Loading...
The URL can be used to link to this page
Your browser does not support the video tag.
Home
My WebLink
About
WPO201600044 Calculations Stormwater Management Plan 2016-05-17
sHimp sHimpAid PENGINEERINGMANAGEMENT LAND PLANNING ENGINEERINGk May 17, 2016 VSMP Reviewer Albemarle County Regarding: Hillbrook Stormwater Management VSMP Amendment To Whom It May Concern, Enclosed are the calculations and details relating to stormwater treatment for the proposed development Hillbrook. The presence of rock in the approved location of the detention facility necessitated its re-location to the right-of-way.The following calculation packet shows all details updated per the as-built design of the detention facility. Pollutant removal is achieved with a combination of impervious disconnection and level 2 bioretention.All pollutant removal is applied to"D.A.A"on the VRRM,which is delineated on the post-development drainage map.The bioretention is designed to be off-line, with a flow-splitter incorporated into the vault STM 5. The 1-year storm flows through the 3"x13"orifice in to the bioretention. STM 4 has a 15"overflow structure set just above the 1-year water surface elevation of the vault to capture the bulk of larger storm flows. On the east,the site sheet flows onto the Raintree property.As shown in the summary table below, the post-development peak flow and runoff volume are significantly reduced for both the 1-year and 10-year storms.The values shown are computed in the HydroCAD reports. On the northwest, the site discharges to a natural channel before the 1% point, so the energy balance equation is applied to limit the peak 1-year discharge. I.F.* (QpYe *RVpre) Qdev — RVdev Qpre and RVpre are shown on the pre-development drainage map and computed in the pre-development HydroCAD report. RVdev is shown on the post-development drainage map and computed in the post- development HydroCAD report. Qdev is computed on the post-development drainage map. Qi, the design flow, is computed in the post-development HydroCAD report. A 48"detention structure limits the 1-year peak discharge to the northwest. The site discharges through existing storm sewer that is adequate to convey the 10-yr storm before reaching the natural channel,which fully contains the 10-yr flow without flooding. Flow Summary: Northwest(X4) Qmax 1.47 cfs Qi 1.47 cfs aa East(Raintree) Q1(pre) 0.32 cfs Q1(post) 0.13 cfs RV1(pre) 0.042 a.f. RV1(post) 0.016 a.f. Q10(pre) 3.29 cfs Q1o(post) 3.10 cfs If you have any questions please do not hesitate to contact me at your earliest opportunity. I may be reached at: Justinna shimp-engineering.com or by phone at 434-953-6116. Yours Truly, Justin Shimp, P.E. 41111 • Alm U JUSTIN/M.SHIMP Lic o. 5183 /6 .°4:k e ssl®NAL Contents: Pre-Development Stormwater Management Calculations: Pre-Development Drainage Map Pre-Development HydroCAD Analysis Post-Development Stormwater Management Calculations: Post-Development Drainage Map Virginia Runoff Removal Method Reports Post-Development HydroCAD Analysis Storm Sewer Calculations: Storm Inlet Drainage Map VDOT LD-204 VDOT LD-229 VDOT LD-268 VDOT LD-347 Self-Cleaning Velocity Check .11 Independent Reports: Excerpt from NRCS Soils Report NOAA Precipitation Report bid Pre-Development Stormwater Management Calculations Pre-Development Drainage Map Pre-Development HydroCAD Analysis kms, famme 1 IIIMIIN 1 ■ I rale ice■ Ilimmil i■■m■1 Iri■1 Yi■i/ Imw muoimmi ■m■■1 mw♦rl wed\ imp■■� ■mmoll am■■a i \ 1 1 I AIL \ \ \ \ \ \ ‘ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ ,\ \ \ / / / I 1 I \ , \ \ \ \ \\ \\ \\ \ \ \ `\ I I / \ \ \ \ \ \ OO , \ \ \ \ ` `/ I \ ) v \ \ \ \ \ \ \ \/ y \ wc ' • \ ` ` ` � � � �/ � � .' - _ _ _ � -- / • Z CO "Ilg' IS). — — —11- — — — — _ II \ r --1 / --- ( / I/ • ' _ _- --\ ,' )::) ,11# II Co to -----, --_. - -__ ----- --... -...„ -______ ,,.._. ....... - -- -\ \ 1 1 r , -\ ---_---- , .•..., •...._ , __.....1... 0,-, N (0 \ • --\ � �i - .,„„,tioo ----- - MAD---A---0-CV- __ ---- - ---- ----- - --- _--:-_-z-s:v___11111111 - \\ i / y 0 c ji \ Env, —I t 0 \En \ \\ \\ oI , -10 / \ i i !L- 114 MI MN um INNINO I) � \ \ \ ) \\ [-3)\ x I II II f' -„,,, ,--- __ Li. ......_ ....._ ,..,...._. __ , \ \ „,___ _ _ _ _ ........ _ ...._ , , \ 1 , \ �� LI � _ _ _ - - _ _ - - I � , //,___ 1 / 1111 Z4'14- �com 0� �Y � / Ili - 0 ■ 11 4m .ice / J I II _■ 11 - - - i1iiiIiiiiiIi 91 \_ _ _ - - 7 � Z _ - , , I Y I __ ____ ____ __ _. _ - _\?, / 1 'MI- — 1 0 m - / \ CC ci No co NJ 0 o N i N D N N o m _ J _ - - x - -z- - i -I "D --I -� Z o xi y /a N a m D / / _ 71 CU .O - - O 1 F. — —1 "(D n 0 o — — " NO p \ . n z _ __ — — __o J _ — _ II • m W N m _ - - X' 0 — / / Q / O — � — - - - N •O – o _ — — TT _ V A� W A W _ _ /V \ __ — — _. — 0, K T �. XErl O Q < Q o nQ < — '-- \Y 71 0 - fD ,p O \ r A W A ? W �� —480— �' 0 N m 7 7 3 3 7 7 \ / Z T• (n Z Ul \ � Il 3 N T1 CD / 3- 3 C 3 a tea die 4 D. .2 ,d 2 D.A.2 Offsite D.A. 1 410 D.A.2 Onsite Subcat Reach •on• Link Drainage Diagram for Hilibrook Pre-Development Prepared by Shimp Engineering, P.C., Printed 7/1/2015 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Hil!brook Pre-Development Type 1124-hr 1yr Rainfall=3.01" Prepared by Shimp Engineering, P.C. Printed 7/1/2015 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 2 wig Summary for Subcatchment 1: D.A.1 Runoff = 0.32 cfs @ 12.12 hrs, Volume= 0.042 af, Depth> 0.27" sist Runoff by SCS TR-20 method, UH=SCS,Time Span=0.00-24.00 hrs,dt=0.01 hrs Type II 24-hr 1yr Rainfall=3.01" Area(ac) CN Description 1.856 58 Woods/grass comb.,Good,HSG B 1.856 100.00%Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) a 14.6 Direct Entry, Summary for Subcatchment 2: D.A.2 Onsite Runoff = 0.23 cfs @ 12.04 hrs, Volume= 0.017 af, Depth> 0.37" Runoff by SCS TR-20 method, UH=SCS,Time Span=0.00-24.00 hrs,dt=0.01 hrs Type II 24-hr 1yr Rainfall=3.01" Area(ac) CN Description Nit 0.568 61 Pasture/grassland/range,Good,HSG B 0.568 100.00%Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.4 Direct Entry, Summary for Subcatchment 3: D.A.2 Offsite Runoff = 1.50 cfs @ 11.96 hrs, Volume= 0.068 af, Depth> 1.59" Runoff by SCS TR-20 method,UH=SCS,Time Span=0.00-24.00 hrs,dt=0.01 hrs Type II 24-hr 1yr Rainfall=3.01" Area(ac) CN Description 0.182 61 Pasture/grassland/range,Good,HSG B * 0.328 98 Impervious 0.510 85 Weighted Average 0.182 35.69%Pervious Area 401 0.328 64.31%Impervious Area Tc Length Slope Velocity Capacity Description eke (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, sir Hilibrook Pre-Development Type 1124-hr lyr Rainfall=3.01" am Prepared by Shimp Engineering, P.C. Printed 7/1/2015 HydroCAD®9.10 sin 07054 ©2011 HydroCAD Software Solutions LLC Page 3 mw Summary for Link 4: D.A.2 Inflow Area= 1.078 ac, 30.43%Impervious, Inflow Depth> 0.95" for 1yr event Inflow = 1.62 cfs @ 11.97 hrs, Volume= 0.085 af Atal Primary = 1.62 cfs @ 11.97 hrs, Volume= 0.085 af, Atten=0%, Lag=0.0 min Primary outflow=Inflow,Time Span=0.00-24.00 hrs,dt=0.01 hrs mig ust m O0 AO WO AO WO OW AM WO AO AO Hil!brook Pre-Development Type N 24-hr 10yr RainfaN=5.51 f'" Prepared by Shimp Engineering, P.C. Printed 7/1/2015 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 4 Summary for Subcatchment 1: D.A.1 Runoff = 3.29 cfs @ 12.08 hrs, Volume= 0.225 af, Depth> 1.45" Runoff by SCS TR-20 method, UH=SCS,Time Span=0.00-24.00 hrs,dt=0.01 hrs Type II 24-hr 10yr Rainfall=5.51" air Area(ac) CN Description 1.856 58 Woods/grass comb.,Good, HSG B 1.856 100.00%Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 14.6 Direct Entry, Summary for Subcatchment 2: D.A.2 Onsite Runoff = 1.47 cfs @ 12.02 hrs, Volume= 0.080 af, Depth> 1.68" Runoff by SCS TR-20 method, UH=SCS,Time Span=0.00-24.00 hrs,dt=0.01 hrs Type II 24-hr 10yr Rainfall=5.51" Area(ac) CN Description tem 0.568 61 Pasture/grassland/range,Good,HSG B 0.568 100.00%Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.4 Direct Entry, Summary for Subcatchment 3: D.A.2 Offsite Runoff = 3.48 cfs @ 11.96 hrs, Volume= 0.163 af, Depth> 3.84" Runoff by SCS TR-20 method,UH=SCS,Time Span=0.00-24.00 hrs,dt=0.01 hrs Type II 24-hr 10yr Rainfall=5.51" Area(ac) CN Description Ar 0.182 61 Pasture/grassland/range,Good,HSG B * 0.328 98 Impervious 0.510 85 Weighted Average 0.182 35.69%Pervious Area mat 0.328 64.31%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Hillbrook Pre-Development Type 1124-hr 10yr Rainfall=5.51" kftii Prepared by Shimp Engineering, P.C. Printed 7/1/2015 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 5 Summary for Link 4: D.A.2 Inflow Area= 1.078 ac, 30.43%Impervious, Inflow Depth> 2.70" for 10yr event dirm Inflow = 4.67 cfs @ 11.97 hrs, Volume= 0.243 af Primary = 4.67 cfs @ 11.97 hrs, Volume= 0.243 af, Atten=0%, Lag=0.0 min Primary outflow=Inflow,Time Span=0.00-24.00 hrs,dt=0.01 hrs gin r Post-Development Stormwater Management Calculations Post-Development Drainage Map Virginia Runoff Removal Method Reports Post-Development HydroCAD Analysis Mormon •••••••••• \ 111.1/1111 1 0117 I t■■■■� f MMM �� 61.1.14 ■�■�rI ,■I■wf \n�\ �...• �..■■ �. �.•. �\ � I \ \ � I \� \ \0 \ \\ \\ �\ \CO \ \, inn\ / i I I II I \ E E F E �E \ \\ Minn \\ \\Z \\ \\ N\\ \\ E E E E , \ \ \1co \,.. \ v\ \ ' O D\ E E E E E \ \ M O p I � V Pi ITI E E E E E E ' \ \ ` O\ /� i 0\ I 1 E E E F E E E E E f E F \ ■ \\O ■ cb 2 / / a WMw > NI \ / /I E E E �_ E \\ y` • \ �w '{jam E F F E -E- _ - _/ \i\ \ = �\ \ E to _k_. Y/ / 4 E E E E �E E E1� �--� \ \ �\ \. 15, iir\•I v J E Br E E siegeststammet _ ■ ■ ■ \ / i / i ' .x: /. `+ �I — ( �� / / ` ins ,' • \ 1 v ii,cip /\ \I / (/' / ........ ( . • / ..,---"'. co (I�• ` \, _ 'lam / \F .....2-4 ....-2-4.--_- 4-......--------_-:--..,-- ., �' 11.1111 - -.; i All_ ---- - _... - --11110 4111K / 1��_ '� E E s �� .-_- 111 1 � ..'44,41A _�� _�\ _� ��\E�\ II Fr �E j i E\ E E I IE I E �/ E E •.t r.Ilt ���! E E E 1F- \ � \ \\ 0 ,- j �E �E \E\ E I E E E E ■ ,. E \E E E E \ �F �E�� I ,• 1- I i ` E �\ IE I � ,M I� E E ._.. \` \ E F F \ \ -i I E E f� E E 1. u\ J I I j E E 1)ill I F E \ I \ \\ \.,�.\1\\.}\_- ' i E E E ..\IE \ / _._ /C ,_-.. 1111 • ". X11 • 3 E E /'/ \ • a ri i\ 1 !1 'I! ':II ( 11,I 1 I E E E \A m. I E E E E E E...__.. _ - fai )P �� ..• �� _ It� E \ E E E I E O OI I . + E E EE EE E E E f Aiik : : : : IIE II ,I • �E \ E - $�E E E iE E E Z E E F I I E \II I E \r_- E i E M• \ \ ,i ' __ 211/Ifier-- , . ..,_ ____, . _ .___c , t '491 I / 11101.101* 4 ):111 • • i® 1 ® , ` - _ - I.ij /_ 1 J ® I ® E ell." ii I - - - cIm Z Z I E liF E 4 4 f E 6 6 Ey-- E E E E E �E E E E I IO NO I E E E * E ` J , 1' . -----4 4 4 E �I v E E( 4 _( -.4'4 E -- Eimill' / <-010* E0 3 I * 4 4 E E E E 6 E E■ E ' E E C CZ L E E E E E f E E E E i A E v El E E i .• E \ E E 7 E • E E E * E ±�E� E E Oll( E E 3/ E r xi le I .f■m" F E E E E E E E E E �E E- E E E E ..,W m T y 6 E , 6 * 6 * / E E E E E E _ E' v E, 4- -- E 4 E + E E clii / E E E EEE s!i <?—j -01'-- - - EE 1 : i * - - m.`J1 E E Z E • E E FMilk 7 E E E // / AIN Iillimk '� E E E F ,w E E E E / AO , E �E E E E Ag�� E E•. E E /E E E E E E E E / / CI O ■ E E E E E E E E E E E E { E-� / I II� E F * E E E 4 E 4 E E ` E -F EE 64 E E F E E _/ E E E / E E E YE E E fr i E E E E E / I O O I I O E E E E F E 4 E E 1 E 4 -- i E E E 6 . # E E / I _ Omil i E E EEEEE - F 6 E E E E � \ IOW nue E E� -4.-. * \E E i FE E E E E VE �,�I✓M I/ — — l JJJ J IE Vel Ti O E -E- -T -� EE E F F EE 4 I-V• * [' 4 4 4 E E_..-- -c-- E E _ E / \ ›.. J IZ _ _ - ` E E� E E E` _'� * *Lt V /_ � / - \ m I� / D \ *.. : • I O Zl ,D O - - • :: 11, 4c . ::P - •* * O O P fri n G G c 7 —1 _ ? .* . ;: ' - * C1 O7-900m O CCD D / - - - - TIO O • O -ri *. i4. m- p (/) � � O •O � O � *.<1 � 3'� * -11 cD �7 O CA N po M .c ' II rJrJ�J � a a ' \ -- - - - - - O p T O I I NJ J l : . J l J—L 1 Z , M 0 0( (n - — (n n -I ((j _ - - - i - - - - OZ xi * Z Z K K z m m - _ — fTl O omcn o o mcn z H< =II � < < = -0 O D0 - - - — O mZm m m Z U) ZD ND -- — —480-- / I \"_11 m Q7 I E E f / O E * _ - 1/ ` W E E 11, G� * Ai E F f W T I >,\Z. \ / O I ' I E E 1 I ✓ D O E E E > n 77:> /XN -0 A ry O — _ ^ Virginia Runoff Reduction Method Worksheet mar Virginia Runoff Reduction Method New Development Worksheet-v2.8-June 2014 Site Data Summary Total Rainfall=43 inches Site Land Cover Summary A Soils B Soils C Soils D Soils Total %of Total Forest(acres) 0.00 0.54 0.00 0.00 0.54 21.52 Turf(acres) 0.00 1.26 0.00 0.00 1.26 49.74 410 Impervious(acres) 0.00 0.73 0.00_ 0.00 0.73 28.73 2.53 100.00 Site Rv 0.38 atm Post Development Treatment Volume(ft3) 3476 Post Development TP Load(lb/yr) 2.18 Post Development TN Load(lb/yr) 15.62 qtr Total TP Load Reduction Required(Ib/yr) 1.15 Total Runoff Volume Reduction(ft3) 1962 Total TP Load Reduction Achieved(lb/yr) 1 ow Total TN Load Reduction Achieved(Ib/yr) 10.77 Adjusted Post Development TP Load(Ib/yr) 0.82 Remaining Phosphorous Load Reduction(Lb/yr)Required O Aim Drainage Area Summary D.A.A D.A.B D.A.C D.A.D D.A.E Total Forest(acres) 0.00 0.00 0.00 0.00 0.00 0.00 111111 Turf(acres) 0.67 0.00 0.00 0.00 0.00 0.67 Impervious(acres) 0.55 0.00 0.00 0.00 0.00 0.55 1.23 ism Drainage Area Compliance Summary D.A.A D.A.B D.A.C D.A.D D.A.E Total TP Load Red.(Ib/yr) 1.37 0.00 0.00 0.00 0.00 1.37 TN Load Red.(Ib/yr) 10.77 0.00 0.00 0.00 0.00 10.77 ittli r tie IN Summary Print Virginia Runoff Reduction Method Worksheet Drainage Area A Summary Land Cover Summary A Soils B Soils C Soils D Soils Total %of Total Forest(acres) 0.00 0.00 0.00 0.00 0.00 0.00 Turf(acres) 0.00 0.67 0.00 0.00 0.67 54.92 Impervious(acres) 0.00 0.55 0.00 0.00 0.55 45.08 1.23 'ioto BMP Selections Practice Credit Area(acres) Downstream Practice 2.a.Simple Disconnection to A/B Soils(Spec#1) impervious 0.122314 6.b. acres Bioretention disconnected #2 6.b.Bioretention#2(Spec#9) Impervious: 0.43152 Turf(Pervious): 0.674839 Total Impervious Cover Treated(acres) 0.55 tarTotal Turf Area Treated(acres) 0.67 Total TP Load Reduction Achieved in D.A.A(Ib/yr) 1.37 Total TN Load Reduction Achieved in D.A.A(Ib/yr) 10.77 atl tea Summary Print Virginia Runoff Reduction Method Worksheet otti Channel and Flood Protection Weighted CN 1-year 2-year storm 10-year storm Adjusted CN storm Adjusted Adjusted CN CN Target Rainfall Event(in) 3.01 3.65 5.51 D.A.A CN 78 69 71 73 D.A.B CN 0 #N/A #N/A #N/A alt D.A.C CN 0 #N/A #N/A #N/A D.A.D CN 0 #N/A #N/A #N/A D.A.E CN 0 #N/A #N/A #N/A artal arr mat tri ri air raiti irY rr Summary Print m [ N » } £ 2 0 O \ - � 20 CO / -cy CD CD 6 co / / o \ � g m k > 7 CD / \ = 2 n \o = CD \ } \ / ) / / - » 2,1 \ \ \ \ \ -XI -1(L'' (I) 0 _\ \ \ \ \ 0 ƒ \ [ f ® Q ) J % I \ Cl) f o \ \\ E E PPP �ES ?_ f 0. E C 2 FA' R Co - - -_ - - - m _ _ CA ca - -_ ® P o g ( ° ° § $ \ 0 7 : o _ / 0 ) 3 ° o # o « 0poo m E j j / a 0 E \ S m ) \ \ \ \ \ \ 0 / ■ > 2 C 2 CD _ 0 -I 0 0 0 0 0 CL ) a Qe ° / < n E g g = -I "" � ca. co a. 0 000 2 R > o _ x / x / \ \ / C / Z $ m m CD [ 0 § > > 0 0 0 g - 0 _, (000c47 mm § § 'CO ? ƒ A S 7 \ \ \ ? m � w E1- ( - - \ -1c ■ � o r 0 < ( 0 0. - r 00 P P P P 0 � a g9P ? > m % \ % % 0 0 N , \ \ / \ noo 0 m - m ƒ mem A)kz �7 ƒo ° Ez ? - } 2 { ( A o \ 0 0 0 3 - > yaF- r = 23 § \ D i . . / / \ - k \ oa cn c\ o\e / o = § $ { 0 < \ $ CO o o \ \ \ \ -1 _ / ( e M } 01 0 \ \ 0 $« \ mE 3 -\ E ] o o o o = § § ; o / b 0 b o \ C � � \ 0 •E ( Q \ P P P o E# ƒ § / 0 0 \ a ° _ al c -0m -0 E 0 0 0 o P ( ) f \ \ o o / \ § a §7 « o DJ O. } ( o g go 9 = E \ - b S \ f E I CA = § \ ;I CD3 \ co \ E \ I I 3 \ o 0. 9 10 4 8 1 Offsite Undetained Inle 4 Onsite Undetained Sheet Flow 11 aill ( 6 D Aa- ® D /\ A Raintree Offsite Detained De4tion Vault Bioretention 5 2 Onsite Detained D.A. A illa ail ilia Subcat Reach •on. Link Drainage Diagram for Hillbrook Post-Development lyr Prepared by Shimp Engineering, P.C., Printed 5/17/2016 mor HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC 411010 Hillbrook Post-Development 1yr Type 1124-hr lyr Rainfall=3.01" Prepared by Shimp Engineering, P.C. Printed 5/17/2016 4110 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 2 Summary for Subcatchment 1: Sheet Flow Runoff = 0.13 cfs @ 12.09 hrs, Volume= 0.016 af, Depth> 0.25" 4161 Runoff by SCS TR-20 method, UH=SCS,Time Span=0.00-24.00 hrs,dt=0.01 hrs Type II 24-hr 1yr Rainfall=3.01" Area(ac) CN Description * 0.550 55 Conservation Area * 0.246 61 Sheet Flow 0.796 57 Weighted Average 0.796 100.00%Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.6 Direct Entry, Summary for Subcatchment 2: D.A.A Runoff = 1.46 cfs @ 11.97 hrs, Volume= 0.069 af, Depth> 0.67" mos Runoff by SCS TR-20 method, UH=SCS,Time Span=0.00-24.00 hrs,dt=0.01 hrs Type II 24-hr 1yr Rainfall=3.01" Area(ac) CN Description * 1.229 69 Adjusted CN a,„ 1.229 100.00%Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Pond 3:Vault tha Inflow Area= 1.229 ac, 0.00%Impervious, Inflow Depth> 0.67" for 1yr event Inflow = 1.46 cfs @ 11.97 hrs, Volume= 0.069 af Outflow = 1.45 cfs @ 11.98 hrs, Volume= 0.069 af, Atten=1%, Lag=0.4 min Primary = 1.45 cfs @ 11.98 hrs, Volume= 0.069 af Secondary= 0.00 cfs @ 0.00 hrs, Volume= 0.000 af tad Routing by Stor-Ind method,Time Span=0.00-24.00 hrs,dt=0.01 hrs Peak Etev=497,36'@ 11.98 hrs Surf.Area=16 sf Storage=20 cf ai Plug-Flow detention time=0.2 min calculated for 0.069 af(100%of inflow) Center-of-Mass det.time=0.1 min(879.7-879.5) Volume Invert Avail.Storage Storage Description #1 496.10' 108 cf COM x 4.00'.x 6.74'l l 4`x4'Vault Storage it Hilibrook Post-Development lyr Type 1124-hr lyr Rainfatl=3.01 Prepared by Shimp Engineering, P.C. Printed 5/17/2016 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 3 Device Routing Invert Outlet Devices atik #1 Primary 496.00' 15.0" Round STM 5-6 L= 180.5' Ke=0.100 Inlet/Outlet Invert=496.00'/495.10' S=0.0050'/' Cc=0.900 n=0.011 #2 Device 1 496.00' 13:0"W x 3.p"H Vert.Weir Plate Orifice C=0.600 #3 Secondary 497.45' 15.0" Round STM 3-4 L=71.5' Ke=0.100 Inlet/Outlet Invert=497.45'/490.20' S=0.1014'/' Cc=0.900 n=0.011 #4 Device 3 496.10' 15.0" Round STM 4-5 L=16.1' Ke=0.100 Inlet/Outlet Invert=496.00'/496.10' S=-0.0062'/' Cc=0.900 n=0.011 Primary OutFlow Max=1.45 cfs @ 11.98 hrs HW=497.36' (Free Discharge) t1=STM 5-6 (Passes 1.45 cfs of 5.19 cfs potential flow) t2=Weir Plate Orifice (Orifice Controls 1.45 cfs @ 5.36 fps) Secondary OutFlow Max=0.00 cfs @ 0.00 hrs HW=496.10' (Free Discharge) t3=STM 3-4 (Controls 0.00 cfs) t4=STM 4-5 (Controls 0.00 cfs) Summary for Pond 4: Bioretention Inflow Area= 1.229 ac, 0.00%Impervious, Inflow Depth> 0.67" for 1yr event Inflow = 1.45 cfs @ 11.98 hrs, Volume= 0.069 af Outflow = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af, Atten=100%, Lag=0.0 min Primary = 0.00 cfs @ 0.00 hrs, Volume= 0.000 af sir Routing by Stor-Ind method,Time Span=0.00-24.00 hrs,dt=0.01 hrs Peak Elev=494.98'@ 24.00 hrs Surf.Area=3,703 sf Storage=3,005 cf Plug-Flow detention time=(not calculated:initial storage excedes outflow) Center-of-Mass det.time=(not calculated: no outflow) Volume Invert Avail.Storage Storage Description #1 488.60' 908 cf Gravel Sump(Prismatic)Listed below(Recalc) 2,270 cf Overall x 40.0%Voids #2 490.85' 820 cf Bioretention Mix(Prismatic)Listed below(Recalc) ®"' 3,279 cf Overall x 25.0%Voids #3 494.10' 1,482 cf Surface Storage(Prismatic)Listed below(Recalc) 3,209 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) rr 488.60 1,009 0 0 490.85 1,009 2,270 2,270 Elevation Surf.Area Inc.Store Cum.Store tor (feet) (sq-ft) (cubic-feet) (cubic-feet) 490.85 1,009 0 0 494.10 1,009 3,279 3,279 Hilibrook Post-Development lyr Type 1124-hr lyr Rainfaii=3.01 Prepared by Shimp Engineering, P.C. Printed 5/17/2016 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 4 Elevation Surf.Area Inc.Store Cum.Store sas (feet) (sq-ft) (cubic-feet) (cubic-feet) 494.10 1,214 0 0 495.10 1,749 1,482 1,482 ass Device Routing Invert Outlet Devices #1 Primary 495.00' 80.0'tong x 2.0'breadth Emergency Spillway Head(feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 Coef.(English) 2.54 2.61 2.61 2.60 2.66 2.70 2.77 2.89 2.88 2.85 3.07 3.20 3.32 Primary OutFlow Max=0.00 cfs @ 0.00 hrs HW=488.60' (Free Discharge) t--1=Emergency Spillway (Controls 0.00 cfs) Summary for Subcatchment 5: Onsite Detained Runoff = 0.55 cfs @ 11.97 hrs, Volume= 0.025 af, Depth> 0.91" ats Runoff by SCS TR-20 method,UH=SCS,Time Span=0.00-24.00 hrs,dt=0.01 hrs Type II 24-hr 1yr Rainfall=3.01" Area(ac) CN Description * 0.116 98 Impervious 0.209 61 >75%Grass cover,Good, HSG B 0.325 74 Weighted Average 0.209 64.31%Pervious Area 0.116 35.69%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 6: Offsite Detained Runoff = 0.63 cfs @ 11.96 hrs, Volume= 0.029 af, Depth> 1.91" Runoff by SCS TR-20 method,UH=SCS,Time Span=0.00-24.00 hrs,dt=0.01 hrs Type II 24-hr 1yr Rainfall=3.01" Area(ac) CN Description * 0.140 98 Impervious tog 0.042 61 >75%Grass cover,Good,HSG B 0.182 89 Weighted Average 0.042 23.08%Pervious Area 0.140 76.92%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, tigte Hillbrook Post-Development lyr Type 1124-hr lyr Rainfall=3.01" Prepared by Shimp Engineering, P.C. Printed 5/17/2016 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 5 Summary for Pond 7: Detention On-Site Bypass is Routed through this node Inflow Area= 0.507 ac, 50.49%Impervious, Inflow Depth> 1.27" for 1yr event Inflow = 1.17 cfs @ 11.96 hrs, Volume= 0.054 af Outflow = 0.32 cfs @ 12.08 hrs, Volume= 0.054 af, Atten=72%, Lag=7.2 min rr Primary = 0.32 cfs @ 12.08 hrs, Volume= 0.054 af Routing by Stor-Ind method,Time Span=0.00-24.00 hrs,dt=0.01 hrs Peak Eiev=491.98'@ 12.08 hrs Surf.Area=454 sf Storage=585 cf Plug-Flow detention time= 12.1 min calculated for 0.054 af(100%of inflow) Center-of-Mass det.time= 11.3 min(844.1-832.8) Volume Invert Avail.Storage Storage Description #1 489.87' 71 cf 15,0"D x 58.0'I.15"Storage S=0.0025'/' WIN #2 490.41' 1,470 cf 48.0"D x 39.0'1 48"Storage S=0.0025'/' x 3 1,541 cf Total Available Storage Device Routing Invert Outlet Devices #1 Primary 489.00' 15.0" Round Pipe 2-1 L=124.2' Ke=0.600 Inlet/Outlet Invert=489.00'/482.80' S=0.0499 7' Cc=0.900 n=0.011 rr #2 Device 1 489.97' 3.0"Vert.1-yr Orifice C=0.600 #3 Device 1 492.00' 46.0"W x 3.5" H Vert.10-yr Orifice C=0.600 Primary OutFlow Max=0.32 cfs @ 12.08 hrs HW=491.98' (Free Discharge) tikt t1=Pipe 2-1 (Passes 0.32 cfs of 8.50 cfs potential flow) E2=1-yr Orifice (Orifice Controls 0.32 cfs @ 6.61 fps) 3=10-yr Orifice (Controls 0.00 cfs) gag Summary for Subcatchment 8: Onsite Undetained Runoff = 0.27 cfs @ 11.97 hrs, Volume= 0.012 af, Depth> 0.86" Runoff by SCS TR-20 method, UH=SCS,Time Span=0.00-24.00 hrs,dt=0.01 hrs Type II 24-hr 1yr Rainfall=3.01" Area(ac) CN Description 0.115 61 >75%Grass cover,Good,HSG B * 0.054 98 Impervious 0.169 73 Weighted Average 0.115 68.05%Pervious Area w 0.054 31.95%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Hillbrook Post-Development 1yr Type II24-hr lyr Rainfall=3.01" Prepared by Shimp Engineering, P.C. Printed 5/17/2016 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 6 Summary for Subcatchment 9: Offsite Undetained Runoff = 0.93 cfs @ 11.96 hrs, Volume= 0.042 af, Depth> 1.52" Runoff by SCS TR-20 method, UH=SCS,Time Span=0.00-24.00 hrs,dt=0.01 hrs Type II 24-hr 1yr Rainfall=3.01" Area(ac) CN Description 0.120 61 >75%Grass cover,Good,HSG B * 0.208 98 Impervious 0.328 84 Weighted Average 0.120 36.59%Pervious Area 0.208 63.41%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Link 10: Inlet X4 rrr Inflow Area= 1.004 ac, 51.59%Impervious, Inflow Depth> 1.28" for 1yr event Inflow = 1.47 cfs @ 11.97 hrs, Volume= 0.107 af Primary = 1.47 cfs @ 11.97 hrs, Volume= 0.107 af, Atten=0%, Lag=0.0 min Primary outflow=Inflow,Time Span=0.00-24.00 hrs,dt=0.01 hrs Summary for Link 11: Raintree Inflow Area= 2.025 ac, 0.00%Impervious, Inflow Depth> 0.10" for 1yr event Inflow = 0.13 cfs @ 12.09 hrs, Volume= 0.016 af Primary = 0.13 cfs @ 12.09 hrs, Volume= 0.016 af, Atten=0%, Lag=0.0 min Primary outflow= Inflow,Time Span=0.00-24.00 hrs,dt=0.01 hrs gigg Hillbrook Post-Development 10yr Type 1124-hr 10yr Rainfaf1=5.51" Prepared by Shimp Engineering, P.C. Printed 5/17/2016 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 7 Summary for Subcatchment 1: Sheet Flow Runoff = 1.49 cfs @ 12.05 hrs, Volume= 0.092 af, Depth> 1.38" Runoff by SCS TR-20 method, UH=SCS,Time Span=0.00-24.00 hrs,dt=0.01 hrs Type II 24-hr 10yr Rainfall=5.51" Area(ac) CN Description * 0.550 55 Conservation Area * 0.246 61 Sheet Flow 0.796 57 Weighted Average 0.796 100.00%Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 11.6 Direct Entry, Summary for Subcatchment 2: D.A.A Runoff = 6.13 cfs @ 11.96 hrs, Volume= 0.275 af, Depth> 2.68" Runoff by SCS TR-20 method,UH=SCS,Time Span=0.00-24.00 hrs,dt=0.01 hrs Type II 24-hr 10yr Rainfall=5.51" sir Area(ac) CN Description * 1.229 73 Adjusted CN 1.229 100.00%Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Pond 3:Vault Inflow Area= 1.229 ac, 0.00%Impervious, Inflow Depth> 2.68" for 10yr event Inflow = 6.13 cfs @ 11.96 hrs, Volume= 0.275 af Outflow = 6.13 cfs @ 11.96 hrs, Volume= 0.275 af, Atten=0%, Lag=0.0 min Primary = 1.95 cfs @ 11.96 hrs, Volume= 0.221 af Secondary= 4.18 cfs @ 11.96 hrs, Volume= 0.054 af gar Routing by Stor-Ind method,Time Span=0.00-24.00 hrs,dt=0.01 hrs Peak Eley=498.35'@ 11.96 hrs Surf.Area=16 sf Storage=36 cf Plug-Flow detention time=0.1 min calculated for 0.275 af(100%of inflow) Center-of-Mass det.time=0.1 min(830.4-830.3) Volume Invert Avail.Storage Storage Description #1 496.10' 108 cf 4.00W x 4.00'1 x 6.74'H 4'x4'Vault Storage Hilibrook Post-Development 10yr Type 1124-hr 10yr Rainfall=5.51" Prepared by Shimp Engineering, P.C. Printed 5/17/2016 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 8 Device Routing Invert Outlet Devices #1 Primary 496.00' 15.0" Round STM 5-6 L=180.5' Ke=0.100 Inlet/Outlet Invert=496.00'/495.10' S=0.0050'/' Cc=0.900 n=0.011 #2 Device 1 496.00' 13.0"W x 3.0" H Vert.Weir Plate Orifice C=0.600 wet #3 Secondary 497.45' 15.0" Round STM 3-4 L=71.5' Ke=0.100 Inlet/Outlet Invert=497.45'/490.20' S=0.1014'/' Cc=0.900 n=0.011 #4 Device 3 496.10' 15.0" Round STM 4-5 L= 16.1' Ke=0.100 Inlet/Outlet Invert=496.00'/496.10' S=-0.0062'/' Cc=0.900 n=0.011 ata Primary OutFlow Max=1.95 cfs @ 11.96 hrs HW=498.35' (Free Discharge) t1=STM 5-6 (Passes 1.95 cfs of 6.87 cfs potential flow) t2=Weir Plate Orifice (Orifice Controls 1.95 cfs @ 7.18 fps) Secondary OutFlow Max=4.17 cfs @ 11.96 hrs HW=498.35' (Free Discharge) t3=STM 3-4 (Inlet Controls 4.17 cfs @ 4.41 fps) t4=STM 4-5 (Passes 4.17 cfs of 7.65 cfs potential flow) Summary for Pond 4: Bioretention Inflow Area= 1.229 ac, 0.00%Impervious, Inflow Depth> 2.16" for 10yr event Inflow = 1.95 cfs @ 11.96 hrs, Volume= 0.221 af Outflow = 1.66 cfs @ 12.07 hrs, Volume= 0.151 af, Atten=15%, Lag=6.6 min Primary = 1.66 cfs @ 12.07 hrs, Volume= 0.151 af Routing by Stor-Ind method,Time Span=0.00-24.00 hrs,dt=0.01 hrs Peak Elev=495.04'@ 12.07 hrs Surf.Area=3,734 sf Storage=3,104 cf tab Plug-Flow detention time= 191.3 min calculated for 0.151 af(68%of inflow) Center-of-Mass det.time=73.7 min(931.6-857.9) Volume Invert Avail.Storage Storage Description #1 488.60' 908 cf Gravel Sump(Prismatic)Listed below(Recalc) 2,270 cf Overall x 40.0%Voids #2 490.85' 820 cf Bioretention Mix(Prismatic)Listed below(Recalc) mei 3,279 cf Overall x 25.0%Voids #3 494.10' 1,482 cf Surface Storage(Prismatic)Listed below(Recalc) 3,209 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) Nags 488.60 1,009 0 0 490.85 1,009 2,270 2,270 Elevation Surf.Area Inc.Store Cum.Store ars (feet) (sq-ft) (cubic-feet) (cubic-feet) 490.85 1,009 0 0 494.10 1,009 3,279 3,279 Hillbrook Post-Development 10yr Type 1124-hr 10yr Rainfa{l=5.51 Prepared by Shimp Engineering, P.C. Printed 5/17/2016 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 9 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 494.10 1,214 0 0 495.10 1,749 1,482 1,482 Device Routing Invert Outlet Devices #1 Primary 495.00' 80.0'long x 2.0'breadth Emergency Spillway Head(feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 Coef.(English) 2.54 2.61 2.61 2.60 2.66 2.70 2.77 2.89 2.88 2.85 3.07 3.20 3.32 Primary OutFlow Max=1.56 cfs @ 12.07 hrs HW=495.04' (Free Discharge) t1=Emergency Spillway (Weir Controls 1.56 cfs @ 0.50 fps) Summary for Subcatchment 5: Onsite Detained Runoff = 1.67 cfs @ 11.96 hrs, Volume= 0.075 af, Depth> 2.77" arr Runoff by SCS TR-20 method, UH=SCS,Time Span=0.00-24.00 hrs,dt=0.01 hrs Type II 24-hr 10yr Rainfall=5.51" ,wg Area(ac) CN Description * 0.116 98 Impervious 0.209 61 >75%Grass cover,Good,HSG B 0.325 74 Weighted Average 0.209 64.31%Pervious Area 0.116 35.69%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Subcatchment 6: Offsite Detained Afig Runoff = 1.34 cfs @ 11.96 hrs, Volume= 0.065 af, Depth> 4.26" Runoff by SCS TR-20 method,UH=SCS,Time Span=0.00-24.00 hrs,dt=0.01 hrs Type II 24-hr 10yr Rainfall=5.51" Area(ac) CN Description * 0.140 98 Impervious 0.042 61 >75%Grass cover,Good,HSG B 0.182 89 Weighted Average 0.042 23.08%Pervious Area 0.140 76.92%Impervious Area Tc Length Slope Velocity Capacity Description Mit (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, eor Hil!brook Post-Development 10yr Type 1124-hr 10yr Rainfall-5.51" Prepared by Shimp Engineering, P.C. Printed 5/17/2016 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 10 Summary for Pond 7: Detention On-Site Bypass is Routed through this node Inflow Area= 0.507 ac, 50.49%Impervious, Inflow Depth> 4.57" for 10yr event Inflow = 7.19 cfs @ 11.96 hrs, Volume= 0.193 af Outflow = 6.42 cfs @ 11.99 hrs, Volume= 0.193 af, Atten=11%, Lag=1.8 min Primary = 6.42 cfs @ 11.99 hrs, Volume= 0.193 af Routing by Stor-Ind method,Time Span=0.00-24.00 hrs,dt=0.01 hrs Peak Eley=493.39'@ 11.99 hrs Surf.Area=415 sf Storage=1,224 cf Plug-Flow detention time=7.4 min calculated for 0.193 af(100%of inflow) Center-of-Mass det.time=7.0 min(790.2-783.2) Volume Invert Avail.Storage Storage Description #1 489.87' 71 cf 15.0"D x 58.0'L 15"Storage S=0.0025'I' #2 490.41' 1,470 cf 48.0"D x 39.0'L 48"Storage S=0.0025'/' x 3 1,541 cf Total Available Storage Device Routing Invert Outlet Devices #1 Primary 489.00' 15.0" Round Pipe 2-1 L=124.2' Ke=0.600 Inlet/Outlet Invert=489.00'/482.80' S=0.0499'/' Cc=0.900 n=0.011 #2 Device 1 489.97' 3.0"Vert.1-yr Orifice C=0.600 #3 Device 1 492.00' 46.0"W x 3.5" H Vert.10-yr Orifice C=0.600 Primary OutFlow Max=6.41 cfs @ 11.99 hrs HW=493.38' (Free Discharge) t1=Pipe 2-1 (Passes 6.41 cfs of 10.74 cfs potential flow) 12=1-yr Orifice (Orifice Controls 0.43 cfs @ 8.73 fps) 3=10-yr Orifice (Orifice Controls 5.98 cfs @ 5.35 fps) rr Summary for Subcatchment 8: Onsite Undetained Runoff = 0.84 cfs @ 11.96 hrs, Volume= 0.038 af, Depth> 2.68" Runoff by SCS TR-20 method, UH=SCS,Time Span=0.00-24.00 hrs,dt=0.01 hrs Type II 24-hr 10yr Rainfall=5.51" Area(ac) CN Description 0.115 61 >75%Grass cover,Good, HSG B "` * 0.054 98 Impervious 0.169 73 Weighted Average 0.115 68.05%Pervious Area 0.054 31.95%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Hillbrook Post-Development 10yr Type 1124-hr 10yr Ra nfa�t=5.51 Prepared by Shimp Engineering, P.C. Printed 5/17/2016 gam HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 11 Summary for Subcatchment 9: Offsite Undetained Runoff = 2.19 cfs @ 11.96 hrs, Volume= 0.102 af, Depth> 3.74" Runoff by SCS TR-20 method,UH=SCS,Time Span=0.00-24.00 hrs,dt=0.01 hrs Type II 24-hr 10yr Rainfall=5.51" Area(ac) CN Description 0.120 61 >75%Grass cover,Good,HSG B * 0.208 98 Impervious 0.328 84 Weighted Average 0.120 36.59%Pervious Area 0.208 63.41%Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Link 10: Inlet X4 tot Inflow Area= 1.004 ac, 51.59%Impervious, Inflow Depth> 3.98" for 10yr event Inflow = 9.26 cfs @ 11.98 hrs, Volume= 0.333 af Primary = 9.26 cfs @ 11.98 hrs, Volume= 0.333 af, Atten=0%, Lag=0.0 min ita Primary outflow=Inflow,Time Span=0.00-24.00 hrs,dt=0.01 hrs Summary for Link 11: Raintree Inflow Area= 2.025 ac, 0.00%Impervious, Inflow Depth> 1.44" for 10yr event Inflow = 3.10 cfs @ 12.07 hrs, Volume= 0.243 af itmig Primary = 3.10 cfs @ 12.07 hrs, Volume= 0.243 af, Atten=0%, Lag=0.0 min Primary outflow=Inflow,Time Span=0.00-24.00 hrs,dt=0.01 hrs aram amo ow Hillbrook Post-Development 10yr Type 1124-hr 100yr Rainfall=9.10" Prepared by Shimp Engineering, P.C. Printed 5/17/2016 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 12 Summary for Pond 4: Bioretention Inflow Area= 1.229 ac, 0.00%Impervious, Inflow Depth> 4.05" for 100yr event Inflow = 2.48 cfs @ 11.96 hrs, Volume= 0.414 af Outflow = 2.47 cfs @ 11.97 hrs, Volume= 0.344 af, Atten=0%, Lag=0.4 min Primary = 2.47 cfs @ 11.97 hrs, Volume= 0.344 af Mit Routing by Stor-Ind method,Time Span=0.00-24.00 hrs,dt=0.01 hrs Peak EIev=495.05' @ 11.97 hrs Surf.Area=3,740 sf Storage=3,122 cf Plug-Flow detention time= 123.2 min calculated for 0.344 af(83%of inflow) Center-of-Mass det.time=44.2 min(892.8-848.6) Volume Invert Avail.Storage Storage Description #1 488.60' 908 cf Gravel Sump(Prismatic) Listed below(Recalc) 2,270 cf Overall x 40.0%Voids #2 490.85' 820 cf Bioretention Mix(Prismatic) Listed below(Recalc) 3,279 cf Overall x 25.0%Voids #3 494.10' 1,482 cf Surface Storage(Prismatic) Listed below(Recalc) 3,209 cf Total Available Storage Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 488.60 1,009 0 0 490.85 1,009 2,270 2,270 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 490.85 1,009 0 0 494.10 1,009 3,279 3,279 Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 494.10 1,214 0 0 495.10 1,749 1,482 1,482 Device Routing Invert Outlet Devices #1 Primary 495.00' 80.0'long x 2.0'breadth Emergency Spillway Head(feet) 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60 1.80 2.00 2.50 3.00 3.50 Coef. (English) 2.54 2.61 2.61 2.60 2.66 2.70 2.77 2.89 2.88 2.85 3.07 3.20 3.32 Primary OutFlow Max=2.24 cfs @ 11.97 hrs HW=495.05' (Free Discharge) t-1=Emergency Spillway (Weir Controls 2.24 cfs @ 0.57 fps) Storm Sewer Calculations Storm Inlet Drainage Map VDOT LD-204 VDOT LD-229 VDOT LD-268 VDOT LD-347 Self-Cleaning Velocity Check A o- 1YYrrr..r kowtow( rrwarai iiiirrorra in.irrr rrrrrrrw r+iromit saimpag mismi m rwwr+e urwirwi ammimat r®rrYt wrwrriti rrnyrrlg rrrrtfi r sure cn GO GO _A _A G' cn � —4 Structure � D -4DwN Number O 0 0 0 0 0 666666 NInlet Type CO 03 CO C0 C0 CO 0D00000 WCurb Opening 0 0 0 0 0 0 — Catchment Area CnOVO -1. CD � O 0 0 0 0 0 4) in Runoff Coef rnoomcn0 000000 G 0CA o CO CO 4 V cn N 0 .p a00000 co Intensity 3 •00 •0+•0 •0 •0 cn w e 00o y c0 Q Catchment CO W N A V V CD .� C) o Q carryover 3 O 000x0 ,. c i0 iv in a, Q Total Cn .PWCDVODcn COW N• V V v O 0 0 0 0 0 0 0 0 0 0 0 � Mannings N C) CA O) 0) CA O) O o 0 0 0 0 • 0 rn w Gutter Slope VCACnCONA O 0 0 0 0 0 N N N N N N. V. Pave X-slope 0 0 0 0 0 0 O 0 0 0 0 0 cococowcoco cn tterX-slope W W W W W W Total Gutter 00 N V °'Spread COVV 0 -� O O P PP 000 cnCD Depth at Curb F ( m 000 0 0 0 0 0 0 � CoD/o EfFcency G CL CD 0 000 00 � 3 V V V N Gn ny, -� '< CO cn o Q intercepted CO W N V V '' 000 CD CD 00 02, NQBypassed 000 0o cc) O 000 00 - r2 Midpoint Depth in N Curb Height 0 CD w WD/H Midpoint Spread i.■.r ihm.r ir.� irk limmil 6mA_ 6moil lima lima iri.-ri b.rri tri ■ ..: _ llama ■.; / i / I I I / \ ) / 1 I I \ � ,/ // /I// 1 / r \ � ` \ - ILLBR00 ,< •/ ,/// / \ / / 1 STORM SEWER MAP / ( / / i / 1 / I �� I I / \ 1 III \ I\//I /\ N#11/Iiiiiiiii \ IMPERVIOUS N. dm '••• 7 ... 111)Alli/ , . _ _ , i 1 1 , / \ \ _ _ _ Th , _, , \ \ ____ 1 \ / , ,/ / , \, , ,_ __/_, — , 4 , t I / / / I/ , I S _ \ 1 N\ Jet' /`� 1 It\ I ' / I I \ � 1 \ I / \ 1 I I I 11 l \,, , „ .\ \�1 \ _ am& 4401 \ \ / 1 1 / / I ) I / v v \ � STM X2AQ'Aw lam' I \ \ I 1 r ( I ` \ Ii, \ \ \ : / 1 .55/ a . . 1. ) ,/ ,_ _ _// ) I 7; \ \ \ \ 1 ( r I / / ' 1 / \ \ \\ � ,\ If 1 / / i , 1 1 / / / // / / L______Ti F7-7/, \ I ./ - -1 \ 17N\/ ) i 1 .- / / I \ \,. , Nio , \ , * \ iti, ___-_< \ N N , \ \ \__ -.... . , , __ ..,, /\ \ \N i J,/,' ----/ ! %L / ,.; __, - , , , , „,,„, , / / , i , 2,,, _ , , / / / i \ \ L. , , / z / P t h - 4 , / / N _ -- \ \ ♦ irL 1 ♦ I 1 / \ — a � �� _ r I / v N / — " / / / /-- i 1' 1` I !- ., 1 \ I \\ \ ----- -.7, x---- ,,,,\,--- ------ . ,-.. ,„ / ,--u---,. ,/ / c: Iht -N___ ,..,,, 1 _ _ / ., 44%,*_ ,, 1.'4 __-- —. — — — — -I- kiilil\--X-'3 13"--A- * 77 '-- ' #144.. \II \ \ TM \X2 D 0 ' --,'49 AC. 1 o1 ‘ \ 01111W -- ...-- f . N 6. \ \ w 'N II , ■ a5 : p ��,v 0.49 I 1 v . , '''0 ST.D\EifF14) IIIENTi /\ Bli 1, '14 _31 --- k., , //1 14. \ \4,- , I , ,;,. �; , .,0. 5 AC■ t �-DA_ , \`N i„,_ /III /1fi'r 4.' ./• /NJ,/If ,/ , - STl L a ,.' ► \-, \ \ / / I ,— N— _ _—s— — icl �C-. 11 i h.I///,;;_-y le -_ _ 01* C 0 w OW ' N- o 00 r0 000 0 00 � 4- o `.° O a) _ 0 0 0 000 0 00000 a 0 0 3 c y o LL c E o a) rn no Co 00 40 M 00 CO o) Cn CD CD ,r u) fir) e- up Ti p ' M C'M et CM M CO O) fes !' O) ' O) N 5 N W a) aira r CC) O 0 V 0 01 (o M <1; C) CO C O Q..4- CA tri tri Cn u1 N <- p) .- 4- e- e- V V G R) ,ii c 'a0 ai art V r u) u) U) u) is to to u) u) co 03 ao t EL' 0 � U co COiniCO 0 o 0 0 C� Cu) CO 0 0 � 0 N co t 0 0o N a ti 06 w > O O O 00 ' N N e- f O N ' M 0 C u) a to N 0 OW .- V OCO V e- to N O '7 10 Nt N '.V} O a) N CO W GO CO n M CO (O' CO 2 a M COcn to t0 0. c w a -I C COC O 00 0 0 0 0 0 0 0 0 0 (0 N CO N � W+ ifi0 0 O OON CO OMNco N- 3- O (O CO CO CO CO CD Cn CA M U) CO M O ++ a) a) a) o) a) co CO ao CO n N. N- N. N CO C 0 o5w E 0 :. O o 0 0 000 0 0000rn rn co 3 voi 0 0 N. e- e- l v CO .- V, oo 0 00 00 to O .- CO CO Cn CO CO n 0 M u) N u) M CM 0 r.. C CD CD CD rnrnrn C) oao0ON. r` n n - 0)Y 0 > W V V V d' V V V V V e1' V V V V To e O 2 CI S2LO CO w 010 C CA N N COO N N CO CNO o CO CD C! o0 O M 00 c w '!O = 3• 0 f0 ,- e- N a- .- N r V u) f0 n � u) � C s.0 I- LLQ) 'y E o AM 04. co ao 03 n aoN- n CO NN- N-CO N- � n co Co, C 4. r c0 c0 co co 0 co ro CO co co co c0 ca Co N � _ ` N iCli Ci 0 O h -O r- 4 O CA . CO h O N C� 0 O O O O O O .- N M O V -Q c u) u) u) ui u) tc) 6 to u) u) u) tr) ui u) a) H• � a) a EE co CA r-- a) O r` V CO N n CO 0 CA N8 to ,- M M N CO 00 0) e- 00 n CO c O O O 000 O 000 .- 4- O N 09 Q Q y Ca L )... co 0O) 0o V C` LO LO CA M O N MI Lo N O C+ C� O O O O O 0 0 0 0 0 O O .c • o C Q O 3 cam coo CO CO co CA CC) O O V N O co_ a 444 0 V CO CO CO CO CC) CO 0 C)? u) CO t[) n :c EO C a) W. O O O 0 O O co O O O 0 C„) ix o = t L M N N N N Nt � Cr CO M M CC( 0• 0 t e 0 O O 0 O 0000 e- e- 0 c . .c a) 3 C '0(cyy fcyy d N CO u) CO CC) VM M N '- XXX X 'X (O,. CD O a o w O O (y t- aw E C V CO to Lo V M M N a- X X X X N N tiO. o a) Z 0 iti>r W in o T O C rn O C stir J N C N m > W 'm i 0 a O a) aYifl 2 O J d FA W > N N C o o O O O miss CE w C) t O J O W > LL ormC (/) O w m m O J > o a rr -C W _ Q 0 W O 0 JO Li. O O C U) W _ N _z 0 LL O O O - 2 OJ L"'L O O O acz U) TICC m m CD = a ••I J m m ILS 0 CC o,_ IAC co C CO 0 o 0 2 C � U r1' NQ J Lr1 tD LU Lr) ui rr s t3 U to O O I— O "Ori Q O eat U C4 in a) U e1 r-1 < o o E2 Q a) U c>v CC N to C) C Z O O -05are m0 %.- Q N m C 0 0 Q los rn U to to O o o civ 0 U c-i N U 0 O a) * 'Miasma* Mamma *imam fir..re i smima r Mamessa — wir.®r ar®® hiwrr.r mamas aww-M sommarmi ...ami rw.R.ri irr.ri orw.wi ...rrwi rwr.Wif 5 z r x m m n C < c: 41s Cr * X W NSC3 �1 C CD Cr .< 0 O CD Mi j C 9 917N jNma, v O C) COO) -I N" < CD = o G7 p co 0) O) co (OD if Q. W CD r CD 5. am 7 N N N C>7 O CT 01 01 O N. O X. (/) • vN Oo 0 CCD CD01 O H O CD N. O 0 N N CO W W O .-� fn A :CO N a O N co) N CD Cn O • 0) to a0D cVs1 2 CO) O Co.) CO 0 C rt O .cri0) O O W W W O Si oC CD U1 O O CA O-. 010 A CA CD j O O O O 0 4). A co 2 v N W W C.) N CO CS) v N ^ CT 0 D) W 0 j N A CT CJ7 0) W W 01 CO CO W A W 0 CT CO 0o 0) v N -1 W N C_ C O O O O O = 7 C.11 N.) AA oa 01 O CO CO CAN CO CO I" O Cn Cn W CO (0 (0CO A CO CD 0 0 0 O O CO O CO vi -.4 -I --4 CO W CA A O O O _ W O co o) -• ca O CO 0) W CO -I 0) O O -A O -1 A W v <J A CO CO 0) v * A 0 0 N = �INo) 0 � � O 00_ 0 co v - N W (O C11 -o a A A - 0')MC CO 0') 01 W N 40 NNCACO CA O) O CA < NN N (D •� A A A Co -4 ^ 3 co O CO CO N • X00 Cn- m cn C O 0 CD Self-Cleaning Velocity Check Hillbrook From To Pipe Slope AC* Int Flow Velocity (in) % (in/hr) (cfs) (ft/s) 4 5 15 0.6% 0.18 2.95 0.54 3.0 5A 5 15 0.6% 0.19 2.90 0.54 3.0 5 6 15 0.5% 0.37 1.90 0.70 3.0 5A, 5 15 0.6% . 0,19 2.90 0.54 3.0 5 4 15 0.6% 0.19 2.95 0.55 3.0 4 3 15 11.5% 0.37 0.50 0.18 6.1 3A 3 15 2.2% 0.06 2.20 0.12 3.0 3 2 15 2.8% 0.49 0.50 0.25 4.1 2 1 15 1.5% 0.81 0.50 0.40 4.2 1 X4 15 6.2% 1.13 0.50 0:56 6.7 *From LD-229 Atm This computation shows the minimum intensity required to achieve the self-cleaning velocityof 3.0 ft/s. Please note that the intensity for a 2-year storm with a 5.0 minute time of concentration is 5.2 in/hr. Independent Reports Excerpt from NRCS Soils Report '"` NOAA Precipitation Report Z 2 4217950 4217980 4218010 4218040 4218070 4218100 78°27 44"W n 78°2T 44"W 411111* el r F N.,,,,:.:-*� mss' v ' 4=4.' ..i',. ., , tilt , . 40 *IV '''''S # ' ..ilr o `' . � � � w �; « •#! 4C tit arff ,..,„ss„... .,,,... still, M o/0f • o 04. NJ ✓ i ` i r '... ... t',01.. ,, ".." , - ;-, \-„, ,;.„----„z•„*.,Al!.,-..* . , -,,,, ,n..,;,- ,-.‘,.,_ ,71,._ - ,.. . :,•_"`. w` a J sir O 0 Qcn O 'CT cT " O it G7 :U o 13 if ,,,* .4:11;:".::' ' ,a z a p No /1/7e ., t o ar r�,.— '"s it. " g it - . t x51 .+' if • e 4 \ ... • # ,240. 4' ,*7 , . .. I...,,its--,. - lid e , " _ '5%-",."-!,2.---''''-',.-111* 'F l; s *r 78°27 30"W a 78°27 30"W 4217950 4217980 4218010 4218040 4218070 4218100 4218130 1 A u] 2o 2 Custom Soil Resource Report Table—Hydrologic Soil Group Hydrologic Soil Group-Summary by Map Unit—Albemarle County,Virginia(VA003) Map unit symbol Map unit name Rating Acres in AOi Percent of AO1 r 27B Elioak loam,2 to 7 B 2.4 63.3% percent slopes 27C Elioak loam,7 to 15 B 1.0 27.7% percent slopes 39D Hazel loam, 15 to 25 B 0.3 8.9% percent slopes Totals for Area of Interest 3.7 100.0% tot Rating Options—Hydrologic Soil Group Aggregation Method: Dominant Condition Component Percent Cutoff None Specified Tie-break Rule: Higher sit 19 3/3/2015 Precipitation Frequency Data Server 11''„ NOAA Atlas 14,Volume 2,Version 3 MO .,' Mem Location name:Charlottesville,Virginia, US* uwr Latitude:38.0831°, Longitude:-78.4624° ¢ Elevation:484 ft* .E., „ *source:Google Maps • t+ am POINT PRECIPITATION FREQUENCY ESTIMATES G.M.Bonnin,D.Martin,B.Lin,T.Parzybok,M.Yekta,and D.Riley ow NOAA,National Weather Service,Silver Spring,Maryland PF tabular I PF graphical I Maps & aerials mis PF tabular PDS-based point precipitation frequency estimates with 90% confidence intervals(in inches)1 g, Duration - Average recurrence interval (years) 1 2 5 10 25 50 100 200 500 1000 1 5-min 0.352 0.420 0.492 0.553 0.624 0.678 0.729 0.778 0.837 0.885 (0.317-0.390) (0.379-0.466) (0.444-0.545) (0.498-0.613) (0.558-0.688) (0.604-0.747) (0.646-0.804) (0.684-0.858) (0.728-0.925) (0.763-0.982)1 itim 10-min 0.562 0.671 0.789 0.885 0.994 1.08 1 1.16 1.23 1.32 1.39 (0.507-0.623) (0.606-0.744) (0.710-0.873) (0.796-0.980) (0.889-1.10) (0.962-1.19) (1.03-1.28) (1.08-1.36) (1.15-1.46) (1.20-1.55) 0.703 0.844 0.998 1.12 1.26 1.37 1.47 1.56 1.671.75 1 15-mm (0.634-0.779 0 762-0.936 0 899-1.10) (1.01-1.24 ma ( ) ( ) (1.13-1.39) (1.22-1.51) (1.30-1.61) (137-1.72) (1.45 1.84) 1 (1.51-1.94) 30-min 0.963 1.17 1.42 1.62 1.87 2.06 2.24 2.42 2.65 2.83 (0.869-1.07) (1.05-1.29) (1.28-1.57) (1.46-1.80) (1.67-2.06) (1.83-2.27) ' (1.99-2.47) (2.13-2.67) (2.31-2.93) (2.44-3.14) i 60-min 120 146 1.82 2.11 2.48 2.79 3.09 340 3.81 j 4.14 sig (1.08-1.33) (1.32-1.62) (1.64-2.01) (1.90-2.34) (2.22-2.74) (2.49-3.08) 1 ) i (2.74-3.40) (2.99 3.75) t (3.31-4.21) I (3.57-4. 95 2-hr (1.27-1.65) -11.44 1.75 2.19 2.58 3.07 3.48 3.91 4.36 4.98 5.51 (1.54 .99) (1.93-2.49) (2.27-2.92) (2.69-3.47) j1 (3.03-3.94) (3.38-4.41) (374-4.92) (4.22-5.62) �(4.62-6.24) 1 mis 3-hr 1.58 1.92 2.40 2.81 3.35 3.81 428 478 5.46 6.05 (1.39-1.81) (1.68-2.20) (2.10-2.75) (2.45-3.21) (2.91-3.83) (3.29-4.34) (3.67-4.88) (4.07-5.44) (4.59-6.23) (5.03-6.91) 6-hr 2.01 2.433.02 3.56 4.28 4.90 5.56 6.28 7.30 8.20 (1.78-2.28) , (2.15-2.76) i (2.66-3.42) (3.12-4.02) (3.73-4.83) (4.24-5.53) (4.77-6.27) (5.33-7.08) (6.10-8.24) Ami (6.76-9.27) 12-hr 2.52 3.05 3.80 4.50 5.47 6.34 7.28 8.32 9.86 11.2 (2.23-2.89) (2.69-3.49) (3.34-435) (3.94-5.13) (4.76-6.22) (5.46-7.20) (6.19-8.26) (6.98-9.43) (8.11-11.2) (9.09.12.8). �„ 24-hr 3.01 3.65 4.66 5.51 ; 6.77 7.85 { 9.04 10.4 12.3 14.0 (2 71-3.39) (3.28-4.10) i (4.17-5.23) (4.92-6.17) I (6.00-7.55) (6.91-8.74) f (7.89-10.1) (8.94-11.5) (10.5-13.7) i (11.7-15.5) 2-day 3.55 4.31 5.48 6.44 7.84 9.01 10.3 11.7 13.7 15.4 (3.19-3.97) (3.87-4.82) (4.91-6.12) (5.76-7.18) (6.95-8.72) (7.93-10.0) (8.98-11.4) (10.1-13.0) (11.7-15.3) (13.0-17.2) 1 ism 3-day 3.79 4.59 5.83 6.85 8.33 9.56 10.9 12.4 14.5 16.3 1 (3.44-4.20) (4.16-5.08) (5.28-6.46) (6.18-7.57) (7.47-9.19) (8.53-10.6) i (9.65-12.0) (10.9-13.7) (12.6-16.0) (14.0-18.0) 1 4-day 4.02 4.87 6.18 725 8.82 10.1 11.5 13.1 153 17.2 (3.68-4.42) (4.45-5.35) (5.64-6.79) (6.61-7.96 Jo [ ) (8.00-9.67) (9.13-11.1) (10.3-12.7) (113-14.3) (13.4-16.8) (14.9-18.9) 7-da 4.67 5.62 7.02 8.18 9.84 11.2 12.7 14.3 16.6 18.5 j y (4.28-5.10) (5.16-6.14) (6.44-7.68) (7.48-8.93) (8.94-10.7) (10.1-12.2) (11.4-13.9) (12.7-15.6) (14.6-18.1) (16.1-20.3) 1 10ami -day 529 635 7.85 9.06 10.8 122 13.6 152 17.4 19.2" (4.88-5.74) (5.86-6.89) (7.23-8.50) (8.32-9.80) (9.85-11.6) (11.1-13.2) (12.3-14.8) (13.7-16.5) I (15.5-18.9) (16.9-21.0) 20-day 6.95 8.29 10.0 11.4 13.2 14.7 16.1 17.6 19.7 21.3 (6.50-7.45) (7.76-8.89) (9.36-10.7) (10.6-12.2) (12.3-14.2) (13.6-15.7) 1 (14.9-17.3) (16.2-18.9) (17.9-21.2) (19.3-23.0) 30-day 8.53 10.1 12.0 13.4 15.2 16.6 17.9 19.3 21.0 22.4 iiii (8.02-9.09) (9.51-10.8) (11.2-12.7) (12.5-14.2) (14.2-16.2) (15.5-17.7) (16.7-19.1) (17.9-20.6) (19.4-22.5) (20.5-24.0) 45-day 10.6 12.6 14.7 163 183 19.8 213 22.7 24.5 25.8 (10.0-11.3) (11.9-13.3) (13.9-15.6) (15.4-17.2) (17.2-19.4) (18.6-21.0) (19.9-22.6) 1 (21.2-24.1) (22.7-26.1) (23.9-27.6) milli 60-day 12.5 14.7 17.0 18.7 20.8 22.4 23.9 25.4 272 28.5 (11.8-13.2) (13.9-15.5) (16.1-17.9) (17.6-19.7) (19.6-22.0) (21.1-23.6) (22.5-25.3) (23.8-26.8) (25A-28.8) (26.5-30.3) ! 1 Precipitation frequency(PF)estimates in this table are based on frequency analysis of partial duration series(PDS). isto 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 NOM Atlas 14 document for more information. r"` Back to Top PF graphical "" http://hdsc.nws.noxa.gov/hdsc/pfds/pfds_printpage.html?Iat=38.0831&lon=-78.4624&data=depth&units=english&series=pds 1/4