Loading...
HomeMy WebLinkAboutWPO201500047 Calculations 2015-09-22 PROJECT MANAGEMENT Si CIVIL ENGINEERING mi IMPLAND PLANNING ENGINEERING . c ) APPROVED July 9, 2015 by the Albemarle County Albemarle County Community Dev��pmept Department ci Date .p// /i s Regarding: The Pants Project File 12�S e Stormwater Management Dear Sir or Madam, Enclosed are the calculations and details relating to stormwater treatment for the proposed development The Pants Project. The area inside the stream buffer or part of the BMP totals 1.47 acres, and is listed as conservation area in the VRRM. Pollutant removal is achieved with a level 2 wet pond. The wet pond was selected in order to capture runoff from the driveway and adjacent managed turf at the low point of the site, as the driveway runoff cannot be otherwise captured. The pond discharges to an existing stream, so the energy balance equation is applied. The existing site is fully covered by woods, so an improvement factor is not required. Qwooded * RVwooded Qdev — RVdev All other discharges are sheet flow with an insignificant increase over pre-development levels. If you have any questions please do not hesitate to contact me at your earliest opportunity. I may be reached at: Justin(.shimp-enqineerinq.com or by phone at 434-953-6116. Yours Truly, Justin Shimp, P.E. • —11r U JU:' a ►, y 7N � •3 / 5 w� SSJONAL �' Contents: Pre-Development Drainage Map Pre-Development HydroCAD Report Post-Development Drainage Map Time of Concentration Calculations VRRM Worksheets Energy Balance Computation Post-Development HydroCAD Report LD-268 NOAA Report NRCS Excerpt R � _�;i i /j. ' -- - \\` \\\` \ • \\ '\ \'\ � � ��— � ' \\\\\\\ \ \\\\ \ \ \\ 10/�//�!/_ � ;� —_\� \ \\ \ \\ I \TH - DA\ TS 9OJ-CT II / i /I / �\\\\ \\\ \\\ � / I \ \ / /- - _� __ � \��.� - \ \ \ \ ) / I. - _ = ^ / PR — EVELOPVENT I I — _ - - �\ '/// _ __— _ _ 1 / I - �� > //� - — \ I� I \ \ /I I 1 I II I - - __ � . // / / /i_ __ 1 I I II III \ / ' _ - __ _— J // / // / / // ce- _ _ \ I I \ \- /DAINAGE MAP \ I — / — \\\\\\\\�\ \\ I\\ \ O \\ \ \ \ \\ 1 I I \ \ // �� ��� ///�j///��i� -_—__=- I \ \\ \\ \ )/ JI F• ; I \ \\\- / —' — '— —�i — �� \ \ \ \\\ \ \ \ \ \ \ \ \ \ I I 1 \ \ \ I / I I ( - // // // / I ' _\\ \\\\\( IIII �/11 1 \ \ �. -/i�- \ \ \ I - - - �'/ // � / / / l / 1 \1I 1 / _ \ \\\ \ \ \ \ \\ \ \ \ \ \ 1 \ \ \ I I I / // // / / �/ � I � -� \ \1 1 \ \ � --�%';. _ \ \ \\ \ \\\ \\ \ \ \\ \\ \\ \ \ 1 \ \ \ \ \ 1 I \ / - // / / \ 1 \_ - \\ \ \\ \ \\ \ \ \\ \ \ \ \ \ 1 \ \ \ \ \ 1 I /- // / // / ( / ( ( `� N\ll\ 1/\\111\I I \ \ \ \ - - - — — — ' \\ \ \ \\ \\ \\ \\\\\ \\\\ \\\ \\\ \\ \ \ \ \ \ \ \ \ 11\ \ l I I I �I �. / // / � l / < � � I I \\\ ��— ��\\ 1 // (( / lllll\\ 1 \\ _— - \ \ \\\ \ \\ \ \\ \ \ \\\ \ \\ \ \ \\ \ \ \ \ \ \ \ \ I 1 I l �" , \ \ I .'..( I I \ \ \ c � I ►l �\ � _ --_ -_ - -- - \ \\ \\\ \ \\ \\ \\ \ \\\\\\\ \ \\ \\\ \\ \\ \ \ \ \ \\ \ 1� \ I I I \ �/ 44r (.62 \ I I I I I I ) \ \ 1 \\ \\\ \\\\ < �� \_ �� -_ -` 1 \ \ \ \\ \ \1 \ \ \ \ \\ \ \ \\ \\ \ 1 1 \ \ I I I I I / I \\� \ � \\ �� �\ ��,. \ \ / )i \ \\ � \ \\ \ \\\ \\ \ , I \ \ \ N \ \\ \\ \ \ \ 1 \ \ \\ \ I 1 I / \ \ \ `L \ \� - \ \ - - , I , / / / \\ \ \\\ \ \ I \ \ \\\ \\\ \ \\\ \ \1 \ \\\\\\ \ \ \ \ \ ` I \ / ` \\\\�\ \\� \ \ / \ \\\ I \\\\ \\�\\\ \\\ • \\\\\ \ \ \ \ \ \ \\ \ \\ \\ �� � \\ \ \ \ \\ \\ \ \ \ \ \ \ ��� \�\\ \--_- \ �\ \ \\( ' �\ \ N\\\ \\\\ \ \ \ \\ \ \ \ \\ \ \ \ \_ \ \\ \� �\ \���1\ / > \ \\\\ \\ \\ \ \ \ \ \\\ \\\ \ \ \\ \ \ \ \\ \ \ \\ \ \ ` \\ \\ \\\ �_ _ \\ \ \\ \\ \\\ - / / NN- / \\ \�N\\\ \\\ \ \ \\ � \ \ \ \ \\ \\ \NN \\\ \ \ \ \ \ \ � \\\ \\\ \ \ \ \ / V�\ \\ ��\ \ \�\ \\ \ \ \ \ \ _ —/ / •/ \\ \�\ \\\ \ \\\\ 1 \\\\ \ \\���� \\\ \\ \\�� ��� \\ \\ \ \\ \ �\ \� \ \ \\ \ \ 1 ) II l \ \ \ \ \\ N. \ \\\ \ \\\ \ \ \ \ \ 1 / / \ \\\ \\ \\\ \\\� \� \ III / / N \ \\\ \\ \ _ \\ � \ \��\\\�� \\ \ � �\ \ \ \\ \ 1 I \N \ \\ \\ \ \\ \ 11 ' Jill/ , / / \ \ \\\ \ \ N \ \\ x _ \ \ \ \ \ \ \ 1 / / \ \ \ \ / / \ \ \ \ \\\\ N \\ \� N \•\\ � ����\� � . ��\� ��� � ��\\\\\\\ \ \ 1 I / �� \ \ \\ \\ \ \ \ I \ I 1 I IIII / // �/ _ - - _ ` \ \ \\ N. \ e \\ \��\\\ \��, , _\„\ .� �� �\\\\ •." \\ l ` 1 ( / / \ \ \\ \\ \ \ I /)IIII/////// / - - - - - - \ \\ \ \\\\ \ / \ \ \ \ \ \ ,\� �., --Nx �� \ \\\ \\\1 \ 11 \ \ \ \ 1\\ 1 / I ) ! l /// / / _ - - — , \ \ v\ \\ \ \\\ ,� - \\ \\ \ \ \ ���„; _ \- \ \ \ \ \� \\\\ I \ \ \ \ \\ \ \ 1 ���\ \\ \ �� ) // l// //i /i/ / /I ( \ \ \ \ , \\ \ \\\\ 40 \ ��- \ \ \ \ >\ Nf , >> > > 1 \� \\\1 1 \\ \ \ \ 1 \\ II l (/ \ , // I) I \ \ \ \\ \ \\ \\ l� l \ > > / - i- -� % /\ \ \ \\ 1,1 \\\\ \\ \ \\1 , \\ \ III \Il (\(((l \(\�\ ( \ - - - \ \ \ \ �\ \ �\ \ \\I ) \ \ \ Ill //ice% ��j� ��j��_� ) 1 I / 1 )/ \/>> 1/, , � �� \ \ \ \\\\\ \\ \\\ \ \ \\ 1 (/l // \ \ I l // / � - 1l/ / , ) T 1 \ \ \\\ \ N. \ \� \ - - - - I I / // - % _ _ - / ////�//// // / �/- \ I \ 1 \\ \ \\\ \\ 1\\ \ I Il �.�1\ \ \\ L/ / / -/ / I / // /i//�, - %-_-- _ / /// /// // / // I\ \ \ 1 1 11/ 1 /Il) IIII 111111 I - - ' — \ \ \\\\\\ —1 / / '/ ll� I IIII r � _ _ , / / / / /�/ / l I _ \\\ \ \ \ \\ / r _ - - '� / IIII 11 II I I - IIII �// / ' \ . I ' // / /// / 1 I I I I \ \ \ \ \ \ \\�\\\\/ // r— — - -/ IIII WWI I - -- / / / /i �j \ 1 ((1// _ I \ \ \ \\\ \I I ( 1/ r�_—_ II 1 I 1 I r �\� \ )1 I I 1 i N \� � / / � � \\ II 11 ('I � //// //// 1 ( IL1=- /- ) 1 it \ \ 1 / // / — - - � \\ \\ \ 11 \ \ \ r i ( ( r � 1 \ I Ir I // - �;// � 11 III i ^\\ \\ \\ \\// IJ / 1� l _ \�__ \\\\ \ \ \ 11 1 \ \� \ ( 1 \ 1 ( I I // / / 1 - - __ - - - - // �/ / / / III 1111T \\\X \\ \\ / III 1/llll =__\�� 1 \\\\ \\\ \ \\ 1 \ \ \ \ \ \ \\ 1 1 \ \ \ I I I \ \ \ II IIII IIII ill ����� /// // �_ \ \\ \ / /// 1 // r� ���� \\\ \\ \ 1 '/ /'�/ / / IIII/// �/ \\ \\ \ \ 1 IIII//^ `, \� .i \\ \ \\\\\\ \\\\ \ `1\\�\�\\\\ \\1 \\ \\ \ 1 \ \ \ III�IIIIIIIIIIII/ 1 ///� '���`_ j�%� ce ///%�/ \\\ \ \ ✓ // l 11111111 I / - = 1 I I III I l 1 - / I 1111 //// ///��//// \ �\\\\\\ \\\\\\v / / /I1'l/j�Illli� � \\\\\\\ \\ \\ \\ \ \\ \ \ \ l 1 1 ��\ �� \ \ \\\ ',',\ \ \ \ \ \ \ II IIII IIII 11I IIILL - / / II 1 / /// / //// / \\ \\\\ \\\ \\ \ \\\ \ \ \\ \ \\ \ \ I \\ I I IIIL� __ - - - - - / / I I // // /////j /� \ //\ \\\ \\ \ yj I 1 l r\ -\\\ \ \ \\\\\ \ \ \\ \\ \\ \ / 1 \111 IIII �`` ___-� / \ \\\\ \ \\ \\ \ \\\ \\\.�� ��� - / -/- / /J 11 I /�i IIII //// _//\\ \\ \\\ / / II I /I I \ .-.._,.` \\ \\\\ \\\\\\\\\ \\\ \\ N - �� �� / / / / / - -//� - /I II / // /� \\ ,\ \\ \ \ \ \� � �� \ \ \ \ 1 \\ �� \ / III / // /ii /�/ /� \ \ \ -, � / // ' _\ _ \ l / /III / // / �/ /Jllllll/1/i///// ///i- - — \\ \\ // ///7/ \`, , " \ \ \ \\\ \ \\\\\ \\ l l l/ l 11 / /%'�j/ %Ill l / /� F \\ \ \\\\\ \ , \ �\/ / �// \ —/ /// / / ,, \\\ __� _ \\\ \\\\\ \ \ \ \ \\\ )l 1 Ill 1 1/ // / / / / / / �/ II 1 / , �// /\\\\� �\_' /iii/�//// --: ' ' ��- \\\�\ \\\\\\\\\�' \\ \\ 1 1 \ \\ ll II I lI 1 /// " //( / ///// /i/// / , 1 I I 1I // / \ \ .� -� // / // � \ \ \ -� — \�\\\ \\\ \ \ \ \ \ \ \ \\ \�\\ III I III 1/ IIII ////// /i// // I 1 I / / / //7\\\ %%---/ //// //^ - -� \ \\ \ \ \ \ \ 1 \ \\ \I 1111 I I I I / ` ‘ //// //-�- //� ) 111 I I I N / \ - -,/ /// ; �,; = ,\\ NN\\ \\\ \ \ 1 \ \ I I I I I I I 1 \ IIII /// - // / // I11I I / / / \\\ i-- - - // - - _ �,,� � ; , _____ _ -N �\ �� 1\ III ) / 1' 1 ))/ \\IIII III ( \ \ 1. 'IIII /�� -/ IIII II1I \/( 1 / /\\I_ ��%%/- - _ -_ =-=�\\ \ N. 1\ / / -� 1 /II I I \\ �` IIII// / II II / �/// / l/ l I / / ���-i / / - - \ !__ _ _ _—!��; �_ �II� I�IIII�I III //(I�` \\ \ \�_�;_- I'111 r ///✓/// //%� �//%/ IIII / �� 11/ I 1 1 1 i �/ 1- / / / , `__ \� �� _ = = % - __ _ = =- /mil) 1 \\\\\\�\\\\\\�_ 11 I �1II j % (-- r l �// / I III I III 11 / / // I \ - --= - /� =- ��" i /�/ �_\��\�\\\\ _ � IIII I 1 \ I 1 11 \ \ \ I I;I II 11 I r Ill 74 1 \ ( — \ \ilk � _ � �-- — � -I _ - / /�� \ �\�\\ '' �\\ �// I i 111.1\ \ I I 1 \ \ \ \ \ \, \ \� Imo\ I, i 1111 \ \\ \ \\ \ \ \\ \\ _ �', s"F �/ / / r' \ i %- ��/ - NNiN ��\ \��\� 150 0 150 300 450 \ \ \ S / 1 eit/P "II . --1. '' - \ \ \ \ \�\\\\\ N \ 7 /' /' \—�/ /l � \_ \ \\( i /// \I \ `\\\ 1 I) \\\\ \\\\\\' L \ \ 1 I )\ \ \ \' 1 \� `\ \\`NN \ \\ \ \\ \� \_-�_ \\`\\\ /\ \ \ \ \ 1 (� NM \ \ \ 1 1 ) \ /,\\�\\ Scale: 1"-150' \ \ Ill \ \ \ \ \ \ �\ � � \� _� � ; �� .\� ���� �� \�\ ; ��/ \�\�\\\� \ 1, 1 \ I I /) ,/// ,// / -/ / / Pants Project Culvert Pre-Development Type 1124-hr lyr Rainfall=3.04" Prepared by Shimp Engineering, P.C. Printed 7/13/2015 HydroCAD®9.10 sin 07054 ©2011 HydroCAD Software Solutions LLC Page 1 Summary for Subcatchment 1: D.A.1 Runoff = 2.50 cfs @ 12.21 hrs, Volume= 0.573 af, Depth> 0.20" 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=3.04" Area(sf) CN Description 1,475,889 55 Woods,Good,HSG B 1,475,889 100.00%Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 18.2 Direct Entry, Pants Project Culvert Pre-Development Type 1124-hr l0yr Rainfall=5.54" Prepared by Shimp Engineering, P.C. Printed 7/13/2015 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 2 Summary for Subcatchment 1: D.A.1 Runoff = 43.35 cfs @ 12.13 hrs, Volume= 3.534 af, Depth> 1.25" Runoff by SCS TR-20 method, UH=SCS,Time Span=0.00-24.00 hrs,dt=0.01 hrs Type II 24-hr l0yr Rainfall=5.54" Area(sf) CN Description 1,475,889 55 Woods,Good,HSG B 1,475,889 100.00%Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 18.2 Direct Entry, � \ 'I / "�/ = /, / — — \\' \\\ �\ \\'\ ' \/ \ \ � � __=/ ' \\\\\\\\\• \ \\\N' \\ / /// // = � � _\\ \\ ` I i i \THE PANTS PROJECT I I I __ _ r %___ _ : _ : _ \ i \ / /l \ \ / / / POST-DEVELOPMENT I ( I / / _ - = = ,-�� - A■ � � �� // 1 \ __ - _ - \\ \ i 1 1 1;1 1 11 \\ \ ,/, ; ii ' - I i I \ \ �/- „ I I II __ i DRAINAGE MAP = _ i%/i //ii - __- \ I I I\ \ / / j i // _ _ Au I 1 \� \ \/ \ = i�i� Vii\ \ \\ 1 \ \ OW \ P. . • r .. r � j � v --- - - - _ \ \ IIll/ l/ -jo,,19 •;. \ \ \ -I / /;. .`- A---._ _��\% j// j / , /, /\\ Ti— — p)\\\\\\\\ \ ,, \ \ \ \\ \ \ , 11,,listAi\ \ \ \ '-fl..',.: 486 __ ,,, ,,,,,,, _ , \ \ \ , , , ,_ _ ___ ______ _ \ \ \ \\ \ \ \\ \ \ \\ \\ !Cot. ,\ 1. \ I I «:; e.► , ii j/c-i-,-.. .;•,.:,.-----L-7-,._,._.:---.--___..1=-__479-141 \4•�- - • • .. ,•..�\ \ 11 1 - - \\\ \ \\\ \\\\ \\\ \ \\ \\\ \\ b \ \\ t...: :\ \ I I I \ \ \ / I I vf,; .•- / '/ •• / ( / r.� \ \�\/ �/ \�.A \� \� - __ \ \ \ \ \\ \ \\\ \\ \ \ \\N'\ \ \ \ I 1 1 i , \ \ ;;• 1 /�0/ / ■\ \ — _ _ \ \\\\\ \ \\\ \\\\� \\ \\\ \\ \ \\\\\\\\\ \ \ \ \ \ .'_._, \ , : 11 1 \ \ \ ( __ - _\ \ \\\\ \ \\ \ \ \ \ \ \\ \ \ \ \ \\ \ \ \ \ \ �� .� \ \• 1 \ I 0 •AsI 1 ,`\\ \\\ \\\\�' � ✓� - - - - - \ \ \ \ \ \ \ \ \ \\ , \ \\ \\ I \ \ I 1 - / ) i'''� 4 \ \\\\\ //'� \� \ \ \�\'1 ` \�.t� � \\ \� ` \ \ \ \ •1 �:. \\ \ \ \ \ \ \ I I 1 I I j / I \'';;, \ `��� � 1,� �__ � , ) / / , \ \ � \ \ \ 1 \ \ \ \ , I \ \ \ I \ \ \\ \ 1 \ \\\'\", 8\ \O4\7 AC.. 4, . \\\\\\ " \\ \ \ , \ 1:k144-T \ \\ \ �( \ �\ N\ \o .)14 .%\ \\ \ 1: \,< XN '-- ---- iim:::--- -- N \ \ \ \ \\\\\\ g 86 '' PiN k\t,4,A --t.:::,.. \ ,ii.N \\ \\ i - , \'\\ N'*1:•i _ Y AN NNNN N N \ \ N _,.. -,- ,\ , „ \ , N -, ----- - ..„,, „,, ----,114., \ \ \ \„, , \ \ \ \ \\ \\\ \ �� - ; \ \ \\ \�\.....„..,_ .„..,----„, .„.....--,.,„„2---. - mit ��\ �� \ \ \\� \ 1 1 j \ \ I 1/ / / / / \� \�\ \\ �\\\\ \\\ ;�� .< � \ \\ \\ - \ �\ �\ \ \\\\\\ \ 1 I ; ':•... '� \ \\\\ 2�4Yrr I� I /1/n // / / ;, \\\ \\\ - \ �� s \ \\ \ ; � \��\\N \\\\� \ \ 1 I I / / / • °� \\ \ Ip9,1S/ / // // _ _ -1-251:64-qrN \ V\-- \ \ .sit,-: \ N, ),.4 r .,,, N .,‘,. :..-4 ---- ----.-: ' \\\„\\ I\\\\\\\\\\ \\ \-\\ 1 '' - .\.... .'•;. 22� IMP.\ \ � ;.: u•!\\..... ...\ - ,�= \ \ og,407/,*-,--„ ,-„--______ __-_„,- ` \ \ \ \ (r / \ \ .�✓. / ,(,.•:--% ; - _ _ �� i l / //// /// // \)1 1\ \\ \\ \\\ \\ 1\\ 1 I I • I ill ; - _ ___-` \ G \\ \\, :.•- ..; - -• / , . , ��'-�"'_"= // //7 / /:.//.. / , ) 1\ \ I /i ) // / / / 1 1111111 \ \ _ - _ _ - \\ \\ \\\\ / / : -\ - 1��' j r � �r � _ �� - - - //�//// /f : // / _, l l/ 11 / �/// l 1I11 11 I - - ■ \ \\' \�\\\�\�\� / l /// / x_=_-_-_-_-_- I / 1 u, lfl ( II I - ;� � //// � // ///, \ // / / // / / / I I /11 \ \ \ \ \ \ \ \ / II L� I I I / /// ' / // —�� \\�� 111\ _\ \\\\ \ \\ \IIr / Iy _ - - 1 I I I I 1 /i // /i ! �r \ 1 II � I �/ // ////////j�/ /�(//j I __/ � — 1 I\1 \ J 1// / - - --� \ I I 1 1 1 �9- „ / / i \ �, // /// - , \>>/I I I I I I \\\ \\ N \ - I l \ � '1 11 \ �`— "� ( ( ( \ /� 1 1 �� / / ( 1_ =_ !I / I I \\ \ \ V / 1 1 Il l l� - _ \\ \\ \\ 1 \ \ \ \ 1 \ I 1 I \o 1 I II 1111 ii /// �/, __ ; � � � � _�l���Piy / / / Ili II — \\ \ \\ \\ \ / / / � /F - _\� \� = I \\ �\ \ \ \ 1 1 \ \ \ \ 1 \ \ I IIII III I111 l�� / � - - - - _ / // )) \ \\ \ \ \ / / l 11 / Il / �_\\_ , \\ \\ \\\ \ �\ \ \\ \ \ I \ \ \ • S ► II ► II III /// Ii' -- _ // / I J /// \ \\\ // 1 \\ \ \ \\\ \\\\ \� \ \ \\\ \ \ \ \ i/gil 1 / - • (; _ \��� �� I11 Ill / / 1 - '� S ; "'T //j/�/// \ \ \\ \ /�/�� 11 1 1/ll l l` ��� \�\�\ \\\\\\\ \\ \\ \\ \ \\\ \ \\ \\ \ \ / I I1/ lll/ \ \\ \\ / 1/ I \ \ \\ \ � \\\ � //�L ___- - _ - ' � �.O i/� /i/ // \ \\\\ \ \\ � � // / I IIII \� _�\\\\\ \\ \\ \� \ \ \ \\ \\\ \ \ \ \\ 1 II III 1lL / II! / / / / \ �\ I I \ \ \\\ \\ \\\ \ \ \\ \ / I N �`� - _� /,...._7 / / / '-- / \ \ �$ 11 1 111 \ \\ \ \ \\\\ \\ \\ \\\ \ \ \ \ \ \ \����\\\ - // /� '7� II 1 l // /ii �i/ / \\ \ \ //// �\ \ \ N \\ , \ \\ \ \\ \ \\ \ \ \ `- �\ �\\\\N\\\ , l/ �/ 1 , l l /i i - //// /// /(//r /// 7/�\\\ \ 1 .�� "// /////// 2- 9:*2' _,-,01,_#% * - \ \\\\\ \\\ \\ \\ \ \ 1 \ \\ \\� 11 1 /// / / //�/ / / /may -, / / l ll( 1 I ( / / 7, -- \„ mot-- // /ice _ - � ; ,��; \\ \ \ \\\N \ - \ \ \ \\\ >> 1111111 /�j / // /// • / % // , ��// / l ,,/ I l / 447 ,, �� �, „ _' ,7,// - \ \ 0 , , , \\\\\\ \\ \ \ \\ \p ,‘ , \I\ \ 111111 I I\ \;\\\\\ hill (1 /I Hi/1 /// /// /i / , ./ , , /j!lj, 1 I I i I I I I \, /, //� ' a \ \ \ 1 1` I / l I I / \_."------ % //� - - - _-_--_ -_-_- - ---,_--- ,-,- -__L -.--y . c . — aTNNN 0 \A 1 - _ - - - N.\,\ �' 1 ' I , /i - I \ I//�//,, 1111 1111 I \\\ `,l_ MANAGED IIII I / / \� % �� ���%/ �� — — LAWN / / / / / %/�% / I 1 I l \\ \� / / 1 / 1 �`�-� i� � � - // 91}ti 1 �Ifl1 - 111 //1llllll\ \ �`� �/ I / �� , - _ _ _ 11 \ \\\\ •\ \\� - =�_ ..._. ... ..i . // / // r I / i I I r`/ / \ _ �� _ _ . ii toll ei1Y- Di. •' ,. ,' i it , v % 1� 1 - - \ \\\ \\ \ \\ _ _ I I I / _ / ' _ \ \ IMPERVIOUS • I I I \ 1 \ \ \ = ------------ 11MVElifitiVn--la_— _ i� �\�\�\��_�� - \�� ,.... . .. 150 0 150 300 450 \ \ \ \\ \\\ \ \ Scale: 1"=150' \ Ill I \ \ \ �\ \` � \� .\\ \\ \\\\\ \ _ i `\\\\\\\\.\ \ I, \ \ I 1 I y ,l// . ,/ //// ./ l Darken Time of Concentration Calculations Overland Flow, C=0.3 Shallow Concentrated Flow-Woods Channel Flow (Seelye Chart) (NEH Figure 15-4) (Kirpich Chart) Length Slope Time Length Slope Velocity Time Length Height Time Total D.A.1 69 ft 7.2% 9.5 92 ft 9 ft 0.1 9.6 D.A.2 200 ft 12.0% 12.7 197 ft 19.3% 1.1 fps 3.0 632 ft 96 ft 2.3 18.0 200 ft 17.0% 11.8 219 ft 46.6% 1.6 fps 2.3 259 ft 37 ft 1.2 15.3 D.A.4 200 ft 16.5% 11.9 269 ft 32.7% 1.3 fps 3.4 738 ft 96 ft 2.9 18.2 D.A.5 200 ft 14.0% 12.1 251 ft 25.1% 1.2 fps 3.5 22 ft 3 ft 0.1 15.7 D.A.6 200 ft 16.0% 11.9 118 ft 19.5% 1.1 fps 1.8 13.7 D.A.7 194 ft 15.5% 11.9 54 ft 11.1% 0.8 fps 1.1 86 ft 10 ft 0.1 13.1 D.A.8 78 ft 11.5% 9.2 108 ft 19 ft 0.1 9.3 D.A.9 99 ft 8.1% 10.6 324 ft 36 ft 1.6 12.2 D.A.10 46 ft 15.2% 7.1 97 ft 3 ft 0.9 8.0 D.A.11 26 ft 26.9% 5.0 21 ft 1 ft 0.1 5.1 D.A.12 87 ft 16.1% 8.6 153 ft 3 ft 1.7 10.3 D.A.13 200 ft 22.5% 11.0 11.0 Virginia Runoff Reduction Method New Development Worksheet - v2.8 - June 2014 To be used w/ 2011 BMP Standards and Specifications Site Data Project Name: The Pants Project Date: 05/15/2015 __________________________data calculationinputcells cells constant values 1. Post-Development Project & Land Cover Information Constants Annual Rainfall(inches) Target Rainfall Event(inches) 1.00 ^ Phosphorus EMC(mg/L) 0.26 Nitrogen EMC(mg/L) 1.86 Target Phosphorus Target Load(Ib/acre/yr) 0.41 Pj 0.90 Land Cover (acres) A soils B Soils C Soils D Soils Totals Forest/Open Space(acres)-undisturbed, protected forest/open space or reforested land 1.47 0.00 0.00 1.47 Managed Turf(acres)-disturbed, graded for yards or other turf to be mowed/managed 0.00 2.01 0.00 0.00 2.01 Impervious Cover(acres) 0.00 0.87 0.0 . 0.87 Total 4.35 Rv Coefficients A soils B Soils C Soils D Soils Forest/Open Space 0.02 0.03 0.04 0.05 Managed Turf 0.15 0.20 0.22 0.25 Impervious Cover 0.95 0.95 0.95 0.95 Land Cover Summary Forest/Open Space Cover(acres) 1.47 Weighted Rv(forest) 0.03 % Forest 34% - Managed Turf Cover(acres) 2.01 Weighted Rv(turf) 0.20 _ % Managed Turf 46% Impervious Cover(acres) 0.87 Rv(impervious) 0.95 % Impervious 20% - Total Site Area (acres) 4.35 Site Rv 0.29 Post-Development Treatment Volume (acre-ft) 0.11 Post-Development Treatment Volume (cubic feet) 4,620 Post_Development Load (TP) (Ib/yr) 2.90 Post_Development Load (TN) (Ib/yr)I 20.761 Total Load (TP) Reduction Required (Ib/yr) 1.12 Virginia Runoff Reduction Method Worksheet 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) 0.00 147 0.00 0 00 1.47 33.79 Turf(acres) 0 00 2 01 0 00 0.00 2 01 46.21 Impervious(acres) 0 00 0 87 0.00 0 00 0.87 20.00 4 35 100 00 Site Rv 0 29 Post Development Treatment Volume(ft3) 4620 Post Development TP Load(lb/yr) 2 90 Post Development TN Load(Ib/yr) 20.76 Total TP Load Reduction Required(Ib/yr) 1 12 Total Runoff Volume Reduction(ft) 0 Total TP Load Reduction Achieved(Ib/yr) 1 Total TN Load Reduction Achieved(Ib/yr) 4.65 Adjusted Post Development TP Load(lb/yr) 1 68 Remaining Phosphorous Load Reduction(Lb/yr)Required 0. 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 Turf(acres) 0.00 0 00 1 54 0 00 0 00 1 54 Impervious(acres) 0 00 0.00 0 43 0 00 0.00 0.43 1 97 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) 0 00 0 00 1.22 0 00 0 00 1.22 TN Load Red.(lb/yr) 0.00 0 00 4 65 0.00 0.00 4 65 Summary Print Virginia Runoff Reduction Method Worksheet Drainage Area C 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 1 54 0.00 0 00 1 54 78.35 Impervious(acres) 0 00 0.43 0 00 0 00 0.43 21 65 1 97 BMP Selections Practice Credit Area(acres) Downstream Practice 13.c.Wet Pond#2(Spec#14) Impervious: 0.426125 Turf(Pervious): 1.542264 Total Impervious Cover Treated(acres) 0.43 Total Turf Area Treated(acres) 1 54 Total TP Load Reduction Achieved in D.A.A(Ib/yr) 1.22 Total TN Load Reduction Achieved in D.A.A(lb/yr) 4 65 Summary Print Virginia Runoff Reduction Method Worksheet 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) 3.04 3.68 5 54 D A.A CN 0 kN/A NN/A eN/A D.A.B CN 0 RN/A NN/A kN/A D A.C CN 69 69 69 69 D.A.D CN 0 eN/A eN/A eN/A D A.E CN 0 eN/A NN/A RN/A Summary Print Drainage Area C )rainage Area C Land Cover (acres) A soils B Soils C Soils D Soils Totals Land Cover Rv IForest/Open Space(acres) 0.00 0 00 0.00 0 00 0.00 0.00 Managed Turf(acres) 0.00 1 54 0.00 0.00 1.54 0.20 mpervious Cover(acres) 0.00 0.43 0.00 0.00 0.43 0.95 Post Development Treatment Volume(cf) 2589 Total 1.97 Apply Runoff Reduction Practices to Reduce Treatment Volume & Post-Development Load in Drainage Area C Phosphorus Untreated Volume from Remaining Load from Phosphorus Phosphorus Remaining Credit Area Upstream RR Runoff Runoff Phosphorus Upstream RR Load to Practice Removed By Phosphorus )ractice Unit Descri•tion of Credit Credit acres Practice cf Reduction cf Volume cf Efficienc % Practices lbs lbs. Practice lbs. Load lbs. Downstream Treatment to be Em•to ed 13. Wet Ponds • impervious acres draining to wet pond 0%runoff volume reduction 0.00 0.43 0 0 1469 75 0.00 0.92 0.69 0.23 13.c.Wet Pond#2(Spec#14) turf acres draining to wet pond 0%runoff volume reduction 0.00 1 54 0 0 1120 75 0 00 0.70 0.53 0.18 TOTAL IMPERVIOUS COVER TREATED(ac) 0.43 TOTAL TURF AREA TREATED(ac) 1.54 PHOSPHORUS REMOVAL BY PRACTICES THAT DO NOT REDUCE RUNOFF VOLUME IN D.A. 1.22 TOTAL PHOSPHORUS REMOVAL IN D.A.C(Ib/yr 1.22 SEE WATER QUALITY COMPLIANCE TAB FOR SITE COMPLIANCE CALCULATIONS NITROGEN REMOVAL BY PRACTICES THAT DO NOT REDUCE RUNOFF VOLUME IN D.A. 4.65 TOTAL NITROGEN REMOVAL IN D.A.C(Ib/yr 4.65 The Pants Project Energy Balance Calculation 24 Hr 1 year Storm I.F.* (Qpre * RVpre) Qdev — RVdev(Qwooded * RVwooded) Qdev RVdev I.F = 0.8 Qpre 2.50 RVpfe 0.573 RVdev 0.599 Qdev (Eq. 1) 1.913 Qdev(Eq. 2) 2.391 <10> ( 9 ) DA10 DA9 0 ( 8 ) DA11 D.A 8 0 O DA12 O 6 D A 7 D A.1 0 D A.6 �p 5P 0 DA5 Lev tPond .. D A 2 4P Q-----.._. (5A) 4 A FOREBAY#2 D A.4 0,40REBAY#1 POND DA D.A 3 I I <Subca) Reach •on• MU Drainage Diagram for Pants Project Culvert Post-Development Prepared by Shimp Engineering, P.C., Printed 7/10/2015 HydroCAD®9 10 s/n 07054 ©2011 HydroCAD Software Solutions LLC I Pants Project Culvert Post-Development Type 1124-hr lyr Rainfall=3.04" Prepared by Shimp Engineering, P.C. Printed 7/10/2015 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 2 Summary for Subcatchment 1: D.A.1 Runoff = 0.07 cfs @ 12.06 hrs, Volume= 0.007 af, Depth> 0.29" Runoff by SCS TR-20 method, UH=SCS,Time Span=0.00-24.00 hrs,dt=0.01 hrs Type II 24-hr lyr Rainfall=3.04" Area(sf) CN Description 10,635 55 Woods,Good, HSG B 1,226 85 Gravel roads, HSG B 803 61 >75%Grass cover,Good, HSG B 12,664 58 Weighted Average 12,664 100.00%Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.6 Direct Entry, Summary for Subcatchment 2: D.A.2 Runoff = 0.14 cfs @ 12.22 hrs, Volume= 0.031 af, Depth> 0.20" 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=3.04" Area(sf) CN Description 78,953 55 Woods,Good, HSG B 829 85 Gravel roads, HSG B 968 61 >75%Grass cover,Good, HSG B 80,750 55 Weighted Average 80,750 100.00%Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 18.0 Direct Entry, Summary for Subcatchment 3: D.A.3 Runoff = 0.42 cfs @ 12.16 hrs, Volume= 0.087 af, Depth> 0.20" 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=3.04" Area(sf) CN Description 221,242 55 Woods,Good, HSG B 1,545 85 Gravel roads, HSG B 1,844 61 >75%Grass cover,Good, HSG B 224,631 55 Weighted Average 224,631 100.00%Pervious Area Pants Project Culvert Post-Development Type 1124-hr lyr Rainfall=3.04" Prepared by Shimp Engineering, P.C. Printed 7/10/2015 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 3 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 15.3 Direct Entry, Summary for Pond 3P: FOREBAY#1 Inflow Area= 5.157 ac, 0.00%Impervious, Inflow Depth> 0.20" for lyr event Inflow = 0.42 cfs @ 12.16 hrs, Volume= 0.087 af Outflow = 0.22 cfs @ 12.62 hrs, Volume= 0.076 af, Atten=47%, Lag=27.2 min Primary = 0.22 cfs @ 12.62 hrs, Volume= 0.076 af Routing by Stor-Ind method,Time Span=0.00-24.00 hrs,dt=0.01 hrs Peak Elev=681.13' @ 12.62 hrs Surf.Area=562 sf Storage=552 cf Plug-Flow detention time=95.9 min calculated for 0.076 af(87%of inflow) Center-of-Mass det.time=38.5 min( 1,011.1-972.6) Volume Invert Avail.Storage Storage Description #1 678.45' 3,447 cf Custom Stage Data(Prismatic) Listed below(Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 678.45 20 0 0 680.00 163 142 142 682.00 868 1,031 1,173 684.00 1,406 2,274 3,447 Device Routing Invert Outlet Devices #1 Primary 680.95' 24.0" Round Culvert L=40.6' Ke=0.400 Inlet/Outlet Invert=680.95'/680.15' S=0.0197'/' Cc=0.900 n=0.013 Primary OutFlow Max=0.22 cfs @ 12.62 hrs HW=681.13' (Free Discharge) L1=Culvert (Inlet Controls 0.22 cfs @ 1.55 fps) Summary for Subcatchment 4: D.A.4 Runoff = 2.41 cfs @ 12.20 hrs, Volume= 0.464 af, Depth> 0.23" Runoff by SCS TR-20 method, UH=SCS,Time Span=0.00-24.00 hrs,dt=0.01 hrs Type II 24-hr lyr Rainfall=3.04" Area(sf) CN Description 995,292 55 Woods,Good, HSG B 11,644 85 Gravel roads, HSG B 53,293 61 >75%Grass cover,Good, HSG B 1,060,229 56 Weighted Average 1,060,229 100.00% Pervious Area Pants Project Culvert Post-Development Type 1124-hr lyr Rainfall=3.04" Prepared by Shimp Engineering, P.C. Printed 7/10/2015 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 4 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 18.2 Direct Entry, Summary for Pond 4P: FOREBAY#2 Inflow Area= 24.340 ac, 0.00%Impervious, Inflow Depth> 0.23" for 1yr event Inflow = 2.41 cfs @ 12.20 hrs, Volume= 0.464 af Outflow = 2.36 cfs @ 12.23 hrs, Volume= 0.447 af, Atten=2%, Lag= 1.9 min Primary = 2.36 cfs @ 12.23 hrs, Volume= 0.447 af Routing by Stor-Ind method,Time Span=0.00-24.00 hrs,dt=0.01 hrs Peak Elev=681.68' @ 12.23 hrs Surf.Area=660 sf Storage=901 cf Plug-Flow detention time=26.6 min calculated for 0.447 af(96%of inflow) Center-of-Mass det.time=9.9 min (974.5-964.6) Volume Invert Avail.Storage Storage Description #1 678.60' 7,652 cf Custom Stage Data(Prismatic) Listed below Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 678.60 20 0 0 680.00 164 129 129 682.00 753 917 1,046 684.00 1,472 2,225 3,271 686.00 2,909 4,381 7,652 Device Routing Invert Outlet Devices #1 Primary 681.12' 36.0" Round Culvert L=40.0' CPP,end-section conforming to fill, Ke=0.500 Inlet/Outlet Invert=681.12'/679.65' S=0.0368'/' Cc=0.900 n=0.011 Primary OutFlow Max=2.35 cfs @ 12.23 hrs HW=681.68' (Free Discharge) t-1=Culvert (Inlet Controls 2.35 cfs @ 2.56 fps) Summary for Subcatchment 5: D.A.5 Runoff = 0.09 cfs @ 12.16 hrs, Volume= 0.016 af, Depth> 0.23" 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=3.04" Area(sf) CN Description 35,036 55 Woods,Good, HSG B 1,060 85 Gravel roads, HSG B 1,263 61 >75%Grass cover,Good, HSG B 37,359 56 Weighted Average 37,359 100.00%Pervious Area Pants Project Culvert Post-Development Type 1124-hr lyr Rainfall=3.04" Prepared by Shimp Engineering, P.C. Printed 7/10/2015 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 5 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 15.7 Direct Entry, Summary for Subcatchment 5A: POND DA Runoff = 0.40 cfs @ 12.00 hrs, Volume= 0.029 af, Depth> 0.29" 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=3.04" Area(sf) CN Description 39,396 55 Woods,Good, HSG B 3,650 85 Gravel roads, HSG B 9,721 61 >75%Grass cover,Good, HSG B 52,767 58 Weighted Average 52,767 100.00%Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Pond 5P: Level 2 Wet Pond Inflow Area= 33.419 ac, 0.00%Impervious, Inflow Depth> 0.22" for lyr event Inflow = 2.67 cfs @ 12.23 hrs, Volume= 0.600 af Outflow = 0.52 cfs @ 16.95 hrs, Volume= 0.412 af, Atten=81%, Lag=283.5 min Primary = 0.52 cfs @ 16.95 hrs, Volume= 0.412 af Routing by Stor-Ind method,Time Span=0.00-24.00 hrs,dt=0.01 hrs Peak Elev=682.42' @ 16.95 hrs Surf.Area=24,189 sf Storage=9,860 cf Plug-Flow detention time=251.2 min calculated for 0.411 af(69%of inflow) Center-of-Mass det.time= 128.8 min( 1,106.0-977.1) Volume Invert Avail.Storage Storage Description #1 682.00' 84,955 cf Custom Stage Data(Prismatic) Listed below(Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 682.00 22,442 0 0 684.00 30,705 53,147 53,147 685.00 32,911 31,808 84,955 Device Routing Invert Outlet Devices #1 Primary 676.00' 36.0" Round Culvert L= 100.0' Ke=0.400 Inlet/Outlet Invert=676.00'/674.00' S=0.0200'/' Cc=0.900 n=0.013 #2 Device 1 682.00' 8.0"Vert.Orifice/Grate C=0.600 #3 Device 1 683.00' 48.0"Horiz.Riser C=0.600 Limited to weir flow at low heads #4 Primary 684.00' 6.0'long x 6.0'breadth Broad-Crested Rectangular Weir Pants Project Culvert Post-Development Type 1124-hr lyr Rainfall=3.04" Prepared by Shimp Engineering, P.C. Printed 7/10/2015 HydroCAD®9.10 sin 07054 ©2011 HydroCAD Software Solutions LLC Page 6 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 4.00 4.50 5.00 5.50 Coef.(English) 2.37 2.51 2.70 2.68 2.68 2.67 2.65 2.65 2.65 2.65 2.66 2.66 2.67 2.69 2.72 2.76 2.83 Primary OutFlow Max=0.52 cfs @ 16.95 hrs HW=682.42' (Free Discharge) -1=Culvert (Passes 0.52 cfs of 80.91 cfs potential flow) E2=Orifice/Grate (Orifice Controls 0 52 cfs @ 2.21 fps) 3=Riser (Controls 0.00 cfs) -4=Broad-Crested Rectangular Weir (Controls 0.00 cfs) Summary for Subcatchment 6: D.A.6 Runoff = 0.15 cfs @ 12.12 hrs, Volume= 0.020 af, Depth> 0.26" 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=3.04" Area(sf) CN Description 37,932 55 Woods,Good, HSG B 1,980 85 Gravel roads, HSG B 1,234 61 >75%Grass cover,Good, HSG B 41,146 57 Weighted Average 41,146 100.00%Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.7 Direct Entry, Summary for Subcatchment 7: D.A.7 Runoff = 0.07 cfs @ 12.10 hrs, Volume= 0.008 af, Depth> 0.28" 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=3.04" Area(sf) CN Description 11,732 55 Woods,Good, HSG B 1,007 85 Gravel roads, HSG B 1,703 61 >75%Grass cover,Good, HSG B 14,442 58 Weighted Average 14,442 100.00%Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.1 Direct Entry, Pants Project Culvert Post-Development Type 1124-hr lyr Rainfall=3.04" Prepared by Shimp Engineering, P.C. Printed 7/10/2015 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 7 Summary for Subcatchment 8: D.A.8 Runoff = 0.06 cfs @ 12.03 hrs, Volume= 0.004 af, Depth> 0.48" 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=3.04" Area(sf) CN Description 2,082 55 Woods,Good,HSG B 983 85 Gravel roads,HSG B 1,142 61 >75%Grass cover,Good, HSG B 4,207 64 Weighted Average 4,207 100.00% Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.3 Direct Entry, Summary for Subcatchment 9: D.A.9 Runoff = 0.16 cfs @ 12.07 hrs, Volume= 0.013 af, Depth> 0.45" Runoff by SCS TR-20 method, UH=SCS,Time Span=0.00-24.00 hrs,dt=0.01 hrs Type II 24-hr lyr Rainfall=3.04" Area(sf) CN Description 6,982 55 Woods, Good,HSG B 2,796 85 Gravel roads, HSG B 4,932 61 >75%Grass cover, Good, HSG B 14,710 63 Weighted Average 14,710 100.00%Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 12.2 Direct Entry, Summary for Subcatchment 10: D.A.10 Runoff = 0.09 cfs @ 12.02 hrs, Volume= 0.006 af, Depth> 0.38" 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=3.04" Area(sf) CN Description 5,699 55 Woods,Good, HSG B 1,258 85 Gravel roads, HSG B 1,741 61 >75%Grass cover,Good, HSG B 8,698 61 Weighted Average 8,698 100.00%Pervious Area Pants Project Culvert Post-Development Type 1124-hr lyr Rainfall=3.04" Prepared by Shimp Engineering, P.C. Printed 7/10/2015 HydroCAD®9.10 sin 07054 ©2011 HydroCAD Software Solutions LLC Page 8 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.0 Direct Entry, Summary for Subcatchment 11: D.A.11 Runoff = 0.11 cfs @ 11.98 hrs, Volume= 0.005 af, Depth> 0.52" 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=3.04" Area(sf) CN Description 1,882 55 Woods,Good, HSG B 1,443 85 Gravel roads, HSG B 2,134 61 >75%Grass cover,Good, HSG B 5,459 65 Weighted Average 5,459 100.00%Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.1 Direct Entry, Summary for Subcatchment 12: D.A.12 Runoff = 0.73 cfs @ 12.03 hrs, Volume= 0.042 af, Depth> 0.78" 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=3.04" Area(sf) CN Description 11,939 85 Gravel roads, HSG B 16,325 61 >75%Grass cover,Good, HSG B 28,264 71 Weighted Average 28,264 100.00%Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.3 Direct Entry, Pants Project Culvert Post-Development Type 1124-hr 10yr Rainfall=5.54" Prepared by Shimp Engineering, P.C. Printed 7/10/2015 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 9 Summary for Subcatchment 1: D.A.1 Runoff = 0.64 cfs @ 12.02 hrs, Volume= 0.036 af, Depth> 1.47" 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=5.54" Area(sf) CN Description 10,635 55 Woods,Good, HSG B 1,226 85 Gravel roads, HSG B 803 61 >75%Grass cover,Good, HSG B 12,664 58 Weighted Average 12,664 100.00%Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 9.6 Direct Entry, Summary for Subcatchment 2: D.A.2 Runoff = 2.39 cfs @ 12.13 hrs, Volume= 0.193 af, Depth> 1.25" 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=5.54" Area(sf) CN Description 78,953 55 Woods,Good, HSG B 829 85 Gravel roads, HSG B 968 61 >75%Grass cover,Good, HSG B 80,750 55 Weighted Average 80,750 100.00%Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 18.0 Direct Entry, Summary for Subcatchment 3: D.A.3 Runoff = 7.35 cfs @ 12.09 hrs, Volume= 0.539 af, Depth> 1.25" 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=5.54" Area(sf) CN Description 221,242 55 Woods,Good, HSG B 1,545 85 Gravel roads, HSG B 1,844 61 >75%Grass cover,Good, HSG B 224,631 55 Weighted Average 224,631 100.00%Pervious Area Pants Project Culvert Post-Development Type 1124-hr 10yr Rainfall=5.54" Prepared by Shimp Engineering, P.C. Printed 7/10/2015 HydroCAD®9.10 sin 07054 ©2011 HydroCAD Software Solutions LLC Page 10 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 15.3 Direct Entry, Summary for Pond 3P: FOREBAY#1 Inflow Area= 5.157 ac, 0.00%Impervious, Inflow Depth> 1.25" for 10yr event Inflow = 7.35 cfs @ 12.09 hrs, Volume= 0.539 af Outflow = 7.19 cfs @ 12.12 hrs, Volume= 0.526 af, Atten=2%, Lag= 1.5 min Primary = 7.19 cfs @ 12.12 hrs, Volume= 0.526 af Routing by Stor-Ind method,Time Span=0.00-24.00 hrs,dt=0.01 hrs Peak Elev=682.09' @ 12.12 hrs Surf.Area=892 sf Storage= 1,251 cf Plug-Flow detention time= 18.2 min calculated for 0.526 af(98%of inflow) Center-of-Mass det.time=5.8 min (891.6-885.8) Volume Invert Avail.Storage Storage Description #1 678.45' 3,447 cf Custom Stage Data(Prismatic) Listed below(Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 678.45 20 0 0 680.00 163 142 142 682.00 868 1,031 1,173 684.00 1,406 2,274 3,447 Device Routing Invert Outlet Devices #1 Primary 680.95' 24.0" Round Culvert L=40.6' Ke=0.400 Inlet/Outlet Invert=680.95'/680.15' S=0.0197'/' Cc=0.900 n=0.013 Primary OutFlow Max=7.19 cfs @ 12.12 hrs HW=682.09' (Free Discharge) t1=Culvert (Inlet Controls 7.19 cfs @ 3.89 fps) Summary for Subcatchment 4: D.A.4 Runoff = 33.52 cfs @ 12.13 hrs, Volume= 2.682 af, Depth> 1.32" 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=5.54" Area(sf) CN Description 995,292 55 Woods,Good, HSG B 11,644 85 Gravel roads, HSG B 53,293 61 >75%Grass cover,Good, HSG B 1,060,229 56 Weighted Average 1,060,229 100.00%Pervious Area Pants Project Culvert Post-Development Type 1124-hr 10yr Rainfall=5.54" Prepared by Shimp Engineering, P.C. Printed 7/10/2015 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 11 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 18.2 Direct Entry, Summary for Pond 4P: FOREBAY#2 Inflow Area= 24.340 ac, 0.00%Impervious, Inflow Depth> 1.32" for 10yr event Inflow = 33.52 cfs @ 12.13 hrs, Volume= 2.682 af Outflow = 33.27 cfs @ 12.14 hrs, Volume= 2.664 af, Atten=1%, Lag= 1.1 min Primary = 33.27 cfs @ 12.14 hrs, Volume= 2.664 af Routing by Stor-Ind method,Time Span=0.00-24.00 hrs,dt=0.01 hrs Peak Elev=683.59' @ 12.14 hrs Surf.Area=1,324 sf Storage=2,812 cf Plug-Flow detention time=5.7 min calculated for 2.663 af(99%of inflow) Center-of-Mass det.time= 2.0 min (886.4-884.5) Volume Invert Avail.Storage Storage Description #1 678.60' 7,652 cf Custom Stage Data(Prismatic)Listed below Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 678.60 20 0 0 680.00 164 129 129 682.00 753 917 1,046 684.00 1,472 2,225 3,271 686.00 2,909 4,381 7,652 Device Routing Invert Outlet Devices #1 Primary 681.12' 36.0" Round Culvert L=40.0' CPP,end-section conforming to fill, Ke=0.500 Inlet/Outlet Invert=681.12'/679.65' S=0.0368'/' Cc=0.900 n=0.011 Primary OutFlow Max=33.25 cfs @ 12.14 hrs HW=683.59' (Free Discharge) L1=Culvert (Inlet Controls 33.25 cfs @ 5.35 fps) Summary for Subcatchment 5: D.A.5 Runoff = 1.29 cfs @ 12.09 hrs, Volume= 0.095 af, Depth> 1.32" 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=5.54" Area(sf) CN Description 35,036 55 Woods,Good, HSG B 1,060 85 Gravel roads, HSG B 1,263 61 >75%Grass cover,Good, HSG B 37,359 56 Weighted Average 37,359 100.00%Pervious Area Pants Project Culvert Post-Development Type 1124-hr l0yr Rainfall=5.54" Prepared by Shimp Engineering, P.C. Printed 7/10/2015 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 12 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 15.7 Direct Entry, Summary for Subcatchment 5A: POND DA Runoff = 3.24 cfs @ 11.97 hrs, Volume= 0.149 af, Depth> 1.47" 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=5.54" Area(sf) CN Description 39,396 55 Woods,Good,HSG B 3,650 85 Gravel roads, HSG B 9,721 61 >75%Grass cover, Good, HSG B 52,767 58 Weighted Average 52,767 100.00%Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.0 Direct Entry, Summary for Pond 5P: Level 2 Wet Pond Inflow Area= 33.419 ac, 0.00%Impervious, Inflow Depth> 1.30" for 10yr event Inflow = 44.54 cfs @ 12.14 hrs, Volume= 3.627 of Outflow = 20.15 cfs @ 12.37 hrs, Volume= 3.096 af, Atten=55%, Lag=14.1 min Primary = 20.15 cfs @ 12.37 hrs, Volume= 3.096 af Routing by Stor-Ind method,Time Span=0.00-24.00 hrs,dt=0.01 hrs Peak Elev=683.58' @ 12.37 hrs Surf.Area=28,980 sf Storage=40,686 cf Plug-Flow detention time= 115.3 min calculated for 3.095 af(85%of inflow) Center-of-Mass det.time=47.3 min(933.7-886.4) Volume Invert Avail.Storage Storage Description #1 682.00' 84,955 cf Custom Stage Data(Prismatic)Listed below(Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 682.00 22,442 0 0 684.00 30,705 53,147 53,147 685.00 32,911 31,808 84,955 Device Routing Invert Outlet Devices #1 Primary 676.00' 36.0" Round Culvert L= 100.0' Ke=0.400 Inlet/Outlet Invert=676.00'/674.00' S=0.0200'/' Cc=0.900 n=0.013 #2 Device 1 682.00' 8.0"Vert.Orifice/Grate C=0.600 #3 Device 1 683.00' 48.0" Horiz.Riser C=0.600 Limited to weir flow at low heads #4 Primary 684.00' 6.0'long x 6.0'breadth Broad-Crested Rectangular Weir Pants Project Culvert Post-Development Type 1124-hr 10yr Rainfall=5.54" Prepared by Shimp Engineering, P.C. Printed 7/10/2015 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 13 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 4.00 4.50 5.00 5.50 Coef.(English) 2.37 2.51 2.70 2.68 2.68 2.67 2.65 2.65 2.65 2.65 2.66 2.66 2.67 2.69 2.72 2.76 2.83 Primary OutFlow Max=20.14 cfs @ 12.37 hrs HW=683.58' (Free Discharge) -1=Culvert (Passes 20.14 cfs of 89.93 cfs potential flow) 12=Orifice/Grate (Orifice Controls 1.88 cfs @ 5.38 fps) 3=Riser (Weir Controls 18.27 cfs @ 2.50 fps) -4=Broad-Crested Rectangular Weir (Controls 0.00 cfs) Summary for Subcatchment 6: D.A.6 Runoff = 1.65 cfs @ 12.07 hrs, Volume= 0.110 af, Depth> 1.40" 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=5.54" Area(sf) CN Description 37,932 55 Woods,Good, HSG B 1,980 85 Gravel roads, HSG B 1,234 61 >75%Grass cover,Good, HSG B 41,146 57 Weighted Average 41,146 100.00%Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.7 Direct Entry, Summary for Subcatchment 7: D.A.7 Runoff = 0.63 cfs @ 12.07 hrs, Volume= 0.041 af, Depth> 1.47" 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=5.54" Area(sf) CN Description 11,732 55 Woods,Good, HSG B 1,007 85 Gravel roads, HSG B 1,703 61 >75%Grass cover,Good, HSG B 14,442 58 Weighted Average 14,442 100.00%Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 13.1 Direct Entry, Pants Project Culvert Post-Development Type 1124-hr l0yr Rainfall=5.54" Prepared by Shimp Engineering, P.C. Printed 7/10/2015 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 14 Summary for Subcatchment 8: D.A.8 Runoff = 0.29 cfs @ 12.02 hrs, Volume= 0.016 af, Depth> 1.94" Runoff by SCS TR-20 method, UH=SCS,Time Span=0.00-24.00 hrs,dt=0.01 hrs Type II 24-hr l0yr Rainfall=5.54" Area(sf) CN Description 2,082 55 Woods,Good, HSG B 983 85 Gravel roads, HSG B 1,142 61 >75%Grass cover,Good, HSG B 4,207 64 Weighted Average 4,207 100.00%Pervious Area Tc Length Slope Velocity Capacity Description P (min) (feet) (ft/ft) (ft/sec)9.3 (cfs) Direct Entry, Summary for Subcatchment 9: D.A.9 Runoff = 0.87 cfs @ 12.05 hrs, Volume= 0.052 af, Depth> 1.85" 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=5.54" Area(sf) CN Description 6,982 55 Woods,Good, HSG B 2,796 85 Gravel roads, HSG B 4,932 61 >75%Grass cover,Good, HSG B 14,710 63 Weighted Average 14,710 100.00%Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 12.2 Direct Entry, Summary for Subcatchment 10: D.A.10 Runoff = 0.55 cfs @ 12.00 hrs, Volume= 0.028 af, Depth> 1.70" Runoff by SCS TR-20 method,UH=SCS,Time Span=0.00-24.00 hrs,dt=0.01 hrs Type II 24-hr l0yr Rainfall=5.54" Area(sf) CN Description 5,699 55 Woods,Good, HSG B 1,258 85 Gravel roads, HSG B 1,741 61 >75%Grass cover,Good, HSG B 8,698 61 Weighted Average 8,698 100.00%Pervious Area Pants Project Culvert Post-Development Type 1124-hr 10yr Rainfall=5.54" Prepared by Shimp Engineering, P.C. Printed 7/10/2015 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 15 Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 8.0 Direct Entry, Summary for Subcatchment 11: D.A.11 Runoff = 0.47 cfs @ 11.97 hrs, Volume= 0.021 af, Depth> 2.02" 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=5.54" Area(sf) CN Description P 1,882 55 Woods,Good,HSG B 1,443 85 Gravel roads, HSG B 2,134 61 >75%Grass cover,Good, HSG B P 5,459 65 Weighted Average 5,459 100.00%Pervious Area I Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 5.1 Direct Entry, Summary for Subcatchment 12: D.A.12 I Runoff = 2.51 cfs @ 12.02 hrs, Volume= 0.137 af, Depth> 2.53" 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=5.54" Area(sf) CN Description 11,939 85 Gravel roads, HSG B 16,325 61 >75%Grass cover,Good, HSG B 28,264 71 Weighted Average 28,264 100.00%Pervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 10.3 Direct Entry, Pants Project Culvert Post-Development Type II 24-hr 10Oyr Rainfall=9.07" Prepared by Shimp Engineering, P.C. Printed 7/10/2015 HydroCAD®9.10 s/n 07054 ©2011 HydroCAD Software Solutions LLC Page 16 Summary for Pond 5P: Level 2 Wet Pond Inflow Area= 33.419 ac, 0.00%Impervious, Inflow Depth> 3.61" for 100yr event Inflow = 157.71 cfs @ 12.12 hrs, Volume= 10.064 af Outflow = 101.24 cfs @ 12.23 hrs, Volume= 9.447 af, Atten=36%, Lag=6.6 min Primary = 101.24 cfs @ 12.23 hrs, Volume= 9.447 af Routing by Stor-Ind method,Time Span=0.00-24.00 hrs,dt=0.01 hrs Peak Elev=684.93' @ 12.23 hrs Surf.Area=32,759 sf Storage=82,695 cf Plug-Flow detention time=51.6 min calculated for 9.443 af(94%of inflow) Center-of-Mass det.time= 19.0 min (873.0-853.9 ) Volume Invert Avail.Storage Storage Description #1 682.00' 84,955 cf Custom Stage Data(Prismatic) Listed below(Recalc) Elevation Surf.Area Inc.Store Cum.Store (feet) (sq-ft) (cubic-feet) (cubic-feet) 682.00 22,442 0 0 684.00 30,705 53,147 53,147 685.00 32,911 31,808 84,955 Device Routing Invert Outlet Devices #1 Primary 676.00' 36.0" Round Culvert L= 100.0' Ke=0.400 Inlet/Outlet Invert=676.00'/674.00' S=0.0200'/' Cc=0.900 n=0.013 #2 Device 1 682.00' 8.0"Vert.Orifice/Grate C=0.600 #3 Device 1 683.00' 48.0" Horiz.Riser C=0.600 Limited to weir flow at low heads #4 Primary 684.00' 6.0'long x 6.0'breadth Broad-Crested Rectangular Weir 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 4.00 4.50 5.00 5.50 Coef. (English) 2.37 2.51 2.70 2.68 2.68 2.67 2.65 2.65 2.65 2.65 2.66 2.66 2.67 2.69 2.72 2.76 2.83 erimary OutFlow Max=101.22 cfs @ 12.23 hrs HW=684.93' (Free Discharge) -1=Culvert (Passes 86.78 cfs of 99.40 cfs potential flow) 12=Orifice/Grate (Orifice Controls 2.71 cfs @ 7.76 fps) 3=Riser (Orifice Controls 84.07 cfs @ 6.69 fps) -4=Broad-Crested Rectangular Weir (Weir Controls 14.44 cfs @ 2.59 fps) Darken Residence Modified LD-268 Roadside and Median Ditch Design Form MIN MAX Earth Protective Lining DITCH C A CA Tc 110 Q10 -:1 _:1 SLOPE SLOPE ALLOW. n=.03 n=.05 n=.015 INCR ACC L R Ft/Ft Ft/Ft VEL. VEL.* Qn VEL* DEP Qn DEP SCC 1 0.3 0.26 0.08 0.08 9.6 5.70 0.44 2 2 0.10 0.14 3 0.02 2.58 0.28 SCC 2 0.3 1.83 0.55 0.55 18.0 4.40 2.42 2 2 0.07 0.09 3 0.12 3.46 0.58 SCC 3N 0.3 5.12 1.54 1.54 15.3 4.75 7.30 2 2 0.02 0.05 3 0.37 3.15 0.97 SCC 35 0.3 5.12 1.54 1.54 15.3 4.75 7.30 2 2 0.03 0.05 3 0.37 3.53 0.97 SCC 4W 0.3 24.28 7.28 7.28 18.2 4.37 31.83 2 2 0.02 0.10 3 1.59 5.46 1.50 SCC 4E 0.3 24.28 7.28 7.28 18.2 4.37 31.83 2 2 0.08 0.15 3 1.59 7.30 1.38 SCC 5 0.3 0.83 0.25 0.25 15.7 4.70 1.17 2 2 0.10 0.17 3 0.06 3.44 0.39 SCC 6 0.3 0.90 0.27 0.27 13.7 4.98 1.34 2 2 0.03 0.15 3 0.07 2.90 0.42 SCC 7 0.3 0.31 0.09 0.09 13.1 5.07 0.47 2 2 0.04 0.15 3 0.02 2.33 0.28 SCC 8 0.3 0.07 0.02 0.02 9.3 5.77 0.13 2 2 0.05 0.20 3 0.01 1.86 0.16 SCC 9 0.3 0.27 0.08 0.08 12.2 5.22 0.43 2 2 0.07 0.17 3 0.02 2.51 0.27 SCC 10 0.3 0.17 0.05 0.05 8.0 6.05 0.31 2 2 0.03 0.12 3 0.02 1.92 0.25 SCC 11 0.3 0.09 0.03 0.03 5.1 6.78 0.19 2 2 0.02 0.08 3 0.01 1.40 0.23 SCC 12 0.3 0.47 0.14 0.14 10.3 5.57 0.79 2 2 0.01 0.16 3 0.04 2.49 0.34 *Velocity calculations performed using average slope for this application 4/14/2015 Precipitation Frequency Data Server �,�. NOAA Atlas 14, Volume 2, Version 3 r,,,....,,,� gat Location name: Charlottesville, Virginia, US' if,. noeA N Latitude: 38.0510°, Longitude: -78.6265° 1,,alir ✓ Elevation: 677 ft` p '*ves - *source Google Maps "'ti,,,,,,�rf POINT PRECIPITATION FREQUENCY ESTIMATES G M Bonnin,D Martin,B Lin,T Parzybok,M.Yekta,and D Riley NOAA,National Weather Service,Silver Spnng,Maryland PF tabular I PF graphical I Maps & aerials PF tabular PDS-based point precipitation frequency estimates with 90% confidence intervals (in inches)1 Duration Average recurrence interval(years) 1 2 5 10 25 50 100 200 500 1000 5-min 0.345 0Al2 0.485 0.545 0.615 0.669 0.720 0.769 0.827 0.874 (0 311-0.382) (0 372-0 456) (0 437-0.536) (0 491-0 602) (0 551-0.678) (0.597-0 737) (0 638-0 794) (0 675-0.848) (0.718-0.916) (0 752-0 973) 10-min (0 0.658 0.776 0.872 1 0.981 1.07 1.15 1.22 1.31 1.38 (0 497-0.610) (0 595-0 729) (0 700-0 858) (0 786-0 963)1 (0 878-1.08) (0 950-1 17) (1 01-1.26) (1.07-1 34) (1 14-1.45) (1 18-1 53) 15-min 0.688 0.827 0.982 1.10 1.24 1.35 1.45 1.54 1.65 1.73 (0 621-0.762) (0 748-0 916) (0.886-1 08) (0 994-1 22) (1.11-1 37) (1 20-1 49) (1.28-1.59) (1 35-1 70) (1 43-1 82) (1 49-1 92) 30-min 0.943 1.14 1A0 1.60 1.84 2.03 2.22 2.39 2.62 2.80 (0 852-1 04) (1.03-1 27) (126-1.54) (1.44-1 77) (165-2.03) (1.81-2 24) (196-244) (2.10-2.64) (2.27-2.90) (2 41-3 12) 60{nin 1.18 1.43 1.79 2.08 2.45 2.75 3.05 3.36 3.76 4.08 (1 06-1 30) (1.30-1 59) (1 61-1 98) (1.88-2.30) (2 20-2 70) (2.46-3.03) (2 70-3 37) (2 95-3 71) (3 26-4.17) (3 51-4 55) 2-hr 1.41 1.71 2.15 2.52 3.01 3A1 3.83 4.26 4.86 5.36 (1 25-1 59) (1.51-1 94) (1 90-2 43) (2.23-2 85) (2 64-3 38) (2.98-3.84) (3 32-4 30) (3 67-4 79) (4 13-5 48) (4 50-6 07) 3-hr 1.54 1.87 2.35 2.75 3.29 I 3.73 4.20 4.68 5.34 5.91 (1 36-1 76) (1 65-2.13) (2 07-2 68) (2 42-3.13) (2 88-3 73) i (3 25-4 23) (3.62-4 75) (4 00-5 31) (4.51-6.08) (4 93-6 74) 6-hr 1.99 2.40 2.99 3.52 4.23 4.85 5.50 6.21 7.21 8.10 (1.77-2.24) (2 14-2 71) (2.65-3.37) (3 10-3 96) (3.71-4.76) (4 21-5 44) (4 74-6 18) (5 28-6 99) (6 04-8 14) (6.68-9.17) 12-hr 2.51 3.04 3.79 4A8 5.45 6.32 7.26 8.29 9.83 11.2 (2.23-2 87) (2 69-3 46) (3.35-4 32) (3 94-5 10) (4.76-6 19) (5 45-7 16) (6.18-8.23) (6 96-9 40) (8 07-11 2) (9 05-12 8) 24-hr l.I* 4.69 6.80 7.88 9.07 10A 12.3 14.0 (2.74-3.40) (3 31-4 11) (4 21-5.24) (4 96-6 17) (6.04-7.56) (8 96-8 73) (7 94-10.0) (8 99-11 5) (10 5-13 6) (11.8-15.5) 2-day 3.58 4.33 5.51 6A7 7.86 9.03 ! 10.3 11.7 13.7 15A (3.22-3.99) (3 91-4 84) (4 95-6.14) (5 80-7 20) (7 00-8.74) (7.98-10 0) i (9 03-11 4) (10.2-13 0) (11 7-15.3) (13.0-17.2) 3-day (3 4.61 5.86 6.87 8.35 9.58 10.9 12A 14.5 16.2 (3 46-4.23) (4 19-5 12) (5 31-6 49) (6.21-7 61) (7 50-9 23) (8.55-10.6) (9 67-12 1) (10.9-13.7) (12 6-16 0) (13.9-18.0) 4-day 4.04 4.89 6.21 7.28 8.83 10.1 11.5 13.0 15.2 17.1 (3 70-4 46) (4.47-5.40) (5 66-6 84) (6.63-8.01) (8 01-9 72) (9 13-11 1) (10.3-12.7) (11 6-14 3) (13 4-16 8) (14 8-18.9) 7-day 4.69 5.65 7.06 8.21 9.86 11.2 12.7 14.2 16.5 18A (4 30-5 13) (5.18-6.17) (6 46-7 71) (7 50-8.96) (8.96-10 8) (10 1-12 2) (11.4-13 8) (12 7-15 6) (14 5-18 1) (16 0-20 2) 10-day 5.32 6.39 7.88 9.08 10.8 12.1 ` 13.6 15.1 17.2 19.0 (4 90-5 77) (5 89-6.92) (7 26-8 53) (8 35-9.83) (9 85-11 7) (11 1-13.1) I (12.3-14 7) (13 6-16.4) (15 3-18 7) (16 8-20 7) 20-day 6.99 8.34 10.1 11 A 13.2 14.7 16.2 17.7 19.7 21.3 (6 54-7 51) (7 80-8.95) (9 40-10 8) (10 6-12.3) (12 3-14 2) (13 6-15.8) (14 9-17 4) (16 2-19 0) (17 9-21 3) (19 2-23 0) 30-day 8.58 10.2 12.0 13A 15.3 16.6 18.0 19.3 21.1 22A (8 07-9 15) (9 57-10.8) (11 3-12 8) (12 6-14.3) (14 3-16 3) (15 5-17.7) (16 8-19 2) (18 0-20 7) (19.5-22 6) (20.6-24.1) 45-day 10.7 12.7 14.8 16A 18A 19.9 21.3 22.7 24.5 25.8 (10.1-11.4) (11 9-13.4) (13.9-15 7) (15 4-17 3) (17.3-19 5) (18 7-21.1) (20 0-22 6) (21 2-24.2) (22 8-26.2) (23.9-27.6) 60-day 12.6 14.8 17.0 18.7 20.9 22A 23.9 25.3 27.1 28A (11 9-13 3) (14.0-15 6) (16 1-18.0) (17 7-19 8) (19.7-22 0) (21 1-23 7) (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 Too PF graphical http.//hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage html?lat=38.0510&Ion=-78.6265&data=depth&units=english&series=pds 1/4 4/14/2015 Precipitation Frequency Data Server PDS-based depth-duration-frequency (DDF) curves Latitude: 38.0510°, Longitude: -78.6265° 30 I 1 I 1 I I I I I 1 1 25 - . . .. ... .. ... - - . - . . --- ..... -- •- - 20 - - •.. ; ' - - Average recurrence n interval ai • . • •, (years) o 3 • , • . 2 10 - . _ 5 a — 10 • 5 - ; ... - — 25 — 50 _ _�.�' — 100 O raern — 200 C C C C C 6. 6. 6. 6 6. >, >.>. 7•. >, 7•. >, T T •� •� .E '� '.' .0 .0 t •C s to ro ro ro ro ro ro ro to — 500 p p N A 64 7 7 7 7 7 7 7 7 7 a' P n1 tD (Si N r: d o o d$ ry 1000 Duration 30 I i r r i • L- 20 -•-•- - • - - - . . . • ..- -- a cu c 15 - - • Y ro • N E a --- - O t —i — r r 1 r i 1 2 5 10 25 50 100 200 500 1000 Average recurrence interval (years) NOAA Atlas 14,Volume 2,Version 3 Created(GMT).Tue Apr 14 20:57:04 2015 Duration ___. 5-min — 2-day — 10-min — 3-day 15-mm — 4-day ----- 30-mrn — 7-day — 60-rnrn — 10-day — 2-hr — 20-day — 3-hr — 30-day — 6-hr — 45-day — 12-hr — 60-day — 24-hr http.//hdsc.nws.noaa gov/hdsc/pfds/pfdsj,rintpage html?lat=38.0510&lon=-78.6265&data=depth&units=englrsh&series=pds 2/4 4/14/2015 Precipitation Frequency Data Server Back to Top Maps & aerials Small scale terrain 1 ' -Morgantown T try 1 Hageostowrt r-———--—— W m 1 rr!! , `;: `' MBARYLAND , Parke g f �, > �i„` i o l - .i f, f )� Germantown. 'BBltlnlo_iiir i 0 o t ' Washington'ornna lis ,, ,,/ �fi t --Fir Manassas. I �1 A l r#ty.�"•� X/ k: �r 11 Pt oodbridge �. w E S I. .3,.;,, e ,Harrisonburg Staff ; ':�isbury VI.RG1NIA- 'p :v0/eit"0 7 S { fit% ' F r M • �,/� ChaIottesville "'i I )� , 7 e iVahonalr'3'" 0 h Al -' t Richmond ' j . 4- J Powhatano o ,‘,,,, - r1,f ite r' /, ., 1'' '('•6.1y F Snake' VIRGINIA r A r o Petersburg Blackstiurgr?` � _- , ' f. -1- ir N►� Halnpt. ' •r a{;' ? i o rrna:r•r Norfolk z .' .r-. .' Danville -., Sutfolko r 'l f f *_--ma tS- �, 50km Map Report thsp-euoifo Large scale��terrrain STON , i r ,�!1Ilk:,1 1 J. _r'1 • ' f ' BALLARD WOODS s' �k . t ,44,-- `!�� t`�� i.'CANDLEWYCK, t fi +. WEST LE164 I I http.//hdsc.nws.noaa.gov/hdsc/pfds/pfds_pnntpage.html?lat=38 0510&lon=-78.6265&data=depth&units=enghs h&series=pds 3/4 4/14/2015 Precipitation Frequency Data Server irj ;V A (C.�., 2km ��_// Map Report a map error Large scale ma ..� CMj• ' �WAVEALY v fJ SroNb ® ® ,fy 2 7. c i f i® —r BALLARDW000S ,CANDLEWYCK 240 •'i • f ! WEST LEIGH oilier 63T PEACOCK Hr4! 'lfi_) 2km Map Report a map error Lar.e scale aerial I • rfliti I • %„A 4 `� � ti . • .46 t�' .. • it C_;oosle 2km Imagery @ Report a map error Back to Top US Department of Commerce National Oceanic and Atmospheric Administration National Weather Service Office of Hvdroloaic Development 1325 East West Highway Silver Spring,MD 20910 Questions? HDSC.Questionsanoaa.gov Disclaimer http://hdsc.nws.noaa.gov/hdsc/pfds/pfds_printpage.html?lat=38.0510&Ion=-78.6265&data=depth&units=english&series=pds 4/4 Custom Soil Resource Report Map—Hydrologic Soil Group 6. , 707900 708000 708100 708200 708300 708400 708500 708600 708700 708800 i 38°3 10"N 38°3'10''N .. - '4.• .'' .,./., do..4".3,. •'.. ..' • 1`. •,•4(1 Jr. r4 / Ail 11141ir'i'.1;11111('1411C"?. '.iii Ilk. . 211. j'''''el;' &:7*- . 4 jit ' II.. -.•-41111111:- : I":114 ' '1'415.C.:<'10...k44:::*:Dr."' . ' . / 4 '..P, ^ - •., 4 . .>.'' 44. , ii, qt• • 4; ' - , • ':. •41, k '-:4' ' •1, ,. ,,,,'4:4,46'4 , .i... ... .* r ' A iiiti- -; , . .... ,i4.4 fit - ..4' .,.,- • .: •'._ *, .)..41111.-'3, '' -1,'si-,fi. .. -41 .:i. ,-...,„,... .•'-lk i 0.:F4b, a . § 4' .* it '. .ti 441";:;i:-.. ,_ ,i„,t. • ,i, .'4%.4.. ....1 ... .. '' • ry /.4- '41.1k ,oN,•,. '- .., 4- • ' , . . , 4 • - ... . ,-,',-,.. -• , ... . ,.. r ' * i itIP 4 ' ' -, ? ., ...,.. . ,... . - --,-- - _ , --, ,,- ..': ' 36B , 1 . ., . ,- • i ,.,i,.3 4„.. ; '.''• 0' 41.,) Int- ' '' , N V',.. -4-'4 I. el. •'I!". 4.0.... s' ' -. • - • se•' „.....---- -, 111111f • 1,:i• - 4 t .• • 6,43,,‘§ .. . . , - 0,„o 14 Jill '.- •1:- t, ' -- - f . t• :-,,Artjo, . ‘te. • , . A?.?,-. • ,,•-s, , e• .•••, • . ,4 --'4' r, 5 ej •, ,..r.:`,,,;:„.1, ,.1-A ... 37C3 . .".n,•, 1.7„ , • "'`k -4 ,'it, .:, ,,•) pi' >1.1,Sq r; .,,,;*;"' , r T .... , ,P,: e.,:'%.‘', • '; ‘,1 *. , . - .. ( a._,.,... ••,, c „!-,-.. .',,.. , • -i, 14,-,,,,•.,.„ ; ,...,-. ..e • • "-t ft- .. ,. ''' • 4 i.4 .i. i A 4 A;4 115.;.7 ' • 36C 37C3 '4 •!', Ji! ,' - -1.—., ' --• •i:,—.' . „ ... ,. ' • 4. §.-.,1,. •^ . ;.-../.. '1r • V. ";.'" -';',R'..1 16 34B 36B-" • ,-, • ' ' -I' „.t,'''....,,,, ".,....,. 2 a ,, r• ,„ , .ir • , i'," , ,,, •• •.4 iv • h..- ; 4•!'„, '. ‘.• -.”37D3 , r, •", f ; ) li' -...0. .. ... .. ..• 4g Ir , - ,,- ... • 4 16 _ ,r ri a-31 (jig &,vr .' .) Cl• rs, ,r an , . 132 Air t• .ri • % . ... ‘,. ______............_____ _ _. .. --.• _ 4 r,•-, - 36C E15@ i 4E \( / 114g 4116,4011116_,4 D : . ., „A• V# :t 'it. ''$ • A ; •..", .),, .1 ''', yl• ' 4 • Nvi. : . ‘4411.1°a). 56 B tv 1,'•-.1 i T-." . , fr A...•''. «it, ...;•.,•,. . tir 1,-...., .. tr . ,; '..." , .4- 2 .'4' i :1' f. "i' •'' `, " . • 1 11 - .• c'4.'tIr • 4.'• . • .. 02 • 4C r )4.4' on ,.. ir•e • i', "f` . '• 0, 'rt... ‘6''',0.. .."-. •‘.2r:.•,_. '::* .;.' 1'1 '''' ,,,,,. . , ,.., WI ,, _., . . ii.*:•.: . '''... ---) . IE 36C r•-, ....."• ..‘,...00. ..X,:lt''III• . 4D 8 ike'''- :- /-14..Itill, ..:' :. 4311 . •.,7.. .,...,. -, . 370-3 .ii, ; ;#,i'l°A .'f1/4' .' -, •:. 711 ' r•-, .Aog' Al '',„n.1i- cyoi eg Nu•'-,4.°'!.7.,,'- -j Tt' ,. • • :c• „,..!•,_.;'r, . :'": -•4-,,," siC' "'tf.if)l:3,.,,:' ' a ., • , § • 14D . ...4.•iir ,,,ritt- f.,,,,‘:1.;...,, EIC@ • . - , .' - " ''.-• xi 4-.?: ••••-i ,if" .. 't,'-' 'i''-;. .-.,-.P-7.;ike' _41F$,.1.,.,,Iti.: ).,• , , it„,:•••1.;,.. „wee •,,, , .• ,r,.i.4 1.)..)i-,9.1 )•..., rif I. . " %.7".. J'!,t. - -). .' • 1 -'4'.4.1.'4. ,* ; - ‘ 10'• .-,4 -• .*:.!A.,,,`.. ' - . 4J- --,r4 ,.),_ 4, c.' ' , .,.!.., ',- '...1 ,,.. i .1!).;_.,,,140/„.1,•---,ci...,,,,r, ., w .7, 4.,,,,,-1 • • • 'Al - .:, .. _44 --4,. ....• , .. 4--0_ ..., •• 4. _ Lan'14::0:11:4:11111111111•.N, 1 .01 •,..!... 4r%Ilk Ir l... 4. . - 41*iti-'4.**.'• . •4.: .n g rs, , , o . 0 ,s1 ...., • . r., .t 0 s 0 •. 1 - f•N ci- 41,••\ , !••• • ,-7 , . I ,, § Ilr • ••••• , -.' , • 4 ' V.• "' 4a. ogit..ewlt. . I\II 38°2 lb 38°216"N Ci-1 708000 708100 708200 708300 708400 708500 708600 708700 , 708900 r. Map Scale.1.4,590 if pnnted on B portrait(11"x 17')sheet , Meters k' N 0 50 100 200 300 Feet °Map projecbon2°°:Web Mercator Comer coordinates:WGS848°° Edge tics-LfTM Zone1127°°N WGS84 A 400 27 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 AOI 4C Ashe loam,7 to 15 B 5 4 4.2% percent slopes 4D Ashe loam, 15 to 25 B 20 8 16 2% percent slopes 4E Ashe loam,25 to 45 B 25 4 19.7% percent slopes 14D Chester loam, 15 to 25 B 25 4 19.8% percent slopes 34B Glenelg loam,2 to 7 B 1.7 1.3% percent slopes 36B Hayesville loam,2 to 7 B 7.3 5 7% percent slopes 36C Hayesville loam,7 to 15 B 23.5 18.3% percent slopes 36D Hayesville loam, 15 to 25 B 6.5 5.1% percent slopes 37C3 Hayesville clay loam,7 to B 8.6 6.7% 15 percent slopes, severely eroded 37D3 Hayesville clay loam, 15 B 2 0 1.6% to 25 percent slopes, severely eroded 56B Meadowville loam,2 to 7 A 1.8 1 4% percent slopes Totals for Area of Interest 128.5 100.0% Rating Options—Hydrologic Soil Group Aggregation Method: Dominant Condition Component Percent Cutoff: None Specified Tie-break Rule: Higher 29