr Runoff Quantity Narrative: SWM Quantity is satisfied by analyzing concentrated runoff from the development at 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, drainage area to the south of the stream (drainage area 1) and 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, most concentrated runoff from this drainage area will be routed to two underground detention facilities and then to site outfall. Drainage area 1 is divided into three segments, drainage area. 1. Drainage area 1 to Detention System 1 (Managed): has 1.924 acres of potential stormwater runoff through a combination of impervious and turf areas which is managed by routing it to a Stormtech MC-3500 detention system 1 and then to site outfall. 2.Drainage Area 2 to Detention System 2 (Managed): has 0.999 acres of potential stormwater runoff, also flowing through a combination of impervious and turf areas, which is managed routing it to a Stormtech MC-3500 detention system 2 and then to site outfall. 3.Drainage area 1 Bypass: has 0.540 acres of potential stormwater runoff flowing through a combination of impervious, turf and wooded areas. The flow from this area is unmanaged and flows directly to site outfall. The runoff from drainage area 1 to site outfall meets the energy balance equation requirements set forth in 9VAC25-870-66-B(3). 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-hour storm event that is less than the predevelopment peak flow rate from the 10-year 24-hour 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. Pre-dev Peak Runoff Max. Allowed Peak Runoff Post-dev Peak Runoff 1-Yr 1.52 cfs 0.28 cfs 0.26 cfs 10-Yr 9.15 cfs 9.15 cfs 8.44 cfs Drainage Area 2: Drainage area 2 lies north of the stream and has 0.399 acres of potential runoff in a stormwater runoff through a combination of impervious and turf areas 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 Qjo while pre development drainage area 2 has 0.21 cfs Qi and 1.23 cfs Qjo. 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 p,e-dev for 1-year = 1.52 cfs + 0.21 cfs = 1.73 cfs Q pre_dev for 10-year = 9.15 cfs + 1.23 cfs = 10.38 cfs The post development drainage area 1 has 0.26 cfs Q, and 8.44 cfs Qjo while pre development drainage area 2 has 0.47 cfs Q, and 1.74 cfs Qjo. Since drainage area 1 and drainage are 2 both flow to the same SHIMP ENGINEERING, P.C. Design Focused Engineering site outfall that is being analyzed, adding the two post development flows together results in the following: Q p�A_d, for 1-year = 0.26 cfs + 0.47 cfs = 0.73 cfs Q p,,A.d, for 10-year = 8.44 cfs + 1.74 cfs = 10.18 cfs When comparing the pre and post development flows, the results show that the post development flow is reduced by 58% for the 1-year storm and by 2% 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 modeiinr notes: 1. The HydroCAD model does not take into account the stone below the underdrain pipe. 2. The 6" underdrain pipe is perforated while embedded in the stone of the detention system, but solid once it leaves the stone storage. 3. The 6" underdrain pipe has a threaded cap installed on the downstream face of the weir wall with a 1.5" threaded nipple that acts as the 1-yr stone orifice. 4. Structure A5 is the control structure for detention system 1 while structure A4 is the control structure for detention system 2. 5. 72" x 1 P' orifice modeled in detention system 1 is the distance between the top of weir wall and the bottom of the precast flat top of the manhole 6. The two (2) 18" HDPE Water Tight pipes between El and A6, and A6 and A5, are part of the detention system and modeled as such in HydroCAD. 7. The proposed natural area is accounted for as `woods" with CN value 55 for water quantity calculations. However, as all the required soil amendments for VRRM open spaces are not provided, it is accounted for as turf for water quality calculations. Refer to the drainage area maps and the VRRM maps for further clarification. If you have any questions about this calculation packet please do not hesitate to contact me at: steohanie(c�r�shimp-en ing eerieg 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 Post -Development Inlets Drainage Area Maps Inlet Drainage Area Summary Post -Development Roofdrains Drainage Area Maps Roofdrains Drainage Area Summary VDOT LD-204 VDOT LD-229 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 Inlet Drainage Area Summary Post -Development Roofdrains Drainage Area Maps Roofdrains Drainage Area Summary VDOT LD-204 VDOT LD-229 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 IN DRAINAGE AREA 1 ARE HSG B Pre-Dev Draina a Area 1 to Site Outfall CN 98 61 55 SF AC % Building & Pavement 7,750 0.178 5.9 Impervious 7,750 0.178 5.9 Turf 124,241 2.852 94.1 Woods 25,687 0.590 19.5 Total Drainage Area 131,991 3.030 100.0 Weighted CN Tnr=l 63 11.2 W, 45-100C d d a\ 4fib\ d QQ ° 44 d° a /♦ i a i a� d s I a ai i) `)\ IP dad\° A9 \\ 1- ° d A `\ C \\ /4 �a d a I i14. 0 i11004. la a I > a )/ I\ \A dd °\d `\ \ �.5 *' a/- a/ a ,a • la 1 a� a'I ai a al\ J a / �d°°IP4 \\ \ aj )i a 'I a '\ a a a \ d° °4, d °° `\ A la al al ♦ a la \a la `�a al\ ♦\ a\ a \'Y I I\ a\\ a l ddd`\\ \ a, I a a 4 \ a \� a\ ♦ \\ \\ a `\ a i� \e \a ` y f\ a A\ \ IN -4 \ d4gq ° \ \ V 1444 44 dd° d Q a \ a\ d° d Pre-Dev Draina a Area 2 to Site Out611 la \ �'\` a \a a ``a \t\ �\ a a \ ` ` a\ .� °' a \ a \ a \ a \� a a •� a ° d a d SF AC % t\\\IIa\\d\} \ °°-d a ao a`P 4% 1*da 17,333 0.398 100.0 Ex141 NR ° d PEw °rl x C I a a a\ a 4i 1 I,a ` Wei hteTdOCCN= 651.0 � \Ia \ a\ a\ a ` \\ a ) y \ 1\ NN' a Drainage Area 17,333 0.398 100.0 OVERLA NANN E v ° ;T° N AIN) > °° aa dd°°FLOVaSD`)'a alaaaaa�aa�a\aa\\;D AIaAE R a Ilaja�a%aa\a a1`aal 444e was I a a' a +• �a a ya / a �a a is �a �a Ia 'la 11 al a' 11 I' a1 a) al\ a la :il\a �'p --A ,a a ai al alb N is IaI al s )a \j a'I a a) ad PRE—DEV DAl a aI Ia Ia I a a \ a lia ?M �. Fo y IaI is a a a a , a l a 1 al a1 TIME OF CONCENTRATION y rnu 4l$-Wl , a l a 1 a) a l a la 14 a 14 \ 1. r CI TI ai a a a8]�a--a--->--S"a' a a I a 1 �I a FLO / a/ $C a jr is B a a a 3.' a� a� ;i i s a a j a l >aC� \ o) / U. 1°. �I Via' 1 alga ; a a a a a a a j� a a a yj'j CHANNEL, ; roP-52�.J6 a \ Ia I a /4 a a + i 7 LO / a `1� `q9 `9� eENCNyARN: a \ �, a `v-_j, a tea. # a a /,,� a a, / a �. a Xg �.a TOP L£ pi°P IN 6,n, , EI ATON=53J.JB\\ "f� a REMAIN '1 y y Y y Y Y I y y y I Y Y Y Y y iaf i Y y Y y Y y y y 'y Y Y y y l 1 YI I I I I I W K/ 'iiA'✓ �i�/ I AC E5 E9yr °.6. IQIJEWTJ 60. SHIMPENGINEERING, P.C,D.S.J °.e. \OM -yes Pua M 45105 o so 664 West Rio ENGGYEERIYG-LANDPLANMNG-PRQIELT MANAGF3rENT .„A„�°,sE. VA �.T...I„a-Ea<„EER °oM ��LL Pre Development Drainage Area Map Sale: 1"=60' ♦00 DIMH W. 45-948 ti 120 180 1S 3S Pre Development Pre Development Drainage Area 1 Drainge Area 2 2L 4L Site Outfall Site Outfall Subcat Reach on Link Drainage Diagram for Pre Dev Prepared by Shimp Engineering, P.C., Printed 2/9/2023 FHydroCADO 9.10 sin 07054 0 2011 HydroCAD Software Solutions LLC Pre Dev DA Report Pre Dev Prepared by Shimp Engineering, P.C. Printed 2/9/2023 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 Report Pre Dev Prepared by Shimp Engineering, P.C. Printed 2/9/2023 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 Report Pre Dev Type H 24-hr I yr; 24 hr Rainfall=3.01 " Prepared by Shimp Engineering, P.C. Printed 2/9/2023 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 Report Pre Dev Type H 24-hr I yr; 24 hr Rainfall=3.01 " Prepared by Shimp Engineering, P.C. Printed 2/9/2023 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 Report Pre Dev Type H 24-hr I yr; 24 hr Rainfall=3.01 " Prepared by Shimp Engineering, P.C. Printed 2/9/2023 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 Report Pre Dev Type H 24-hr I yr; 24 hr Rainfall=3.01 " Prepared by Shimp Engineering, P.C. Printed 2/9/2023 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 A 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 Report Pre Dev Type H 24-hr I yr; 24 hr Rainfall=3.01 " Prepared by Shimp Engineering, P.C. Printed 2/9/2023 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 Report Pre Dev Type 1124-hr 10 yr; 24 hr Rainfall=5.51 " Prepared by Shimp Engineering, P.C. Printed 2/9/2023 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 Report Pre Dev Type 1124-hr 10 yr; 24 hr Rainfall=5.51 " Prepared by Shimp Engineering, P.C. Printed 2/9/2023 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 Report Pre Dev Type 1124-hr 10 yr; 24 hr Rainfall=5.51 " Prepared by Shimp Engineering, P.C. Printed 2/9/2023 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 Report Pre Dev Type 1124-hr 10 yr; 24 hr Rainfall=5.51 " Prepared by Shimp Engineering, P.C. Printed 2/9/2023 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 n-,7-T,T--6T--fIoW'Araa:g ac l ■ Primary cfs 9 III III III III II IIII 8 -III -II -III -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 Report Pre Dev Type 1124-hr 10 yr; 24 hr Rainfall=5.51 " Prepared by Shimp Engineering, P.C. Printed 2/9/2023 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 Report Pre Dev Type H 24-hr 100 yr, 24 hr Rainfall=9.04" Prepared by Shimp Engineering, P.C. Printed 2/9/2023 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 Report Pre Dev Type 1124-hr 100 yr, 24 hr Rainfall=9.04" Prepared by Shimp Engineering, P.C. Printed 2/9/2023 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 '-_ 24 23 ,_ _.JI_-.-_-_J_-YL_-rL_-YT1_-TL_-T1_-TJ_-*1_-.J_-.J_-_ y__-rJ_1- TPlF2"rJ'i90-_ 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�2.04F� 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 Q�ih=4.'38r1 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 Report Pre Dev Type H 24-hr 100 yr, 24 hr Rainfall=9.04" Prepared by Shimp Engineering, P.C. Printed 2/9/2023 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 Report Pre Dev Type H 24-hr 100 yr, 24 hr Rainfall=9.04" Prepared by Shimp Engineering, P.C. Printed 2/9/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paize 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 Report Pre Dev Type H 24-hr 100 yr, 24 hr Rainfall=9.04" Prepared by Shimp Engineering, P.C. Printed 2/9/2023 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:) LEGEND ® POST DEV DETENTION SYSTEM 1 DA 1 TO SITE OUTFALL IMP. POST DEV DETENTION SYSTEM 1 DA 1 TO SITE OUTFALL TURF. POST DEV DETENTION SYSTEM 2 DA 1 TO SITE OUTFALL IMP. POST DEV DETENTION SYSTEM 2 DA 1 TO SITE OUTFALL TURF. ® POST DEV BYPASS DA 1 TO SITE OUTFALL IMP. tt tt POST DEV BYPASS DA 1 TO SITE OUTFALL TURF. POST DEV BYPASS DA 1 TO SITE OUTFALL WOODS. °o POST DEV DA 2 TO SITE OUTFALL IMP. POST DEV DA 2 TO SITE OUTFALL TURF. -- SOILS -� - POST DEVELOPMENT DETENTION SYSTEM 1 DRAINAGE AREA A (MANAGED) -- POST DEVELOPMENT DETENTION SYSTEM 2 DRAINAGE AREA B (MANAGED) POST DEVELOPMENT DETENTION SYSTEMS BYPASS DRAINAGE AREA C (UNMANAGED) -.. - POST DEVELOPMENT DRAINAGE AREA 2 (SHEET FLOW) Post-Dev Detention System 1 Drainage Area 1 (Managed) SF AC % luilding & Pavement 66,5781 1.5281 79.4 CN mnervious 66578 1.528 79.4 98 Drainage Area I 83,845I 1.9251 100.0 'IOC= 5.0 SHIMPENRNEERM P.C. EW,T&BIMG-/ANDHAWW-PR &EL7MANA0E1fF,Mf cHARLO eSMUE. v 22902 .uznR.s«—..'Ee— —.. NOTE: ALL SOILS IN DRAINAGE AREA 1 ARE HSG B I WM 45-100C 11 i q` ST DEV DA1 BYPASS CHANQ TO SITE OUTFALL FI n /'7%`/f ice/ - I 1 AV4 120 0�/.�Il r �� 1//�• i YlIVZ M2RA1 $ITE 1 4*0!n�W:-M,�E 'Poll /. 1. �/�/��ihs ♦• s♦•< _ . :mac ,,ice/ .♦�.��.5�•, ''•fir '� �Y� ���I/.Q/- ���• � a�;..���, --• �. /7 ���.�. %/ :I//L�% l.:i� T•�- —�,�~► •r Ali•.+.. "r POST DEVELOPMENT DRAINAGE AREA 2 (SHEET FLOW) TM, 45-173 I ` I TI I 4P " Post Development Detention System 2 Detention System 2 Drainage Arai iS (Managed) Post Development Detention System 1 Drainage Area 1 2P 5S (Managed) Detention System 1 Past Development 5L Drainage Areal Bypass (Unmanaged) Site Outfall Subcat Reach Aon L4 7S V Drainage Area 2 8L Site Outfall Post Dev DA Report Post Dev Prepared by Shimp Engineering, P.C. Printed 2/9/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 2 Area Listing (all nodes) Area CN Description (acres) (subcatchment-numbers) 0.448 55 Woods, Good, HSG B (5S) 0.845 61 >75% Grass cover, Good, HSG B (1S, 3S, 5S, 7S) 2.569 98 Paved parking, HSG B (1S, 3S, 5S, 7S) 3.862 85 TOTAL AREA Post Dev DA Report Post Dev Prepared by Shimp Engineering, P.C. Printed 2/9/2023 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 3.862 HSG B 1 S, 3S, 5S, 7S 0.000 HSG C 0.000 HSG D 0.000 Other 3.862 TOTAL AREA Post Dev DA Report Post Dev Prepared by Shimp Engineering, P.C. Printed 2/9/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 4 Pipe Listing (all nodes) Line# Node In -Invert Out -Invert Length Slope n Diam/Width Height Fill Number (feet) (feet) (feet) (ft/ft) (inches) (inches) (inches) 1 2P 505.00 498.50 107.3 0.0606 0.012 24.0 0.0 0.0 2 4P 494.00 493.54 15.2 0.0303 0.012 24.0 0.0 0.0 Post Dev DA Report Post Dev Type H24-hr 1-Year Rainfall=3.01 " Prepared by Shimp Engineering, P.C. Printed 2/9/2023 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 5 Time span=0.00-999.00 hrs, dt=0.01 hrs, 99901 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 DevelopmentDetention System 1 Subcatchment3S: Post DevelopmentDetention System 2 Runoff Area=1.924 ac 79.42% Impervious Runoff Depth=1.99" Tc=5.0 min CN=90 Runoff=6.88 cfs 0.320 of Runoff Area=0.999 ac 94.09% Impervious Runoff Depth=2.56" Tc=5.0 min CN=96 Runoff4.24 cfs 0.213 of Subcatchment5S: Post DevelopmentDrainage Areal Bypass Runoff Area=0.540 ac 2.59%Impervious RunoffDepth=0.25" Tc=9.3 min CN=57 Runoff=O.10 cfs 0.011 of Subcatchment7S: Drainage Area 2 Pond 2P: Detention System 1 Pond 4P: Detention System 2 Link 6L: Site Outfall Link 8L: Site Outfall Runoff Area=0.399 ac 21.80% Impervious Runoff Depth=0.68" Tc=5.0 min CN=69 Runoff=0.47 cfs 0.022 of Peak Elev=506.88' Storage=10,502 cf Inflow=6.88 cfs 0.320 of Outflow=0.08 cfs 0.320 of Peak Elev=497.33' Storage=5,876 cf Inflow 4.24 cfs 0.213 of Outflow=O.I I cfs 0.213 of Inflow=0.26 cfs 0.544 of Primary=0.26 cfs 0.544 of Inflow=0.47 cfs 0.022 of Primary=0.47 cfs 0.022 of Total Runoff Area = 3.862 ac Runoff Volume = 0.567 of Average Runoff Depth = 1.76" 33.48% Pervious =1.293 ac 66.52% Impervious = 2.569 ac Post Dev DA Report Post Dev Type H24-hr 1-Year Rainfall=3.01 " Prepared by Shimp Engineering, P.C. Printed 2/9/2023 HydroCAD® 9.10 s/n 07054 © 2011 Hydroi Software Solutions LLC Page 6 Summary for Subcatchment 1S: Post Development Detention System 1 Drainage Area 1 (Managed) Runoff = 6.88 cfs @ 11.96 hrs, Volume= 0.320 A Depth= 1.99" Runoff by SCS TR-20 method, UH=SCS, Time Span-- 0.00-999.00 hrs, dt= 0.01 hrs Type II 24-hr 1-Year Rainfall=3.01" Area (ac) CN Description 1.528 98 Paved parking, HSG B * 0.396 61 >75% Grass cover, Good, HSG B 1.924 90 Weighted Average 0.396 20.58% Pervious Area 1.528 79.42% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 1S: Post Development Detention System 1 Drainage Area 1 (Managed) Hydrograph I I I I I I I I I I I I I I I I ■Runoff 6.88 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 Type II,24rhr'1l-Year I I I I I I I I I I I 6 l�pitaflf=.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 --=--- ------ ---- Ruftoff_Are9_=_11924_Ic_ I I I I I I I I I I I I 5 Kueoff V616me=0.320 of I I I I I I I _ I I I I I I I I I I I I w---,--- ---I -RUnOff D 4 elpfH=f;.99'• = I I I I I I I I T'c=6JO! miln _ 3 I I C M=90 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 300 350 400 450 500 550 600 650 700 750 800 850 900 950 Time (hours) Post Dev DA Report Post Dev Type H24-hr 1-Year Rainfall=3.01 " Prepared by Shimp Engineering, P.C. Printed 2/9/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 7 Summary for Subcatchment 3S: Post Development Detention System 2 Drainage Area 1 (Managed) Runoff = 4.24 cfs @ 11.96 hrs, Volume= 0.213 A Depth= 2.56" Runoff by SCS TR-20 method, UH=SCS, Time Span-- 0.00-999.00 hrs, dt= 0.01 hrs Type II 24-hr 1-Year Rainfall=3.01" Area (ac) CN Description 0.940 98 Paved parking, HSG B * 0.059 61 >75% Grass cover, Good, HSG B 0.999 96 Weighted Average 0.059 5.91% Pervious Area 0.940 94.09% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 3S: Post Development Detention System 2 Drainage Area 1 (Managed) Hydrograph � � ■Runoff 4.24 cfs ...... - -------=-Typ�r11,24rihrf-Year- Rei nfal''11=3.01 rr Runoff Areal=01999 arc 3 ''Kueoff V616me=0.213 of RUnbff :De'pth=2.56" 3 Tc=6.-O m1n u 2 CN=56 300 350 400 450 500 550 600 650 700 750 800 850 900 950 Time (hours) Post Dev DA Report Post Dev Type H24-hr 1-Year Rainfall=3.01 " Prepared by Shimp Engineering, P.C. Printed 2/9/2023 HydroCADV 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 8 Summary for Subcatchment 5S: Post Development Drainage Area 1 Bypass (Unmanaged) Runoff = 0.10 cfs @ 12.06 hrs, Volume= 0.011 A Depth= 0.25" Runoff by SCS TR-20 method, UH=SCS, Time Span-- 0.00-999.00 hrs, dt= 0.01 hrs Type II 24-hr 1-Year Rainfall=3.01" Area (ac) CN Description 0.014 98 Paved parking, HSG B 0.078 61 >75% Grass cover, Good, HSG B 0.448 55 Woods_ Good_ HSG B 0.540 57 Weighted Average 0.526 97.41 % Pervious Area 0.014 2.59% Impervious Area Tc Length Description 9.3 Direct Entry, TOC Subcatchment 5S: Post Development Drainage Area 1 Bypass (Unmanaged) -----;------;----------;---------------------------------------------- 0.10 cfs _UT r____ r n 4r r = eer- 0.095 _---r---r--r--r--�---r---r--T----r__�___r---r--T---0.085 0.08 r-- 0.09 ft�rr�fafN 0 .0 r1off A rea= 0,54 0 -arc 0.075-----------~--�___�-----'---r--11---'---+- + - ---' -'--- ---' -+ ---+ I urlofi-WtIMOO-40-of- _0.065------ r--- r__y___r___,___y___r__y___r___r__y___r___,___y___r___,___r --- r__ 0 0.06___r---r__---r---r--T---r------T---r--T_ ftnbff-Eiebth-V.-Zg" - 3 0.055 i i___T---r__l___r___r--�___r___r--T---r--T---r---r--T---r------T--:r-- LL 0.05 T �---7---r-----r-----------r------r---r---,---r---r-- - Tc Trm:i 1- 0.045--___1_________i______1_________i_________i___i___1i---I--- 0.04 i___ _____i______1___L______i___�__�___i___�___i___�___�CN=57_ 1 1 0.03 0.025 ____'___r_____r______'___r---___'_____�___�___�___"---r------'---�-- 0.02--__r___-__--___r______--___--______7___r__ 7___ r__ 0.01 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 Time (hours) ■ Runoff Post Dev DA Report Post Dev Type H24-hr 1-Year Rainfall=3.0111 Prepared by Shimp Engineering, P.C. Printed 2/9/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 9 Summary for Subcatchment 7S: Drainage Area 2 Runoff = 0.47 cfs @ 11.97 hrs, Volume= 0.022 A Depth= 0.68" Runoff by SCS TR-20 method, UH=SCS, Time Span-- 0.00-999.00 hrs, dt= 0.01 hrs Type II 24-hr 1-Year Rainfall=3.01" Area (ac) CN Description 0.087 98 Paved parking, HSG B 0.312 61 >75% Grass cover, Good, HSG B 0.399 69 Weighted Average 0.312 78.20% Pervious Area 0.087 21.80% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, TOC Subcatchment 7S: Drainage Area 2 Hydrograph .47 -- --`---',--- I - - - ` - - - - - `- - - `- 0- - --- ■Runoff ----------------; ---; -- -----,------ ,­- T-ypa11,2&hr4-Year 0.45- r. - - 0.4 ------------------------r-- ---- Runoff Area OL,399 ac- U.35-----------------r------ --- -----,-Aurtoff-1/-iD1ume=d.0-22_af- w 0.3 , - - -r ; -- R 'D h= -- n ---ff,- ept,--0; �$r' 0.25 -- - - -- Tic=6A'' min 0.2 CM=69 0.15 0.1 0.05 0 50 100 150 200 250 300 1 411 1 560 1 600 650 700 750 800 850 900 950 Post Dev DA Report Post Dev Type H24-hr 1-Year Rainfall=3.01 " Prepared by Shimp Engineering, P.C. Printed 2/9/2023 HydroCADV 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paize 10 Summary for Pond 2P: Detention System 1 Inflow Area = 1.924 ac, 79.42% Impervious, Inflow Depth = 1.99" for 1-Year event Inflow = 6.88 cfs @ 11.96 hrs, Volume= 0.320 of Outflow = 0.08 cfs @ 19.28 hrs, Volume= 0.320 of Atten= 99%, Lag= 439.2 min Primary = 0.08 cfs @ 19.28 hrs, Volume= 0.320 of Routing by Stor-Ind method, Time Span= 0.00-999.00 hrs, dt= 0.01 hrs Peak Elev= 506.88' @ 19.28 hrs Surf Area= 8,758 sf Storage= 10,502 cf Plug -Flow detention time=1,573.3 min calculated for 0.320 of (100% of inflow) Center -of -Mass det. time=1,573.4 min ( 2,378.7 - 805.3 ) Volume Invert Avail.Storage Storage Description # 1 505.00' 13,972 cf Stone Storage Data (Prismatic)Listed below (Recalc) 47,729 cf Overall - 12,798 cf Embedded = 34,931 cf x 40.0% Voids #2 505.50' 12,548 cf StormTech MC-3500 x 114 Inside # 1 Effective Size= 69.0"W x 45.0"H => 15.35 sf x 7.171, = 110.1 cf Overall Size= 75.0"W x 45.0"H x 7.50'L with 0.33' Overlap #3 505.50' 250 cf StormTech MC-3500 Cap x 16 Inside # 1 Effective Size= 48.2"W x 44.0"H => 8.30 sf x 1.88'L = 15.6 cf Overall Size= 71.0"W x 45.0"H x 2.21'L with 0.33' Overlap #4 505.50' 177 cf 18.0" D x 100.0'L (2) 18" HDPE Water Tieht 26,947 cf Total Available Storage Elevation Surf Area Inc.Store Cum.Store (feet) (sq-ft) (cubic -feet) (cubic -feet) 505.00 8,678 0 0 510.50 8,678 47,729 47,729 Device Routing Invert Outlet Devices # 1 Primary 505.00' 24.0" Round 24" HDPE Pipe L= 107.3' Ke= 0.600 Inlet / Outlet Invert= 505.00' / 498.50' S= 0.0606 'P Cc= 0.900 n= 0.012 #2 Device 1 505.00' 1.5" Vert. 1.5" Orifice C= 0.600 #3 Device 1 507.10' 14.0" W x 8.0" H Vert. 14"x 8" Orifice C= 0.600 #4 Device 1 508.10' 72.0" W x 11.0" H Vert. 72"x 11" Orifice C= 0.600 Primary OutFlow Max=0.08 cfs @ 19.28 hrs HW=506.88' (Free Discharge) L1=24" HDPE Pipe (Passes 0.08 cfs of 13.45 cfs potential flow) 2=1.5" Orifice (Orifice Controls 0.08 cfs @ 6.50 fps) 3=14"x 8" Orifice ( Controls 0.00 cfs) =72"x 11" Orifice ( Controls 0.00 cfs) Post Dev DA Report Post Dev Type H24-hr 1-Year Rainfall=3.01 " Prepared by Shimp Engineering, P.C. Printed 2/9/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paye 11 Pond 2P: Detention System 1 Hydrograph ■ Inflow 6.88 cfs --r -- - 'r -- --- - , --- -- ■ Primary Inflow Area=' .024 aic s Freak:EIav-506�88' r-- - tora a=�U,i50 Cf-- 4 'r--_i---r------r---r--r--- 0.08 cfs 0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 Time (hours) Post Dev DA Report Post Dev Type H24-hr 1-Year Rainfall=3.01 " Prepared by Shimp Engineering, P.C. Printed 2/9/2023 HydroCADV 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paize 12 Summary for Pond 4P: Detention System 2 Inflow Area = 0.999 ac, 94.09% Impervious, Inflow Depth = 2.56" for 1-Year event Inflow = 4.24 cfs @ 11.96 hrs, Volume= 0.213 of Outflow = 0.11 cfs @ 14.22 hrs, Volume= 0.213 of Atten= 97%, Lag= 135.9 min Primary = 0.11 cfs @ 14.22 his, Volume= 0.213 of Routing by Stor-Ind method, Time Span= 0.00-999.00 hrs, dt= 0.01 hrs Peak Elev= 497.33' @ 14.22 hrs SurfArea- 2,820 sf Storage= 5,876 cf Plug -Flow detention time= 662.7 min calculated for 0.213 of (100% of inflow) Center -of -Mass det. time=662.8 min ( 1,434.2 - 771.4 ) Volume Invert AvalLStorage Storage Description # 1 494.00' 6,311 cf Custom Stage Data (Prismatic)Listed below (Recalc) 19,740 cf Overall - 3,963 cf Embedded = 15,777 cf x 40.0% Voids #2 494.50' 3,302 cf StormTech MC-3500 x 30 Inside # 1 Effective Size= 69.0"W x 45.0"H => 15.35 sf x 7.171, = 110.1 cf Overall Size= 75.0"W x 45.0"H x 7.50'L with 0.33' Overlap #3 494.50' 660 cf StormTech MC-3500 x 6 Inside # 1 Effective Size= 69.0"W x 45.0"H => 15.35 sf x 7.171, = 110.1 cf Overall Size= 75.0"W x 45.0"H x 7.50'L with 0.33' Overlap 10,274 cf Total Available Storage Elevation Surf Area Inc.Store Cum.Store (feet) (sq-ft) (cubic -feet) (cubic -feet) 494.00 2,820 0 0 501.00 2,820 19,740 19,740 Device Routing Invert Outlet Devices # 1 Primary 494.00' 24.0" Round 24" HDPE Pipe L= 15.2' Ke= 0.600 Inlet / Outlet Invert= 494.00' / 493.54' S= 0.0303 'P Cc= 0.900 n= 0.012 #2 Device 1 494.00' 1.5" Vert. 1.5" Orifice C= 0.600 #3 Device 1 497.50' 12.0" W x 12.0" H Vert. 12" x12" Orifice C=0.600 #4 Device 1 499.30' 6.0' long Sharp -Crested Rectangular Weir 2 End Contraction(s) Primary OutFlow Max=0.I 1 cfs @ 14.22 hrs HW=497.33' (Free Discharge) L1=24" HDPE Pipe (Passes 0.11 cfs of 21.63 cfs potential flow) 2=1.5" Orifice (Orifice Controls 0.11 cfs @ 8.70 fps) 3=12" x12" Orifice ( Controls 0.00 cfs) =Sharp -Crested Rectangular Weir( Controls 0.00 cfs) Post Dev DA Report Post Dev Type H24-hr 1-Year Rainfall=3.01 " Prepared by Shimp Engineering, P.C. Printed 2/9/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paye 13 Pond 4P: Detention System 2 Hydrograph I I I I I I I I I I I I I I I I I I ■Inflow 4.24 Cfs ■ Primary inflow Acrei--b.99 a 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 Peak: Elav-497:3$' -- -- + - - -I 7---i,--7---'- -- StQnage;5Vtof- 3 I I I I I I I I I I I I I I I tl I I I I i I I I I I I I I I I I I E 0.11 cfs 0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 Time (hours) Post Dev DA Report Post Dev Type H24-hr 1-Year Rainfall=3.01 rr Prepared by Shimp Engineering, P.C. Printed 2/9/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Pale 14 Summary for Link 6L: Site Outfall Inflow Area = 3.463 ac, 71.67% Impervious, Inflow Depth = 1.89" for 1-Year event Inflow = 0.26 cfs @ 12.06 hrs, Volume= 0.544 of Primary = 0.26 cfs @ 12.06 hrs, Volume= 0.544 A Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span-- 0.00-999.00 hrs, dt= 0.01 hrs Link 6L: Site Outfall Hydrograph I I I I I I I I I I I I I I I I I I ■Inflow 0.26 cts I I I I I I --L--J___L__J___L__J___L__J___L__J___L__J___L__J___L__J___L__J_-- Ip�JJrJIIIIIIIIIIII----_-_----_-_ oArea=�.463aC-- ■ Primary 0.26 - II II II II II II II 0.24 ----_-_LrIIIILIrIILIrIILII -_--- ----_-_LrIIIILIrIILIrIILII 0.22 0.2 0.18 0.16 _L__J--- L__J--- ___J--- L__J --- L__J --- L__ --- JrJ1J7JIIIIIIIIIIII _---_-_----_-_JrJ1JrJIIIIIIIIIIII __---__-_---_-_1 --- --- __---_-_-_---_-_J_iJ'JIIIIIII 0.14 01 .2 _-_1rIIIILIrIIILIrIILII 01 . 008 0.06 0 Post Dev DA Report Post Dev Type H24-hr 1-Year Rainfall=3.01 rr Prepared by Shimp Engineering, P.C. Printed 2/9/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paye 15 Summary for Link 8L: Site Outfall Inflow Area = 0.399 ac, 21.80% Impervious, Inflow Depth = 0.68" for 1-Year event Inflow = 0.47 cfs @ 11.97 hrs, Volume= 0.022 of Primary = 0.47 cfs @ 11.97 hrs, Volume= 0.022 A Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span-- 0.00-999.00 hrs, dt= 0.01 hrs Link 8L: Site Outfall Hydrograph ■ Inflow ■ Primary 0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 Time (hours) Post Dev DA Report Post Dev Type 1124-hr 10-Year Rainfall=5.51 " Prepared by Shimp Engineering, P.C. Printed 2/9/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paize 16 Time span=0.00-999.00 hrs, dt=0.01 hrs, 99901 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 DevelopmentDetention System 1 Subcatchment3S: Post DevelopmentDetention System 2 Runoff Area=1.924 ac 79.42% Impervious Runoff Depth=4.37" Tc=5.0 min CN=90 Runof€14.35 cfs 0.701 of Runoff Area=0.999 ac 94.09% Impervious Runoff Depth=5.04" Tc=5.0 min CN=96 Runoff--8.00 cfs 0.420 of Subcatchment5S: Post DevelopmentDrainage Areal Bypass Runoff Area=0.540 ac 2.59%Impervious Runoff Depth=1.39" Tc=9.3 min CN=57 Runoff--1.12 cfs 0.062 of Subcatchment7S: Drainage Area 2 Pond 2P: Detention System 1 Pond 4P: Detention System 2 Link 6L: Site Outfall Link 8L: Site Outfall Runoff Area=0.399 ac 21.80% Impervious Runoff Depth=2.34" Tc=5.0 min CN=69 Runoff--1.74 cfs 0.078 of Peak Elev=507.92' Storage=16,450 cf Inflow=-14.35 cfs 0.701 of Outflow=-2.65 cfs 0.701 of Peak Elev=499.05' Storage=8,077 cf Inflow=8.00 cfs 0.420 of Outflow=-5.02 cfs 0.420 of Inflow=8.44 cfs 1.183 of Primary=8.44 cfs 1.183 of Inflow=1.74 cfs 0.078 of Primary=1.74 cfs 0.078 of Total Runoff Area = 3.862 ac Runoff Volume = 1.260 of Average Runoff Depth = 3.92" 33.48% Pervious =1.293 ac 66.52% Impervious = 2.569 ac Post Dev DA Report Post Dev Type 1124-hr 10-Year Rainfall=5.51 " Prepared by Shimp Engineering, P.C. Printed 2/9/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paize 17 Summary for Subcatchment 1S: Post Development Detention System 1 Drainage Area 1 (Managed) Runoff = 14.35 cfs @ 11.96 hrs, Volume= 0.701 A Depth= 4.37" Runoff by SCS TR-20 method, UH=SCS, Time Span-- 0.00-999.00 hrs, dt= 0.01 hrs Type II 24-hr 10-Year Rainfall=5.51" Area (ac) CN Description 1.528 98 Paved parking, HSG B * 0.396 61 >75% Grass cover, Good, HSG B 1.924 90 Weighted Average 0.396 20.58% Pervious Area 1.528 79.42% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 1S: Post Development Detention System 1 Drainage Area 1 (Managed) Hydrograph 16 -__-__ 14.35 s I-_2�_II a4-r_h�_lI ra__11111I 1_0=_-_-5Y_�II e__1t------r---------- --- _. _II .-- -- 13 12 ■Runoff ------- iyUyoff Areca-r 692w QY_ 10 AU110-OVQ16W 70-1_al__ - rr---r---rr--- r--- -4-Rkinoff Depth 4.3-7"-- .a I I I I I I I c 8 ___I___i___i ___liII___�if��.Oli min__ 1 7 N ___1---y___r---I---T---*---1---�___*___T--T---T---T---I---�---*---I---T---*___ 6 -- C117-90 �--- �---�---I--- I--_ �_ I I I I I I I I I I 1 1 1 1 5 1 1 1 1 1 1 I I 4 I VA -I I I I I I I I I I I I I I I I I I I 3 1 1 1 I I 1 1 1 1 1 I I 1 1 1 1 I I I 1 1 1 I I 1 1 1 1 1 I I I 1 1 1 1 I I 2 1 1 1 I I 1 1 1 1 1 I I I I 1 I I I I 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 Time (hours) Post Dev DA Report Post Dev Type 1124-hr 10-Year Rainfall=5.51 " Prepared by Shimp Engineering, P.C. Printed 2/9/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paize 18 Summary for Subcatchment 3S: Post Development Detention System 2 Drainage Area 1 (Managed) Runoff = 8.00 cfs @ 11.96 hrs, Volume= 0.420 A Depth= 5.04" Runoff by SCS TR-20 method, UH=SCS, Time Span-- 0.00-999.00 hrs, dt= 0.01 hrs Type II 24-hr 10-Year Rainfall=5.51" Area (ac) CN Description 0.940 98 Paved parking, HSG B * 0.059 61 >75% Grass cover, Good, HSG B 0.999 96 Weighted Average 0.059 5.91% Pervious Area 0.940 94.09% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 3S: Post Development Detention System 2 Drainage Area 1 (Managed) Hydrograph I I I I ' ' ' ' ' : : : � ' :� ■Runoff 8.00 cfs I I I Type fl 24-hr 110-Year Raitlaff=.5�,. Rur►off-Area=0-+999 ale- 6 I I I I I I I I I I I I I I I I --Ru6off Yo um_-0=4.410 -af 5 RUnbff :De'pth=5.04" I LL 4 -- 'II--- ;---;---;--- ;---; ---II--- ---; ---II--- ;---,---;--- ,---' Tlrc=6.Oimiln I I I I � � I I I I 3 I I I I � � � � I I- _ - 2 300 350 400 450 500 550 600 650 700 750 800 850 900 950 Time (hours) Post Dev DA Report Post Dev Type 1124-hr 10-Year Rainfall=5.51 " Prepared by Shimp Engineering, P.C. Printed 2/9/2023 HydroCADV 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paize 19 Summary for Subcatchment 5S: Post Development Drainage Area 1 Bypass (Unmanaged) Runoff = 1.12 cfs @ 12.02 hrs, Volume= 0.062 A Depth= 1.39" Runoff by SCS TR-20 method, UH=SCS, Time Span-- 0.00-999.00 hrs, dt= 0.01 hrs Type II 24-hr 10-Year Rainfall=5.51" Area (ac) CN Description 0.014 98 Paved parking, HSG B 0.078 61 >75% Grass cover, Good, HSG B 0.448 55 Woods_ Good_ HSG B 0.540 57 Weighted Average 0.526 97.41 % Pervious Area 0.014 2.59% Impervious Area Tc Length Description 9.3 Direct Entry, TOC Subcatchment 5S: Post Development Drainage Area 1 Bypass (Unmanaged) ■ Runoff 1.12 cfs I -Type 11 24-hr 10-Year Rainfal'11=$.51 Runoff Areai=01540 aic Runoff Vplume=0.002 of RUnbff Depth=1',.39" LL Tc=0.3''miln �CN=57 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 Time (hours) Post Dev DA Report Post Dev Type 1124-hr 10-Year Rainfall=5.51 " Prepared by Shimp Engineering, P.C. Printed 2/9/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 20 Summary for Subcatchment 7S: Drainage Area 2 Runoff = 1.74 cfs @ 11.96 hrs, Volume= 0.078 A Depth= 2.34" Runoff by SCS TR-20 method, UH=SCS, Time Span-- 0.00-999.00 hrs, dt= 0.01 hrs Type II 24-hr 10-Year Rainfall=5.51" Area (ac) CN Description 0.087 98 Paved parking, HSG B 0.312 61 >75% Grass cover, Good, HSG B 0.399 69 Weighted Average 0.312 78.20% Pervious Area 0.087 21.80% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, TOC 0 LL Subcatchment 7S: Drainage Area 2 Hydrograph 74 Cfs I I I I Type 11 24-hr 110-Year R'ainfal'l11=$.51" Runoff Areai=013919 aic I I I I kueo#F Volume=0.018 of I I I I I I ------------ ---' I I II � : Unoell5f I = I. I Tc=6A'Imiln I I I I I I I I I I I I I =/wyI ICN V9 I I I I I I I I I I I I 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 I I I I I I I I I I I I I I I i I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 100 150 200 250 300 350 400 450 500 550 600 65011 750 800 850 900 950 ■ Runoff Post Dev DA Report Post Dev Type 1124-hr 10-Year Rainfall=5.51 " Prepared by Shimp Engineering, P.C. Printed 2/9/2023 HydroCADV 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Pale 21 Summary for Pond 2P: Detention System 1 Inflow Area = 1.924 ac, 79.42% Impervious, Inflow Depth = 4.37" for 10-Year event Inflow = 14.35 cfs @ 11.96 hrs, Volume= 0.701 of Outflow = 2.65 cfs @ 12.11 firs, Volume= 0.701 of Atten= 82%, Lag= 9.3 min Primary = 2.65 cfs @ 12.11 firs, Volume= 0.701 of Routing by Stor-Ind method, Time Span= 0.00-999.00 firs, dt= 0.01 firs Peak Elev= 507.92' @ 12.11 firs SurfArea-- 8,678 sf Storage= 16,450 cf Plug -Flow detention time= 926.6 min calculated for 0.701 of (100% of inflow) Center -of -Mass det. time= 926.7 min ( 1,710.0 - 783.3 ) Volume Invert AvalLStorage Storage Description # 1 505.00' 13,972 cf Stone Storage Data (Prismatic)Listed below (Recalc) 47,729 cf Overall - 12,798 cf Embedded = 34,931 cf x 40.0% Voids #2 505.50' 12,548 cf StormTech MC-3500 x 114 Inside # 1 Effective Size= 69.0"W x 45.0"H => 15.35 sf x 7.171, = 110.1 cf Overall Size= 75.0"W x 45.0"H x 7.50'L with 0.33' Overlap #3 505.50' 250 cf StormTech MC-3500 Cap x 16 Inside # 1 Effective Size= 48.2"W x 44.0"H => 8.30 sf x 1.88'L = 15.6 cf Overall Size= 71.0"W x 45.0"H x 2.21'L with 0.33' Overlap #4 505.50' 177 cf 18.0" D x 100.0'L (2) 18" HDPE Water Tieht 26,947 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic -feet) (cubic -feet) 505.00 8,678 0 0 510.50 8,678 47,729 47,729 Device Routing Invert Outlet Devices # 1 Primary 505.00' 24.0" Round 24" HDPE Pipe L= 107.3' Ke= 0.600 Inlet / Outlet Invert= 505.00' / 498.50' S= 0.0606 'P Cc= 0.900 n= 0.012 #2 Device 1 505.00' 1.5" Vert. 1.5" Orifice C= 0.600 #3 Device 1 507.10' 14.0" W x 8.0" H Vert. 14"x 8" Orifice C= 0.600 #4 Device 1 508.10' 72.0" W x 11.0" H Vert. 72"x 11" Orifice C= 0.600 Primary Outflow Max--2.65 cfs @ 12.11 hrs HW=507.92' (Free Discharge) L1=24" HDPE Pipe (Passes 2.65 cfs of 19.64 cfs potential flow) 2=1.5" Orifice (Orifice Controls 0.10 cfs @ 8.14 fps) 3=14"x 8" Orifice (Orifice Controls 2.55 cfs @ 3.28 fps) =72"x 11" Orifice ( Controls 0.00 cfs) Post Dev DA Report Post Dev Type 1124-hr 10-Year Rainfall=5.51 " Prepared by Shimp Engineering, P.C. Printed 2/9/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paye 22 Pond 2P: Detention System 1 Hydrograph FE Inflow 14.35 cfs --;---;---; ---; -- I ---I, -- I ---I --,--- I ---,--- ; ---; -- ;---; -- ;---I --,--- ■ Primary -Y -I -T -I -Y -r -Y -r -r -T -I -T -I -Y -r ,5 I ---L-- �---1---1---1---L--�---�--�--lnflnw_Ar�a=_�- 2- -arc-- 14 13 J___L__ J___ L__I___ 1245��f-- ----r------T------T---r--,---r--,---•-- „ I __I___L__J___1___1___1___L__J___L__J___1__J___1___1___ J___ L__J___L__I___ r___1___r___1___r___ 7__�___7___1___r___1___�___r__�___r__r___ p 9- 1 1 L__J___1--- 1___1--- L__L--- L__JI___L__J___ 1__J___ J--- L__ J___ L__I___ $- I I I I I I I I I I I I I I I I I 3 1 I r___1___r___1___r___r__7___r__r___r___1___r___1___�___r__�___r__r___ LL 7- 1 1 1 1 1 1 1 1 1 1 I_ _L _I 6. 1 1 r--- r--r--r-r--r-r--- r--- r--r--1---4--- r-r--r--I--- 5' 1 1 1 1 1 1 1 1 1 1 ___1_-J -1 -1 -1 -L -J -L -J I 1 1 1 1 I I I I I I 1 1 1 1 1 1 I I 2.65jCffS r-- r-- 1--- --'r-- I I I I I I 1 I I 2 0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 Time (hours) Post Dev DA Report Post Dev Type 1124-hr 10-Year Rainfall=5.51 " Prepared by Shimp Engineering, P.C. Printed 2/9/2023 HydroCADV 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paize 23 Summary for Pond 4P: Detention System 2 Inflow Area = 0.999 ac, 94.09% Impervious, Inflow Depth = 5.04" for 10-Year event Inflow = 8.00 cfs @ 11.96 hrs, Volume= 0.420 of Outflow = 5.02 cfs @ 12.03 hrs, Volume= 0.420 of Atten= 37%, Lag= 4.1 min Primary = 5.02 cfs @ 12.03 hrs, Volume= 0.420 of Routing by Stor-Ind method, Time Span= 0.00-999.00 hrs, dt= 0.01 hrs Peak Elev= 499.05' @ 12.03 hrs SurfArea- 2,820 sf Storage= 8,077 cf Plug -Flow detention time= 444.1 min calculated for 0.420 of (100% of inflow) Center -of -Mass det. time=444.0 min ( 1,199.4 - 755.4 ) Volume Invert AvalLStorage Storage Description # 1 494.00' 6,311 cf Custom Stage Data (Prismatic)Listed below (Recalc) 19,740 cf Overall - 3,963 cf Embedded = 15,777 cf x 40.0% Voids #2 494.50' 3,302 cf StormTech MC-3500 x 30 Inside # 1 Effective Size= 69.0"W x 45.0"H => 15.35 sf x 7.171, = 110.1 cf Overall Size= 75.0"W x 45.0"H x 7.50'L with 0.33' Overlap #3 494.50' 660 cf StormTech MC-3500 x 6 Inside # 1 Effective Size= 69.0"W x 45.0"H => 15.35 sf x 7.171, = 110.1 cf Overall Size= 75.0"W x 45.0"H x 7.50'L with 0.33' Overlap 10,274 cf Total Available Storage Elevation Surf Area Inc.Store Cum.Store (feet) (sq-ft) (cubic -feet) (cubic -feet) 494.00 2,820 0 0 501.00 2,820 19,740 19,740 Device Routing Invert Outlet Devices # 1 Primary 494.00' 24.0" Round 24" HDPE Pipe L= 15.2' Ke= 0.600 Inlet / Outlet Invert= 494.00' / 493.54' S= 0.0303 'P Cc= 0.900 n= 0.012 #2 Device 1 494.00' 1.5" Vert. 1.5" Orifice C= 0.600 #3 Device 1 497.50' 12.0" W x 12.0" H Vert. 12" x12" Orifice C=0.600 #4 Device 1 499.30' 6.0' long Sharp -Crested Rectangular Weir 2 End Contraction(s) Primary OutFlow Max=5.02 cfs @ 12.03 hrs HW=499.05' (Free Discharge) L1=24" HDPE Pipe (Passes 5.02 cfs of 28.54 cfs potential flow) 2=1.5" Orifice (Orifice Controls 0.13 cfs @ 10.75 fps) 3=12" x12" Orifice (Orifice Controls 4.88 cfs @ 4.88 fps) =Sharp -Crested Rectangular Weir( Controls 0.00 cfs) Post Dev DA Report Post Dev Type 1124-hr 10-Year Rainfall=5.51 " Prepared by Shimp Engineering, P.C. Printed 2/9/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 24 Pond 4P: Detention System 2 Hydrograph 8.00 cfs---------1---I 8 I I s 5.02 cfs le 5 3 I I I LL : 4 L- ' ■ Inflow _F _y _f _y _f _I _f _I _} _ ■ Primary Inflow Area=b.099 al II I- I, -- Peak: EIev-499:06' }II Storage 8,07 cf-- L__J___L__J___ 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 I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 11 150 200 250 300 350 400 450 500 550 600 611 750 800 850 900 Post Dev DA Report Post Dev Type 1124-hr 10-Year Rainfall=5.51 " Prepared by Shimp Engineering, P.C. Printed 2/9/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Page 25 Summary for Link 6L: Site Outfall Inflow Area = 3.463 ac, 71.67% Impervious, Inflow Depth = 4.10" for 10-Year event Inflow = 8.44 cfs @ 12.04 hrs, Volume= 1.183 of Primary = 8.44 cfs @ 12.04 hrs, Volume= 1.183 A Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span-- 0.00-999.00 hrs, dt= 0.01 hrs Link 6L: Site Outfall Hydrograph I ___'- - r--�---r---1---r---� --T--- ■Inflow y ■ Primary 8.44 cfs ------- Inflow A6rea�.461ac I I I 8 1 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 7 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 N I I I I I I I I I I I I I I I I I I I .V_. 5 1 1 7--- r--r--- r--7--- r--- 1---r--- r--r--- 3 I 1 I I I 1 1 1 1 I o I 1 I I I 1 1 1 1 I u 4 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 1 1 1 1 I 1 1 1 I 2 1 1 0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 Time (hours) Post Dev DA Report Post Dev Type 1124-hr 10-Year Rainfall=5.51 " Prepared by Shimp Engineering, P.C. Printed 2/9/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paize 26 Summary for Link 8L: Site Outfall Inflow Area = 0.399 ac, 21.80% Impervious, Inflow Depth = 2.34" for 10-Year event Inflow = 1.74 cfs @ 11.96 hrs, Volume= 0.078 of Primary = 1.74 cfs @ 11.96 hrs, Volume= 0.078 A Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span-- 0.00-999.00 hrs, dt= 0.01 hrs 'u t c u Link 8L: Site Outfall Hydrograph 0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 Time (hours) ■ Inflow ■ Primary Post Dev DA Report Post Dev Type H 24-hr 100-Year Rainfall=9.04" Prepared by Shimp Engineering, P.C. Printed 2/9/2023 HydroCADO 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paize 27 Time span=0.00-999.00 hrs, dt=0.01 hrs, 99901 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 DevelopmentDetention System 1 Subcatchment3S: Post DevelopmentDetention System 2 Runoff Area=1.924 ac 79.42% Impervious Runoff Depth=7.83" Tc=5.0 min CN=90 Runof€24.72 cfs 1.256 of Runoff Area=0.999 ac 94.09% Impervious Runoff Depth=8.56" Tc=5.0 min CN=96 Runoff--13.25 cfs 0.712 of Subcatchment5S: Post DevelopmentDrainage Areal Bypass Runoff Area=0.540 ac 2.59%Impervious Runoff Depth=3.76" Tc=9.3 min CN=57 Runoff--3.21 cfs 0.169 of Subcatchment7S: Drainage Area 2 Pond 2P: Detention System 1 Pond 4P: Detention System 2 Link 6L: Site Outfall Link 8L: Site Outfall Runoff Area=0.399 ac 21.80% Impervious Runoff Depth=5.25" Tc=5.0 min CN=69 Runoff--3.83 cfs 0.174 of Peak Elev=508.99' Stomge=21,672 cf Inflow=-24.72 cfs 1.256 of Outflow-21.05 cfs 1.256 of Peak Elev=499.78' Storage=8,899 cf Inflow-13.25 cfs 0.712 of Outflow-13.01 cfs 0.712 of Inflow=-36.56 cfs 2.137 of Primary=36.56 cfs 2.137 of Inflow--3.83 cfs 0.174 of Primary=3.83 cfs 0.174 of Total Runoff Area = 3.862 ac Runoff Volume = 2.312 of Average Runoff Depth = 7.18" 33.48% Pervious =1.293 ac 66.52% Impervious = 2.569 ac Post Dev DA Report Post Dev Type 1124-hr 100-Year Rainfall=9.04" Prepared by Shimp Engineering, P.C. Printed 2/9/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paize 28 Summary for Subcatchment 1S: Post Development Detention System 1 Drainage Area 1 (Managed) Runoff = 24.72 cfs @ 11.96 hrs, Volume= 1.256 A Depth= 7.83" Runoff by SCS TR-20 method, UH=SCS, Time Span-- 0.00-999.00 hrs, dt= 0.01 hrs Type II 24-hr 100-Year Rainfall=9.04" Area (ac) CN Description 1.528 98 Paved parking, HSG B * 0.396 61 >75% Grass cover, Good, HSG B 1.924 90 Weighted Average 0.396 20.58% Pervious Area 1.528 79.42% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 1S: Post Development Detention System 1 Drainage Area 1 (Managed) Hydrograph I I I I --I I I I I I I I I I I I I ■Runoff 24.72 cfs-I---�---II--J---I---�---J---;---IL--J I --- L--- ;--- I --- L --- I,I _L_1 _I _J _1 _L _I _1 _L _I _I _L _I _J _L 24 : ; T e It 24-hr 100-Year --J------L------J---1------J---1---L--J---1-- L --- --- ---L------J---L--- I ai Ifal'11= 0 " z2 nn __J--- 1--- L--- L__J___1--- L__J___ L__L__J___1___L___I__!iL___ 20 --J___1___L_--I---J___1___I__-J___1___L_ I_ ,I�\/44 -4 __J--- J--- L--- ___J___1___1___J___1___L__1t1��MQ_i/ 66 9MM I I I I I I I I I 16 ---; ---1, J - -- - I---JII-Rkj"ff Depth=7.83"-- - 14 I/� 3---J--- L--- ---J---1---L--J---1--- L--J--- J--- L-------�`IV=S. �I11711111-- G IL 12 __J___A___L___I___J___1___I___J___1___L__J___1___L___I___J___1___I___J___1___ I I I I I I I I I I I I I I � I I I 10 I --- L--- I___J--- 1--- I___J--- 1--- L__J___ 1___ L___I___ J___ L___I___ ___L___ $ I I I I A___L___I___J___1__J___J___1___L__J___J___L___I___J___L___I___J___L___ 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 I I 4 1___L___I___1___1___I___J___1--- L__J___J___L___I___J___L___I___J___L___ I I I I I I I I I I I I I I I I 7 I I I I I I I I I I I I I I I I I I 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 Time (hours) Post Dev DA Report Post Dev Type H 24-hr 100-Year Rainfall=9.04" Prepared by Shimp Engineering, P.C. Printed 2/9/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paize 29 Summary for Subcatchment 3S: Post Development Detention System 2 Drainage Area 1 (Managed) Runoff = 13.25 cfs @ 11.96 hrs, Volume= 0.712 A Depth= 8.56" Runoff by SCS TR-20 method, UH=SCS, Time Span-- 0.00-999.00 hrs, dt= 0.01 hrs Type II 24-hr 100-Year Rainfall=9.04" Area (ac) CN Description 0.940 98 Paved parking, HSG B * 0.059 61 >75% Grass cover, Good, HSG B 0.999 96 Weighted Average 0.059 5.91% Pervious Area 0.940 94.09% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Subcatchment 3S: Post Development Detention System 2 Drainage Area 1 (Managed) Hydrograph IIIII _____, 1325 cfs I___�___ r___ 13 Ty e It 24�y-__m_hr}rt 1_0_ 0-YyyI e a�+rtI r ____r___rr___r___rr_r__rr___I___r___rr___r_____ _ 12 L______----_--- I--- _ --- __--- _ I _l1FQ�:I r' _ 1I --- J1--- L__J 110 __�MT{Vff A{eO,y9q-�- nofFVo I___yt___ f___ u 8 _r4^y I___r____,___r____1___r___r,r ■Runoff 7 LL0 r1 --,--- -I - :a11I 6 1 1 I 1 L___L___1__J___J___1___L__J___1___ L___I___!___1__J _ 5 _I _J _L _I I 4 3 I I I _4 _I _y _4 _F I I I I --- r--- r--I--- r--- r--- r__r--- r--- r-- r---r-- r---r --_ 2 I 1 1 I I I I 1 I I I I I I I I 1 1 1 I I I 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 Time (hours) Post Dev DA Report Post Dev Type H 24-hr 100-Year Rainfall=9.04" Prepared by Shimp Engineering, P.C. Printed 2/9/2023 HydroCADV 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paize 30 Summary for Subcatchment 5S: Post Development Drainage Area 1 Bypass (Unmanaged) Runoff = 3.21 cfs @ 12.01 hrs, Volume= 0.169 A Depth= 3.76" Runoff by SCS TR-20 method, UH=SCS, Time Span-- 0.00-999.00 hrs, dt= 0.01 hrs Type II 24-hr 100-Year Rainfall=9.04" Area (ac) CN Description 0.014 98 Paved parking, HSG B 0.078 61 >75% Grass cover, Good, HSG B 0.448 55 Woods_ Good_ HSG B 0.540 57 Weighted Average 0.526 97.41 % Pervious Area 0.014 2.59% Impervious Area Tc Length Description 9.3 Direct Entry, TOC Subcatchment 5S: Post Development Drainage Area 1 Bypass (Unmanaged) I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 3.21 cfs ---a--Typ lk 24-ht-400-1(-ear- 3 l Rainfal'Ill=9.04.. I I I I I I I I I I I I I I I I Runoff Areal=01I540 aic I i i i i i I I I I I I I I I ----------------------------Ru6ot V614m_e=O.109 of ! RUnbff:D9pth=3.76" I I I I I I I I I I I I I I I Yc=J.3''I miln 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 ICN=57 I I I I I I I I I I I I I I I I I I I I I I I I I I I I 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 Time (hours) ■ Runoff Post Dev DA Report Post Dev Type H 24-hr 100-Year Rainfall=9.04" Prepared by Shimp Engineering, P.C. Printed 2/9/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paize 31 Summary for Subcatchment 7S: Drainage Area 2 Runoff = 3.83 cfs @ 11.96 hrs, Volume= 0.174 A Depth= 5.25" Runoff by SCS TR-20 method, UH=SCS, Time Span-- 0.00-999.00 hrs, dt= 0.01 hrs Type II 24-hr 100-Year Rainfall=9.04" Area (ac) CN Description 0.087 98 Paved parking, HSG B 0.312 61 >75% Grass cover, Good, HSG B 0.399 69 Weighted Average 0.312 78.20% Pervious Area 0.087 21.80% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, TOC Subcatchment 7S: Drainage Area 2 Hydrograph 3.8Cfs - 3 ■Runoff Typo II: 24-hr 100-Year I Rainfal'1,1=0.04" L__I___J___L__J--- J___L___I--- J___L___I___ 3 Runoff Areal=01399 arc 11 1 1 1 � I I I I kueo#F Volume=0.114 of I I I I I I I I I I I I 1 1 1 1 1 1- �---b-----p---�--- Rl�nbff De' th-5 25" 0 2 TIC=S.01'Imiln 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 ICN=69 1 1 300 350 400 450 500 550 600 650 700 750 800 850 900 950 Time (hours) Post Dev DA Report Post Dev Type H 24-hr 100-Year Rainfall=9.04" Prepared by Shimp Engineering, P.C. Printed 2/9/2023 HydroCADV 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Pale 32 Summary for Pond 2P: Detention System 1 Inflow Area = 1.924 ac, 79.42% Impervious, Inflow Depth = 7.83" for 100-Year event Inflow = 24.72 cfs @ 11.96 firs, Volume= 1.256 of Outflow = 21.05 cfs @ 12.00 hrs, Volume= 1.256 at Atten= 15%, Lag= 2.4 min Primary = 21.05 cfs @ 12.00 firs, Volume= 1.256 of Routing by Stor-Ind method, Time Span= 0.00-999.00 hrs, dt= 0.01 hrs Peak Elev= 508.99' @ 12.00 firs SurfArea-- 8,678 sf Storage= 21,672 cf Plug -Flow detention time= 549.4 min calculated for 1.256 of (100% of inflow) Center -of -Mass det. time= 549.5 min ( 1,317.4 - 768.0 ) Volume Invert AvalLStorage Storage Description # 1 505.00' 13,972 cf Stone Storage Data (Prismatic)Listed below (Recalc) 47,729 cf Overall - 12,798 cf Embedded = 34,931 cf x 40.0% Voids #2 505.50' 12,548 cf StormTech MC-3500 x 114 Inside # 1 Effective Size= 69.0"W x 45.0"H => 15.35 sf x 7.171, = 110.1 cf Overall Size= 75.0"W x 45.0"H x 7.50'L with 0.33' Overlap #3 505.50' 250 cf StormTech MC-3500 Cap x 16 Inside # 1 Effective Size= 48.2"W x 44.0"H => 8.30 sf x 1.88'L = 15.6 cf Overall Size= 71.0"W x 45.0"H x 2.21'L with 0.33' Overlap #4 505.50' 177 cf 18.0" D x 100.0'L (2) 18" HDPE Water Tieht 26,947 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic -feet) (cubic -feet) 505.00 8,678 0 0 510.50 8,678 47,729 47,729 Device Routing Invert Outlet Devices # 1 Primary 505.00' 24.0" Round 24" HDPE Pipe L= 107.3' Ke= 0.600 Inlet / Outlet Invert= 505.00' / 498.50' S= 0.0606 'P Cc= 0.900 n= 0.012 #2 Device 1 505.00' 1.5" Vert. 1.5" Orifice C= 0.600 #3 Device 1 507.10' 14.0" W x 8.0" H Vert. 14"x 8" Orifice C= 0.600 #4 Device 1 508.10' 72.0" W x 11.0" H Vert. 72"x 11" Orifice C= 0.600 Primary Outflow Max=21.01 cfs @ 12.00 hrs HW=508.99' (Free Discharge) L1=24" HDPE Pipe (Passes 21.01 cfs of 24.53 cfs potential flow) 2=1.5" Orifice (Orifice Controls 0.12 cfs @ 9.54 fps) 3=14"x 8" Orifice (Orifice Controls 4.67 cfs @ 6.00 fps) =72"x 11" Orifice (Orifice Controls 16.22 cfs @ 3.03 fps) Post Dev DA Report Post Dev Type 1124-hr 100-Year Rainfall=9.04" Prepared by Shimp Engineering, P.C. Printed 2/9/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paize 33 Pond 2P: Detention System 1 Hydrograph I I I I I I I I I I I I I I I I I I I 24.72 CfS ■ Primary zs __ _1___L__1-LL-- L Illflew Area=1.02 aic - I I I I I I I I I I I '-----r---------r--+---r-----r-----------t---------r-----r---1--- 24 21.05cfs ;---r----------i---7---r- ; r r I�eaki€�ie�50$'r9' I I I I I I I I I I I I I I I I I I I 20 IVVV 18 --I I I I I I I I I I I I I I I I I 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 16 -I I I I I I I I I I I I I I I I I I I � IL__J___L______1___L__J___L__J___L__J___1__J___J___L__J___L__L___ 14 I I I I I I I I I I I I I I I I I I I 3 O _L _J _L _I _1 _L _J _L _J _L _J _1 _I _1 _L _J _L _J u 12 I I I I I I I I I I I I I I I I I I I I _L _I _L _I _1 _L _J _L _J _L _I _1 _I _1 _L _J _L _I 10 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 6 I I I I 1-����uiiiiiiiiiiiiiiiiiiiiiiiii 1 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 • 1 Post Dev DA Report Post Dev Type H 24-hr 100-Year Rainfall=9.04" Prepared by Shimp Engineering, P.C. Printed 2/9/2023 HydroCADV 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paize 34 Summary for Pond 4P: Detention System 2 Inflow Area = 0.999 ac, 94.09% Impervious, Inflow Depth = 8.56" for 100-Year event Inflow = 13.25 cfs @ 11.96 hrs, Volume= 0.712 of Outflow = 13.01 cfs @ 11.97 hrs, Volume= 0.712 of Atten= 2%, Lag= 0.8 min Primary = 13.01 cfs @ 11.97 his, Volume= 0.712 of Routing by Stor-Ind method, Time Span= 0.00-999.00 hrs, dt= 0.01 hrs Peak Elev= 499.78' @ 11.97 hrs SurfArea- 2,820 sf Storage= 8,899 cf Plug -Flow detention time= 306.3 min calculated for 0.712 of (100% of inflow) Center -of -Mass det. time= 306.3 min ( 1,051.5 - 745.1 ) Volume Invert AvalLStorage Storage Description # 1 494.00' 6,311 cf Custom Stage Data (Prismatic)Listed below (Recalc) 19,740 cf Overall - 3,963 cf Embedded = 15,777 cf x 40.0% Voids #2 494.50' 3,302 cf StormTech MC-3500 x 30 Inside # 1 Effective Size= 69.0"W x 45.0"H => 15.35 sf x 7.171, = 110.1 cf Overall Size= 75.0"W x 45.0"H x 7.50'L with 0.33' Overlap #3 494.50' 660 cf StormTech MC-3500 x 6 Inside # 1 Effective Size= 69.0"W x 45.0"H => 15.35 sf x 7.171, = 110.1 cf Overall Size= 75.0"W x 45.0"H x 7.50'L with 0.33' Overlap 10,274 cf Total Available Storage Elevation Surf Area Inc.Store Cum.Store (feet) (sq-ft) (cubic -feet) (cubic -feet) 494.00 2,820 0 0 501.00 2,820 19,740 19,740 Device Routing Invert Outlet Devices # 1 Primary 494.00' 24.0" Round 24" HDPE Pipe L= 15.2' Ke= 0.600 Inlet / Outlet Invert= 494.00' / 493.54' S= 0.0303 'P Cc= 0.900 n= 0.012 #2 Device 1 494.00' 1.5" Vert. 1.5" Orifice C= 0.600 #3 Device 1 497.50' 12.0" W x 12.0" H Vert. 12" x12" Orifice C=0.600 #4 Device 1 499.30' 6.0' long Sharp -Crested Rectangular Weir 2 End Contraction(s) Primary OutFlow Max=12.99 cfs @ 11.97 hrs HW=499.78' (Free Discharge) L1=24" HDPE Pipe (Passes 12.99 cfs of 31.01 cfs potential flow) 2=1.5" Orifice (Orifice Controls 0.14 cfs @ 11.51 fps) 3=12" x12" Orifice (Orifice Controls 6.40 cfs @ 6.40 fps) =Sharp -Crested Rectangular Weir (Weir Controls 6.44 cfs @ 2.27 fps) Post Dev DA Report Post Dev Type 1124-hr 100-Year Rainfall=9.04" Prepared by Shimp Engineering, P.C. Printed 2/9/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paize 35 Pond 4P: Detention System 2 Hydrograph 13.25 I I I I I I I I I I 1 1 I I I I I I cfs --; ---;-- l------ I nflawArea=Q I I I I I I I I } I�eaf�ifi�ev�499t�$' ■ Primary 13.0s 13 12 I I I I I I I I I I I I I I I I I I ---F ---I--- ---� -- ---I -----I -- ---T Storage�8,, 99 cf - ,o I I I _1 _L _J _L _J _1 _I _1 _I _J _L _J 9 I I I I I I I I I I I I I I I I I I I 3 o 7 I LL 6 I___L__ I___1___I___1___L__J___L__J___1__I___1___I___J___L__J___L__I___ I I I I I I I I I I I I I 5 _i _r 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--r 3 L__ I___1___I__ _J___L__J___1__ I___1___I___J___L__J___L__ I I I I 1 I I I I 1 1 I I 1 1 I I 2 1 1 50 100 150 200 250 300 350 411 450 500 550 .11 650 700 750 811 850 911 • 1 Post Dev DA Report Post Dev Type H 24-hr 100-Year Rainfall=9.04" Prepared by Shimp Engineering, P.C. Printed 2/9/2023 HydrOCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Pale 36 Summary for Link 6L: Site Outfall Inflow Area = 3.463 ac, 71.67% Impervious, Inflow Depth = 7.41 " for 100-Year event Inflow = 36.56 cfs @ 11.99 hrs, Volume= 2.137 of Primary = 36.56 cfs @ 11.99 hrs, Volume= 2.137 A Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span-- 0.00-999.00 hrs, dt= 0.01 hrs Link 6L: Site Outfall Hydrograph --1---r--- I---r--- r--7--- r--7--- r--1--- T--- I---T---i--,---r--,---r---I--- I I - _r___I___r___r__7___Ir__i___7__r___r___I___r___�__T___r__�___r___I___ ■ Inflow I I I I I--- - --------------------------------------------- ---------------------------------I r€Ilwv Aroma =' -40 cic-- ■Primary 56 cfs ___!____ '---L-- I---I---I---I---I---J---L--J---I I I I--J- - - I --- I --- 128- I I I I I I I I I I I___I_____ J___L__J___1___1___1___L__J___L__J___L__J___1___I___!_ 1___J___L__J___ 1 --- 1--- --- 1___ 1 1 I 1 _L _I _1 _I _1 _L _J _L _J _L _I _1 _I _� _L _J _L _I 26 1 i _L _I _1 _I _1 _L _J _L _J _L _I .�. 24 I 22 _I _1 _I _� 20 I F _I _i _I O 8 1 -F -i -F -1 -f -y -h -I -♦ -I _i _F -y -F -I .16 -I -f -1 _+ -1 -♦ -r -1 -r -y -r -I -+ -I -y -r -y -r -I •14 •12 10 1 1 1 1 1 1 1 1 1 I I 6 r______1 r__�r___I--- 6 1 1 1 1 1 1 1 1 1 1 r______r___r__r___r__r___r__r___r___I___r___r__ T___r__r___r___I___ 4 0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 Time (hours) Post Dev DA Report Post Dev Type H 24-hr 100-Year Rainfall=9.04" Prepared by Shimp Engineering, P.C. Printed 2/9/2023 HydroCAD® 9.10 s/n 07054 © 2011 HydroCAD Software Solutions LLC Paye 37 Summary for Link 8L: Site Outfall Inflow Area = 0.399 ac, 21.80% Impervious, Inflow Depth = 5.25" for 100-Year event Inflow = 3.83 cfs @ 11.96 hrs, Volume= 0.174 of Primary = 3.83 cfs @ 11.96 hrs, Volume= 0.174 A Atten= 0%, Lag= 0.0 min Primary outflow = Inflow, Time Span-- 0.00-999.00 hrs, dt= 0.01 hrs Link 8L: Site Outfall Hydrograph I I I I I I I I I I I I I I I __! I __! I 1 �I___II___!! !! ! ___II___ ___ ■Inflow 3.83 cfs I ■ Primary Inflow Area=O.$99 acl 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 r___ --- r-- ,--- r---I-- -r - - - r — r--- I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I I 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 N I I I I I I I I I I I I I I 3 0 2 I I I I I I I I I I I I LL 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 0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 Time (hours) Flow 24 Hr 1 year Storm Comparison: 24 Hr 1 year Storm Comparison: 664 West Rio Time of Concentration Calculations Pre Dev DA 1 to Siteoutfall TOC (Onsite) 100 ft Overland Flow 10.20% slope 035 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 2D5.0ft Channel 24.0ft height 1.2 min. Kirpich Chart TOC= 11.2 min. Appendix 6D-1 Overland Flow Time - Seelye 42 -1.0 S-D.19 C Tc= 0.225 L0 Te = O e,IaM Flow Thee, mnlmes I =1 nglh or ship reel 35 s•.S"ier l C = Ralloeal'C V.I. Inc G,v.m Ch»per 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. 3 LL f59 Sua J 1- 0.5 Grass\ 0 0.3 Q °- 100 1.0 0 \ �5�' O ¢ 90 Surface .0 in��� BO Dense\\ 0 \ W Z v 70 \ 5. 0.2 W � 60 i�� 10 w i \ / L~7 50 20 U 40 t0 u 30 0 9 ¢ z F 8 2D Natl.l "C' value roc Seleoleo erouno Crpocrer 07ae Oroaa 0.215 Fvaa1 0.25 7 /,vro0s Grove Sumac. 0.Pe ov 0.50 vppr GrOee 5ur1oca 0.36 Poaturs 0. 40 B 1p Bore $or1 0.49 Pa.ao 0.90 OVERLAND FLOW TIME REPRINTED WITH PERMISSION FROM "DATA BOON FOR CIVIL ENGINEERS" vOL. I - DESIGN 2n0 EDITION 119S11 BY E. E. SEELYE SI NVENGINEERING, P.C. EAM ELUNG-MADPLANMNG-PRQIEL7MANA6EAFM 112 40 .1T.aLo ES LLE. V. a,re= �ar..a IMa_E < eEe . 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/s) 664 West Rio 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 uae with natural channels; a 0 10 ( or pevea chamels, II ply 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 Time of Concentration Calculations Post Dev DA 1 Bypass to Siteoutfa➢l TOC (Onsite) 100 ft Overland Flow 20.20% slope 1 0.35IC-value 6.9 min I Seelve Chart 98.9 ft S.C. Flow 15.17% slope 2.7 fps velocity 0.6 min. I NEH Figure 15-4 337.5 ft Channel 8.0 ft height I 1.8 min. Kirplch Chart TOC= 9.3 min. Appendix 6D-1 Overland Flow Time - Seelye 42 -1.0 Te= 0.225 LD S-"a C = Ors1MM Flow T1. mnuits I aL"th oI so I, 1a 35 - s . som BPU1aet C = R.h.n.J'C' Values 1w G,o lm Ch»cN. Boo 30 Soo Paved 0.9 400 0.8 25 - 0.7 300 0.8 m Bare 20' 200 Sol] 0.5 z Poor 0.4 Lu 2 W Surass F 0.5 O 0.3 Q 1.0 0 100 S Aace\� 0 90 '15�- - 2.0 in so o `• O 70 0 80 0.2 v w w z 10 - n U 20 z 40 � 10 ? t0 u 30 p c 9 a 20 O Aarlm l 'C' vowe Iv Ssleatb Ora Cnarocrer Oonx Gross 0.215 Fvas1 0.25 7 Av4roae Groea 9ur400a 0.Pe mn a. w Poor Grose Surf oos 0.la Posture 0.40 a 10 a,. so 1� 0.4e Pa.aa 0.90 OVERLAND FLOW TIME REPRINTED WITH PERMISSION FROM "DATA BOOK FOR CIVIL ENGINEERS" vOL. I - DESIGN 2n0 EDITION 119511 BY E. E. SEELYE SI IMPENGINEERING, P.C. EAMWEUNG-MADPLANMNG-PRQIELT MANAGEMENT 40 .H.eLo11ES-E. V. 22102 �.I.IS IMa_E < EER . oM TRAVEL TIME FOR CHANNEL FLOW (Kirpich Chart) .. 11 ' 200 .. 0 10000 50 � � � I1 II 1 :1 1 1 1 .1 1 1 1 1 1 1 1 1 1 I • 1 I: 1 I, 11 e2�e�e2�e2.e����..eu�o�ne2�e2�e2�e2.e����.eueuome2�e2�e� e2e2e2��e2��e�e.��..elen��nse� ����. ..�� ne2e2e2�e2e2�e� �•�� ��IIIIIII■I■ ��■ a'a�a�a�a�alalalalal������1� --���■������111111-� IIIIIIIIIIII■IIIIIII■III■II■I■■■■■■1�111111 �_��■■■■■■■11111111����■■►I 111111111111111111111,11111„1111111111,1111I,,-lll'�II1�,�F`i1 11111/11/ ■■■■„111111III I' `Iyq ,- ■I/,�/a'I IVA . iun ���.vuo�ue4e4e4e�e4e4�e� ;III ,/ 1111111111■■1AS . d11 11 I I f ��•%: f �al�ii��iiiilia'a�a� MrAMFAM alrlal•I /' I I■1■11111111��■ ..1 �•I■■1■11111111��■ /'I!.:.•,� i�1111111111111■■1I al������1�a1•a1•a1• ::::::::��� NEIINE 2e2e2�e2e2�e� ■. ■■■11111111 e4e4e4e�e4e4e.e4�4e�e�e.��..� ��������.. ��������■ ���■■■ /■1111 • 1■■111 1 ���■■ MEN I! III I ,�� I Q� Li L-100 0.01 S y'Li TIME OF CONCENTRATION OF SMALL DRAINAGE BASINS 0106 O O O O O OOOOri N Velocity (full) 664 West Rio Post Development Drainage Area 1 Bypass Time of Concentration 1992 11 Source: VDOT Plate 5-3 11 V-13 664 West Rio Iidets Dramage Area Summary Impervious C 0.9 Pervious C 0.3 Str. Type Str. No. A ea l % Imp Imp. (1t) Turf (ft) C Agree) 8' DI-313 A8C 5,960 60% 3,576 2,384 0.66 0.14 10' DI-3B A813 7,153 90% 6,438 715 0.84 0.16 8' D1-3B A8A 16,281 959/ 15,467 814 0.87 037 8' DI-313 A713 18,632 95% 17,700 932 0.87 0.43 8' DI-313 A6 5,666 85% 4,816 850 0.81 0.13 6 DI-313 A5 1,295 100% 1,295 0 0.90 0.03 8' DI-3C B2 11,686 909/ 10,517 1,169 0.84 0.27 8' DI-3C C2 5,481 95% 5,207 274 0.87 0.13 6 D1-3B D3 1,685 100% 1,685 0 0.90 0.04 6 DI-313 D2 5,356 100% 5,356 0 0.90 0.12 6' DI-3B IDI 1 1,537 100%D 1 1,537 1 0 0.90 1 0.04 18"Nyloplast Dram Basin F2 6,418 30% 1,925 4,493 0.48 0.15 SHNVENGINEERING,P.C. EAMWEUNG-MADPLANMNG-PRQIELT MANAGEIIBM B o Es LLE.. „ e= �s H.PH�E�HIHa_(4<4) 227-5140 D.B. 1OW-185 PLAT -'664 West Rio Post Development Inlet Drainage Area Map Scale: 1 0 173 TCH TM. 45-94B 120 180 664 West Rio Inlets Drainage Area Summary Impervious C 0.9 Pervious C 0.3 Str. Type Str. No. al Area Totea % Imp Imp. (ft) Turf (ft) C �a 8' DI-3B A8C 5,960 60% 3,576 2,384 0.66 0.14 10' DI-3B A8B 7,153 90% 6,438 715 0.84 0.16 8' DI-3B A8A 16,281 95% 15,467 814 0.87 0.37 8' DI-3B A7B 18,632 95% 17,700 932 0.87 0.43 8' DI-3B A6 5,666 85% 4,816 850 0.81 0.13 6' DI-3B A5 1,295 100% 1,295 0 0.90 0.03 8' DI-3C B2 11,686 90% 10,517 1,169 0.84 0.27 8' DI-3C C2 5,481 95% 5,207 274 0.87 0.13 6' DI-3B D3 1,685 100% 1,685 0 0.90 0.04 6' DI-3B D2 5,356 100% 5,356 0 0.90 0.12 6' DI-3B D1 1,537 100% 1,537 0 0.90 0.04 18" Nyloplast Drain Basin F2 6,418 30% 1,925 4,493 0.48 0.15 664 West Rio Roofdram Drainage Area Summary Impervious C 0.9 Pervious C 0.3 Str. Type Str. No. Area eft) al % Imp Imp. (ft) Turf (ft) C Ar (ac� 8" SCH.40 PVC or Dual WaHHDPE GI -El 13,105 l00% 13,105 0 0.90 0.30 Roofdram 8" SCH.40 PVC or Dual WaBHDPE G2-E2 8,609 l00% 8,609 0 0.90 0.20 Roofdram 8" SCH.40 PVC or Dual WaBHDPE G3-B1 10,195 l00% 10,195 0 0.90 0.23 Roofdram 8" SCH.40 PVC or Dual WallHDPE G4-A4B 8,648 100% 8,648 0 0.90 0.20 Roofdram SHNVENGINEERING,P.C. EAMWEUNG-MADPLANMNG-PRQIELT MANAGEAFM D.B. 195-Z' R i '664 West Rio Post Development Roofdrain Drainage Area Map Scale: 1 0 173 ITp TM. 45-94B 120 180 664 West Rio Roofdrain Drainage Area Summary Impervious C 0.9 Pervious C 0.3 Total Area Str. Type Str. No. % Imp Imp. (ft) Turf (ft) C Area (ae) 8" SCH.40 PVC or Dual Wall HDPE GI -El 13,105 100% 13,105 0 0.90 0.30 Roofdrain 8" SCH.40 PVC or Dual Wall HDPE G2-E2 8,609 100% 8,609 0 0.90 0.20 Roofdrain 8" SCH.40 PVC or Dual Wall HDPE G3-131 10,195 100% 10,195 0 0.90 0.23 Roofdrain 8" SCH.40 PVC or Dual Wall HDPE G4-A4B 8,648 100% 8,648 0 0.90 0.20 Roofdrain 664 West Rio LD-204 Stormwater Inlet Computations Inlets on Grade Only Sag Inlets Only za�c v n m ua a' U a ca m o 0 z 0o o o y y 5 U m a d cc L1 pp chi o rn 1 2 3 5 6 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 (ft) (inthr) (ifs) (cfr) (cfr) V) ('P) ('P) (ft) (ft) (ifs) (eft) (ft) (ft) (ft) A8C 8' DI-3B 8' DI-3B 0.14 0.66 0.09 4.00 0.36 0.000 0.36 0.015 0.126 0.020 0.083 1.23 0.10 100.0% 0.36 0.000 6.5 0.59 0.000 0.59 148 0.12 96.7% 0.57 0.019 A8B 10' DI-3B 10' DI-3B 0.16 0.84 0.14 4.00 0.55 0.000 0.55 0.015 0.126 0.020 0.083 1.44 0.12 100.0% 0.55 0.000 6.5 0.90 0.000 0.90 1.73 0.14 98.1% 0.88 0.017 A8A 8' DI-3B 8' DI-3B 0.37 0.87 0.33 4.00 1.30 0.000 1.30 0.015 0.050 0.016 0.083 0.13 0.5 0.27 1.61 6.5 2.11 0.000 2.11 0.18 0.5 0.37 114 A7B 8' DI-3B 8' DI-3B 0.43 0.87 0.37 4.00 1.49 0.000 1.49 0.015 0.041 0.020 0.083 0.15 0.5 0.29 1.76 6.5 2.42 0.000 2.42 0.20 0.5 0.40 3.79 A6 8' DI-3B 8' DI-3B O.13 0.81 0.11 4.00 0.42 0.000 0.42 0.015 0.I00 0.020 0.000 3.30 0.07 100.0% 0.42 0.000 6.5 0.68 0.000 0.68 3.95 0.08 91.7% 0.63 0.057 A5 6' DI-3B 6' DI-3B 0.03 0.90 0.03 4.00 0.11 0.000 0.11 0.015 0.069 0.020 0.000 2.14 0.04 100.0% 0.11 0.000 6.5 0.17 0.000 0.17 2.52 0.05 100.0% 0.17 0.000 B2 8' DI-3C 8' DI-3C 0.27 0.84 0.23 4.00 0.90 0.000 0.90 0.015 0.0I1 0.015 0.083 0.10 0.5 0.21 1.26 6.5 1.46 0.057 1.52 0.15 0.5 0.30 1.78 C2 8' DI-3C 8' DI-3C O.13 0.87 0.11 4.00 0.44 0.000 0.44 0.015 0.019 0.014 0.083 0.07 0.5 0.13 0.78 6.5 0.71 0.000 0.71 0.09 0.5 0.18 1.07 D3 6' DI-3B 6' DI-3B 0.04 0.90 0.03 4.00 0.14 0.000 0.14 0.015 0.090 0.020 0.083 0.03 0.5 0.07 0.41 6.5 0.23 0.019 0.25 0.05 0.5 0.10 0.61 D2 6' DI-3B 6' DI-3B O.12 0.90 0.11 4.00 0.44 0.000 0.44 0.015 0.090 0.020 0.083 0.07 0.5 0.15 0.89 6.5 0.72 0.017 0.74 0.10 0.5 0.21 1.25 DI 6' DI-3B 6' DI-3B 0.04 0.90 0.03 4.00 0.13 0.000 0.13 0.015 0.050 0.029 0.083 0.03 0.5 0.07 0.39 6.5 0.21 0.000 0.21 0.05 0.5 0.09 0.54 F2 18" Nyloplast Drain Basin 18" Nylt Drain Basin 0. I5 0.48 0.07 4.00 0.28 0.000 0.28 0.015 0.017 0.055 0.000 0. I2 - 2.93 6.5 0.46 0.000 0.46 0.17 - - 3.78 664 West Rio LD-229 STORM DRAIN DESIGN COMPUTATIONS From To Catch_ Runoff Inc Act. ToC Total Total Up Do Pipe Inv Pipe Pipe Velocity Flow time Point Point Area Coef AC AC Intensity Flow(cfs) invert Invert Length Slope Diameter Capacity Inc (ac) (min) ow ) EI El (it) % (in) (cfs) (01s) (min) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 A8C A8B 0.14 0.66 0.09 0.09 500 5.17 0.47 506.96 506.78 27.65 0.65% 15 6.07 279 0.17 A8B A8A 0.16 0.84 0.14 023 517 5.13 1.17 506.58 506.18 61.79 0.65% 15 6.07 363 028 AIIA A8 0.37 0.87 0.33 0.55 528 5.10 2.82 505-98 505.70 42.54 0.66% 15 611 462 0.15 F2 F l 0.15 048 0.07 0.07 500 5.17 0.37 52700 526.55 22.37 2.01% 6 0.93 421 0.09 r'1G2 E2 020 0-90 018 025 5.09 515 1.28 - 1.00% 8 141 428 - r1t Gl EI 0.30 0-90 027 027 500 5.17 1.40 - 1.00% 8 141 420 - A711 A7A 043 0-87 0.37 0.37 500 5.17 1.92 50924 507.64 59.92 2.67% 18 2000. 679 0.15 A7A A7 0.37 0.37 515 5.13 1.91 50744 507.00 8.14 5 4l % 1 18 2847 870 0.02 D3 D2 0.04 0-90 0.03 0.03 500 5.17 0.18 496.59 496.35 22. 13 1.08% 15 7.82 2.50 0.15 D2 Dl 0.12 0-90 0.11 0.15 515 5.13 0.75 496. 15 495.51 3204. 2.00% 15 10.64 475 0.11 DI A4B 0.04 0-90 0.03 0.18 5.11 5.14 0.91 495.31 494.90 18. 15 2 26% 15 11.31 525 0.06 I4IG4 A4B 020 0-90 0.18 0.18 500 5.17 0.92 - - - 1.00% 8 141 406 - r01 G3 B t 023 0.90 021 021 5.00 517 1.09 1.00% 8 141 420 C2 Cl 0.13 0-87 0.11 Oil 500 5.17 0.57 50100 500.50 1466 3 41% 15 13.90 529 0.05 B2 B t 027 0.84 023 023 5.00 5.17 1.16 501.00 500.50 13.90 3.60% 15 1428 665 0.03 I5IA5 A4 - - - - - - 2.72 505.00 498.50 1073 6.06% 24 64.90 970 0.18 r6jA4 A3 - - - - - - 7.44 494.00 493-54 1521 3-02% 24 45-81 10.19 0-02 r61A3 A2 - - - - - - 7.44 49334 48542 8331 951% 24 8130 1531 0-09 (6)A2 Al - - - 7.44 483-92 48350 4174 1.01 % 24 2649 6.87 010 Notes: 1 G2 is roofdrain assumend at minimum sloe 1.00% for most conservative design, G2 accumulates area from pipe F2-F1 (2) G1 is roofdrain assumend at minimum slope 1.00% for most conservative design (3) G4 is roofdrain assumend at minimum slope 1.00% for most conservative design 4 G3 is roofdrain assumend at minimum sloe 1.00% for most conservative design (5) Flow for A5-A4 is obtained from 10-yr 24-hr storm out of detention system 1 HydroCAD Calculations (6) Flow for A4-A3, A3-A2, A2-Al is obtained from 10-yr 24-hr storm out of detention system 1 & 2 HydroCAD Calculations Ci 0.9 cp 0.3 a2 b2 a10 bill 106.02 15.51 1616 18.73 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. _._._LOD ----SOILS NOTE: ALL SOILS IN DRAINAGE AREA 1 ARE HSG B SNIMPENGINEERING, P.C. ENGlM'EVN6-L4NDPLINMN6 -FRaIELT MANAGEMENT R o E LLE. A „PO= �srN.PH�E�HINa_(4<4) 227-5140 � WWI W. 45-1000 LIMITS OF DISTURBANCE A=4.02 AC 1a i W W ' � W W W ,W W W �4Y-100W W W W W W W W W� �!W W W W"FKFF W-i W W W W W W W W W W W W W W W NW 4 ,00 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 OW W W . W . . W W W . W . . W W W W W W W W jH W W `W W W W W W W W W W W W W W W W :.. N N W W W W W YI W W W W W W W W W W W W W W W W W W W W W YR 1 W W• W W W W W W W W W W W W W W W WIW W W 1, .v wOK 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 r� W ylp 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 TMW45-%l W W W W W W W W W W W W ` W W W W W W W �7B�W W W W W W W W W W W W W WHSG B W+ W W W W W W W W W W W W W W W W W W 4C WSCy. B / BENCHMARK: W W W W W W W W W * W W W W W W W W W W W W W W I W W W W i0P C£ g p INLET EI ATMN-527.78 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 00'.pINT a 10 ESNT D.B. IPIJ-S27 Y] D.B. 10M_KSPIAT 664 West Rio -�- 60 0 60 Pre Development VRRM Map Sale: 1"=60` TM. 45-1J3 TM. 45-94B 120 180 LEGEND POST DEV IMP. POST DEV TURF. LOD --- SOILS NOTE: ALL SOILS IN DRAINAGE AREA 1 ARE HSG B SHIMPENGINEERM P.C. ENGGYEEVN6-L4NDFMAMN6 -PRQIELT MANAGEMENT n 664 West Rio Post Development VRRM Map R. 45-105 60 Scale: 1 0 60 120 173 :• 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 data input cells Project Name: 664 West Rio Date: 2/9/2023 constant values Linear Development Project? No calculation cells Site Information Post -Development Project (Treatment Volume and Loads) Enter Total Disturbed Area (acres) 4 a.o2 Check., BMP Design Specifications List. 2013 Draft Stds & Specs Linear project? No 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 Turf (ware) -- disturbed, graded for yards or other turf to be mowed/managed 3.26 3.26 Impervious Cover (acres) 0.17 0.17 4.02 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 Turf (ware) -- disturbed, graded for yards or other turf to be mowed/managed 1.44 1'40 Impervious Caver (acres) 2.58 2.58 Area Check OK. OK. OK. OK. 4.02 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/yr) 0.41 Pj (u artless correction factorl aw L • • •' • COVER SUMMARY POSTDEVELOPMENT Land Cover Summary -Pre Land Cover Surnrnary-PoFf(Final) Land Cover Summo189% Land Cover Summary -Post Pre-ReDevelopmern Listed Adjusted' Post ReDev. & New Impervious Pe[-ReDevelopPost-Develo t New Im omen pervious Forest/Open Space Forest/Open Space Forest/Open Space Cover (acres) 0.59 0.00 000 Cover (acres) Cover(acresl Weighted Rv(forest) 0.03 0.00 Weighted Rv(Wrest) 0.00 Weighted Rv(forest) %Forest 15% 0% %Forest 0% %Forest Managed Turf Cover (acres) 3.26 1.44 Managed Turf Cover 144 Managed Turf Cover (acres) (acres) Weighted RvWi 0.20 0.20 Weighted Rv (turf) 0.20 Weighted Rv (tur0 %Managed Turf 81% 89% %Managed Turf 36% %Managed Turf Impervious Cover (acres) 0.17 0.17 Impervious Cover (acres) 2.58 ReDev. Impervious 011 New Impervious Cover 241 cover(acresl (acres) Rv(impervious) 0.95 0.95 Rv(impervious) 0.95 Rv(impervious) 0.95 Rv(impervious) 0.95 %Impervious 4% 11% %Impervious 64% %Impervious 119" Total Site Area (acres) 4.02 1.61 Final SRe Area (acres) 4.02 Teal ReDev. Site Area 1.61 (a res) site Rv 0.21 0.28 Final Post Dev Site Rv 0.68 ReDev Site Rv 0.28 Treatment Volume and Nutrient Load Treatment Volume and Nutrient Load Pont -Development Pre-ReDevelo tTreatment Volume omen Final Post -Development Post-ReDevelopment (acre-ft) 0.M93 0.0375 Treatment Volume (acre-ftl 0.2283 Treatmem Volume (aue-fq OA3T5 Trezw tnrd Volume 0.1908 taare-tt) Pre-ReDevelo tTreatment Volume pmen Final Post -Development Post-ReDevelopment Post-0evelopment (cubic fee) 3,017 1,632 Treatment Volume 9,943 Treatmem Volume 1,632 Treatment Volume (cubic 8,311 (cubic feet) (cubicfeet) feet) Pre-ReDevelopment TP Load anal Port- Post-ReOeveopmeM Port -Development 10 Load (lb/yr) 1.90 1.03 Development TP Load 6.25 Load (TP) 1.03 (Ib/yr) IIb/yr) (lb/yr)• hPRenevelapmen[ TP toad pera[re Final Post -Development TP PoSCReDevelopmeni TP (Ib/acre/yr) D.91 D.W toad peracre 1.55 toad peracre D.W pb/aci Ilb/acre/n) Baseline TP Load jb/yr) Max. Reduction Required (OAS Ibs/acre/yr applied to pre -redevelopment area enrieing pervious 0.66 (Below Pre- 2m6 IaM proposed for new Impervious cover) ReDevelopment Load) ' Adjusted Land Cover Summa j rya TP Load Reduction TP Load Reduction Pre ReDevelopment land rover minus pervious land cover 6 resVopen space ormanoged Required for 0.21 Required for New 4.23 turf) acreage proposed for new impervious rover. Redeveloped Area Impervious Area (lb/yr) (lb/yr) Adjusted tom( acreage is consistent with Post-ReDevelopment acreage (minus acreage of newimperviouscover). Column Islari land reduction requdemeat for newimpervious rover (bnsedon new developmentmed limit, 0.411bs/acre/year). Post -Development Requirement for TP Load Reduction Required (Ib/yr) 4.44 Nitrogen Loads (Informational Purposes Only) Final Post -Development TN Load Pre-ReDevelopment TN Wad(Ib/yr) 13.56 (Port-ReDevelopment&New Impervious) 44.69 (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) 9,94B 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 ( 0 0 0 0 0 TP LOAD AVAILABLE FOR REMOVAL (Ib/yr) 0.00 U0.00 0.00 0.00 0.00 0.00 TP LOAD REDUCTION ACHIEVED (Ib/yr) 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 -DEVELOPMENT TP LOAD (Ib/yr) 6.25 TP LOAD REDUCTION REQUIRED (Ib/yr) 4.44 TP LOAD REDUCTION ACHIEVED (Ib/yr) 0.00 TP LOAD REMAINING (Ib/yr): 6.25 REMAINING TP LOAD REDUCTION REQUIRED (Ib/yr): 4.44 Total Nitrogen (For Information Purposes) POST -DEVELOPMENT LOAD (Ib/yr) 44.69 NITROGEN LOAD REDUCTION ACHIEVED (Ib/yr) 0.00 REMAINING POST -DEVELOPMENT NITROGEN LOAD (Ib/yr) 44.69 �I ones -ver.ero,.vel DEQ Virginia Runoa Red uoion MCMod in, Deve lopment Compliance Sp re roister - Version 3.0 aMPnodiv Sp akwarvulis[: 2033O[als3Ms&Spers Site Summary Project Title: 660 Wert Rio note: 40%3 Total several (in) 43 Total DlrtuAed Aural 1 4D2 Site land Cover Summary Pre-ReOeveiopment land Cover (acres) Alan assets C3alk D3tlls Trials %afTWl Forest/open(acres, a00 os9 oa0 oao 0.s9 Is Managed Turt(anes) (L. 326 no] nN 3.E6 BI Imnnoocor(a00 rywum) (LIT 0 000 oN 0.17 a 4.02 Rin Post-Reoevelopment land cover (aces) Asials 1 ..l 1 C.,k D.In Trials ..,.I Forertl (acre[) 1 400 1 OD] i Dan i nN non 0 Manal Turl(ave[) a. IGG nD] Ran1.40 36 ImpervlwaCnwr(avm) an, z.sa oa0 Ron 2S. 66 a.. 1m Site Tv and land Cover Nutrient loads FI'aPoserr elopn .1 Pint Adjusted aea�nt ReOeuebpment rnt Reoe apment ewm w Ree�e mtt Rv 0.6a o29 Des O.za Treatmeitt Volumelhs) 9e43 1,632 . Wad Ri l 6.zs ln3 S.. 1.03 Total. Wad Manuel Re9ulrea(al 1 4.44 0.z1 e.A Real Port-Devebpnent Wad wa (pore-RmeMogneitt As New lmprnm eoun Raoloprienr Tx Wad(m/yrl GG.69 13.16 Site Compliance Summary Mntlmum % Reautlen RryuiM Belnx pe.amFnwn W.a Thal RupN Vobme RMu[tbn (11 0 Total. Wd Redu[tlon ANlcea(Ill 0.00 Todd Tx Led reduction AcelcM(Ill (l Remamlry Pon DevNo-1. Wad szs (bl Remaining TP Load Reduetdon Ril area Required Drainage Area Summary Pre Final Port-Davebpnent Port-Reoevelopmenr TP RleMopnen[ .Wad par.[. Lead per ave TPLoadper acre Ravacre r (b/au./yrl IIB/are/yrl [ sot Lail 0.. DAA DAB DAC DAD olr 1. Forest/opens R rea) nD] O.on 0.00 000 O.D] O.CO Managed red local nD] O.N not 000 O.D] r.. ImpervlwaCwarlavm) I ,. noo not 000 0.00 0.00 Twl Area(avm) I ... ... o.. Den Dm Oil Drainage Area Compliance Summary Runoff Volume and CN Calculations 1-ynrreorm bveirrtorm to-mrreonn Target Ralntan Event Rini 000 000 Ran Ddmye Are. Rv&ex Indra AroA odmye AreaB Dram$¢Areas Drainage Arno Dram[¢ Area m RR IkI 1jear return pedad "n(—) aRIl wwy v 2-yur returnperlad .I.anl wi lw>Inl a wyv ul.. peried al "al Few a.yve Rae., res 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) 1 (3.28-4.10) 1 (4.17-5.23) 1 (4.92-6.16) 1 (6.00-7.55) 1 (6.91-8.73) 1 (7.89-10.0) 1 (8.94-11.5) 1 (10.5-13.6) 1 (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