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HomeMy WebLinkAboutWPO201700081 Plan - As-built 2021-09-30D_ D VEMP A S B SAAf u2FIZ Af,11z1z2FR D197p J(CT UAT=o VG,1iVL4l_ PROJECT SPONSOR BROOKDALE PARTNERS LP A T TN: MR. WILLIAM PARK 1821 AVON STREET, SUITE 200 CHARLOTTESVILLE, VIRGINIA 22902 PHONE: 434-979-2900 CHARLOTTESVILLE 1LyTFRSTgT� PLAN SHEET INDEX DATA S T E D 64 SHEET NO. DESCRIPTION SURVEY SOURCE: HAMRICK ENGINEERING, P.C., 540-248-7407 1 TITLE SHEET DATUM: NAVD 1988 �p 2 AS BUILT PLAN VIEW BENCHMARK: CHISELED SQUARE IN CURB AT N3890170.613 & Ell475999.85 ON TAX PARCEL 76-1205G, ELEVATION 500.272 TAX MAP -PARCEL GNTq\NwOpp o=d 3 AS BUILT TOPGRAPHIC SURVEY AND SITE GRADING AND DRAINAGE IMPERVIOUS COVER BREAKDOWN: LAND USE: SQ. FT. ACRES 76-46C1 Z 4 AS BUILT PUBLIC STORM SEWER PROFILES BUILDINGS: 37,769 0.87 CO(/NTRy J 5TH ST' 5 AS BUILT DRAINAGE AREA MAP GREEN RD. SIDEWALKS: 6,970 0.16 ASPHALT PARKING PAVING 74,923 1.72 TOTAL IMPERVIOUS AREA: 119,662 2.75 0' 1000, 2000' 3000' VICINITY MAP SCALE: 1" = 1,000' PROJECT LEGEND ABBREVIATIONS SYMBOLS 5 yy— PROPOSED WATER LINE W/ SIZE REFERENCE CC CG CENTER TO CENTER CURB & GUTTER . 8S— PROPOSE SEWERREFERENLINE W/ SIZE CENTERLINE IENGINEERING,P —may-- EXISTING WATER LINE W SIZE REFERENCE CMP CORRUGATED METAL PIPE CONC. CONCRETE STORMWATER MANAGEMENT FACILITIES CERTIFICATION --8-- EXISTING SEWER LINE DIP DUCTILE IRON PIPE W/ SIZE REFERENCE C IL DELTA - — _ - - EXISTING CONTOURS 1H ESMT EASEMENT Land PlQGb3lDlling * Public Works *Environmental 43 PROPOSED CONTOURS ELEV. ELEVATION PURSUANT TO 9VAC25-870-55 I HEREBY CERTIFY THAT TO THE BEST OF MY SANITARY MANHOLE EX. EXISTING ]Brasfl W. HiamTrkk, 1�EXISTING Jr., F.E. KNOWLEDGE AND BELIEF, THE STORMWATER MANAGEMENT FACILITIES SHOWN � PROPOSED SANITARY MANHOLE F.H. FIRE HYDRANT ON THESE RECORD DRAWINGS, HAVE BEEN CONSTRUCTED IN ACCORDANCE 156Laurel HMRoad WITH THE APPROVED PLANS AND SPECIFICATIONS.Route EXISTING DRAINAGE STRUCTURE GR GROUND SHOT 612 East INVERT Verona, VA �82 bwheng�-�®n� ¢ T PROPOSED DRAINAGE STRUCTURE L L LENGTH BRASIL W. HAMRICK, JR. --__—__—_—__ EXISTING STORM SEWER MH MANHOLE NAME SIGNATURE PROPOSED STORM SEWER N/F NOW OR FORMERLY - FENCE LINE O.C. ON CENTER 19318 AUGUST 25, 2021 R PROPERTY LINE VIRGINIA LICENSE DATE 03,3 UTILITY POLE PVMT. PAVEMENT GUY WIRE EP EDGE OF PAVEMENT "CERTIFY" MEANS TO STATE OR DECLARE A PROFESSIONAL OPINION BASED ON R RADIUS SUFFICIENT AND APPROPRIATE ONSITE INSPECTIONS, MATERIAL TESTS, AS —BUILT OVERHEAD UTILITY LINE RCP REINFORCED CONCRETE PIPE SURVEY DATA, AND INFORMATION PROVIDED BY OTHER PROFESSIONAL AND U-T UNDERGROUND TELEPHONE R.D. ROOF DRAIN THE CONTRACTOR, CONDUCTED DURING OR AFTER CONSTRUCTION. "G EXISTING POWER UNDERGROUND R/W RIGHT OF WAY SAN SANITARY ❑ TELEPHONE PEDESTAL WM WATER MAIN EG EXISTING GAS TBM TEMPORARY BENCH MARK F/C FACE OF CURB 6SL� W� SIZE REFERENCE POSED SEWER LATERAL T/C TOP OF CURB 2 3fS� yPROPOSED REFERENCETERAL SIZET/S T/P TOP OF PAVEMENT TOP OF SIDEWALK EXISTING FIRE HYDRANT T/G TOP OF GROUND PROPOSED FIRE HYDRANT W/ WITH C.O. SAN. SEW. CLEAN OUT EXISTING CURB & GUTTER IPF IRON PIN FOUND PROPOSED CURB & GUTTER IPS IRON PIN SET S/W SIDEWALK AL Ak REVERSE CURB & GUTTER NOTE: NOT ALL LEGEND ITEMS MAY APPEAR IN THESE PLANS NLT H off~ o G U� BRASI 1.. HMCK, Jr. LICENSE No. PLOT DATE.• 09125121 ✓OB No. 17-0192 SHEET 1 OF 5 W CURVE DATA (� lu /A• NO. R 0 ARC TAN CHORD 1,J Z 20 X15'ALBEMARLE COUNTY / I J SERVICE AUTHORITY Cl 525.00' 13'00 25" 119. 18' 59.85' S32'05'51 "W 1 18.93' WATER LINE EASEMENT C2 360.00' 20'43 21 " 130.20' 65.82' S3557'19 "W 129.49' DB.5278,P.49 (??) C3 400.00' 26'04'32" 182.04' 92.63' 55921'15"W 180.47' C4 260.00' 22'09'54" 100.58' 50.93' 583'2828"W 99.96' AD C5 590.00' 11'46'33 1 121.26' 60.84' N79'33'18"W 121.05' OUNROAD l �ST"gTE- ,007E C6 260. 00' 662547" '124. 64' 183.33' S84'3643 E 306.76' jug„ WAS INE T* — 777 C71 25.00' 1 90'00'00" 1 39.27' 1 25.00' 1 56'23'50'E 35.36' � 8 sq/=Y S (2) D8.5156, P.312 VARIABLE WIDTH VEPCO EASEMENT STORM INLET — " STORM SE 15' DRAINAGE EASEMENT (9) — DB.570, P.286 20' DRAINAGE EASEMENT (1) DB. 5047, P. 168 TO OLD LYNCHBURG RD_y (STATE ROUTE 760) ST❑RMWATER MANAGEMENT GE❑-C❑❑RDINATES LATITUDE 38,0069 N L❑NGITUDE 78.5226 W IPF IRON PIN FOUND IRON PIN SET UTILITY POLE AND GUY ANCHOR • MANHOLE AND SANITARY SEWER DROP INLET AND STORM SEWER FIRE HYDRANT. VALVE AND WATER LINE FSL FIRE SERVICE LINE FDC FIRE DEPARTMENT CONNECTION 2"WS 2" WATER SERVICE 6'SL SANITARY SEWER LATERAL UGE UNDERGROUND ELECTRIC LINES FACILITY z 0 n Fy U U) W • Ii A in P'l, U III CD z c� z W I I • 1 1 1 if Z a n JOB No. 17-0182 SCALE 1" = 40' DATE 03/10/2021 REVISION DATES: SHEET No. 2OF51 PLOT DATE: 08/25/21 I I II II °Il SOUTHERN RIDGE DRIVE / s � ;?� / / 2R illy EXISTING CULVERT 12" CMP I I� SPEED LIMIT INV IN = 519.99 II INV OUT = 518.57 SIGN, 30 MPH,/ 0 \ I I ° hryti ' I � AS -BUILT ELEVATION (TYP) I I I DETENTION CONTROL STR- NO8.76' SIN PARKING _ I I I SEE DETAIL THIS SHEET TOP ELEVATION = 462.01' 462.05' I 100YR WSE = 460.96' 20' EMERGENCY SPILLWAY I I ELEVATION = 460.51' 60.49' I o I v EXISTING 18" I I I N 1OYR WSE = 459.32 RCP STORM �u SEWER �. IN=517.16 INV I 2YR WSE = 457.57 IIN I I I I I 43 L.F. 30" IIIII I / r BOTTOM ELEV. = 450.00ADS N-12 04.0 ' I II IN I I I TRENCH III11 dl�1--- 4 IIIII I� I In I I Illhl I I II I I 1 CONSTRUCTED CUTOFF TRENCH W/ 1:1 SIDE SLOPES INV IN = 447.68 TO STR NO. 20 I0 ° TYPICAL EMBANKMENT SECTION N Il�uj I x NOT -TO -SCALE NOT TO SCALE DETAIL OF STORMWATER MANAGEMENT BASIN I N I II _-518 _ - III I I Z------- _ 516 EXISTING DI-3 514 - CURB INLET I I I\ /1 I I1 - �I�-512- ,/ 510 508 _ 1 C / \ EXISTING B1 3 p� I r e es CURB/INLET 9 1 / ST / e'er- ► / \ �8ae'Es ^ ) 8 / COTTAGE -�- I 9 /i I y°� o /'C GREEN WAY ilij ,' ' 1 I 8"W J \ N (RT. 879) II NVA I \\ eEW_ I / sa \ \ r N� T \ \ EXIST] G DI-3 ��i o� /� I i/ , -T-50] - CURB INLET o I�� M /I I I " MP II II :1) I I CVUgw BP EME I I�\ I I ;/ ONE STO HE1G E` 37 T G) ilk 493• / \ I S10 _ \J /\ O cC 7ti �0, A sgs' Lcs 49.51' _ E V-449.53 _ CL 30' ORIFICE INV=456.60 456.58' OO Gj h5 Dc 6ro 48" PYRAMID TRASH RACK 30.00" ORIFICE - OPENING INV. = 456.60' 56.58' 49.55' BOTTOM OF POND = 450.00' PLAN VIEW 5.0' 449.5 I , 6.00" ORIFICE OPENING INV. = 449.53' q P TF-ALL TnP FI FV = 459.51' 459.49' STD. MH BASE �30" OUTFALL PIPE INV. = 449.43' 449.40' CONTROL STRUCTURE (STR NO. 26) PRIVATE RUN CONFIRMED IN PLACE W/ MATERIAL & DIAMETER IN COMPLIANCE PUBLIC RUN CONFIRMED IN PLACE WITHIN EASEMENT MATERIAL & DIAMETER IN COMPLIANCE. SEE SHEET 4 PROFILE. PRIVATE RUN CONFIRMED IN PLACE W/ MATERIAL & DIAMETER IN COMPLIANCE PUBLIC RUN CONFIRMED IN PLACE WITHIN EASEMENT MATERIAL & DIAMETER IN COMPLIANCE. SEE SHEET 4 PROFILE. PRIVATE RUN CONFIRMED IN PLACE W/ MATERIAL & DIAMETER IN COMPLIANCE REVISED PER PLAN NOTES SEE SHEET 4 FOR PROFILE. STORM SEWER PIPES STR PIPE RUN DESCRIPTION FROM TO 1 2 197 L.F. 15" ADS N-12 0 2.97% 2 3 168 L.F. 15" ADS N-12 ® 1.46% 3 4 167 L.F. 15" ADS N-12 ® 2.33% 4 5 172 L.F. 15" ADS N-12 ® 2.38% 5 6 54 L.F. 15" ADS N-12 0 3.91% 6 7 47 L.F. 15" ADS N-12 ® 23.94% 8 9 5 L.F. 18" ADS N-12 0 5.00% 9 10 117 L.F. 18" ADS N-12 0 8.11% 10 11 79 L.F. 18" ADS N-12 0 7.65% 12 TEE 55 L.F. 15" ADS N-12 ® 0.50% 13 TEE 51 L.F. 15" ADS N-12 0 1.00% 14 4 57 L.F. 15" ADS N-12 ® 0.51% 15 5 57 L.F. 15" ADS N-12 0 1.30% 17 16 108 L.F. 15" ADS N-12 ® 2.00% 16 6 1 50 L.F. 15" ADS N-12 ® 2.00% EX. 18 81 L.F. 30" ADS N-12 0 11.27% 18 19 143 L.F. 30" ADS N-12 ® 7.83% 19 20 85 L.F. 30" ADS N-12 0 8.03% 20 21 49 L.F. 42" ADS N-12 0 1.29% 22 23 19 L.F. 15" ADS N-12 ® 1.00% 23 24 77 L.F. 15" ADS N-12 ® 1.00% 24 20 31 L.F. 15" ADS N-12 ® 2.50% STORM SEWER STRUCTURES STR INVERTS NO TYPE TOP IN OUT 1 C.F. CB-74 CURB GRATE N/A 497.09 503.85 2 C.F CB-74 CURB GRATE 491.24 489.45 495.16 3 C F CB-74 CURB GRATE 487.00 486.90 491.52 4 C F CB-74 CURB GRATE 483.01 FM 3 484.87 FM 14) 482.91 488.12 5 C.F. CB-74 CURB GRATE 478.81 FM 4 478.81 FM 1 478.71 482.73 6 C F CB-74 CURB GRATE 476.60 FM 5) 470.29 FM 16 461.25 480.52 7 ES-2 N/A 450.00 N/A 8 DI-7 N/A 504.21 507.25 9 C.F. CB-74 CURB GRATE 503.96 501.80 508.59 10 MH-1 492.31(6" RD) 492. 1 492.21 500.50 11 ES-2 N/A 486.17 N/A 12 C F CB-74 CURB GRATE N/A 496.72 499.20 13 C.F. CB-74 CURB GRATE N/A 489.33 492.97 14 C.F. CB-74 CURB GRATE N A / 485.16 487.50 15 CURBCGRATE N/A 479.55 483.47 16 C.F. CB-74 CURB GRATE 471.39 471.29 478.13 17 CURBCGRATE N/A 473.55 477.47 18 DI-7 465.91 465.81 469.25 19 MH-1 454.61 454.51 465.00 DI-7 4471620 8 8 FM 19 4476FM 26 447.58 457.25 21 MH-1 446.95(FM 20) 446.85 457.50 22 C F CB-74 CURB GRATE 453.19(6" RD) 453.04 456.29 23 CURBCGRATE 452.85 452.75 457.02 24 MH-1 451.98 450.75 463.00 26 STORMWATER BASIN CONTROL STR.(SEE SHEET 9 & 20) of �.% 4" \ \ sSC 0000 \ \\ � \ ADO o ' G�% . `\9�T�q�ti`\ o �\ / \ m \ \\ \ \ M. I I I II I V \I I / \ i n 498 4J�\ I I\ �� m �G '/ \\ Z \\ \ o Lfl� I T io z i �i� \` \\ (J1 \\\ yL--� \ e `\ I I I \\ oG \ o s \\\ RIP RAP OUTLET II Z \ I oo n �1 I / \ \ r 1 1 EXISTING STORM INLET \mom / I I I I p c' TOP = 488.24 INV OUT - N EXISTING 12" °__ 1 Uo 1 \ { n \\ \\\\\ I I \ \ \ kan \ RCP CULVERT II / I I I a I I I 1 T Z ST / /\ - 503.40 / I I I ° I\ 2 \ c \ w INV IN= 517.30 l - O \ \ / ➢ 0 INV OUT= w I\ / -1 ° s \\ 0 1. A 0a I �� 1 \ g \ / �0 11/�\\ \ o\ �1�,� 1 n mVi 10 \\ �1 �\ 13 \ y N ?� 03 oR e \ Z o 11' J ♦ �s seos° \\ \ 6/ �) I I I I 1 I s 1 1 o cn 11 � ♦ I \ � \ \ -I T As94ya /o o � \ N1 1 ER 8 l B pUMPs/ /� p � J v� \ \ GAO G� �0. 498 _ a -� \ - ,� 1 1 \\ 1 1 1 1 1 11 o w` \ ♦ I - ti / . vo 0 \ -�/ice 7 z,)/• EXISTING 12 I \ \ \ I I N 11 / \ \ \ \ G O �Gi 2S \ \ - - 472 CMP CULVERT III I I 1 1 I 1 \ - 496 _T�-i / - - �C } /\ s INV IN= 500.96 1 / 1 1 I , T _ /_ - - - o INV OUT= l \\� 49 _ �� ice/ �l �� � \ 478 , ♦ \ -. (� / 492 4a0 �1 S3 \ - = > 14 \ \ \ I o ���\� ova A ,r -o / Rood RONT�T FGpSBCr/C�Ry 28 ona C CLFC ° F�ch /Tgos2 0 o*Ln A9 T o T \ 3seo/Cu1410 490.0 \\ \ \ �2A \\ \\ \r AR 2 \ \ 1b4�9.26 \ \\l rn \ \ \ ^ \ EXISTING r\ \ 4ll \ \\ UTILITY o \ \ � j C \ POLE \ \ \ �76 \1�j \ \ \ \ \ / \ <Q C \ \ J \ y� G,p G) �O 4 9 F` �O GJ, Co/ �A V/ \ 18" NYLO-PLAST AREA DRAIN W/ TOP = 465.25 & INV TO FIT EXISTING LINE Z O w U (n w 0 O z w w fs r- 4 q, in 13 rm r g U R as a`a in W Q JU 0 Jim: Q C) 0 p L z W O 470 ( C 400 - 0 J ,� 468 _j I.I_I � I ti O QQC �� 462.51 I CC L L 466 ■ Q W M W - 464 Q 1 1 1 462ST _ 460 J, a ® - 4\ 55 C\ \\ \ ,/' / //\X�� \ 1► I e�� 11 / JOB No. 17-0182 Il \ �. UNIT APT gU1LDIN ❑ -� J //6' / INv= g�ILD1NG 300 ,.� ♦ II I 458 486.71 s1oRY, 2$ _ / ////// / / ��/ ��k/ �����\\\\�\\\ • SCALE 1" _ N7 : 35 30' 3/4 _SPLIT UILDING HEIG 36 / FRONT 8 EL > 490. 1 / sTR \ \ \ \ / I �� DATE 03 10 2021 147.01 1Nv _ /i�/ �� / �� �11� ohs 7 S6 i - RpOM / - FIRE SPRINKLER ER EL = 480.61 1472.50/ / / / / / gp51NCV�t1 460 III o I ( Jam_ _\ I ■■ ' I 1 _+ REVISION DATES: _ -- _ - 1- -„ g INV OUT=445.72 ` 450 \\ SEWTU ER 4I I s �r-I-1I EXISTING INLE T TOP=454.32INV 6RO 478.61 THROAT INV=45 2.64 60 INV N=446.02FNNV OUT=445.92477-462D �6 WIDE DV4T 10UBLE - SWING GATE \ STR 1 ��-�7� _ -- ------ --- INV=455.50-�` �� \ ` C 470 - - C6] - _ �� �- STORMWATER MANAGEMENT FACIDTr €ASEMENT - - \ - 462 \s I I 464 \ \\o \ \ INV=465.50 \ ` 47 468 466 \ \ 1 I II EXI-STI-NG -UT-ILI-P LINE _OLES^ \\ 4 EXISTING RHEAD UTILITY �-O'I IrB° UTILITY POLE �� \ �' __7 II \1 I m o II I s \ Ln I O II Z 35 L.F. 15" ADS N-12 STORM SEWER FROM STR 24 TO STR 20 ® 2.00%. RUN FROM STR 24 TO STR 25 PLUGED. I I INV OUT AT STR 24 = 450.75 I J I INV IN AT STR 20 = 450.05 I o I I o I 1 I 1 I UTILITY POLE SHEET No. 3OF5 PLOT DATE: 08/25/21 1A 00 O 520 520 550 550 Z O 510 510 540 540 tY C) (n Ld 500 500 530 530 CN 490 490 520 520 Ln O Z W 480 480 510 510 Ld W > > vl� Q 470 470 500 500 ~a 460 460 490490 0� CD �? 450 450 480 480 Ll W z� of z� 440 440 470 470 W b0 Ed •� � � N 430 430 460 460 a in 420 420 450 450 1+00 1+50 2+00 2+50 1+00 1+50 2+00 2+50 3+00 3+50 STORM SEWER PROFILE STORM SEWER PROFILE STRUCTURES NO. 22 THRU 20 STRUCTURES NO. 8 THRU 11 w SCALE: HORIZONTAL: 1 "-30', VERTICAL: 1 "=10' SCALE: HORIZONTAL: 1 "=30', VERTICAL: 1 "=10' J U� O J � m a- W W m � U 520 520 Q O r� VJ 510 510 500LO 500 W z LO U C� Q490 490 z 4809 480 J O toJ J W 470 470 0 CQ L `Q^ I..I m vJ 460 460 W a 450 450------------ 440 440 JOB No. 17-0182 SCALE 1" = 30' DATE 03/10/2021 430 430 REVISION DATES: 420 420 1+00 1+50 2+00 2+50 3+00 3+50 4+00 4+50 5+00 5+50 6+00 STORM SEWER PROFILE STRUCTURES NO.18 THRU 21 SCALE: HORIZONTAL: 1 "=30', VERTICAL: 1 "=10' SHEET No. 4 OF 5 PLOT DATE: 08/25/2021 (TYP) STR 24 STR 23 STR 22 STIR 0 M O N � N r pp r Orn0 O � ll) rn O� O r � � � O n�� N Ma II in r � � +III � �NZ +II �n `! � rna a tea» II�O �zz �a> u � � �z µ O Z � r W Z_ O O N O In O�� � NZ � j + II j µ NZp � �zz PROPOSED GRADE 7 0% LF 15" ADS N-12 ® 1. 35 LF N-12 1 ®2.00% HG (TYP) 19 L 15" ADS N-1 ® 1.00% w z O Z J Q w z_ a 3 rn � o, U i0 CST 11 e STR 8 S R 9 z ESE � � w voi o rn ' 0o � � rno� O �p� in o t 11 I cm, I ONODMZrrn Z U �NZ u0'1 N o a o z oa OHO O� � OMMN N N� W J Q N ^� Oil O� ��ll Z p wa � r+� voi'io +j + II II O�> N IIO 1p II�� w 3- � Nz I a> � <» > wv~i? � Nzzz ao PROPOSED GRADE EXISTING GRADE 5 LF 18" ADS N-12 ®5.00% ADS N- „� �651- 7� 1J LF ,8 ADS N,1 HGL j9 EX STR EX STR e CR e 0 STR 19 o iri 0 0 m � 'i o � � a N � ro II O � ro a > EXISTING GRADE o_ � _ z � o � � O O v'�a > N � Ma II t II j �ZZ rn NOS � Nrn � O r M a0�� � M � + II ] � j arnOQ I + II ^ � I � � II zp z � II � � u o PROPOSED GRADE vi » msr> sa > � �cn?? rn�rn? �v~i z RC +� " EX• y9 o z a > ? a 0 EXTEND NEW 22 LF 30" ADS v~i N-12 ® 11.27% w ®7 83 � , 30 N_12 g.03% HGL (TYP) �� g5 � �EN�T EX. 66 LF 4 "RCP ® 1.26% 49 LF 2" ADS N-12 ® 1.29% \ HIN N�MINA `EX. 16 LF 42" RCP ® 1.25% W I HS ALLZ 0 O W Z �S¢GZI.IIA z N z U NN a ��000 O Virginia Runoff Reduction Method Workshest DEQ Virginia Runoff Reduction Method New Development Compliance Spreadsheet - Version 3.0 BMP Design specifications List: 2013 Draft Stds 8, Specs Site Summary Total Rainfall = 43 inches Site Land Cover Summary Site Tv and Land Cover Nutrient Loads Z Totat TP Load Reduction Required (lb/yr) 5.31 O Site Compliance Summary W_ U Cn W Summary Prim � Z w w Q 0 � ac Virginia Runoff Reduction Method Worksheet ( l h p Virginia Runoff Reduction Method Worksheet Virginia Runoff Reduction Method Worksheet N o> CD Drainage Area A Summary Land Cover Summary w O U z Runoff Volume and CN Calculations z � x Drainage Area Summary 5.76 1-yearstorm 2-year storm 10.year storm a Target Rainfall Event (in) 3.05 3.69 5.58 e ti BMP Selections t � -0 LJ Y N ti W d (� N Fri � Drainage Area Compliance Summary i; lI Z o a> Q W < Z W � r_1 Summary Prim Summary Print Summary Prim Q z O Z I- W 0 CO W Wg OFFSITE 8.64 ACRES OFFSITE � � � Z 2.42 ACRES ( _ --- m ter= \� 't \� ,I F- >- e 4 \ �� `� I / - .eo A \ r^ d� I z OFFSITE l��a , \ ( I /' / - IAND/ORW � 4.40 ACRES '` $ ( j \ \ i J O I PS = PRINCIPAL SPILLWAY _J U \� I W �' STORMWATER BASIN I O J W i ryC \ j b / Hydrograph Summary Report papa t m +Z _ �� / - goo Q'Snyc a eui�/ / l/ / �sr /, / ,z� / 7� / ° \ \\ \! �/ / / y� b Ar�' ' JOB No. 17-0182 gCRFS ® , / / / --+a SCALE 1" = 60' d A \ \ I +� �/ `y _ i�, / ,' '/ DATE 03/10/2021 REVISION DATES: p71 -ago 2.98 ACRES 402 ■oar '°• pper�/ \ � \' \ � � - _ _ .e. \ \ \ \ \ ®, PRE -DEVELOPED TC PATH r \ _ - - / POST -DEVELOPED TC PATH \ \ \ \ sag �y --- - SHEET No. SOPS PLOT DATE: 08/25/21 Time of ConceMratlon Misting Conditions Flooding STORMWATER MANAGEMENT CALCULATIONS 65 LF sheet flow over woods &grass at C.0.20 w/ 4.62%slope, TC=13.25 min 1180 LF ditch flow w/ H=63.15', TC�.O min DESIGN NARRATIVE Pro/ect Location, Description &Justification Hydrographs 13, 14 and 15 represent the off -site runoff for the2, 10 and 100-year, 24 Drainage Area Total TC=13.25+ 6.0 = 19.25 min (use 19.0 min) hour storm events. Hydrographs 16, 17 and 18 combine hydrographs 9, 10 and 11 with Total on -site area = 5.76 acres Proposed Condition to Detention Pond The subject property is located between the south side of Country Green Road and the 13, 14, and 15 to establish the total 2, 10 and 100-year runoff directed to the stormwater facility. Hydrographs 19, 20 and 21 routes the total 2, 10 and 100-year Total on -site area to detention basin = 5.00 acres north side of Mountainwood Road. Access to the property is via Country Green Road events through the basin determining the basin size and ouffall structures are Total on -site area released uncontrolled = 0.76 acres 22 LF sheet flow over grass at C=0.20 w/ 12.50%slope, TC.6.80 min 209 LF pipe flow w/ H=18.0a', TC = 1.25 min x 0.20 = 0.25 min and Mountainwood Road. The total acreage of the project is 5.756 acres. The property is bound by a planned residential development to the west side and a vacant residential adequately sized to control the flooding hydrographs within the basin and that all down p�/p/tat/on Data for 24-hour Storms 857 LF ditch flow w/ H=36.7a', TC = 4.so min property on the east side. stream drainage components are adequate to pass the flooding events. The release rate for the 2, 10, and 100-year post developed events are less than the historical pee Total TC = 6.80 + 0.25 +4.90 =11.95 min (use 12.0 min) The proposed site development consists of 96 apartment units contained within four development rates. 1 year = 3.05 inches 2year = 3.69 inches Proposed Condition for uncontrolled Area buildings. The developed site also includes a community building, along with all of the Quality 10yr = 5.58 inches LF flow TC-7.8o associated parking and utilities. To facilitate the project, Albemarle County issued a 100year = 9.16 inches t 5 sheet over grass at C-o.20 w/ a.00%slope, min zoning certification for 96 units on September 26, 2017. 3a5 LF pipe flow w/ H=t 7.16', TC = 2.2o min x o.20 = o.aa min Offsite nutrient credits will be purchased to satisfy the 5.11 pounds of phosphorus per Natural Resources and Existing Conditions year that must be removed from the development. Soil Hydrologic Groug Total TC = 7.80 + 0.44 = 8.24 min (use 8.0 min) DA A DAB DA C D.A. D DA E Total Forest/Open (acres) O.lx) 0.00 0.110 O.lx) 0.00 O.lx) Managed Turf (acres) 3.01 0.00 0.00 0.00 0.00 3.01 Impervious Cover (saes) 2.75 0.00 0.00 0.00 0.00 2.75 Total Area (acres) 5.78 0.00 0.00 0.00 D.A. A DAB DAL D.A. D DA E Total TP Load Reduced (Ib/yr) 0.00 0.00 O.lx) D.00 0.00 0.00 TN load Reduced (Ib/yr) 0.00 0.00 0.00 0.00 0.00 0.00 A Soils B50115 CSoils DSolls Total %of Total Forest/Open (acres( 0.00 0.00 0.00 D.00 0.00 0 Managed Turf (acres) 0.00 0.00 3.01 0.00 3.01 52 Impervious Cover (acres) 0.00 0.00 2.75 0.00 2.75 48 Managed Turf Impervious Cover TP Load from Total Impervious Cover Treated (acres) 0.00 Total Turf Area Treated (acres) 0.00 Total TP Load Reduction Achieved in D.A. 0 00 (Ib/yr) Total TN Load Reduction Achieved in D.A. 0 00 (Ib/yr) A soils BSoils CSoils DSolls Totals %Of Total Forest/Open (acres) 0.00 0.00 0.00 0.00 0.00 0 Managed Turf (acres) 0.00 0.00 3.01 0.00 3.01 52 Impervious Cover (acres) 0.00 0.00 1.75 0.00 2.75 48 5.76 300 She Rv 0.57 Treatment Volume 11,887 TP Load (lb/Yr) 7.47 TN Load (lb/Yr) 53.43 Total Runoff Volume Reduction (fts) 0 Total TP Load Reduction Achieved (Ib/yr) 0.00 Total TN Load Reduction Achieved (Ib/yr) 0.00 Remaining Post Development TP Load 7 47 (Ib/yr) Remaining TP Load Reduction (Ib/yr) 5.11 Required Drainage Areas RVaCN Drainage AreaA Dralnaga AreaB Dnlinaga AreaC Drainage AreaD Drainage AreaE CN 85 0 0 0 0 RR (ks) D 0 0 0 0 1-year return period PV w°RR (ws-in) 1.63 0.00 0.00 0.00 0.00 RVwRR (ws-In) 1.63 0.00 0.00 0.00 0.00 a adjusted as a o 0 0 2-year return period RV wo RR (ws-in) 2.18 0.00 0.00 0.00 O.oO RVwRR IwYIn) 2.18 0.00 0.00 0.00 0.00 CN adjusted 85 0 0 0 0 10-year return period RV wo RR (ws-In) 3.91 0.00 0.00 0.00 0.00 RVwRR (ws-in) 3.91 0.00 0.00 0.00 0.00 CN adjusted 85 0 0 0 0 SWM BASIN OPERATION AND MAINTENANCE PLAN MAINTENANCE TASK FREQUENCY GENERAL INSPECTION AND DEBRIS CLEANUP ANNUAL OR AS NEEDED CLEANOUT SEDIMENT ONCE EVERY 3 TO 5 YEARS REMOVE DEBRIS, BLOCKAGES &OBSTRUCTIONS FROM PS INFLOWS AS NEEDED REMOVE DEBRIS BLOCKAGES &OBSTRUCTIONS FROM PS OUTFLOWS AS NEEDED MOW EMBANKMENT GRASS, PERIMETER TURF &EMERGENCY SPILLWAY AT LEAST 4 TIMES PER YEAR REMOVE AND REPLANT DEAD LANDSCAPE MATERIAL, THIN AQUATIC OR EMERGENT VEGETATION ANNUAL OR AS NEEDED RESEED REPAIR CONTRIBUTING DRAINAGE AREA, POND BOTTOM & POND SLOPE TURF AREAS TO PREVENT EROSION AS NEEDED CLEAR DISCHARGE CHANNEL OF BRUSH OR WEEDS ANNUAL OR AS NEEDED Hyd. No. Ffydrogreph type (origin) Peak flow (efa) Time interval (min) Time to peYt (min) Volume (etdt) Radzm period (yre) Inflow hyd(a) Maximum slavatlon (it) Na:lmum storage (Dull) Nydrogreph description 1 SCS Runoff 27.8 6 726 112,706 2 --- -- --- 2-yr conslmcl'wn 2 SCS Runoff 82.0 8 726 255,873 25 --- -- --- 25-yr construction 3 Reservoir 25.9 8 732 112,705 2 1 480.15 57,687 2-yr construction 4 Reservoir 81.4 8 792 255,872 25 2 480.64 82,588 25-yr construction 5 SCS Runoff 4.8 6 728 18,428 1 --- -- --- 1yr Pre 8 SCS Runoff 7.4 8 726 24,444 2 --- -- --- 2yr Pre 7 SCS Runoff 18.7 8 720 52,013 10 --- -- --- 1 Dyr Pre 8 SCS Runoff 11.5 1 721 29,048 1 --- -- --- 1yr Post 9 SCS Runoff 12.1 8 720 97,141 2 --- -- --- 2yr Past 10 SCS Runoff 21.5 8 720 88,483 10 --- -- --- 1 Dyr Post 11 SCS Runoff 99.4 8 720 124,842 100 --- -- --- 100yr Post 12 Rese