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HomeMy WebLinkAboutWPO202000037 Plan - VSMP 2022-04-29GENERAL NOTES OWNERS: TMPo92oo-oo-oo-oo9oo GALAXIE FARM INVESTMENTS, LLC 600 EAST WATER STREET, SUITE H CHARLOTTESVILLE, VA 22902 TMP ogioo-oo-oo-o25oo GALAXIE FARM INVESTMENTS, LLC 600 EAST WATER STREET, SUITE H CHARLOTTESVILLE, VA 22902 DEVELOPER: RNERBENDDEVELOPMENT, INC. 455 SECOND STREET SE, SUITE 400 CHARLOTTESVILLE, VA 22903 ENGINEER: COLLINS ENGINEERING 2ao GARRETT ST, SUITE K CHARLOTTESVILLE, VA 22902 TAX MAP: 09100-00-00-00900 D.B. 5445, PG. 5o 5.og ACRES 09200-00-00-02500 D.B. 5445, PG. 54 8.27 ACRES ZONING: PLANNED RESIDENTIAL DEVELOPMENT (PRD) WITH ENTRANCE CORRIDOR OVERLAY DISTRICT(EC) AND MANAGED & PRESERVED STEEP SLOPES OVERLAY DISTRICT PRD ZONING WAS APPROVED BY THE BOS ON DECEMBER 4TH, 2029. TOTAL PROJECT AREA: 09100-00-00-00900 - 5.09 AC. 09100-00-00-01500 - 8.27 AC. TOTAL = 23.36 AC PROPOSED USE: 65 TOTAL DWELLING UNITS (43)SIVIGLE-FAMILY DETACHED UNITS (6) TOWNHOUSE UNITS W/ ACCESSORY UNITS (12 UNITS TOTAL) (io)TOWNHOUSE UNITS NOTE: THE TYPICAL NUMBER OF BEDROOMS IN THETH UNITS WILL BE (3) BEDROOMS. THE (6) BASEMENT ACCESSORY UNITS WILL BE 2 BEDROOM UNITS & THE UPPER TH UNITS WILL BE 2 BEDROOM UNITS. 00) - 3 BEDROOM UNITS, (6) - 2 BEDROOM UNITS, & (6) 2 BEDROOM UNITS THE SINGLE FAMILY DETACHED UNITS SHALL HAVE (3) OR (4) BEDROOMS. ALLOWABLE DENSITY: 65 UNITS PER APPROVED PRD REZONING & APPLICATION PLAN 65 TOTAL DWELLING U N ITS123.36 ACRES = DWELLING UNITS/ACRE PROPOSED DENSITY: 65 DWELLING UNITS/23.36 ACRES = 4.42 DWELLING UNITS/ACRE OPEN SPACE: REQUIRED: 3.83 ACRES PER APPROVED PRD REZONING & APPLICATION PLAN PROVIDED=4.3aAC OPEN SPACE A: 0.24 ACRES OPEN SPACE D: 2.25 ACRES OPEN SPACE B: 0.44 ACRES OPEN SPACE E: 2.44 ACRES OPEN SPACE C: 0.04ACRES NOTE: OPEN SPACE TO BE OWNED AND MAINTAINED BY THE HOMEOWNERS ASSOCIATION. ALL OPEN SPACE SHALL BE RESERVED IN A DEED FOR COMMON USE OF LOTS OWNERS IN THE SUBDIVISION. RECREATION AREA: OPEN SPACES D & E SHALL PROVIDE ACTIVE & PASSIVE RECREATIONAL AMENITIES, INCLUDING A WALKING TRAIL ALONG THE STREAM AS SHOWN ON THE SITE PLAN SHEETS. ACTIVE RECREATION SHALL BE PROVIDED WITHIN OPEN SPACE B, INCLUDING A GRASS RECREATIONAL FIELD, MEETING AREA, AND PLAYGROUND EQUIPMENT. TOTAL RECREATIONAL AREA REQUIRED: zoo SF x 65 UNITS = 13,o0O SF (o.3oAC) TOTAL RECREATIONAL AREA PROVIDED: 29,267 SF (0.44 ACRES) BUILDING HEIGHTS: NO MINIMUM HEIGHT REQUIREMENT. MAXIMUM - 35 FEET PER PRD REZONING APPLICATION PLAN SETBACKS: FRONTSETBACK:5'MIN. SIDE SETBACK: 5' MIN. REAR SETBACK: 20' MIN. (EXCEPT FOR UNITS ADJACENT TO VERA RUBIN PLACE WHICH SHALL HAVE A 5' REAR SETBACK) GARAGE SETBACKS: a8' MIN. NOTE: FRONT LOADED GARAGE UNITS, THE PORCH OR BUILDING FACE SHALL BE A MINIMUM OF FEETCLOSERTO THE STREET AS MEASURED FROM THE FACE OF THE GARAGE DOOR. SUBDIVISION STREETS: CURB & GUTTER WATERSHED: MOORES CREEK (MOORES CREEK IS NOT A WATER SUPPLY RESERVOIR WATERSHEDAREA) AGRICULTURAL/FORESTAL DISTRICT: NONE TOPOGRAPHY& SURVEY: BOUNDARY ANDTOPOGRAPHY INFORMATION WAS PROVIDED BY ROGER RAY & ASSOCIATES, INC IN FEBRUARY, 2020. FIELD VERIFIED BY COLLINS ENGINEERING IN FEBRUARY OF 2021. DATUM: NAVD 88 EXISTING VEGETATION: PARTIALLY WOODED WITH (2) EXISTING RESIDENTIAL HOUSES PRESERVED/MANAGED SLOPES: MANAGED AND PRESERVED STEEP SLOPES ARE SHOWN WITHIN THE LIMITS OF THE PROPERTY. SEE EXISTING CONDITIONS SHEET 2 FOR LOCATIONS. LIGHTING: NO STREET LIGHTING IS PROPOSED WITH THIS PROJECT. PARKING: TWO (2) OFF-STREET PARKING SPACES ARE PROVIDED FOR EACH DWELLING UNIT AND (i) OFFSTREET SURFACE PARKING SPACE IS PROPOSED FOR EACH ACCESSORY UNIT. ADDITIONAL PARKING SPACES PROVIDED ALONG THE PROPOSED ROADWAYS. PARKING REQUIRED: 59 RESIDENTIAL UNITS ==8 PARKING SPACES 6 ACCESSORY UNITS = 6 PARKING SPACES 22 ATTACHED UNITS x (i PARKING SPACE/4 UNITS) = 6 SPACES TOTAL PARKING REQUIRED: 230 PARKING SPACES PARKING PROVIDED: GARAGE PARKING SPACES: 53 GARAGE PARKING SPACES DRIVEWAY PARKING SPACES: 65 DRIVEWAY PARKING SPACES SURFACE PARKING SPACES: 9 SURFACE PARKING SPACES ON -STREET PARKING SPACES: 4 TOTAL ON -STREET SPACES TOTAL PARKING PROVIDED: 3.32 SPACES BUILDING SITES: EACH LOT CONTAINS A BUILDING SITE THAT COMPLIES WITH THE REQUIREMENTS OF SECTION 4.2.2 OF THE ALBEMARLE COUNTY ZONING ORDINANCE, LAND AREAS: OPEN SPACE: 187,744SF 4.31 ACRES (32.3%) LOTS: 265,375 SF 6.og ACRES (48.36%) ROW DEDICATION: 128,464SF 2.95ACRES (22.2%) PROPOSED IMPERVIOUS AREAS: ROADS: 72,750SF SIDEWALKS: 19,450 SF BUILDINGS, PATIOS/DECKS: 93,278 SF DRIVEWAYS: 28,320 SF TOTAL IMPERVIOUS AREAS: 224,098SF (5.14ACRES) BURIAL SITES: NO CEMETERIES WERE FOUND DURING FIELD INVESTIGATION OF THIS PROPERTY. FLOODPLAIN: THERE IS NO FLOODPLAIN LOCATED ON THIS SITE. FEMA MAP ID 53.003Co426D DATED FEBRUARY 4, 2005. LANDSCAPING: A LANDSCAPING PLAN WILL BE PROVIDED WITH THE FINAL SITE PLAN IN ACCORDANCE WITH ALBEMARLE COUNTY ORDINANCE SECTION 2. .9 . STREET 3 7 TREES ARE INCLUDED WITH THE LANDSCAPING DESIGN TO INCORPORATE STREET TREES EVERY 4o' ALONG THE ROADWAYS. RETAINING WALLS: RETAINING WALLS ARE PROPOSED WITH THIS PROJECT. SEE GRADING & DRAINAGE PLAN FOR WALL LOCATIONS. TRASH SERVICE: EACH LOT SHALL HAVE AN INDIVIDUALTRASH CONTAINER. UTILITIES: ALBEMARLE COUNTY WATER & SEWER AFFORDABLE HOUSING: AFFORDABLE HOUSING TO BE PROVIDED IN ACCORDANCE WITH THE APPROVED PROFFERS. TOTAL PROPOSED NUMBER OF AFFORDABLE HOUSES: io UNITS SEE LAYOUT SHEETS FOR LOCATION OF AFFORDABLE UNITS, AS SHOWN WITH AN ASTERISK (*) PHASING: THIS PROJECT SHALL BE DEVELOPED IN ONE PHASE. GALAXIE FARM SUBDIVISION VSMP PLAN AMENDMENT #2 (AMENDMENT TO WP0202000037) T.M.ga-a3 COUNTY SCHOOL BOARD OF ALBEMARLE COUNTY, VIRGINIA D.B.1033-313 D.B.2033-313 D.B.629-368 PLAT 40 L T.M.goA.a-E AVINITY ESTATES LLC AVINITY ESTATES OPEN SPACE E D.B.2267-750 D.B.5124, PG.676 I \ 37 C GRAPHIC/ SCALE ( IN FEET ) 1 inc 80 ft. 33 SCOTTSVILLE MAGISTERIAL DISTRICT ALBEMARLE COUNTY, VIRGINIA \ LOT 30 : T.M.9 a-a6D SCOTTSVILLE ROAD HOLDINGS,LLC C/O KAPPA SIGMA FRATERNITY D.B.3257, PG.7o2 D.B.550, PLAT6o8 T.M.9a-aa SCHOOL BOARD COUNTY OF ALBEMARLE,VIRGINIA D.B. 5258-620 D.B-979-46 & 47 PLAT OT \OPEN �PACE.4 \ / , OT 5�yt� � \ LOT T.M.ga-w COUNTYOPALBEMARLE,VIRGINIA D.B.a979.44,46&47PL, SPACE,:,' \ \ \ \ OT \ _ az / r I a3 j / LOTao / r �2v LOT LOT8 / Mal 9 _ OPEN a'( 4'M v v / �O d SPACE OPEN LOTIL Y % LOTS LOTaB , PROPOSED 4/ \ i RECREATION AREA FF O /LOT RF r LOT \\ z6 z4 \ LOT \ \\ LOT r I /'� `\ `. '•. z3 LOT i � \ 43 LOT LOT LDT LOT OPEN SPACE E \ \ PROPOSED \ \� SWM FACILITY STREAM BUFFERS: THE STREAM BUFFERS SHOWN HEREON SHALL BE MANAGED IN ACCORDANCE WITH THE ALBEMARLE COUNTY WATER PROTECTION ORDINANCE BUILDING SITES: LOTS 1-59 SHALL EACH CONTAIN A BUILDING S17E THAT COMPLIES WITH SEC77ON 4.2.1. OF THE ALBEMARLE COUNTY ZONING ORDINANCE. PRIVATE STREET.- VERA RUBIN PLACE IN THIS SUBDIVISION MAY NOT MEET 774E STANDARDS FOR ACCEPTANCE INTO THE SECONDARY SYSTEM OF STATE HIGHWAY AND WILL NOT BE MAINTAINED BY THE DEPAR7MENT OF TRANSPORTATION OR THE COUNTY OF ALBEMARLE. OFFSITE DISTURBANCE. OFFSI7E DISTURBANCE IS PROPOSED WITH THIS PLAN ON THE ADJACENT AVINITY ESTATES PROPERTY, WHICH IS ALSO OWNED BY THE SAME DEVELOPER. AVAILABLE FIRE FLOW." 1,750 GPM AT MINIMUM 20 PSI ISO CALCULATIONS: MAXIMUM REQUIRED FIRE FLOW FOR RESIDEN77AL STRUCTURE IS 1,100 GPM. G W SCOTTSVILLE ROAD C/O O KAPPA SIGMA FRATERNITY D.B.3z57, PG.7oa D.B.wBo, a73 PLAT \ � s SHEET LAYOUT SCALE: 1" = 80' I T 7 6 ' I 07 ' s r OPEN` SPACE D I--- RD )R�V�E 20 GENERAL BUILDING DEPARTMENT NOTES.- 1. WHERE THE FLOOD LEVEL RIMS OF PLUMBING FIXTURES ARE BELOW THE ELEVA77ON OF THE MANHOLE COVER OF THE NEXT UPSTREAM MANHOLE IN THE PUBLIC SEWER, 774E FIXTURES SHALL BE PR07ECTED BY A BACKWATER VALVE INSTALLED IN THE BUILDING DRAIN, BRANCH OF THE BUILDING DRAIN OR HORIZONTAL BRANCH SERVING SUCH FIXTURES PLUMBING FIXTURES HAVING FLOOD LEVEL RIMS ABOVE 774E ELEVA77ON OF THE MANHOLE COVER OF THE NEXT UPSTREAM MANHOLE IN THE PUBLIC SEWER SHALL NOT DISCHARGE THROUGH A BACKWATER VALVE. 2. DUE TO REQUIRED DISTANCES FROM LOT LINES AND STRUCTURES AS REQUIRED BY THE NFPA, UNDERGROUND PROPANE TANKS MAY BE PROHIBITED. 774E BUILDER/DEVELOPER SHALL PLAN ACCORDINGLY. 3, RETAINING WALLS GREATER THAN 3' IN HEIGHT REQUIRE A SEPARATE BUILDING PERMIT. WALLS EXCEEDING 4' IN HEIGHT REQUIRE A STAMPED ENGINEERED DESIGN. WALLS CROSSING LOT LINES REQUIRE AN EASEMENT. 4. ALL WATER LINES, SEWER LINES, AND FIRE LINES FROM THE MAIN TO THE STRUCTURE MUST HAVE A VISUAL INSPEC77ON PERFORMED BY THE BUILDING DEPARTMENT. NO7ES` 1) 7HIS PROPERTY DOES NOT LIE WITHIN AN AGRICULTURAL AND/OR FORESTAL DISTRICT 2) ONLY (1) DWELLING PER LOT SHALL BE PERMITTED. 3) STREET TREES SHALL BE PROVIDED ALONG ALL THE PUBLIC STREETS 50' (MAXIMUM) O.C. IN ACCORDANCE WITH VDOT AND ALBEMARLE COUNTY STANDARDS AND REZONING DOCUMENTS. 4) THIS PROPERTY IS NOT LOCATED 1417HIN A DAM INUNDATION ZONE. 5) ROADWAYS AND PAVED CIRCULA77ON AREA = 60,634 SF. / , 0 70 RICHMOND SOUTHERN PARKWAY MILL CREEK JO Q INTEO roe 64 PIEDMONT VIRGINIA COMMUNITY COLLEGE u MONTICELLO HIGH LAKE REYNOVIA O MOUNTAIN VIEW ),ELEMENTARY 4 LJ SCHOOL THIS PROJECT MILL CREEK fA� 4! SOUTH O� R P VICINITY MAP: SCALE: 1" = 2000' 00 © • .Islam•_ . F.W.919 ffm_ 11 al 111 © •.,, - 4 TOTAL SHEETS VSMP PLAN AMENDMENT #2: BELOW IS A SUMMARY OF THE PROPOSED REVISIONS TO THE APPROVED VSMP PLAN AMENDMENT #a WITH THIS VSMP PLAN AMENDMENT #2. A NEW RISER (STIR. A24) AND 0UTFALL SYSTEM IS PROPOSED, RELEASING RUNOFF TO �A LEVEL SPREADER AND A VEGETATED FILTER STRIP. THIS ADDITION PROVIDES STORMWATER QUALITY TREATMENT ONSITE. YARD DRAINS HAVE BEEN ADDED TO THE DEVELOPMENT SENDING ADDITIONAL RUNOFF TO THE DETENTION BASIN 'A'. THIS ADDITIONAL RUNOFF WILL RECEIVE ATTENUATION IN THE BASIN, AND WILL REDUCE THE RUNOFF EXITING THE SITE UNDETAINED. THE BASIN's GRADES AND RISER (STR. A6) HAVE ALSO BEEN MODIFIED WITH THIS AMENDMENT. AN UPDATED SWIM ANALYSIS HAS BEEN COMPLETED & IS ATTACHED. THIS ANALYSIS SHOWS COMPLIANCE WITH CHANNEL & FLOOD PROTECTION REQUIREMENTS FOR THE ONSITE SUBAREAS A & B. THE ANALYSIS ALSO SHOWS THE PEAK POST -DEVELOPMENT FLOWS IN THE COW BRANCH STREAM DOWNSTREAM FROM THE GALAXIE FARM SUBDIVISION ARE LESS THAN THE PEAK PRE -DEVELOPMENT FLOWS AT THE POINT OF ANALYSIS ('POA') SHOWN & LABELED ON SHEET 22. EROSION CONTROL IIRGINIA HAND800K SP� CA 77ONSEDIMENT J�OL NUMBER CE CONSTRUCTION ENTRANCE 3.02 CR CR CONSTRUCTION ROAD 3.03 STABILIZATION SF x SIL T FENCE J. 05 ST SEDIMENT TRAP 3.13 SB SEDIMENT BASIN 3.14 OP OUTLET PROTECTION 3.18 RR RIPRAP 3.19 CD ' CHECK DAM 3.20 O---�- TEMPORARY SEEDING 3.31 PS O PS PERMANENT SEEDING 3.32 OTREE PROTECTION 3.38 OC DC DUST CONTROL 3.39 • PUMP AROUND DIVERSION Lic. No. 035791 4129122 z O � ul d Z LU ca Z) 0o Z J O 'n N � ~ LU z w W N N N 4 L9 C)-) z W zuj z W N a o z [n W N Q N J Z> W a � W W , w 0 LLJ V) > Lf w Z � z o � O U Q W'11-ma-^4 U Iv ,4 ul W Z i W W C J (( oC J ~ U. W W W 1­I Q 0 O X O O q J N u w � w (� w a v Ln JOB NO. 202194 SCALE 1 =80' SHEET NO. 1 STORMWATER MANAGEMENT AMENDMENT #2 NARRATIVE: POST -DEVELOPMENT STORMWATER MANAGEMENT PLAN, SCALE 1"=80' 1 1 I \ \ \ / \ / / NTH OOVERVIEW THIS VSMP AMENDMENT #2 WAS CREATED TO PROVIDE ONSITE WATER QUALITY TREATMENT AND TO DETAIN ADDITIONAL RUNOFF WITHIN THE PROPOSED SWM FACILITY, WHILE SIMULTANEOUSLY REDUCING THE RUNOFF EXITING THIS DEVELOPMENT UNDETAINED. / / PROPOSED / ESp,/LIMITS O DISTUR AN�jE BOUNDARY DEFIfVES THE�OPO ED/ S(,'OTT R. LINS`Z, WATER QUALITY SUMMARY 4t# VRRM WATR QUACK Bo NDP,RY TyP. \ THE DEVELOPMENT REQUIRES THE REMOVAL OF 9.21 Ibs/yr OF PHOSPHOROUS. THE REMOVAL RATE IS BASED ON THE DEQ VRRM. THIS VSMP -� / UPLAND OFFSITE DRI�INAG TO REMAIN 100' OF OLF w� A EI;EV.=6', 'TO ALB UNDARY ARE/A�-12.7 ACRES. � Li Lie. NO. 035791 AMENDMENT #2 PROPOSES A LEVEL SPREADER THAT WILL DISCHARGE THE TREATMENT VOLUME TO A VEGETATED FILTER STRIP WITH TYPE B SOILS. / UNDIURBED & TO,BE ROITED TO THE 25' of CONC. FLOW W� A / �O 4�29�22 THIS BMP IS SUPPLEMENTED WITH THE BEST MANAGEMENT PRACTICE OF PURCHASING NUTRIENT CREDITS. SEE BELOW FOR A BREAKDOWN OF THE / / PRO�P0 SED BYPASS STORM SEWER/ RUNOF� ELEV.=14' & 825' OF CHNL. FLO ��� / / (� tV PHOSPHOROUS REMOVALS ASSOCIATED WITH THIS PLAN AMENDMENT #2, AND SHEET 13A FOR THE LEVEL SPREADER & FILTER STRIP DESIGN. / / TO BE DIRECTED I 0 STR. 4. +� IONAL Overall Phosphorous Removal Rate Required = 9.21 Ibs/yr 25% of the Phosphorous Removal Rate Required to be Onsite = 2.30 Ibs/yr Z Phosphorous Removal Rate Provided via previously purchased Nutrient Credits 5.59 Ibs/yr \ \ J Phosphorous Removal Rate Provided via a Vegetated Filter Strip with B Soils= 5.41 Ibs/yr Total Phosphorous Removal Rate Provided (Purchased Nutrient Credits + Vegetated FilterStrip) = 11.00 Ibs/yr Percent of Total Required Phosphorous Removal Rate Provided Onsite (min. 25% required)= 59 % \ / / Overall Phosphorous Removal Rate Surplus / Credit = 1.79 Ibs/yr 1� WATER QUANTITY SUMMARY • C THIS VSMP AMENDMENT #2 CONTINUES TO TREAT THE BULK OF THE DEVELOPMENT VIA A PROPOSED DRY DETENTION BASIN NAMED DETENTION BASIN 0 1\ W. DETENTION BASIN 'A' PROVIDES STORMWATER QUANTITY TREATMENT BUT NOT STORMWATER UALITY TREATMENT AND DISCHARGES INTO SITE OUTFALL #1. THIS AMENDMENT #2 SENDS MORE RUNOFF TO THE DETENTION BASIN, AND SUBSEQUENTLY DETAINS MORE RUNOFF BEFORE THE FLOWS \ \ y I„ �� ')-" - / �� Z O _ m �� --� ITE / F Q n ARE RELEASED TO SITE OUTFACE #1. THIS AMENDMENT #2 ALSO RESHAPES THE BASIN &MODIFIES THE RISER STR. A6. IN CONJUNCTION WITH THESE \ ,; IMPROVEMENTS,THIS AMENDMENT #2 SENDS LESS DRAINAGE TO SITE OUTFALL #2 UNDETAINED. WITH THESE ADJUSTMENTS, THE PEAK RUNOFF \ \ I, \ I I / ,� T ALL # ''moo \ I RATES EXITING THIS DEVELOPMENT TO THE COW BRANCH STREAM ARE LESSENED. \\ \\ \ \ 1 �' PROPOSED �STORM SEWER i ;' "L / � m r_ U \ 2 TO REDIRECT THE OFFSftTE _ , w � CHANNEL PROTECTION & FLOOD PROTECTION REQUIREMENTS ARE MET FOR THE ONSITE SUBAREAS A & B. CHANNEL PROTECTION IS MET FOR THE \ \ \ ' \ \ \ \ RUNOFF THROUGH THE \ Ln ONSITE RUNOFF VIA 9 VAC 25-870-66, SUBSECTION B.3.a ENERGY BALANCE). THE LIMITS OF ANALYSIS FOR THE CHANNEL PROTECTION TERMINATE AT 1 \ \ ' 1 ,-' ;; ` 45' OF OLF w/ ELEV.=B', .Z z o IMPROVEMENTS ASSOCIATED 4� "' ' 300' OF CHNL FLOW-----. O p s ( ) \ \ I PROPOSED DRAINAGE DEVELOPMENT, INTO sT THE SUBAREAS SINCE SUBSECTION 6.3.a IS SATISFIED. FLOOD PROTECTION FOR SUBAREAS A & B IS MET VIA 9 VAC 25-870-66, SUBSECTION C.2.b I l\ AI R " _ '�,%� -� __ r POST -DEVELOPMENT 10- r PEAK FLOW < PRE -DEVELOPMENT 10- r PEAK FLOW THE LIMITS OF ANALYSIS FOR THE FLOOD PROTECTION ALSO ENDS AT \ -� \ ,I. "" NE ' in ( Y Y ) �il�� TOFF WDIRECT ADDTIDNA RUNOFF p`�XIEF Z THE SUBAREAS SINCE SUBSECTION C.2.b IS MET. V UNDISTURBED 0 BE ROUTED TO THE V I � )/ �� �- - 'r w p ORUNA TO DETENTIO BAS TY --/� ONSITE DA 'B-�� _ __ A 1 K U - EE DIRECTEDI F _ ;� �� PLEASE SEE THE TABLES BELOW FOR A SUMMARY OF THE ONSITE AREAS USED IN THE CHANNEL &FLOOD PROTECTION COMPLIANCE. POOSED BYPASS- D�NTO S ES-1. -�SE GA AX ONSITE SUBAREAS A & B _ r - Uj \ /- ( (USED IN THE CHANNEL &FLOOD PROTECTION CALCULATIONS) I I I � I I I I \ - 1 �^ -_ i I _ - x - - � � / '• I) s1r % � o Area, 1-year Flow, 2-year Flow, 10-year Flow, - '7 - OUTFACE 1 Pre -Development CN ac. cfs cfs cfs - - o i., , �� Onsite DAA (Pre-Dev.) 64 6.40 4.45 7.29 18.02x. - ONSITE DA 'A' s. ,' y ,. _ ,,• o Onsite DA B (Pre-Dev.) 64 3.00 2.10 3.43 8.46 o 64 9.40 6.55 10.72 26.49 Post -Development ) CN Area, 1-year Flow, 2-year Flow, 10-year Flow, Onsite DAA Post-Dev. 78 8.67 0.35 6.69 19.95 ` J N E J( Onsite DA B (Post-[ 83 0.73 1.73 2.34 4.28 L - , _ ... � m 79 9.40 2.08 9.03 24.23 / 1 --- - - I PROPOSED LEVEL SPREADER 'A'. LEVEL C o SPREADER W TO OUTFALL INTO A VEGETATED /1J FILTER STRIP WITH B SOILS. VEGETATED ° L- / FILTER TRIP T TREAT RUNOFF FR M N ITE 1 7 _ S O0 ONSITE NOTES' - �-o 1. COLLINS ENGINEERING PERFORMED AN ENERGY BALANCE CALCULATION FOR THE ONSITE SUBAREAS A & B. THIS CALCULATION DETERMINED A / I / / I I / ,-�-� f Y777V cif I - DA 'A'. SEE SHEET 13A FOR DETAILS.' MAXIMUM PEAK FLOW OF 2.10 cfs WAS ACCEPTABLE TO BE IN COMPLIANCE WITH MINIMUM CHANNEL PROTECTION CALCULATIONS. THE PROPOSED // / / J _ �___ :;__i- ___ ___f--- i___F ), i j '' VSMP AMENDMENT #2 MEETS THIS THRESHOLD. PLEASE SEE THE CALCULATIONS PACKET FOR DETAILS. / J / i -r L--- F --'� i \ I 2. THE ORIGINALLY APPROVED WPO 202000037 PLAN BY SHIMP ENGINEERING PERFORMED ENERGY BALANCE CALCULATIONS ALONG THE COW I `� // 1�'IT• BRANCH STREAM AS WELL. SHIMP ENGINEERING USED THE 'REDUCTION METHOD' IN THEIR ENERGY BALANCE CALCULATIONS, AS SHOWN IN / � �_ I Ir THEIR 10/16/20 SWM CALCULATION PACKET. SHIMP ENGINEERING DETERMINED A 4.25 cfs RUNOFF REDUCTION WAS REQUIRED DURING THE 1-YR STORM EVENT TO MEET ENERGY BALANCE REQUIREMENTS FOR THE PROJECT. THIS VSMP AMENDMENT #2 REDUCES THE 1-YEAR RUNOFF BY 4.47 cfs, AS SHOWN ABOVE 6.55-2.08 . THIS 4.47 cfs IS CONSISTENT WITH THE PREVIOUSLY APPROVED SHIMP ENGINEERING RUNOFF REDUCTION OF 4.52 cfs, AND EXCEEDSTHEMINIMUM 4.25 cfs REQUIRED REDUCTION COMPUTED IN THE 10/16/20 CALCULATION PACKET. / / \\ j / ." n, rye- M- AfF� - n -.eo-� / / z 3 PROTECTION RETHE PEAK AUIREMENTS EPLOPMENT EASE SEEFLOWS CALCULATIONSPACKET FOR DETAIRS RE -DEVELOPMENT FLOWS, HEREBY SATISFYING FLOOD SITE OUTFACE #3 R / L9 AVINITY II SWM Q \\ EDIRECTS .= "' L FACILITY OUTFALL (AMENDMENT #2 - f LAND, OF RAI E T RE IN j ��� / Uj c OFFSITE RUNOFF AROUND THE `��j ?��+ �% = _ TO WPO 201500057 UNDI5TUR8 TO E ROUTE E -06*\ r -- PROPOSED DEVELOPMENT APPROVED AVINITYI - �� / Cn `> ) � =� � \, �-- PROPOSE-0-BYPASS STORM PROPOSED STOR EWER RUNG > IN ADDITION TO MEETING THE ONSITE CHANNEL & FLOOD PROTECTION REQUIREMENTS DISCUSSED ABOVE, THIS VSMP AMENDMENT #2 ANALYZED THE / /� / �. SWM FACILITY -� - C DIN O STRU UR S 6 & 8. n / N FLOWS TO THE COW BRANCH STREAM AT THE POINT OF ANALYSIS, OR'POA' AS LABELED ON THIS SHEET. THE FLOWS IN THE COW BRANCH STREAM ARE I I III OUTFALL (AMENDMENT \ EWER _R REDIRECT THE I , J �{FEFSITE RtiNOFF AROUND -_ IN THE POST -DEVELOPMENT STATE AT THE POINT OF ANALYSIS THAN IN THE PRE -DEVELOPMENT STATE. THIS ANALYSIS ACCOUNTED FOR THE - - - .,,�, TO WPO 201300044). `: a - / // - - THE SUBJECT PROPERTY -� \ / 3 PROPOSED GALAXIE FARM IMPROVEMENTS OUTSIDE OF ONSITE SUBAREAS A & B THAT ARE RELEASED IN ANON -CONCENTRATED FASHION. PLEASE SEE '` ' � "--- � �" "`� `'" ' THE TABLES BELOW FOR A SUMMARY OF THIS, AS WELL AS THE ATTACHED EXHIBIT SHOWING THE OVERALL WATERSHED TO THE COW BRANCH STREAM. °J PRE -DEVELOPMENT STORMWATER MANAGEMENT PLAN, SCALE 1'=80' 1 1 I \ \ / / / w e OVERALL FLOWS TO COW BRANCH STREAM (AT POA) \ / 100' OF LF w A ELEV.=10', n 265' of 4NC. FLOW W/ A ELEV.=42'// (USED TO CONFIRM POST -DEVELOPMENT FLOWS ARE LESS THAN PRE -DEVELOPMENT FLOWS \ / o / I 100' OF OLF w� A ELEV.=6% PROPOSED ESC/LIM S DISTURBANCE DOWNSTREAM FROM THE GALAXIE FARM DEVELOPMENT) // \ / / I I �125' of CONC. FLOW W/ A ELEV.=3 ' y. BOUNDARY DEFINES THE griOPo ED/ VRRM WATER QUALITY BOUND•°po-V• TvP / N ✓/� UPLAND r OFFSITE DRAINAGE TO REMAIN � I , I • .� � TOTAL BOUNDARY AREA=12.72 ACf�ES. / � I � Z � Area, 1-year Flow, 2-year Flow, 10-year Flow, / / UNDISTURBED & TO,BE ROUTED TO THE I \ \ / Pre -Development CN ac. CPS cfs cfs / PROPATO E DIRECTED SEWER RUNOF A% / / / TO BE DIRd=CTED I0 ST4. i a Onsite DAA (Pre-Dev.) 64 6.40 4.45 7.29 18.02 Onsite DA B (Pre-Dev.) 64 3.00 2.10 3.43 8.46 , / / / / \ ♦ � \ Q J Offsite DAC (Pre-Dev.) 58 226 13.58 27.35 68.39 / / / \ ♦ y i �1 a Offsite DAD Pre-Dev. 57 146 7.95 17.72 47.84 ,� I / / / ♦ ♦ ♦ ♦ �♦ ♦ / \ LL co Avinity I Routings ) 61.9 35.37 3.41 4.74 37.20 / / / / / / A \ ♦ 14 Avinity II Routings 80.5 7.95 1.04 2.09 8.50 a SpringHill Village DA'A' Routings 74.4 19.10 2.34 12.60 39.91 g g / �� 1 o Spring Hill Village DA'B' 72 12.25 7.41 11.54 25.66 V / I 59 456.07 42.28 86.75 253.99 \ V / / / / / / / / / IA V� / \ / LLI W 3 V� � ♦ i , , , / I / I , aa' �� �� L9 PDA Area, 1-year Flow, 2-year Flow, 10-year Flow, Post -Development CN I \ ( ( / / I \ _ � /1 ac. cfs cfs cfs � � I � V \ \ V / � � � I i � � oN B � � �/ � � Z Onsite DAA�Post-Dev. 78 8.67 0.35 6.69 19.95 I \ V / A �` \ '� O Q n Onsite DAB Post-Dev. 83 0.73 1.73 2.34 4.28 \ , 1 \ I\ 1 1 15" CMP CULVERT RELEASES RUNOFF FROM Offsite DAC (Post-Dev.) 58 226 13.69 27.48 68.47 \� \ I \ OFFSITE AREAS ONTO THE SUBJECT \ / �• ( n Offsite DAD Post-Dev. 57 146 7.95 17.72 47.84 \ \` PROPERTY. IN THE POST -DEVELOPMENT' ( ) STATE THE RUNOFF WILL CONTINUE TO BE Avinity I Routings 61.9 35.37 3.41 4.74 37.20 I \ \ ' \ 1 \ COL ECTED WITH A CULVERT & THE RUNOFF \ 1 1 1 \ \ \ ' I \ \ L . . I T / / / -- - / �Z' Avinity I I Routings 80.5 7.95 1.04 2.09 8.50 I � I I l � WILL OUTFALINTO STR4� � \ 1 E Spring Hill Village DA'A' Routings 74.4 19.10 2.34 12.60 39.91 / J p g g g UP NDjOFFSITE DRAINAGE T\R A N Spring Hill Village DA'B' 72 12.25 7.41 11.54 25.66 'DI STURBED & TO BE ROUTED kHi �� V W 7� / / 60 456.07 37.92 85.21 251.81 1 ooEDIRECTED rzb F � � � � � _ ��� � \ � PLC D BYPASS vVV Q I I I BE INTO STR,�E� \ / �i \ �\ \.. f' * * • _ -_.... GALAXI _ C--.... �, \l\ / d / ,C / , " , /i'/ _ �t ti = -� '1 ✓k ;' U� L.L_ �-�, 175,200 sf m« ye / / / / / / f i �i \ o Buildings 2,800 sf / / I I-s„ t_ , / // / 100' OF F w/ LEV. /\ / ` f \ ~ a Post -Development DA B Impervious Areas Paved Roads 3,100 sf I I I I ) \ \ \ // / 25fY0�ON FL / A LEJ�--36' - ` /^� W ,975750 ssff I'III I I F w/A ELE., { Residences 1,500 sf - >\ Paved I-� OF OL >' s & Drivewa s ,200' of CON FLOW Uj Roads 161Q825 sf v. oo' oFcTI OF QOSidewalks RoaoseDmow ft s 19,225 sfVRRM WaterQuality ImperviousArea Summary FACILITY X 0 Proposed Impervious Areas to Offsite DA C Total Impervious Areas Undetained 32,450 sf Proposed Impervious Areas to Offsite DA D Total Impervious Areas Undetained 1,125 sf 219,450 5f w 0219 PPROVED AVINITY II SWM CHANNEL AND FLOOD PROTECTION SUMMARY - L- - ---� \�\ SCALE FACILITY OUTFACE (AMENDMENT #2 �� LAND, OF RAINAGE T RE IN = TO WPO 201500057) _ UNDiSTURB TO BE ROUTE TOE AS SHOWN Method of 9VAC25-870-66 Method of 9VAC25-870-66 Method of 9VAC25-870-66 Method of 9VAC25-870-66 _ _ -APPROVED AVINITYI _ PROPOSED STOR EWER RUNOFF Channel Protection Compliance Limits of Analysis for Channel Protection Flood Protection Compliance Limits of Analysis for Flood Protection SWMOUT FACILITY C D I o STRU UR S 6 & 8. p Y P Y ( I I 4 , ��\/ SHEET N0. n OUTFACE AMENDMENT �__ m Onsite Subareas A & B Section B.3.a (Energy Balance) N/A (Energy Balance Satisified) Section C.2.b (10-yr Post < 10-yr Pre) N/A (Section C.2.b) 7o wao zol3000aa) Y -� UI \ % �12 � - - / =. , , DRY DETENTION BASIN CONSTRUCTION NOTES: FACILITY PLANTING SPECIFICATIONS: 1. THE DETENTION BASIN SHALL HAVE TURF GROUND COVER, SUCH AS GRASS OR SOME OTHER FORM OF A VEGETATIVE GROUNDCOVER. LANDSCAPING BEYOND THIS IS OPTIONAL AND IS NOT REQUIRED. 2. THE PROPOSED INTERIOR SIDE SLOPES OF THE BASIN SHALL BE A MAXIMUM OF 3:1 TO REDUCE THE RISK OF EROSION. THE PROPOSED FLOOR SLOPES SHALL BE GRADED TO PROVIDE POSITIVE DRAINAGE AT ALL TIMES TO THE RISER STRUCTURE. 3. WOODY VEGETATION SHALL NOT BE PLANTED OR ALLOWED TO GROW WITHIN 15 FEET OF THE TOE OF THE EMBANKMENT NOR WITHIN 25 FEET OF THE PRINCIPAL SPILLWAY STRUCTURE. 4. THE SOILS IN THE STORMWATER BUFFER AREA ARE OFTEN SEVERELY COMPACTED DURING THE CONSTRUCTION PROCESS, TO ENSURE STABILITY THE DENSITY OF THESE COMPACTED SOILS CAN BE SO GREAT THAT IT EFFECTIVELY PREVENTS ROOT PENETRATION AND, THEREFORE, MAY LEAD TO PREMATURE MORTALITY OR LOSS OF VIGOR. AS A RULE OF THUMB, PLANTING HOLES SHOULD BE THREE TIMES DEEPER AND WIDER THAN THE DIAMETER OF THE ROOTBALL FOR BALL -AND -BURLAP STOCK, AND FIVE TIMES DEEPER AND WIDER FOR CONTAINER -GROWN STOCK. 5. AVOID SPECIES THAT REQUIRE FULL SHADE, OR ARE PRONE TO WIND DAMAGE. EXTRA MULCHING AROUND THE BASE OF TREES AND SHRUBS IS STRONGLY RECOMMENDED AS A MEANS OF CONSERVING MOISTURE AND SUPPRESSING WEEDS. 1. THE CONTRACTOR SHALL BE RESPONSIBLE FOR LAYOUT OF ALL WORK COVERED UNDER THESE PLANS. 2. LANDSCAPE CONTRACTOR SHALL REFER TO THE STANDARDIZED LANDSCAPE SPECIFICATIONS FORTH ESTATE OF VIRGINIA FOR ADDITIONAL INFORMATION. THE CONTRACTOR SHALL ABIDE BY ITS CONTENTS; HOWEVER ANY NOTES OR SPECIFICATIONS ON THE PLANS SHALL SUPERSEDE THOSE OUTLINED IN THE SPECIFICATIONS MANUAL (COPIES ARE AVAILABLE FOR A FEE FROM THE VIRGINIA CHAPTER OF THE AMERICAN SOCIETY OF LANDSCAPE ARCHITECTS, VIRGINIA NURSERYMEN'S ASSOCIATION, INC. AND THE VIRGINIA SOCIETY OF LANDSCAPE DESIGNERS). ALL DISCREPANCIES SHALL BE BROUGHT TO THE ATTENTION OF COLLINS ENGINEERING PRIOR TO THE CORRESPONDING CONSTRUCTION ACTIVITY. 3. ALL PLANT MATERIAL SHALL MEET THE MINIMUM SPECIFICATIONS AND STANDARDS DESCRIBED IN THE CURRENT ISSUE OF THE AMERICAN STANDARD FOR NURSERY STOCK, PUBLISHED BY THE AMERICAN ASSOCIATION OF NURSERYMEN, 1250 STREET, NW, SUITE 500, WASHINGTON, DC 20005. 4. THE CONTRACTOR SHALL VERIFY ALL DIMENSIONS IN THE FIELD AND NOTIFY THE DESIGNER OF ANY VARIANCE FROM THE PLAN. 5. THE LANDSCAPE CONTRACTOR IS RESPONSIBLE FOR VERIFYING THE LOCATION OF ANY ONSITE UTILITIES (CALL MISS UTILITY AT 1-800-552-7001 BEFORE ANY EXCAVATION). 6. REFER TO THE APPROVED FINAL SITE PLANS FOR ANY DETAILED SITE INFORMATION. 7. ALL WORK SHALL BE COORDINATED WITH OTHER PARTIES. 8. PLANTS WILL BE PREPARED FOR SHIPMENT IN A MANNER THAT WILL NOT CAUSE DAMAGE TO THE BARK, BUDS, BRANCHES, STEMS, OR OVERALL SHAPE OF THE STOCK. CONTAINER GROWN PLANTS WILL BE TRANSPORTED IN THE CONTAINERS IN WHICH THEY HAVE GROWN. 9. ALL PLANT MATERIAL, UNLESS OTHERWISE SPECIFIED, SHALL BE UNIFORMLY BRANCHED AND HAVE A VIGOROUS ROOT SYSTEM. PLANT MATERIAL SHALL BE HEALTHY, VIGOROUS, AND FREE FROM DEFECTS, DECAY, DISEASES, INSECT PEST EGGS, AND ALL FORMS OF INFESTATION. ALL PLANT MATERIAL SHALL BE FRESH, FREE FROM TRANSPLANT SHOCK OR VISIBLE WILT. PLANTS DEEMED UNHEALTHY WILL BE REJECTED. 10. ALL CONTAINER STOCK SHALL HAVE BEEN PROPAGATED IN A CONTAINER LONG ENOUGH FOR THE ROOT SYSTEM TO HAVE DEVELOPED SUFFICIENTLY TO HOLD ITS SOIL. CONTAINER STOCK WITH POORLY DEVELOPED ROOT SYSTEMS WILL NOT BE ACCEPTED. 11. PLANTS NOT INSTALLED ON THE DAY OF ARRIVAL ON SITE SHALL BE STORED AND PROTECTED BY THE CONTAINER. OUTSIDE STORAGE AREAS WILL BE SHADED AND PROTECTED FROM THE WIND AND SUN. PLANTS STORED ON SITE SHALL BE PROTECTED FROM ANY DRYING AT ALL TIMES BY COVERING THE BALLS OR ROOTS WITH MOIST SAWDUST, WET BURLAP, WOOD CHIPS, SHREDDED BARK, PEAT MOSS, OR OTHER SIMILAR MULCHING MATERIAL. 12. THE OWNER RESERVES THE RIGHT TO SUBSTITUTE PLANT MATERIAL TYPE, SIZE AND/OR QUANTITY. ANY SUBSTITUTIONS MUST BE APPROVED BY THE INSPECTOR INITIALLY, AND THEN THE DESIGNER. 13. MINOR FIELD ADJUSTMENTS MAY BE NECESSARY DUE TO SITE CONDITIONS (EX: ROOTBALL AND UTILITY CONFLICT). MAJOR ADJUSTMENTS MUST BE APPROVED BY THE DESIGNER. 14. NO PLANTING SHALL OCCUR WHEN THE SOIL IS FROZEN. 15. PLANT MATERIAL SHALL BE PLACED IN EXISTING SOIL WITH EACH PLANTING PIT EXCAVATED TO A SIZE SUFFICIENTTO CONTAIN THE ENTIRE ROOT BALL OR ROOT MASS, WITHOUT CRAMPING ROOTSTOCK. 16. THE CONTRACTOR SHALL MAINTAIN A ONE (1) CALENDAR YEAR 90%CARE AND REPLACEMENT WARRANTY FOR ALL PLANTINGS. THE PERIOD OF CARE AND REPLACEMENT SHALL BEGIN AFTER INSPECTION AND APPROVAL OF THE COMPLETE INSTALLATION OF ALL PLANTS AND CONTINUE FOR ONE CALENDAR YEAR. 17. THE CONTRACTOR IS RESPONSIBLE FOR REMOVAL AND DISPOSAL OF TRASH AND DEBRIS WITHIN THE LIMITS OF THE PLANTING ON A DAILY BASIS. 18. THE CONTRACTOR WILL NOT BE RESPONSIBLE FOR PLANT MATERIAL THAT HAS BEEN DAMAGED BY VANDALISM, FIRE, OR OTHER ACTIVITIES BEYOND THE CONTRACTOR's CONTROL. FACILITY CONSTRUCTION 1. DETENTION BASINS MAY SERVE AS SEDIMENT BASINS AND/OR TRAPS DURING PROJECT CONSTRUCTION. IF THIS IS DONE, THE VOLUME SHALL BE BASED ON THE MORE STRINGENT SIZING RULE (EROSION AND SEDIMENT CONTROL REQUIREMENTS VS. STORMWATER TREATMENT REQUIREMENTS). INSTALLATION OF THE PERMANENT RISER SHALL BE INITIATED DURING THE CONSTRUCTION PHASE, AND DESIGN ELEVATIONS SHALL BE SET WITH FINAL CLEANOUT OF THE SEDIMENT BASIN AND CONVERSION TO THE POST -CONSTRUCTION POND IN MIND. APPROPRIATE PROCEDURES SHALL BE IMPLEMENTED TO PREVENT DISCHARGE OF TURBULENT WATERS WHEN THE BASIN IS BEING CONVERTED TO AN DETENTION BASIN. 2. THE DETENTION BASIN SHALL ONLY BE CONSTRUCTED AFTER THE CONTRIBUTING DRAINAGE AREA TO THE POND IS COMPLETELY STABILIZED. IF THE PROPOSED POND SITE WILL BE USED AS A SEDIMENT TRAP OR BASIN DURING THE CONSTRUCTION PHASE, THEN THE FACILITY WILL BE DEWATERED, DREDGED AND RE -GRADED TO DESIGN DIMENSIONS AFTER THE ORIGINAL SITE CONSTRUCTION IS COMPLETE. MODIFICATIONS SHALL BE MADE TO THE RISER, ORIFICES AND BARRELS AS REQUIRED SO THAT THEY ARE CONSISTENT WITH THE FINAL CONSTRUCTION SPECIFICATIONS. 3. THE CONTRACTOR SHALL ASSEMBLE CONSTRUCTION MATERIALS ON -SITE, MAKING SURE THEY MEET DESIGN SPECIFICATIONS AND ARE PREPARED AT STAGING AREAS WHEN POSSIBLE. 4. THE CONTRACTOR SHALL CLEAR AND STRIP THE PROJECT AREA IF REQUIRED TO THE DESIRED SUB -GRADE. 5. INSTALL E&S CONTROLS PRIOR TO CONSTRUCTION OF THE BASIN, INCLUDING TEMPORARY DE -WATERING DEVICES AND STORMWATER DIVERSION PRACTICES. ALL AREAS SURROUNDING THE BASIN THAT ARE GRADED OR DENUDED DURING CONSTRUCTION SHALL BE PLANTED WITH TURF GRASS, NATIVE PLANTINGS, OR OTHER APPROVED METHODS OF SOIL STABILIZATION. 6. CONTRACTOR SHALL EXCAVATE THE CORE TRENCH AND INSTALLTHE SPILLWAY PIPE DURING THE ESC PHASE. 7. CONTRACTOR SHALL ALSO INSTALLTHE RISER, OUTFLOW STRUCTURE AND/OR THE BARREL(s) WITH PERMANENT COLLARS DURING THE ESC PHASE. CONTRACTOR SHALL ENSURE THE TOP INVERT OF THE OVERFLOW WEIR IS CONSTRUCTED LEVEL ATTHE DESIGN ELEVATION. 8. THE CONTRACTOR SHALL CONSTRUCT THE EMBANKMENT AND ANY INTERNAL BERMS IN 8-TO 12-INCH LIFTS, COMPACTION SHALL BE COMPLETED IN LIFTS WITH APPROPRIATE EQUIPMENT. THE CONTRACTOR SHALLALSO ADHERE TO THE CLAY LINER SPECIFICATIONS OUTLINED IN TABLE 14.4 BELOW: Table 14.4. Clay Liner SpecRcadons Property Test Method Unit Specification Perrneabiltty ASTM D-2434 Cmisec 1 x 10 Plasticity Index of Gay ASTM D-4231424 % Not less than 15 Liquid mdofClay ASTM D-2216 % Not less than 30 Clay Particles Passing ASTM D-422 % Not less than 30 Clay Compaction ASTM D-2216 % 95%of standard proctordens 9. RADE UNTILTHE APPROPRIATE ELEVATION AND DESIRED CONTOURS ARE ACHIEVED FOR THE BOTTOM AND SIDE SLOPES OF THE BASIN. 10. CONTRACTOR SHALLTHEN CONSTRUCT THE EMERGENCY SPILLWAY IN CUT OR STRUCTURALLY STABILIZED SOILS. 11. THE CONTRACTOR SHALLTHEN FINISH CONSTRUCTION OF ALL OUTLET STRUCTURES, INCLUDING DOWNSTREAM RIP -RAP APRON PROTECTION IF APPLICABLE. 12. THE CONTRACTOR SHALL NEXT STABILIZE EXPOSED SOILS BY HYDROSEEDING OR SEEDING OVER STRAW. 13. THE CONTRACTOR SHALLTHEN INSTALLTHE APPROPRIATE BASIN LANDSCAPING IN ACCORDANCE WITH THE APPROVED PLANS IF APPLICABLE. FACILITY MAINTENANCE: MAINTENANCE OF THE DETENTION BASIN IS DRIVEN BY ANNUAL INSPECTIONS THAT EVALUATE THE CONDITION AND PERFORMANCE OF THE FACILITIES. DURING THESE INSPECTIONS THE FOLLOWING TASKS SHALL BE PERFORMED BY THE CONTRACTOR IN THE FIRST YEAR FOLLOWING INSTALLATION, AND THE OWNER THEREAFTER: 1. MEASURE SEDIMENT ACCUMULATION LEVELS IN THE BASIN. 2. MONITOR THE GROWTH OF THE GROUNDCOVER AND ANY TREES AND SHRUBS PLANTED, AS APPLICABLE. RECORD THE SPECIES AND THEIR APPROXIMATE COVERAGE AND NOTE THE PRESENCE OF ANY INVASIVE PLANT SPECIES AS APPLICABLE. 3. INSPECTTHE CONDITION OF STORMWATER INLETS TO THE BASIN FOR MATERIAL DAMAGE, EROSION OR UNDERCUTTING. 4. INSPECTTHE BANKS OF UPSTREAM AND DOWNSTREAM CHANNELS FOR EVIDENCE OF SLOUGHING ANIMAL BURROWS BOGGY AREAS WOODY GROWTH OR GULLY EROSION THAT MAY UNDERMINE EMBANKMENT INTEGRITY. 5. INSPECT BASIN OUTFALL CHANNEL FOR EROSION, UNDERCUTTING, RIP -RAP DISPLACEMENT, WOODY GROWTH, etc. 6. INSPECT CONDITION OF PRINCIPAL SPILLWAY AND RISER FOR EVIDENCE OF SPALLING JOINT FAILURE LEAKAGE CORROSION OR OTHER FAILURES. 7. INSPECT CONDITION OF ALL TRASH RACKS, REVERSE SLOPED PIPES OR FLASHBOARD RISERS AS APPLICABLE FOR EVIDENCE OF CLOGGING, LEAKAGE, DEBRIS ACCUMULATION OR OTHER FAILURES. 8. INSPECT MAINTENANCE ACCESS TO ENSURE IT IS FREE OF WOODY VEGETATION AND CHECK TO SEE WHETHER VALVES MANHOLES AND LOCKS CAN BE OPENED AND OPERATED. 9. INSPECT INTERNAL AND EXTERNAL SIDE SLOPES OF THE BASIN FOR EVIDENCE OF SPARSE VEGETATIVE COVER, EROSION, OR SLUMPING. 10. OWNER OR CONTRACTOR SHALL MAKE NEEDED REPAIRS IMMEDIATELY. FACILITY INSPECTION: MULTIPLE INSPECTIONS ARE CRITICAL TO ENSURE THE BASIN(s) ARE PROPERLY CONSTRUCTED. BECAUSE THE TIMING OF THE INSTALLATION IS DICTATED BY THE CONTRACTOR, THE CONTRACTOR SHALL BE RESPONSIBLE FOR CONTACTING THE ENGINEER AND INSPECTOR PRIOR TO INSTALLATION. MULTIPLE SITE VISITS AND INSPECTIONS ARE REQUIRED TO BE SCHEDULED BY THE CONTRACTOR WITH THE ENGINEER AND INSPECTOR DURING THE FOLLOWING STAGES OF THE DETENTION BASIN's CONSTRUCTION PROCESS: 1. PRE -CONSTRUCTION MEETING 2. INITIAL SITE PREPARATION (INCLUDING INSTALLATION OF PROJECT E&S CONTROLS) 3. EXCAVATION/GRADING (e.g., INTERIM/FINAL ELEVATIONS) 4. INSTALLATION OF THE EMBANKMENT, THE RISER/PRIMARY SPILLWAY, AND THE OUTLET STRUCTURE(s). 4. DETENTION BASIN INSTALLATION e.. INTERIM AND FINAL ELEVATIONS 5. PLANTING PHASE (WITH AN EXPERIENCED LANDSCAPE ARCHITECT PRESENT/DIRECTING IF APPLICABLE) 6. FINAL INSPECTION (DEVELOP A PUNCH LIST FOR FACILITY ACCEPTANCE) nceVirgnwater Management Handbook {1999) nn THE FAAOAsvencnT GRADING Tuo General Construction notes for Stormwater Management Plans 1. All dams and constructed fill to be within 95% of maximum dry density and 2% of optimum moisture content. All fill material to be approved by a geotechnical engineer. A geotechnical engineer is to be present during construction of dams. 2. Pipe and riser joints are to be watertight within stormwater management facilities. 3. For temporary sediment traps or basins which are to be converted to permanent stormwater management facilities; conversion is not to take place until the site is stabilized, and permission has been obtained from the County erosion control inspector. GENERAL SWM NOTES: 2. STATE APPROVED TRASH RACKS SHALL BE INSTALLED ON ALL ORIFICE OPENINGS. SEE THIS SHEET, OR EQUIVALENT, FOR DETAILS. 2. CONCRETE FOUNDATIONS SHALL BE INSTALLED ON ALL RISER STRUCTURES MEETING MINIMUM VESCH 3.14 SPECIFICATIONS. 3. CONTRACTOR SHALL HIRE ATHIRD PARTY GEOTECHNICAL ENGINEER TO ENSURE THE EMBANKMENTS ARE STRUCTURALLY SOUND. ALL EXISTING AND PROPOSED FILL MATERIAL AND PROPOSED CONSTRUCTION SHALL BE APPROVED BY AN ONSITE GEOTECHNICAL ENGINEER PRESENT DURING THE CONSTRUCTION OF THE EMBANKMENTS AND FILL AREAS, AND PRESENT DURING THE CORE SAMPLING. 4. THE DOWNSTREAM EMBANKMENT SIDE SLOPES OF ALL PERMANENT FACILITIES SHALL HAVE A MAXIMUM 3:1 SLOPE. 5. CONTRACTOR SHALL EXCAVATE SEDIMENT LADEN MATERIAL IN THE ESC SEDIMENT BASINS ATTHE TIME OF THE FACILITIES' CONVERSIONS TO PERMANENT SWM FACILITIES, IF APPLICABLE. AT SUCH TIME THE CONTRACTOR SHALL REGRADE THE SEDIMENT BASINS TO THE PROPOSED GRADES SHOWN ON THE SWM SHEETS. THE CONTRACTOR SHALL MINIMIZE SOIL COMPACTION DURING THE CONVERSIONS. ALL SLOPES GREATER THAN 3:i SHALL BE PLANTED WITH NON -EROSIVE LONG GRASSES OR OTHER TYPES OF NON -EROSIVE PLANTINGS. SECTION A-9: TYPICAL GRAPHICAL DETAELS Homogeneous till 1 I 4' min �\ Cut off trench-4- below suitable ) material Sal or rock L-----------, TYPICAL HOMOGENEOUS EMBANKMENT Perforated a FOUNDATION DRAIN Blanket drain BLANKET DRAIN III or grovel / dMin Sorel, qr. Or =k dlon outlet Rode or gravel Rat Fa Aftin aTronsition tiller Transition filter CHIMNEY DRAIN TOE DRAIN Figure A -la. Homogeneous Embankntefus ts: Seepage Controls EMBANKMENT NOTES: THE EMBANKMENTS SHALL HAVE A COMPACTED CLAY CORE WITH A CUTOFF TRENCH & BE IN ACCORDANCE WITH THE DETAILS SHOWN IN THIS PLAN. BERMS AND SPILLWAYS SHALL BE STABILIZED WITH EC-3 MATTING & RIPRAP AND THE REMAINING DISTURBED SLOPES SHALL BE STABILIZED WITH EC-2 MATTING. ALL BERM FILL MATERIAL SHALL CONSIST OF ML, CL, SC OR GC SOILS & BE FREE OF WOOD, ROOTS, ROCKS OR ANY OTHER NON COMPACTING SOIL. COMPACTED FILL SHALL BE PROCTOR MAXIMUM DRY DENSITY ASTM D698 AND HAVE A MINIMUM OF 95%OF MAXIMUM DRY DENSITY AND 2%OF OPTIMUM MOISTURE CONTENT. ALL FILL MATERIAL AND CONSTRUCTION SHALL BE APPROVED BY AN ONSITE GEOTECHNICAL ENGINEER PRESENT DURING THE CONSTRUCTION OF THE EMBANKMENTS AND FILL AREAS. Sterm!I TM ROUND SERIES TRASH RACK (OR EQUIVALENT) CONCRETE MANHOLE STANDARD 60 INCH RACK SHOYVN DIMENSIONS IN INCHES PLAN StormRI Round Series for Concrete Manhole Part Na Blow Dim Is dlmC Min ID 1111111011111 RS-24 17k 14% 28 24 3D RS-36 21W 14 40 36 43 RS48 27 14 K . 48 57 RS-60 27% .V, 66?i 6o 70 Plastic SOIUUons, Inc. CUSTOMER PO BOX 4356, N'Irclrsicr, VA 22604 238 hK3x: W. YNnchesxr, VA 2260 :977) 877-5727 phone PROJECT. (540) 722-2219 fax httµ//www.plutle-eoWtlon.em, Splash Block Instructions Before installation of the Splash Block, or any rain diverting accessory, make sure the grade around the foundation slopes away from the house. There should be a 6 inch fall in the first 10 feet from the house. s 10 Feet � 6 in 1 • xoe emucruxwr vwncer MA9rC90rUnP19. IX4 ISOMETRIC CONCRETE STRUCTURE DIMEMSONS INSIDE STRUCTURE DIMENSION OUTSIDE STRUCTURE DIMENSION AVAILABLE OPTIONS CROSS BRACING FOR OVERHANG HDPE ANTI -VORTEX PLATE DAM DRAWN W. APPO BY: DETAIL Patent -pending cut-out to allow for fitment of downspout with low clearance of elbow Water directing chevron pattern reduces washout AMERIMAX amerimax.com 1 800-347-2586 mfnrrrlamwnmwx rnm Hole for landscape spike at front of splashblock allows it to be secured to ground BASIN A DETAIL, SCALE 1"=30' I - ^ /I 0 CONTRACTOR SHALL FASTEN A 12 GAUGE STEEL PLATE TO THE INSIDE OF THE CONCRETE STR. A6's RISER WHERE STR. AS's 018" OPENING IS LOCATED. STEEL PLATE TO BE CONTRACTOR SHALL FASTEN A 12 GAUGE FASTENED VIA GROUT, OR IN A SIMILARLY SUFFICIENT STEEL PLATE TO THE CONCRETE STR. A6 MANNER, AND SHALL COVER THE UPPER io"OF THE RISER VIA GROUT, ORIN A SIMILARLY / \ OPENING. BLOCKING THE UPPER io"OF THE OPENING SUFFICIENT MANNER, TO PLUG ITS / WILL REDUCE THE OPENING's AREA, RESULTING IN AN OPENING. STEEL PLATE TO COVER THE / EQUIVALENT AREA TO A 12" OUTFALL PIPE. STEEL PLATE AMENDMENT ft s 05" LOW -FLOW ORIFICE I TO EXTEND BEYOND THE LIMITS OF THE 018" OPENING & OPENING(INV.=470.o0). STEEL PLATE TO TO BE INSTALLED AT THE TIME OF THE CONVERSION FROM EXTEND BEYOND THE LIMITS OF THE OS" A TEMPORARY ESC BASIN TO A PERMANENT SWM BASIN. OPENING & TO BE INSTALLED AT THE TIME F THE CONVERSION FROM ATEMPORARY \ CONTRACTOR SHALL RETROFIT THE ASBUILT STR. A6 RISER. THE AMENDMENT #Vs LOWER ESC BASIN TO A PERMANENT SWM BASIN. SECTION SHALL REMAIN, WHICH CONSISTS OF A VDOT STD. B-1 (CONCRETE MANHOLE BASE WITH A 048") & A REINFORCED CONCRETE FOUNDATION. THE ASBUILT STR. A6's 05" / LOW -FLOW ORIFICE OPENING SHALL BE PLUGGED WITH A STEEL PLATE. SIMILARLY, A 018" OPENING FOR STR. AS PORTION OF THE RISER's 018" OPENING FOR STR. AS SHALL BE BLOCKED WITH A STEEL RISER STR. A6 � � / TO BE PARTIALLY BLOCKED. � PLATE. SEE STR. A6 PLUGS DETAIL ON THIS SHEET. ABOVE THESE TWO PLATES, THE RISER'S UPPER RINGS SHALL BE REMOVED. NEW UPPER 48" RINGS SHALL BE INSTALLED - - -- - - - WITH A RIM ELEVATION OF 481.50'. UPPER 048" RINGS TO INCLUDE (5) FIVE Oil3" 05" LOW -FLOW ORIFICE ---- MID -FLOW ORIFICES WITH INVERT ELEVATIONS=479.75'. IF THE STRUCTURAL INTEGRITY TO BE PLUGGED. IS NOT MAINTAINED WITH THE RETROFIT, CONTRACTOR SHALL REMOVE & REPLACE STR. A6 WITH A NEW RISER & FOUNDATION MEETING THIS PLAN's SPECIFICATIONS. ALL STR. A6 PLUGS DETAIL ORIFICE OPENINGS SHALL HAVE STATE APPROVED TRASHRACKS, TYPICAL. SEE THE NOT TO SCALE DETAILS WITHIN THIS SET FOR ADDITIONAL INFORMATION. io' WIDE TOP OF _ - 485 ELEV.1-484.0( MH-2 (60" ^�� ID) 2 INV IN: 471.30 (4) INV IN: 468.90 (A3) INV OUT: 468.80 (1) 2 EMBAN MENT ACCO DANCE / THE DE IGNS S OWN WTHIN THIS SET. 2 10' ELIEV.TO 4.0o M PR POSED 485 , 485 480 G ?ADE PROPOS D VDOT STD. EC 1, CLAS 148 100-yr PEAK WSE=482.99 ( STR A4 FILTER FABRIC NDERIA MENTT 10-yr PEAK WSE=482.30 VDOT MH-1 EXTENDTO THE CHANN 's BANK 2-yr PEAK WSE-480.33 RIM-478.28' ONTRA OR SH LL NOT MPACT T E 1-yr PEAK WSE=479.68 -- 11=469.16 TREAM' CHANNEL WITH HE BYP SS 0� 10-469.06 (A3) STORM SEWER INSTAL TION. 480 480 475 { (L=110' , W,=1 .s', W2 S', D=2) 47 EXISTING PROPOSED 2 GRADE PROPOSED 40' WIDE VDOT CL. Al RIPRAP PROPOS D VDOT PROPOSED BASINsFLOOR SHALL - - _ LINED EMERGENCY SPILLWAY w/ 4:1 SIDE PED TO DRAIN TO THE SLOPES & FILTER FABRIC UNDERLAYMENT. T . A14 IS (o.59b MIN.) WITH 468.2 ' SPILLWAYCREST ELEV.= 4 2.5o. 2 475 LOPES THROUGHOUT. STRA , 124.80 LF OF 47 o TO PREVENT FLOTATION THE RISER BASEJT�-INV OUR 469.9 SHALL BE FIRMLY EMBEDDED 6" INTO AN 18" STR A3, 26.3 LF OF THICK REINFORCED CONCRETE FOUNDATION 018. HDPE @ 0.61% THAT IS 8'x8', AND BURIED BELOW GROUND. S R 1, 36. 2 LF OF EXISTIN 0 6 HOPE ROXIMA E LOCATION OF 470 GRADE 470 465 EXISTING8" ANITARY SEWERi,� A 46 t� 0O� � Q �J � 0� Or M cc00 OcO OO 0 0 �N r5 r- �O N N M 00 00 00 r 001--0000 r� I-- � 1--00 r �JJ J UJ W W0Wli � 0+50 1+00 0+50 1+00 1+50 2+00 2+50 3+00 3+50 3+75 BASIN A SPILLWAY PRO FILE1°=5' S(CA V)LES BASIN A SECTION lT SCOTT/R. C!LLINSZ H Lic. No. 035791,a p 4/29/22 4) N L9 0-)LU I- z LLJ ZN � � Q - � z L W N Q z C7 WN Q z N /^� Q I..L Z z > U) LCLJ 0 Cn \ G W / W V Z o z z Q O Q W ~I U , ) H� QF--I Ul w 0 3: Zi� ''Z) Lr T� W V l 0 W U-) tTtTJ U J~ LL W W Q 0� 1­4 X U 0 Q O N F w w a- U') JOB NO. 202194 SCALE AS SHOWN SHEET NO. 13 VAACR D STORMWATER DESIGN SPECIFICATION NO. 2 SHEET FLOW TO FILTER OR OPEN SPACE KEY LEVEL SPREADER WO EXISTING GRADE RIPRAP PLUNGE POOL RIPRAP APRON RF.ATm .1 n MBERS OR CONCRETE LIP WL A LENGTH OF LEVEL SPREADER Oy LIP TO BE BASED ON DESIGN FLOW AND ALLOWABLE VELOCITY TOP OF LEVEL SPREADER - I A�A.Y SHALL BE FLAT 1-3 IN. COURSE AGGREGATE OR OTHER LINING AS DESIGNED FOR STABILITY PLAN VIEW DIMENSION BASED ON UNp5%)MBED "11131nNti DE DESIGN DISCHARGE 5% r20:1) OR LEM IF W630ATSD FLTER STRIP OR GONSERV W 2' MIN � apP E lz 3 to FEET LE96 3 MIN 1O'MIN S MIN 12a �- 4 MN. DEPTH BASEDO --r REQUIRED STONE SIZE SECTION A -A Figure 2.4: Level Spreader: Pipe or Chanel Flow to Filler Strip or>Weser+pA-Conserved n Space 1 /2" sine plates noon attached with a/8' fastener ®®® 2-I/E' dla, holes e ®®m QQ0 ®®® lsomctric 1/4' HOPE plate (optiondl) pipe culvert HUPB sl al plastic with hole. 0 B-1/8' nol ea and 1/�" plate manutaelured by Plastic OOOSolutions lneor equal 0000 ,. Ke r-= =' •- a - q, -L'e=''e^Y•�;•r: • III with oplie4al plate e_Xt} i HDPE Ar..Wral plaetic wlth 2-I/R" holes and 1/4- plate SCCLIOR msnufaatur.4 by Phalle Solutions Inc. or equal 8' she hole 0 0 e 0 0 00 0 0 et. ..ne singlBAP Elevation PLASTIC DEBRIS CAGE Ro Rox 49116 SOLUTIONS Rinower VA P2e04 INC. 877-877-0727 ns.pletio-[slun[.eoln Table 2.4. Vegetated Filter Strip Materials Specifications LEVEL SPREADER 'A' & VEGETATED FILTER STRIP DETAIL, SCALE 1"=30' LEVEL SPREADER NOTES: 1. FIRST IO'FROM LEVEL SPREADER LIP MUST BE 2%OR LESS. 2. TIE BACK ENDS OF LEVEL SPREADER INTO THE SLOPE TO AVOID SCOURING. 3. CONTRACTOR SHALL NOTIFY COLLINS ENGINEERING A MINIMUM OF i WEEK PRIOR TO THE CONSTRUCTION OF THE LEVEL SPREADER. COLLINS ENGINEERING's PRESENCE IS REQUIRED AT THE TIME OF THE LEVEL SPREADER'S CONSTRUCTION SO THAT THE LEVEL SPREADER's FINAL LOCATION CAN BE FIELD VERIFIED. FINAL LOCATION MAY VARY SLIGHTLY FROM THE APPROVED PLAN IN ORDER TO PRESERVE A LARGE TREE(s). 4. CONTRACTOR SHALL USE A GEOTEXTILE FILTER FABRIC UNDERLAYMENT BELOW THE PROPOSED LEVEL SPREADER STONE. THE GEOTEXTILE FILTER FABRIC SHALL BE TENSAR TX-5 TRIANGULAR GRID, OR EQUIVALENT. Material Specification Quantity Pea Gravel (#8 or ASTM equivalent) or Diaphragm should be 2 feet wide, 1 Gravel where steep (6% +) use clean bank -run foot deep, and at least 2 inches Diaphragm VDOT #57 or ASTM equivalent (1-inch below the edge of pavement. maximum). Permeable 40% excavated soil, 40% sand, and 20% pea gravel to serve as the media for the Berm berm. Geotextile material appropriately selected for placement under rip rap or gravel to Fitter Fabrc effectively separate the stone from the ground below. Engineered Level Spreader lip should be concrete, metal, timber, or other rigid material; Level Reinforced channel on upstream of lip. VDOT EC-3. Spreader See Hathaway and Hunt (2006) or Hennco County Program Manual for aRemate designs. Erosion Control Where flow velocities dictate, use woven biodegradable erosion control fabric or Fabric or mats that are durable enough to last at least 2 growing seasons. (e.g., VDOT Erosion Control matting EC-3). Mattis If existing topsoil is inadequate to support dense turf growth, imported top soil ( loamy sand or sandy loam texture), with less than 5% clay content, corrected pH Topsoil at 6 to 7, a soluble salt content not exceeding 500 ppm, and an organic matter content of at least 2% shall be used. Topsoil shal be uniformly distributed and liahtly tom acted to a minimum depth of 6 to 8 inches Compost Shall be denved from plant material and provided by a member of the Compost U.S. Composting Seal of Testing Assurance (STA) program, as outlined in Stormwater Design Specification No. 4. 1T 1411 _\tea]y1110:13.90:11I:1111:1111Ma1.11i191:121xin1:74b1:1010 MAINTENANCE INSPECTIONS: ANNUAL INSPECTIONS SHALL BE CONDUCTED IN THE NON -GROWING SEASON DURING THE FALL AND WINTER MONTHS. INSPECTIONS SHALL TRIGGER MAINTENANCE OPERATIONS, AS REQUIRED. MAINTENANCE OPERATIONS MAY INCLUDE, BUT IS NOT LIMITED TO, SEDIMENT REMOVAL, PERIODIC MOWING, REPAIR OFTHE LEVEL SPREADER AND ENSURING A DENSE, HEALTHY VEGETATED GROUN DCOVER. MOWING SHALL BE COMPLETED AT LEAST TW ICE A YEAR TO PREVENT FURTHER WOODY GROWTH AND SPOT RE -VEGETATION OFTHE FILTER STRIP IS REQUIRED IN ORDER TO MAINTAIN Ago% MINIMUM COVERAGE RATE. THE CONTRACTOR SHALL CONDUCT THE INSPECTIONS FOLLOWING THE FIRST YEAR THE PROJECT IS COMPLETED, AND THE OWNER SHALL CONDUCT THE INSPECTIONS THEREAFTER. INSPECTIONS SHALL INCLUDE THE FOLLOWING AT A MINIMUM: i. ENSURE FLOW PATHS ARE NOT SHORT-CIRCUITED IN THE LEVEL SPREADER AND THROUGH THE VEGETATED FILTER STRIP. 2. ENSURE DEBRIS AND SEDIMENT HAS NOTACCUMULATED. 3. CHECK FOR SCOUR AND EROSION WITHIN THE LEVEL SPREADER SYSTEM AND FILTER STRIP. 4. CHECK FOR FOOT OR VEHICULAR TRAFFIC DAMAGE IN THE STONE. S. ENSURE VEGETATIVE DENSITY MEETS OR EXCEEDS go%OFTHE FILTER STRIP AREA. IN THE EVENT MAINTENANCE IS REQUIRED DURING THE ABOVE NOTED INSPECTIONS, CORRECTIVE MEASURES SHALL BE COMPLETED IMMEDIATELY. W _3 III I I - � ... • / � ...., --� < IT \ / WI 1LHIH � y� PROPOSED PUBLIC ROAD & SIDEWALK AND ' / TRbi I GRADEDGRASS LINED ACCESS TO SERVE AS STD.? ACCESS TO STR. A14, LEVEL SPREADER'A'& \,j THE VEGETATED FILTER STRIP. \ % WPROPOSED RISER STR. A14 &/I/TS \ \ / 1 / /4FR Al DOWNSTREAM PIPES TO CONVEYTHE TREATMENT VOLUME FLOW0-10' MAX. SLOPE= 2% TO LEVEL SPREADER'A'&THE .75 VEGETATED FILTER STRIP FOR I I /n7 F�<iWATER QUALITY TREATMENT. Rao-4dlv.��AWA STR 470.92- BEGINNING OF LEVEL SPREADER _ \ \ 469.75- BOTTOM OF LEVEL SPREADEdddRSRR777���""" 470.75 TOP OF LEVEL SPREADER \\\P44'LONG FLAT LEVEL LUNGE POOL& AWI DE RID RIGID LIP. LSTOR CLUDEAVDOT CL. Al RIPRAP LINING AND A SLOPED 3'(MIN.) VDOT CL. Al RIPRAP LINED EMBANK M ENT / ^ DOWNSTREAM FROM THE RIGID LIP EXTENDING TO THE FILTER STRIP. ALL / RIPRAPTO INCLUDE FILTER FABRIC UNDERLAYMENTS& BEA MIN. OF 6" DEEP. assail x / S S S / NN�- - Gj \\ 0 469.90 PROPOSED 44'WX35L'VEGETATED FILTER STRIP. FILTER STRIP TO BE UNIFORMLY GRADED TO THE SLOPES SHOWN TO ENSURE SHEET FLOW BELOW THE LEVEL SPREADER. \ // / ' COMPACTION BY HEAVY EQUIPMENT WITHIN THE E LIMITS s \ /� OF THE FILTER STRIP. SEE THIS SHEET FOR ADDITIONAL 0 2FILTER STRIP DETAILS & DESIGN REQUIREMENTS. SLOPE RANGE= 69.90 1-4`0 `- SITE OUTFALI( #1 SEE THIS SHEET FOR A SCALED \ PROFILE OF THE DRAINAGE 'Il SYSTEM, LEVEL SPREADER 'A' & \ THE VEGETATED FILTER STRIP. IIIIIII9I- IIullII IL4 // C� / l TO PREVENT FLOTATION THE RISER BASESHALLBEFIRM LYEMBEDDED6" \ C(( D 1 INTO AN i8" THICK REINFORCED / 100' WPO \ , I \CONCRETE FOUNDATION THAT IS 4'4/ BUFFER, TYP. 7 - \ \ / 1 / CONTRACTOR SHALL CALL THE COUNTY INSPECTOR & ' \ l ENGINEERING DEPARTMENT 24-HOURS BEFORE ANY ANTICIPATED CONSTRUCTION ACTIVITIES FOR THE BIVI THIS / IS INCLUSIVE OF WHEN THE LEVEL SPREADER IS READY FOR 'J \ CONSTRUCTION, BUT BEFORE STRUCTURE A7IS INSTALLED. Vegetated Filter Strips Planting Requirements 0 Vegetated Filter Strips shall be )anted at such a density to achieve a 90 /o grass/herbaceous herbaceous 9 P P Y 9 / cover after the second growing season. Vegetated Filter Strips shall be seeded, not sodded. Seeding establishes deeper roots, and sod may have muck soil that is not conducive to infiltration (Wisconsin DNR, 2007). The filter strip vegetation shall consist of turf grasses, meadow grasses, other herbaceous plants, shrubs, and trees, as long as the primary goal of at least 90% coverage with grasses and/or other herbaceous plants is achieved. Vegetation at the toe of the filter, where temporary ponding may occur behind the permeable berm, shall be able to withstand both wet and dry periods. The planting areas can be divided into zones to account for differences in inundation and slope. Additionally, the trees selected to be planted shall be 10' on -center and shall be an even mix of River Birch (Betula Nigra), Red Maple (Ater Rubrum) and Sweetgum (Liquidambar Styraciflua). No trees shall be planted within the ACSA easement. TO PREVENT FLOTATION THE RIS SHALL BE FIRMLY EMBEDDED 6" INT THICK REINFORCED CC FOUNDATION THAT IS 4k4'. FOUL` TOP TO BE SET AT GRADE, BURY REMAINDER OF THE FOUN NOTE: STRUCTURES A7-Ai4, LEVEL SPREADERW AND THE FILTER STRIP SHALL BE INSTALLED AT THE TIME OF THE TEMPORARY ESC BASIN'S CONVERSION TO A PERMANENT SWM FACILITY. STR: Al 24" RISER w/ TRASHRACK RIM=481.50' 485 IMV =47s sn' .1 PROPOSED ANOUT 24" CL GRADE RIM 47 .50 H H 480 000 N 480 00 a II STR A7- 2.7 LF > 012" HDPE ®21.: Z (A ELEV.=7") 475 I 470.92- BEGINNING STR - 469.75- BOTTOM-C ER BASE " HDPE ® 0.57 470.75- TOP OF AN z8" NCRETE DATION - - - - ING THE 10 )ATION. 470 IT 470 XI TIN � GRADE 1)AINAG _CO TR. A3 PR OSED WALL i7 465 DRAINAGE 465 STR. 1 STR All- 39.E LF OF STR A)- 18.5 LF OF 012" HDPE @ 2.8% 012" HDPE 1.5% 460 460 1 W W 00 r to O O to I J J W W prj N (V N (D N N I!') c�c5 �� �00 W W 0+50 1+00 1+50 2+00 2+50 STR. A14 -FILTER STRIP PROFILE SCALES 1"=5' (V) 1"=50' (H) OF i% OF LEVEL SPREADER=STR. A7 INV. OUT F LEVEL SPREADER LEVEL SPREADER IROPOSED 44'WX35L' VEGETATED FILTER STRIP. FILTER iTRIPTO BE UNIFORMLY GRADED TO THE SLOPES SHOWN r0 ENSURE SHEET FLOW BELOW THE LEVEL SPREADER. :ONTRACTOR TO TIE BACK GRADES AT I & PREVENT SOIL :OMPACTION BY HEAVY EQUIPMENT WITHIN THE LIMITS )F THE FILTER STRIP. SEE THIS SHEET FOR ADDITIONAL :ILTER STRIP DETAILS & DESIGN REQUIREMENTS. PROPOSED 44' LONG FLAT LEVEL SPREADER W. LS TO HAVE A 1.2" DEEP PLUNGE POOL & A 6" WIDE RIGID LIP. LS TO INCLUDE A VDOT CL. Al RIPRAP LINING AND A SLOPED 3' (MIN.) VDOT CL. Al RIPRAP LINED EMBANKMENT DOWNSTREAM FROM THE RIGID LIP EXTENDING TO THE FILTER STRIP. ALL RIPRAP TO INCLUDE FILTER FABRIC UNDERLAYMENTS & BE A MIN. OF 6" DEEP. 1PPROXIMATE LOCATION OF .XISTING 8" SANITARY SEWER INV.=461.04't) tT SCOTT/R. C!1UINSZ Lic. No. 035791,a p 4/29/22 4) z O � a � LU Do Z O Z In Z J 0 Q Z � Z w W W N L9 O- z W ZN � LU � Q - � z W 0 a z � l n W N N Iesessell ZQ I� LUa o W C I� W G � V) z (n > LU W I LU O 11�z Q W (On CQ v , G Hsesell y > LU Ul W Q ZU IW W C DC IIIIIJ ~ LL IW 0 W Q Hesell x 0 U0 Q 0 J N LU W w 0- U) JOB NO. 202194 SCALE AS SHOWN SHEET NO. 1