Loading...
HomeMy WebLinkAboutWPO202000034 Plan - As-built 2022-07-01D 9VAC25-870-6& WATER QUALITY DESIGN CRITERIA REQUIREMENTS. 1. NEW DEVELOPMENT, THE TOTAL PHOSPHORUS LOAD OF NEW DEVELOPMENT PROJECTS SHALL NOT EXCEED 0.41 POUNDS PER ACRE PER YEAR, AS CALCULATED PURSUANT TO 9VAC25-870-65. CALCULATIONS SHOWN ON THIS PLAN WERE DETERMINED FROM ACCEPTABLE METHODOLOGY "DEQ VRRM FROM NEW DEVELOPMENT COMPLIANCE SPREADSHEET —VERSION 3.0.0 CONCLUSION: BASED ON NEW DEVELOPMENT OF BELVEDERE PHASE 5 (A AND B), TMP 62-16D, SHOWN HEREON THESE PLANS, THE WATER QUALITY PORTIONS OF THIS PLAN WILL BE SATISFIED WITH PURCHASING 9.68 IB/YR OF OFFSITE NUTRIENT CREDITS IN THE SAME OF ADJACENT HYDROLOGIC UNIT CODE (02080204). COMPLIANCE OF 9VAC25-870-65.F: OFFSITE ALTERNATIVE IAW 9VAC25-870-69 PURCHASE OF NUTRIENT OFFSET CREDITS IS PROPOSED AND AFFIRMED. HLt=AiiLhN(.� VVA I Lij QUANITY" ANALYSIS FOR FIN'T OF DISCHARGE #1: COMPLIANCE OF 9VAC25-870, 13.1.13_(CHANNEL PROTECTIONNNN�, POINT OF ANALYSIS 2: 1YR QDEVELOPED S I.F.• (1YR QPRE—DEVELOPED * RVPRE—DEVELOPED)/RVDEVELOPED 0.772 S 0.80* (1.597 * 0.515)/ 0.680 2 0.772 S 0.97 ch J. POINT OF ANALYSIS 2: 010POST—DEVELOPED S %OPRE—DEVELOPED &31 cb S 7.63 de 0111111 1 I m u1111111 IIII I ulll I,I III IIII', Inonaou!uun!an II I nuennlla:;pl II III Inuonnl!u!au!n I I Ilumuullluulonulul II a Illlpullnlll;ll Imanvonuuum' Vlllll4gl lu!uumaol:ul'I IIIII IIIp IIII IIIII III IIIIII I III! III: IIIII ' ICI' ilI IIIIIIIIII I I'I'Ili IIII ! III I III II II ;III uql rI illlllll IIII II,I, lull p �. I �glll I III I,IIIIII II I II!IIIIIIIIIIIII I �. IIII III IIIIIIIIIIIIIIIIII"II!' I I 'III � �'I ' ; � I I I 41111111111111II IIII IIII IIII III IIIII IIII IIIIIIIIIIIIIIIIIIIIIIII ! III IIII IIIII IIIIII N I I I IIIIIIII!IIIIIIIIIIIIII IIII IIIIIII IIlll,lll lfllllll' I;pIII II!IIIIIIII, IIII IIII V¢ullWnrllulllll IIIIII IIII I! J!II IIIIII III IIIIIII III. tl11111IIII1111111111I1A1 III iI I un!numull IIII IIIII I Iluln!mrloll I IIII I ,dll ,dill dllllnuunluuurmll III I ua!ue IIn1101 IIIII,. IIIIIIIIIIIIIIIIII IIIIIIIIIIIIilllllllllllll I I' IIIIIIIIIIIIIIIIIIIIIIIIII Illllllllllliilgl IIIIIIIIIIIIIIIIIIIIIIIIII IIIIIIIIIIIIIIIIIII IIIIIIIIIIIIIIIIillillllll IIIIIIIIIIIIIpIII IIIIIpIpIIIIllllllll IIIIIIIIIIIIIIIIIIIIUIIII IIIIIIIIIgII111111 ' ' III �) �� Ip IIuII I �I�I) III �I DII �...... I ,III IIIVII IIIIIIIIIIIIIIIIIIIIII Illlllllllllllllllllllu I I � ( IIIIIIIIIIIIIIIIIIIIIIII I IIIIIIIIIIIIIIIIIIIIIIP IIIIIIIIIIIIIIIIIII I Ilplllllllllllllllllpl IIIIIIIIIIIIIIIIIII) I IIIIIIIIIIIIIIIIIIIIIII .) IIIIIIIIIIIilllllllll IlpUpppppl4lpll ill Ilpllllllllllllll II I) II I) I I � IIIIIIIIIIIIIIIII II it ( I I IIIIIIIIII-I III illlllllllllllllllllllllll IIIIIIIIIIIIIIIIIIIIII IIIIII) IIIIIIIIIIIIIIIIIIIIIIIIII IIIIIIIIIIIIIIIIIIIIIIII IIIIIIIIIIIIIIIIIIIIIIIIII I I) IIII. Ililllllllllllllllllllllll IIII IIIIII IIIIIIIIIIIIIItIIIIIIIIIIIIII I IIIII IIIIIIIIIIIIIIIIII III Iluuullnuuulluou WPO 0 0 00034 TM P 62 PARCEL 16D RIO MAGISTERIAL DISTRICT, COUNTY OF ALBEMARLE, VA L EXISTING INTERMEDIATE CONTOUR EXISTING INDEX CONTOUR PROPOSED CONTOUR EXISTING EDGE OF PAVEMENT PROPOSED EDGE OF PAVEMENT EXISTING CURB AND GUTTER PROPOSED CURB AND GUTTER TRANSITION FROM CG-6 ROLL-TOP EXISTING STORM SEWER VICINITY MAP SCALE: 1 "=1000 FEET LEGEND 20 _-- EX. EP— EP EX. C&G CG-6 CG-6 ROLL-TOP EX. 15" RCP 15" RCP PROPOSED STORM SEWER EXISTING SANITARY SEWER — S — S — S — PROPOSED SANITARY SEWER PROPERTY LINE EASEMENT LINE --- CENTERLINE — LIMITS OF CLEARING AND/OR GRADING EXISTING SPOT ELEVATION PROPOSED SPOT ELEVATION +12.0 EXISTING TREE DRIP LINE EXISTING TREE PROPOSED TREE OAK EXISTING WATERLINE PROPOSED WATERLINE EXISTING FIRE HYDRANT PROPOSED FIRE HYDRANT EXISTING WATER VALVE PROPOSED WATER VALVE PROPOSED WATER METER EXISTING REDUCER PROPOSED REDUCER HANDICAP RAMP (CG-12) DENOTES LOCATION OF STD. VOOT CG-12 AND/OR JURISDICTIONAL STANDARD RAMP CONSTRUCTION PARKING INDICATOR INDICATES THE NUMBER OF TYPICAL PARKING SPACES BENCHMARK SOILS BOUNDARY VEHICLES PER DAY COUNT PROPOSED STREET NAME SIGN EXISTING SIGN PROPOSED SIGN SANITARY MANHOLE IDENTIFIER w w --� w w Q STORM DRAIN STRUCTURE IDENTIFIER —w 10 w U 1,234 VPD T 12 18 ASSOCIATED PLANS WITH THIS PARCEL: 1. FINAL SITE PLAN SDP-2020-00036 2. ROAD & UTILITY PLAN SUB-2019-00170 3. EASEMENT PLAT SUB-2020-00123 4. RETAINING WALL DESIGN PLANS SHEET INDEX 2 BFEET 1 CONB181$T ,;UALITY CALCULATIONS ATIONS & COW �OMPUANCR `ERSION 2 SHEET 18 --- c�y�cr p�qN 0 VSMP AMENDMENT 02 NARRATIVE THE PURPOSE OF THIS AMENDMENT IS TO SHOW THAT THE PRIVATE STORSEWER PIPES FOR LOTS 245-254 ARE NO LONGER DRAINING TO THE RETENTION BASIN AS SHOWN ON SHEET 3 OF VSMP AMENDMENT #3 OF BELVEDERE PHASE IIB (WPO201600071). THE REAR OF THESE LOTS NOW DRAIN TO THE FIRE ROAD DRY POND AS SHOWN ON SHEET 18 OF THIS VSMP SUBMITTAL CHANGES TO THE OUTLET STRUCTURE ENSURE THAT THE REGULATED STORMS ARE BELOW THE APPROVED, POST —DEVELOPED FLOWS. PER CONVERSATION WITH COUNTY ENGINEER 6/7/22 0.18 LBS/YR OF NUTRIENT CREDITS WILL BE USED TO OFFSET THE PHOSPHOROUS REMOVAL THAT WOULD HAVE BEEN GENERATED FROM THE DRAINAGE GOING TO THE RETENTION POND. i twajed /l{>n+e I BELV'®ENE PHASE S DatC 16 WI= � YMMtWI1R,INIMi�". YMPDemon spcokatkms1w. Z0130raftSt&&5wS Site Information Post -Development Project (TreatmentVolume and Loads) Land cmu t"esi [aslta is amff [oamenu liar) Post -Development ,P Lea a�el�, i�d� t�yrt u>8 A Sons B Soig C SoOs D Sots lotat Psxs�torct/'0W1 sWoc orrdarstsd W � Mr�atadm�auesl +zuroca.,xaaaator Aft afallei9tNlso Ec " trona� Q2a 0� Ir+oen+ols cara+,aa*sl 030 a.w 030 43 A s.r. a Seib c Soft D x,s 0 PF SHEET NUMBERING KEY ,,,Al2,71Nm -INDICATES ORIGINAL SHEETN0.'cATEs AMENDMENT N0. T AMENDMENT co LD j LLj LLJ > cr cl D 7/4 '/20'22 d O w CO o ZC�JN O �►/� Z � Q JQ � 0 Q CO QWUZma W=w pg o �Q Q� — D:\RGA\TMPROJ\0438-BELVEDERE\ADAMS PHASE S\BdiB-BELVEDERE-PHASE 5-VSMP Awn.6A0/2022 11:SL41 AM. Auin('Ap POF lSmalixt Filnlnr3 _ - PO 210 7-O 000 MODIFIED SEDIMENT TRAP DESIGN TOTAL REQUIRED BASIN STORAGE =134CY X 3.04 AC = 407 CY TOTAL AVAILABLE BASIN STORAGE= 4,040 CY WET STORAGE REQUIRED HALF OF TOTAL STORAGE MINIMUM 67 CY X 3.04 AC - 204 CY SET WET STORAGE AT ELEVATION 432.5 WHICH CORRESPONDS TO THE TOP OF THE RISER. 461 CY OF STORAGE IS AVAILABLE AT ELEVATION 432.5. SET CLEANOUT ELEVATION ® 429 = 211 CY OF STORAGE AVAILABLE DRY STORAGE MINIMUM 67 CY X 3.04 AC = 204 CY TOTAL DRY STORAGE AVAILABLE BETWEEN 432.5 - 440 = 2592 CY EMBANKMENT TOP 444 (ELEVATION OF FIRE ROAD) EMBANKMENT WIDTH = 30 FEET (WIDTH OF FIRE ROAD) AS -BUILT STAGE STORAGE TABLE ELEV AREA (sq. ft.) DEPTH (ft) AVG END INC. VOL. (cu. ft.) AVG END TOTAL VOL. (cu. ft.) 426.50 120 N/A N/A 0.00 428.00 2,607 2.00 3,159 3,841 430.00 3,711 2.00 8,795 12,636 432.00 5,084 2.00 11,643 24,279 434.00 6,559 2.00 14,834 39,113 436.00 8,275 2.00 18,571 57,684 438.00 12,656 2.00 22,952 80,636 440.00 15,799 2.00 28,455 109,091 WATERSHED SUMMARY TO POA #2 PRE DEVELOPMENT POST DEVELOPMENT SITE AREA = 2.68 ACRES ITE 3.0 CURVE NUMBER (CN) = 65 C E 9 �"�6 TIME OF CONCENTRATION = 9.9 MIN TIME OF CONCENTRATION = 9.9 MIN 9VAC25-870-66.B.3: CHANNEL PROTECTION ENERGY BALANCE CALCULATIONS - 1 YEAR PRE -DEVELOPMENT CONDITIONS POST -DEVELOPMENT CONDITIONS POST -DEVELOPMENT CONDITIONS ROUTED 1 YR Q(PEAK) - 1.597 CFS 1-YR Q(PEAK) = 2.69 CFS 1 YR Q(PEAK) 0.76 CFS TIME TO PEAK = 12.03 HRS TIME TO PEAK = 12.03 HRS TIME TO PEAK = 12.03 HRS VOLUME = 5,169 CU.FT VOLUME = 7,735 CU.FT VOLUME = 1,937 CU.FT 9VAC25-870-66C: FLOOD PROTECTION - 10 YEAR PRE -DEVELOPMENT CONDITIONS POST -DEVELOPMENT CONDITIONS POST -DEVELOPMENT CONDITIONS ROUTED 10-YR Q(PEAK) = 7.63 CFS 10-YR Q(PEAK) = 10.19 CFS ("TIME 10-YR Q(PEAK) = 1.55 CF;: TIME TO PEAK = 12.03 HRS TIME TO PEAK - 12.03 HRS TO PEAK = 12.43 HRS VOLUME = 20,152 CU.FT OLUME = 26,667 CU.FT VOLUME = 26,659 CU.FT 2 ENERGY BALANCE EQUATION: QDEVELOPED S I.F.*(QPRE-DEVELOPED* RVPRE-DEVELOPED)/RVDEVELOPED Y DEVELOPED 5 I.F.* (1YR QPRE-DEVELOPED * RV PRE-DEVELOPED)/RV DEVELOPED 0.76 S 0.80* (1.597 * 0.515) / 0.680 0.76 2 S 0.97 cfs FLOOD PROTECTION: Q10POST-DEVELOPED S Q10PRE-DEVELOPED 1.55 cfs S 7.63 cfs 2 12" TABLE 1. RECOMMENDED MINIMUM TRENCH WIDTHS HP STORM TRENCH INSTALLATION DETAIL MIN. COVER TO MIN. COVER To RIGID PAVEMENT H I FLEXIBLE PAVEMENT, H FINAL 1 BACKFILL _.. _ __� - - �- INITSPRINGLINE BACKFILL BACKFLL P PIPE DIAM MIN. TRENCH WIDTH 12- 30' 300mm) 762mm) 15' 34• 375mm 864mm 18" 39• 450mm 991MM 24" 4W 600mm 1219mm 30" 6- 750mm 1422mm 36" 64' 900mm 1626mm 42" 72" 1050mm 1829mm 48" 1200mm 2032mm 60" 96' (1500mm 2438mm) HAUNCH TABLE 2, MINIMUM RECOMMENDED COVER BASED ON VEHICLE LOADING CONDITIONS BEDDING 4" FOR 12'-24" PIPE j 6'FOR 30.6(1' PIPE j AN TRENCH WIDTH SUITABLE } + (SEE TABLE'} FOUNDATION NOTES: 1. ALL PIPE SYSTEMS SHALL BE INSTALLED IN ACCORDANCE WITH ASTM D2321, "STANDARD PRACTICE FOR UNDERGROUND INSTALLATION OF THERMOPLASTIC PIPE FOR SEWERS AND OTHER GRAVITY FLOW APPLICATIONS", LATEST ADDITION, SURFACE LIVE LOADING CONDITION HEAVY CONSTRUCTION PIPE DIAM. M-25 (75TAXLE LOAD)' 12" - 48" 12" 48" (300mm -1200mm (305mm) 1219mm) 60" 14" 60- (1500mm) (610mm) 1524Rvn) VEHICLES IN EXCESS OF 75T MAY REQUIRE ADDITION COVER WITH THE EXCEPTION THAT THE INITIAL BACKFILL MAY EXTEND TO THE CROWN OF THE PIPE. SOIL CLASSIFICATIONS TABLE 3, MAXIMUM COVER FOR ADS HP STORM PIPE, R ARE PER THE LATEST VERSION OF ASTM D2321. CLASS IVB MATERIALS (MH. CH) AS DEFINED IN PREVIOUS VERSIONS OF ASTM D2321 ARE NOT APPROPRIATE BACKFILL MATERIALS. 2. MEASURES SHOULD BE TAKEN TO PREVENT MIGRATION OF NATIVE FINES INTO BACKFILL MATERIAL. WHEN REQUIRED. 3. FOUNDATION: WHERE THE TRENCH BOTTOM IS UNSTABLE, THE CONTRACTOR SHALL EXCAVATE TO A DEPTH REQUIRED BY THE ENGINEER AND REPLACE WITH SUITABLE MATERIAL AS SPECIFIED BY THE ENGINEER. AS AN ALTERNATIVE AND AT THE DISCRETION OF THE DESIGN ENGINEER THE TRENCH BOTTOM MAY BE STABILIZED USING A GEOTEXTILE MATERIAL. 4. BEDDING: SUITABLE MATERIAL SHALL BE CLASS 1. 11, 111, OR IV. THE CONTRACTOR SHALL PROVIDE DOCUMENTATION FOR MATERIAL SPECIFICATION TO ENGINEER. COMPACTION SHALL BE SPECIFIED BY THE ENGINEER IN ACCORDANCE WITH TABLE 3 FOR THE APPLICABLE FILL HEIGHTS LISTED. UNLESS OTHERWISE NOTED BY THE ENGINEER, MINIMUM BEDDING THICKNESS SHALL BE 4" (100mm) FOR 17-24" (300mm-600mm) DIAMETER PIPE; 6" (150mm) FOR 30"-60" (750nwnn1500mm) DIAMETER PIPE. THE MIDDLE V3 BENEATH THE PIPE INVERT SHALL BE LOOSELY PLACED. PLEASE NOTE, CLASS IV MATERIAL HAS LIMITED APPLICATION AND CAN BE DIFFICULT TO PLACE AND COMPACT! USE ONLY WITH THE APPROVAL OF A SOIL EXPERT. 5. INITIAL BACKFILL: SUITABLE MATERIAL SHALL BE CLASS L 11, 111, OR IV IN THE PIPE ZONE EXTENDING TO THE CROWN OF THE PIPE. THE CONTRACTOR SHALL PROVIDE DOCUMENTATION FOR MATERIAL SPECIFICATION TO ENGINEER. MATERIAL SHALL BE INSTALLED AS REQUIRED IN ASTM 02321. LATEST EDITION. COMPACTION SHALL BE SPECIFIED BY THE ENGINEER IN ACCORDANCE WITH TABLE 3 FOR THE APPLICABLE FILL HEIGHTS LISTED. PLEASE NOTE. CLASS IV MATERIAL HAS LIMITED APPLICATION AND CAN BE DIFFICULT TO PLACE AND COMPACT, USE ONLY WITH THE APPROVAL OF A SOIL EXPERT. 6. MINIMUM COVER: MINIMUM COVER, H, IN NON -TRAFFIC APPLICATIONS (GRASS OR LANDSCAPE AREAS) IS 12" (300mm) FROM CLASS 1 CLASS II CLASS III N PIPE DIA COMPACTED 96% 90% 85% 95% 90% 95% 12" 41 28 21 16 20 16 16 (300mm) (12.5m) (8.5m) (6.4m) (4.9m) (6.1m) (4.9m) (4.9m) 15- 42 29 21 16 21 IB 16 (375mm) (12.8m) (8.8m) (6.4m) (4.9m) (6Am) (4.9m) (4.9m) 18" 44 30 21 16 22 17 16 (450mm) (13.4m) (9.1m) I (6.4m) I (4.9m) (6.7m) (5.2m) (4.9m) 24" 37 26 18 14 19 14 14 (600mm) (11.3m) (7.9m) (5.5m) (4.3m) (5.8m) (4.3m) (4.3m) Nr 39 27 19 14 19 15 14 (750mm) (11.9m) (8.2m) (5.8m) (4.3m) (5.8m) (4.6m) 1 (4.3m) 36- 28 20 14 10 14 11 10 (900mm) (urf%) (6.1m) (4.3m) (3.0m) (4.3m) (3.4m) (3.0m) 42" 30 21 14 10 15 11 10 (1050rnm) (9.1m) (6-4m) (4.3m) (3.0m) (4.6m) (3.4m) (3.0m) 48" 29 20 14 9 14 10 10 (1200mm) ($.am) (6.1m) (4.3m) (2.7m) (4.3m) (3.0m) (3.0m) 60' 29 20 1 14 9 r 14 10 9 (1500mm) (8.8m) (6.1m) I (4.3m) (2.7m) I (4.3m) (3.0mI, (2.7m) THE TOP OF PIPE TO GROUND SURFACE. ADDITIONAL COVER MAY BE REQUIRED TO PREVENT FLOTATION. FOR TRAFFIC FILL HEIGHT TABLE GENERATED USING AASHTO SECTION 12. LOAD APPLICATIONS: CLASS I OR 11 MATERIAL COMPACTED TO WA SPD AND CLASS III COMPACTED TO 95% SPD IS REQUIRED. RESISTANCE FACTOR DESIGN (LRFO) PROCEDURE WITH THE FOLLOWING FOR TRAFFIC APPLICATIONS. MINIMUM COVER, H. IS 12" (300mm) UP TO 48" (1200mmI DIAMETER PIPE AND 24• (600mm) OF ASSUMPTIONS: COVER FOR 60" (1500mm) DIAMETER PIPE. MEASURED FROM TOP OF PIPE TO BOTTOM OF FLEXIBLE PAVEMENT NO HYDROSTATIC PRESSURE OR TO TOP OF RIGID PAVEMENT. UNIT WEIGHT OF SOIL (Ys) = 120 PCF 7. FOR ADDITIONAL INFORMATION SEE TECHNICAL NOTE 2.04. 6 REV. MAXIMUM COVER HEIGHTS RWD 01i 11J77 -1, M.AM M REV. DESCRIPTION BY MM.ODM I C- OVANCED DRAINAGE SYSTEMS. INC, ('ADS') HAS PREPARED THIS DETAIL BASED ON INFORMATION PROVIDED TO ADS. THIS DRAWING IS - .:As 4TENDED TO DEPICTTHE COMPONENTS AS REQUESTED. ADS HAS NOT PERFORMED ANY ENGINEERING OR DESIGN SERVICES FOR THIS ► -+ 0111111�,Ly "ROJECT, NOR HAS ADS INDEPENDENTLY VERIFIED THE INFORMATION SUPPLIED. THE INSTALLATION DETAILS PROVIDED HEREIN ARE GENERAL TRENCH INSTALLATION 4640 TRUEMAN BLVD � RECOMMENDATIONS AND ARE NOT SPECIFIC FOR THIS PROJECT. THE DESIGN ENGINEER SHALL REVIEW THESE DETAILS PRIOR TO DETAIL (HP STORM) HILLIARD, OHIO 43026 :ONSTRUCTIOM IT IS THE DESIGN ENGINEERS RESPONSWILITY TO ENSURE THE DETAILS PROVIDED HEREIN MEETS OR EXCEEDS THE WITS 1PPLICABLE NATIONAL. STATE, OR LOCAL REOUIREMENTS AND TO ENSURE THAT THE DETAILS PROVIDED HEREIN ARE ACCEPTABLE FOR THIS.n+w� ,en.rnr DRAWING NUMBER: STi}101D cnN..,vz areinu x+_ "u t Oc 0 cD I I I i ( I', I I / I I 1 0 I I II ) Ln I I T / POA = A l #2 1 \ \ I I I I -`� y �� ( ( 20' PUBLIC DRAINAGE & \ \ \ \ I \ \ \ 1 I 1 I �4. OP#2 MAINTENANCE EASEMENT _ REVERSE SLOPE BENCH / % 1 \ v \ V A A v \ \\�A v�;^zSENv ��A,.. - )-■:;�� SWM EASEMENT . yo rrr+!is,./. 40' ACCESS EASEMENT it S L 4,� ON.-L R- ti ATbo 140 PRE -DRAINAGE AREA TO POA#2: 2.68 sc �,/ ` - ��i �\ `.\ • We CN=65 -_ Tc: 100' sheet flow w/ 0 ELEV = V & 459i OF CONC. FLOW W/ A ELEV. = Wi / , ��\� � � \ \\ ------ i � � ����i �:. `c W���` �� Tc: 9.9 min 1' PRE - Q 1 year - 1.60 cis I \ \ , /�• re \ \ O \ Lr - -�� \ ••• 4 CCS SLICE R F T \ \ \\ PRE -Q10year =7.63cis 174E y • t � -V" -� _ice i 1 J� I "F� I l g�'�`��/\ I I I m \ 1�j'. FIRE ROAD PLAN VIEW NARRATIVE: THE EXISTING SEDIMENT TRAP (WPO-2016-00071) WILL BE MODIFIED AS SHOWN HEREON THESE PLANS TO CAPTURES A DRAINAGE AREA OF APPROXIMATELY 3.04 ACRES. A 15" PIPE WITH A 48" RISER AND ANTI -VORTEX DEVICE HAS BEEN BUILT AND SHOWN. A PRINCIPAL SPILLWAY WEIR PLATE IS NECESSARY IN ORDER TO REDUCE THE ENERGY BALANCE AND 10YR STORMWATER POST -DEVELOPED PEAK FLOWS TO BENEATH THE APPROVED PLAN LEVELS. THE WEIR PLATE ON THE RISER IS SHOWN BELOW. DURING THE EROSION CONTROL PHASES, CONTRACTOR TO INSTALL A HORSESHOE RING OF AGGREGATE AROUND THE RISER THAT WILL SERVE AS A FILTER FOR WATER TO PASS THROUGH SIMILAR TO THAT FOUND WITH THE TRADITIONAL SEDIMENT TRAP DESIGN. THE STORMWATER QUANTITY REQUIREMENTS AT POINT OF ANALYSIS #2 (POA #2) MEET THE MINIMUM CHANNEL AND FLOOD PROTECTION REQUIREMENTS SET FORTH IN 9VAC25-870-66. (9) J"TAPCON((ORLEQUAL� EPDXY SEALED 24" OUTFALL PIPE HORSESHOE RING OF AGGREGATE (EROSION CONTROL PHASE) c 1' 1.5' 2.5' COARSE AGGREGATE ELEV = 429.00 3' HIGH ELEV = 426.00 CLASS I RIPRAP I 'HOLE 1" FROM TOP TO BE SED FOR CLEVIS ATTACHMENT LIFT. THEN BOLD ATTACHMENT (typ. OF 3) 18" Jr HOLE 1" FROM SIDE WALL FOR BOLTS (TYP. OF 6) PLATE TO BE ARCHED TO FIT EXTERIOR RADIUS OF A STD. 4 FT. MANHOLE 24" 455 450 445 440 435 430 425 420 415 410 405 400 395 9-4 FIRE ROAD PIPE PROFILE HORIZ. SCALE: 1 "=30' VERTICAL SCALE: 1 "=10' DAM = 444.00 PROPOSED FIRE ACCESS ROAD FINISHED GRADE WITH REVERSE SLOPE BENCH - - - - - - - - r i - - - EXISTING GRADE _ J 75 10+00 11 +00 98 oP# OUTLET PROTECTION SPECIFICATIONS VDOT EW-1 HEADWALL 15" HP PIPE 455 450 445 440 fd 35 AS -BUILT 48" RISER CREST ELEVATION AT 432.50' 11 425 2 420111 BASIN BOTTOM & STABILIZED FINISHED GRADE = 426.50. 41 RISER TO HAVE STEEL PLATE COVER THE BOTTOM HALF OF THE 12" LOW FLOW ORIFICE AT 41 ELEVATION 426.5 WHICH SATISFIES THE ENERGY BALANC REQUIREMENTS. TRASH RACK T 40 BE INSTALLED OVER ORIFICE Role] C 1110 OUTLET PROTECTION IS SIZE IN ACCORDANCE WITH PLATE 3.18-3 OF THE VIRGINIA EROSION CONTROL MANUAL. 3Do = 15" * 3 = 3.75' La = 8.5' MIN W = Do + La = 1.25 + 8.5 = 9.75' *DESIGN ENGINEER RECOMMENDS FULL CHANNEL WIDTH MIN 8.5' CL I RIPRAP Ql - 0.76 cfs EC-1 CLASS I A 02 - 1.02 cfs '' RIPRAP Q10 - 1.55 cfs 24" MIN. DEPTH W/UNDERLYING F.F STANDARD EC-1 CLASS 1 REQUIRED TYPE A INSTALLATION OUTLET PROTECTION MIN DEPTH OF RIPRAP = 24" I M LO U o LU CO w U)c) U O z L4 z0N J J Q 2 0 Q W � Ow z �y d U = LU m "O pU) wo W UQ Ln< LL z_ ZU V O > w 0rl- N q = 91 d w p N Nt Lu N Z Q <z > o J _ � O mow z LU O Q rnV z O d U 1n w 0 z Ooz W uJ z a V) Ln Ln Ln * 4t zzzz�- o� Z W W W W Z V Z O 2 uj z 2 o = o S 0 0 z z o o o uj uj < f < o z z z Z 0- >0 >0 0> o Z N o > Z > Lu O O O O '1 'I N fV N. N N N N ui CD O O O O O O CV N N N N N Q M M O IJl 23 .-i 0 e-1 N M •'-1 O O 0 0 0 Ln 00 .-1 .-1 .-, O CD Z­4 tV M e1 Ln tG n DRAFTER: IDEG DESIGNER: IDEG PRODUCTION: I JLT � b�yTa oj► ol�� 7�i Jimmy L Taggart 14 8411 • 00, gar+ 7/1/2022 Q.�F e010NAL W -I Oo ^ L i W Z w co Q J� W LL O z Q 2 O 0 Z LLJ N (c) v W 0 0- U LLI Q 2 oc (1) J C > ~ W F_ U) 0 cQ G DATE: 07-1-2020 SCALE: NA FILE: WPO-2020-00034 RGA#: WIS SHEET: 1 v • 2 OF 18 ]:\RGA\TMPROJ\8438-BELVEDERE\ADAMS PHASE 5\8438-BELVEDERE-PHASE 5-VSMP dw .6130/2022 11*S1d5 AM. AutoCAD POE!General Onrumentationl ml