Loading...
The URL can be used to link to this page
Your browser does not support the video tag.
Home
My WebLink
About
WPO201600009 Plan - VSMP 2016-06-28
OWNER/DEVELOPER / APPLICANT MARCH MOUNTAIN PROPERTIES, LLC 1005 HEATHERCROFT CIRCLE, SUITE 100 CROZET, VIRGINIA 22902 ATTN: MR. DAVE BROCKMAN PHONE: (702) 985-9088 BASE TOPOGRAPHY/SURVEYOR ROUDABUSH, GALE & ASSOCIATES, INC. 914 MONTICELLO ROAD CHARLOTTESVILLE, VIRGINIA 22902 CONTOUR INTERVAL: 2 FEET DATUM: VERTICAL - NAVD 88, HORIZONTAL - NAD 83 ENGINEER STANTEC CONSULTING SERVICES INC. 5209 CENTER STREET WILLIAMSBURG, VIRGINIA 23188 PHONE: (757) 220-6869 FAX: (757) 229-4507 ATTN: GLENN MUCKLEY, P.E. SITE DATA TOTAL PROPERTY AREA: APPROXIMATE PROJECT AREA (THIS PHASE) TAX MAP PARCEL NO: ZONING: FLOODPLAIN REFERENCE: HUC: 237.35 ACRES 40.15 ACRES PORTION OF 055E0-01-00-OOOA1 NEIGHBORHOOD MODEL DISTRICT IN ACCORDANCE WITH PROFFERS OF ZMA-04-204, APPROVED SEPTEMBER 14, 2005 PER FIRM 51003CO237D DATE: 02/04/2005 12-DIGIT-020802040102 VAHU6- JR02 OLD TRAIL VILLAGE BLOCKS 10, 16117) 18 AND 30* STORMWATER MANAGEMENT PLAN CROZET, VA 0 500 1000 MMENI APPROXIMATE SCALE (FEET) APPROVED by the Albemarle County Community Development Department Date 07/20/2016 File WP0201600009 GENERAL NOTES: 1. SEE ROUDABUSH GALE AND ASSOCIATES OTV BLOCKS 10 16 17118 & 30 EROSION CONTROL PLANS FOR AREAS OF DISTURBANCE AND DETAILS REGARDING EROSION AND SEDIMENT CONTROL DESIGN. 2. NOTE AREA (AC) AND CURVE NUMBERS (CN) FOR THIS PLAN VARY SLIGHTLY FROM MASTER PLAN APPENDIX C HYDROLOGY SUPPORT INFORMATION (APRIL 4, 2016). SLIGHT VARIATION IN AREA /CN VALUES IS ANTICIPATED FROM CURSORY MASTER PLAN (MP) LEVEL ESTIMATE OF FUTURE DEVELOPMENT UNDER THE OLD TRAIL STORMWATER MASTER PLAN UPDATE (ACCEPTED APR. 121SIGNED: APR. 25, 2016). THIS AND FUTURE REVIEWS SHOULD EXPECT SLIGHT DEVIATIONS IN THIS REGARD AS MORE DETAILED DESIGN DEVELOPMENT AND REFINEMENT OCCURS AT THE POINT OF INDIVIDUAL BLOCK DESIGN DEVELOPMENT. STANTEC PRESENTS THE MOST ACCURATE INFORMATION AVAILABLE UNDER THIS DETAILED STORMWATER MANAGEMENT PLAN (BLOCKS 10, 16, 17, 18, 30). STANTEC UNDERSTANDS THAT ALBEMARLE COUNTY HAS RECOGNIZED THAT SLIGHT VARIATION BETWEEN SWMP AND MP DA OR CN VALUES HAS NO EFFECT ON COMPLIANCE. FRACTIONAL OR EVEN WHOLE NUMBER CN VARIATIONS IN SOME INSTANCES MAY HAVE NO SUBSTANTIVE EFFECT ON IMPERVIOUS AREA PERCENTAGE PROPOSE, AND HENCE COMPLIANCE AS IS THE CASE WITH THIS PLAN. THE PERMITTEE SHALL HANDLE MORE SUBSTANTIVE CN DEVIATIONS AS NECESSARY THROUGH MITIGATORY DESIGN MEASURES WHICH WOULD APPEAR UNLIKELY IN THE FUTURE GIVEN THE NATURE OF THE CONSERVATIVE APPROACH UNDER THE MP. AERIAL MODIFICATIONS THAT ARISE FROM MORE DETAILED PLANNING AND DESIGN ARE TO BE ADDRESSED UNDER THE WATER QUALITY COMPLIANCE TRACKING LEDGE AND APPLICABLE MINIMUM TREATMENT AREAS DEFINED UNDER MP. REVIEWERS SHOULD BE ALERT TO EFFECT ON COMPLIANCE IF DISCREPANCIES EXIST BETWEEN MASTER PLAN AND SWM PLANS SUBMITTED FOR DISCRETE BLOCKS. 3. THE PROJECT AND THESE PLANS ARE TO BE COVERED UNDER EXISTING CONSTRUCTION GENERAL PERMIT (CGP) VAR100043. THIS PERMIT WILL BE MODIFIED TO INCLUDE ANY ADDITIONAL LAND DISTURBANCE PROJECTS AT OLD TRAIL VILLAGE (EXCEPT SLABTOWN SEWER EXT. PROJECT- A LINEAR PROJECT- OR OTHER SIMILAR FUTURE LINEAR CONSTRUCTION ACTIVITIES). 4. *THE BLOCKS NOTED INCLUDE THOSE WITHINAREAS OF DISTURBANCE AND CONSTRUCTION FOR THIS PHASE. ADDITIONAL BLOCKS OF INTEREST THAT ARE AFFECTED BY THE STORMWATER MANAGEMENT FACILITIES INCLUDE BLOCKS 1, 2, 3, AND 13. PROJECT NARRATIVE A SUCCESSFUL STORMWATER MANAGEMENT (SWM) MASTER PLAN STRATEGY DISCUSSION BETWEEN OLD TRAIL VILLAGE AND ALBEMARLE COUNTY HAS CULMINATED IN AN ACCEPTED SWM MASTER PLAN (APRIL 12, 2016). THE BELOW SUMMARIZES KEY POINTS OF THE MASTER PLAN AND OVERALL PROJECT SWM COMPLIANCE. 1. THE PROJECT IS TO BE DESIGN IN ACCORDANCE WITH PART IIC TECHNICAL CRITERIA UNDER THE VIRGINIA STORMWATER MANAGMENT PROGRAM (VSMP): 1.1. PER ALBEMARLE COUNTY (COUNTY) GUIDANCE LETTER OF AUGUST 6, 2015, PART IIC TECHNICAL CRITERIA SHALL APPLY TO OLD TRAIL FOR TWO PERMIT CYCLES, OR UNTIL 2024, PROVIDED CGP COVERAGE IS MAINTAINED. 1.2. A COMPREHENSIVE PROJECT -WIDE APPROACH TO WATER QUALITY CENTERING ON BIORETENTION FILTERS IN ACCORDANCE WITH REFINEMENTS TO THE GENERAL DEVELOPMENT PLAN (GDP) SHEET 3 PLAN. COMPLIANCE WITH PART IIC TECHNICAL CRITERIA IS TO BE ACHIEVED PRIMARILY THROUGH ON -SITE TREATMENT IN ORDER TO REDUCE TREATMENT BURDEN ON LICKINGHOLE REGIONAL BASIN (LRB). 2. REGARDING COMPLIANCE WITH 9VAC25-870-96: 2.1. OLD TRAIL VILLAGE FALLS UNDER SITUATION 2, WHICH REQUIRES THAT POLLUTANT DISCHARGE AFTER DISTURBANCE NOT EXCEED EXISTING POLLUTANT DISCHARGE. EXISTING 2.11% IMPERVIOUS AREA (ZMA) YIELDS LOAD =37.32 LB (TP) PER YEAR. PART IIC APPLIES. PART IIC REQUIRES SWM DESIGN (VIA MASTER PLAN) LIMIT POST -DEVELOPED (DEVELOPMENT -WIDE) DISCHARGE TO THE AVERAGE WATERSHED (16%), OR 104.98 LB TP/YR. PROPOSED IMPERVIOUS AREA (AVE. FOR 237.35 AC.)=43.45%. PROPOSED POLLUTANT LOAD (43.45%)=238.66 LB TP/YR. MASTER PLAN DESIGN REMOVES 133.68 LB TP/YR, TO COMPLY WITH STATE STORMWATER PART IIC (WATER QUALITY) REQUIREMENTS. SEE TABLE 7, MASTER PLAN. 2.2. COMPLIANCE WITH THIS PROVISION WILL BE ACHIEVED THROUGH APPROPRIATE ON -SITE BMPS PER MASTER PLAN, OR APPROVED VARIATION. ACCEPTABLE METHODS TO MEET ALBEMARLE COUNTY GUIDANCE AND MEET VSMP COMPLIANCE REQUIRES OLD TRAIL VILLAGE TO CAPTURE: 2.2.1. BIORETENTION: 92%, OR 51.15, ACRES OF THE TOTAL MAXIMUM MASTER PLAN TARGET ACROSS THE PROJECT BY BIORETENTION FACILITIES (0.5 INCH, 50% EFFICIENCY) AS A MINIMUM. 2.2.2. RETENTION BASINS: 100% OF TOTAL MAXIMUM MASTER PLAN TARGET, OR 92.58 ACRES ACROSS THE PROJECT TO RETENTION BASINS AS DEFINED HEREIN. 2.3. REMAINDER TREATMENT REQUIRED FOR VSMP COMPLIANCE WILL BE PROVIDED BY LRB UNDER A TREATMENT TRAIN APPROACH FOR BIORETENTION CAPTURE ONLY. ALTERNATE METHODOLOGY FROM MASTER PLAN REQUIRES ALBEMARLE COUNTY APPROVAL. 2.4. AS LONG AS APPROVED PLANS MEET OVERALL MINIMUM TOTAL AREA CAPTURE NOTED UNDER MASTER PLAN, THE PROJECT SHALL BE DEEMED TO REMAIN IN COMPLIANCE BY ALBEMARLE COUNTY TO THE MASTER PLAN, COUNTY GUIDANCE, AND VSMP WATER QUALITY REQUIREMENTS. 2.5. PROOF OF OVERALL COMPLIANCE WILL BE PROVIDED UNDER EACH WPO SUBMITTAL WITH AN UPDATED WATER QUALITY COMPLIANCE TRACKING LEDGER, WHICH IS PROVIDED ON SHEET 20. 3. REGARDING COMPLIANCE WITH 9VAC25-870-97, 98, COMPLIANCE OF PEAK FLOW ATTENUATION PER BMP ARE PROVIDED HEREIN PER MASTER PLAN. MASTER PLAN DRAINAGE AREAS HAVE BEEN REFINED BASED ON DESIGN; HOWEVER, NOMENCLATURE HAS BEEN KEPT CONSISTENT FOR CLARITY. ADDITIONALLY, TEH DRAINAGE AREAS HAVE BEEN BROKEN INTO SUB -WATERSHEDS WHERE APPLICABLE FOR MODELING PURPOSES. AS SUCH, STANTEC HAS WORKED WITH MARCH MOUNTAIN PROPERTIES, LLC AND ITS SUBCONSULTANT, ROUDABUSH, GALE, AND ASSOCIATES (RGA), TO DESIGN FOUR (4) STORMWATER BEST MANAGEMENT PRACTICES (BMPS) IN SUPPORT OF THE OLD TRAIL VILLAGE DEVELOPMENT BLOCKS (PORTIONS OR ALL) 1, 2, 3, 4, 10, 13, 14, 15, 16, 17, 18, AND 30, COLLECTIVELY KNOWN AS THE EAST SIDE FOR PURPOSES OF THIS PLAN. IT IS THE INTENTION OF OLD TRAIL VILLAGE THAT THESE BMPS SATISFY VSMP COMPLIANCE IN ACCORDANCE WITH THE MASTER PLAN FOR THIS AREA OF DEVELOPMENT. THE BMPS CONSIST OF THREE BIORETENTION FACILITY COMPLEXES INCORPORATING DETENTION AREAS FOR STORMWATER QUANTITY CONTROL AND MODIFICATION OF AN EXISTING WET POND TO A STORMWATER RETENTION BASIN III. THE DETAILED DESIGNS FOR THESE FACILITIES ARE INCLUDED HEREIN. SEE SHEET 20 FOR A VSMP SUMMARY PER THE SWM MASTER PLAN. WHILE THESE PLANS REPRESENT ONLY SWM DESIGN PLANS, DETAIL ON FACILITY CONVERSION AND REQUIRED MEASURES HAVE BEEN INCLUDED FOR COMPLETENESS. SEE RGA PLANS FOR DETAILED ESC DESIGN FOR THIS DEVELOPMENT AREA. STREAM BUFFER IMPACTS WILL ALSO BE ADDRESSED ON A DETAILED STREAM BUFFER MITIGATION PLAN BY RGA. SHEET INDEX 1. COVER SHEET 2. EXISTING CONDITIONS 3. PROPOSED CONDITIONS 4. S-3 BIORETENTION GRADING AND LAYOUT 5. S-3 BIORETENTION PROFILE AND SECTIONS 6. S-12 BIORETENTION GRADING AND LAYOUT 7. S-12 BIORETETNION PROFILE AND SECTIONS 8. L-2 RETENTION BASIN GRADING AND LAYOUT 9. L-2 RETENTION BASIN PROFILE AND SECTIONS 10. L-3 BIORETENTION GRADING AND LAYOUT 11. L-3 BIORETENTION PROFILE AND GRADING 12. BIORETENTION CONSTRUCTION NOTES AND SEQUENCE 13. RETENTION BASIN L-2 CONSTRUCTION PHASING 14. CONSTRUCTION DETAILS 15. CONSTRUCTION NOTES 16. S-3 BIORETENTION PLANTING PLAN 17. S-12 BIORETENTION PLANTING PLAN 18. L-2 RETENTION BASIN PLANTING PLAN 19. L-3 BIORETENTION PLANTING PLAN 20. VSMP COMPLIANCE SUMMARY _ ,,t,TH 37D3 26C3 W W W,W W ■ W W W W W W W W W W W W W W W W W W W W W W ■ W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W W WWW WWWWWWWWWW WWW W 1 7 L-3 OUT L-2 OUT 4D 4 66E 37C3 ri 1 B 6.90 AC 1000 14.19 0 56B 4E o � ♦ 12B 9.65 o o � S-3 OUT 25B AC - - I 36B \ \ 37D3 to to \\ ' W 26C3 ♦ _ \ / W W / `WWW WW 4 36C N 0 125 250 Tn APPROXIMATE SCALE (FEET) LEGEND . ' PROJECT LIMITS EXISTING CONTOURS 00 APPROXIMATE LOCATION OF 0� EXISTING STREAM BUFFER OUTFALL NODE SOIL SERIES SUMMARY WATER TABLE / MAP SLOPE FLOODING PERMEABILITY HYDROLOGIC DEPTH TO SYMBOL SOIL NAME (%) DRAINAGE FREQUENCY HYDRIC (Ksat) SOIL GROUP BEDROCK SOMEWHAT 4D ASHE LOAM 15-25 EXCESSIVELY >80 INCHES/ N VERY LOW - HIGH B 24 - 79 NONE INCHES DRAINED SOMEWHAT >80 INCHES/ 24 - 79 4E ASHE LOAM 25 - 45 EXCESSIVELY N VERY LOW - HIGH B NONE INCHES DRAINED >80 INCHES/ HIGH - VERY >80 17 CRAIGSVILLE LOAM 0-2 WELL N A NONE HIGH INCHES >80 INCHES/ MODERATELY >80 25B DYKE SILT LOAM 2-7 WELL N B NONE HIGH - HIGH INCHES >80 INCHES/ MODERATELY >80 26133 DYKE CLAY LOAM 2-7 WELL N B NONE HIGH - HIGH INCHES >80 INCHES/ MODERATELY >80 26C3 DYKE CLAY LOAM 7 - 15 WELL N B NONE HIGH - HIGH INCHES >80 INCHES/ MODERATELY >80 36B HAYESVILLE LOAM 2-7 WELL N B NONE HIGH - HIGH INCHES >80 INCHES/ MODERATELY >80 36C HAYESVILLE LOAM 7 - 15 WELL N B NONE HIGH - HIGH INCHES >80 INCHES/ MODERATELY >80 37C3 HAYESVILLE CLAY LOAM 7 - 15 WELL N B NONE HIGH - HIGH INCHES >80 INCHES/ MODERATELY >80 37D3 HAYESVILLE CLAY LOAM 15 - 25 WELL N B NONE HIGH - HIGH INCHES 36 - 60 INCHES/ MODERATELY >80 56B MEADOWVILLE LOAM 2-7 WELL N A NONE HIGH - HIGH INCHES SOMEWHAT >80 INCHES/ 48 - 80 66D PARKER VERY STONY LOAM 15 - 25 EXCESSIVELY N VERY LOW A NONE INCHES DRAINED SOMEWHAT >80 INCHES/ 48 - 80 66E PARKER VERY STONY LOAM 25 - 45 EXCESSIVELY N VERY LOW B NONE INCHES DRAINED W WATER - - - - - - - SOURCE: U.S. DEPARTMENT OF AGRICULTURE, NATURAL RESOURCE CONSERVATION SERVICE SOIL SURVEY GEOGRAPHIC DATABASE FOR ALBEMARLE COUNTY, VIRGINIA �zs ♦ '_,� S-12 OUT � 1561.86 � AC I 26C38,0- � -— �• 4D � �36C EXISTING CONDITIONS NARRATIVE THE EXISTING EAST SIDE BLOCKS ARE UNDEVELOPED LAND, GENERALLY UNFORESTED, FLANKED ON THE NORTH BY LICKINGHOLE CREEK AND ON THE SOUTH BY SLABTOWN BRANCH. A SMALL EXISTING EROSION AND SEDIMENT CONTROL BASIN IS LOCATED ON THE EAST SIDE OF THE PROPOSED DEVELOPMENT. REGARDLESS OF CURRENT CONDITION, ALL PREDEVELOPMENT HYDROLOGY WAS GENERATED FROM PREEXISTING TOPOGRAPHY AND LANDUSE, CIRCA 2005. FEMA FLOOD INSURANCE RATE MAP (FIRM) PANEL 51003CO237D (FEBRUARY 4, 2005) SHOWS SOME OF PROPERTY INSIDE ZONE AE, BUT NO DEVELOPMENT IS PROPOSED TO OCCUR IN FLOODPLAIN. THE PREDEVELOPMENT SITE IS CHARACTERIZED BY MODERATE SLOPES THAT TRANSITION TO STEEPER SLOPES TOWARD THE BORDER OF THE DEVELOPMENT AREA ADJACENT TO THE STREAM BUFFERS OF LICKINGHOLE CREEK AND SLABTOWN BRANCH. EXISTING WETLANDS ARE LOCATED BELOW THE PROPOSED DEVELOPMENT, AND TO BE LEFT UNDISTURBED. SOILS ARE GENERALLY HYDROLOGIC SOIL GROUP (HSG) B AND CHARACTERIZED AS DYKE SILT LOAM/CLAY LOAM, HAYESVILLE LOAM/CLAY LOAM, MEADOWVILLE LOAM. EXISTING DRAINAGE AREA SUMMARY DRAINAGE AREA ID AREA (AC) CURVE NUMBER TC (HR) 10B 14.19 61.54 0.550 11 B 6.90 60.90 0.229 12B 9.65 61.00 0.598 15B 1.86 60.71 0.256 1 06/28/16 REVISED PER COUNTY AJT I JGM JGM COMMENTS REV DATE DESCRIPTION DSN CHK APP PREPARED BY: Stantec 5209 Center Street Williamsburg, VA 23188 PHONE: (757) 220-6869 FAX: (757) 229-4507 FOR: OLD TRAIL VILLAGE CROZET,VA TITLE: EXISTING CONDITIONS DRAWN BY: DESIGNED BY: �.I,TH OF L f AJT JGM CHECKED BY: JGM APPROVED BY: JGM %( PROJECT NUMBER: SCALE: J. GLENN MUCKLEY a Lie. No. 038970 203400430 1" = 125' DATE: FILE PATH: �,0jO� �SSICNAL E 05/20/2016 U:/203400430 SHEET: 2 U � - I IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII \ ,~7mg--w i ON MEN- IIII ok ®- • h u IN. , mjA- Aw yam: �►►� \ I III ,�j i VIN'll,. ,)j j WA.0211M �� ♦ .� X III WIN ill 10 Ilk NIEMEN ww) 0:11 \. �/' `�1 i . , �;, • . • � moo, 11 ��• ���1�j1�� \�!'��� ♦ �, `�,♦ � . -tom-�- / �. . ��'`,�,, ;, `lit c '�� ♦ ,\ , :.,. . •� / ���� 1� dim. � - � ♦ ♦ \ _ 1� I�� � � � ��`' • - � � �� � z,1 \III . moo. ���. r� � � � �`�. ��., �� '� � .-lam►_ ,_ � �� f�/rr�.�, � ' i IIII �� \ �i• .. �i��� � �� f i• �' - •� �► � .�_-- . -• 1 `� 1�,� �� f N 0 125 250 APPROXIMATE SCALE (FEET) PROPOSED DRAINAGE AREA SUMMARY DRAINAGE AREA ID AREA (AC) CURVE NUMBER TIC (HR) 10B-1 23.81 87.07 0.267 1OB-2 0.12 61.00 0.083 11 B-1 6.88 80.84 0.340 11 B-2 1.86 70.34 0.083 11 B-3 0.41 61.00 0.083 12B-1 6.32 81.54 0.256 12B-2 0.63 61.00 0.083 1513-1 4.36 83.13 0.361 15B-2 0.55 61.00 0.083 15B-3 0.15 61.00 0.083 NOTE: FLOWS AT NODES S-12 OUT AND L-3 OUT DO NOT INCLUDE FLOWS FROM UPSTREAM BEYOND THE DEVELOPMENT. PROPOSED CONDITIONS NARRATIVE THE THREE EAST SIDE BIORETENTION FACILITY COMPLEXES, DESIGNED WITH BOTH WATER QUALITY TREATMENT AND QUANTITY DETENTION COMPONENTS, ARE ENVISIONED TO SUPPORT DEVELOPMENT OF BLOCKS 10, 16-18, AND 30. IN ADDITION, IMPROVEMENTS TO THE PREVIOUSLY APPROVED RETENTION BASIN L-2 WILL PROVIDE BENEFITS TO EXISTING BLOCKS 1-3, 13, AND 14. THE BIORETENTION FACILITIES ALSO INCORPORATE A STORMWATER DETENTION ELEMENT IN THE FORM OF DETENTION BASINS TO PROVIDE SIGNIFICANT WATER QUANTITY CONTROL FOR THE PROPOSED DEVELOPMENT PER THE APPROVED SWIM MASTER PLAN. THE FACILITIES ARE OUTSIDE THE FEMA 100-YEAR FLOODPLAIN PER FEMA FLOOD INSURANCE RATE MAP (FIRM) PANEL 51003CO237D (FEBRUARY 4, 2005). AESTHETIC CONSIDERATIONS ARE ALSO OF SIGNIFICANT CONCERN FOR THE FOUR FACILITIES BECAUSE OF THEIR HIGHLY VISIBLE LOCATIONS. THE FACILITIES ARE DESIGNED TO BE ATTRACTIVE FEATURES AND WILL INCORPORATE THE FUTURE GREENWAY TRAIL IN SEVERAL INSTANCES. MAINTENANCE ACCESS TO THE BMPS IS ALSO PROVIDED. EXISTING FACILITY L-2 HAS BEEN REDESIGNED TO PROVIDE ENHANCED WATER QUALITY TREATMENT AND CONSIDER ADDITIONAL RUNOFF FROM PROPOSED DEVELOPMENTS OF THE EAST SIDE.FOR ULTIMATE WATER QUALITY BENEFIT. THE PLAN REQUIRES EMBANKMENT RECONSTRUCTION AND A OUTLET STRUCTURE REPLACEMENT. ENHANCED PLANTINGS ARE ALSO PROVIDED. THE BIORETENTION FACILITY COMPLEX L-3 IS PROPOSED TO TREAT PORTIONS OF BLOCKS 10 AND 16 AND TO PROVIDE WATER QUANTITY AND QUALITY CONTROL FOR DRAINAGE AREA 11 B. THE FACILITY WILL ALSO SERVE TO TRANSITION THE PROPOSED GREENWAY TRAIL FROM THE DEVELOPMENT DOWN TO THE EXISTING STREAM BUFFER. BIORETENTION FACILITY COMPLEX S-3 IS PROPOSED TO TREAT AREAS OF BLOCKS 16, 17, AND 18 AND TO PROVIDE WATER QUANTITY AND QUALITY CONTROL FOR DRAINAGE AREA 12B. THE FACILITY WILL PROVIDE FLOW FOR THE DESIGN STORMS PER THE MASTER PLAN. AESTHETICS ARE A CONSIDERATION FOR THIS FACILITY, GIVEN ITS PROMINENT LOCATION BY THE ROADSIDE. BIORETENTION FACILITY COMPLEX S-12 IS PROPOSED TO TREAT AREAS OF BLOCKS 17, 18, AND 30 CURRENTLY UNDER DESIGN DEVELOPMENT. IT WILL PROVIDE WATER QUANTITY AND QUALITY CONTROL FOR DRAINAGE AREA 15B. ALL BIORETENTION FACILITIES HAVE BEEN DESIGNED WITH HIGH FLOW BYPASS CAPABILITY GIVEN THE RELATIVE SIZE OF THE CONTRIBUTING DRAINAGE AREAS AND TO FURTHER AVOID HYDRAULIC OVERLOADING. LEGEND .' PROJECT LIMITS EXISTING CONTOURS APPROXIMATE LOCATION OF EXISTING STREAM BUFFER PROPOSED GRADES PROPOSED BIORETENTION FOOTPRINT PROPOSED STORM SEWER NETWORK COUNTY CRITICAL SLOPES / (2007) OUTFALL NODE 1 06/28/16 REVISED PER COUNTY COMMENTS AJT I JGM JGM REV DATE I DESCRIPTION DSN CHK APP PREPARED BY: itantec 5209 Center Street Williamsburg, VA 23188 PHONE: (757) 220-6869 FAX: (757) 229-4507 FOR: OLD TRAIL VILLAGE CROZET, VA TITLE: PROPOSED CONDITIONS DRAWN BY: DESIGNED BY: �ALTH op j AJT JGM CHECKED BY: JGM APPROVED BY: JGM PROJECT NUMBER: SCALE: J. GLENN MUCKLEY a Lic. No. 038970 203400430 1" = 125' DATE: FILE PATH: S`sICNAL ��� 05/20/2016 U:/203400430 SHEET: 3 Off\ OUTLET PROTECTION S-3-2 a9 STRUCTURAL WALL ' DEVELOPMENT GRADES CONTRACTOR SHALL (BY OTHERS) DRAINAGE PROVIDE SEALED SHOP / TO BE GENERALLY DRAWINGS FOR DIRECTED TO STREET OWNER REVIEW 18 INCH RCP - °�9 LENGTH = 25.25 FT - / \ INV UP = 652.75 FT INV DOWN = 652 FT, DI-1 RISER CREST ELEVATION = 656 FT 31905 SF BIORETENTION FACILITY FLOOR ELEVATION = 655.5 FT / CHANNEL C-S3-2 (0/1 co /f co ��� , 165 � / 656- r0�°� � 654 652 BERM CREST ELEVATION = 657.0 FT � V LEVEL SPREADER ELEVATION = 655.5 FT (3.6 CY) PRETREATMENT \ 0 25 50 APPROXIMATE SCALE (FEET) SILL SHALL BE KEYED IN MIN. 4 FEET LEFI BANK SILL SHALL BE SECTION A-AKEYED IN MIN. 4 FEET SECTION A - A' ELEVATION = 654.00 FT DETAIL: S-3 HIGH FLOW BYPASS STRUCTURE 0_ to to \ 0 � VJ CONSTRUCTION NOTES 1. MINIMUM STONE SIZE SHALL BE 2 FT X 2 FT X 2 FT. SEE IMBRICATED BOULDER ROCK SIZING DEFINITION DETAIL ON SHEET 14. 2. ALL STRUCTURE CREST WIDTHS (BETWEEN POINTS 2 AND 4) SHALL BE AS SHOWN. 3. SEE SHEET 15 FOR ADDITIONAL CONSTRUCTION SPECIFICATIONS. 4. CONTRACTOR IS RESPONSIBLE FOR CLEAN UP. 5. MAXIMUM ALLOWABLE FOOTER ELEVATION SHALL BE 654.00 FT. SHOULD THIS BE ABOVE THE BOTTOM OF THE INSTALLED TOP ROCK, NO ADDITIONAL FOOTER ROCK SHALL BE NECESSARY. 6. STEP HEIGHT = 0.00 FEET. CREST ON GRADE WITH DOWNSTREAM CHANNEL. 7. CONTRACTOR SHALL SUBMIT SHOP DRAWINGS FOR OWNER & ENGINEER APPROVAL SHOULD ALTERNATE METHOD OF BYPASS (TREATED TIMBER OR CONCRETE) BE PROPOSED. STRUCTURE ELEVATIONS POINT ELEVATION (FT) 1 657.0 2 656.0 3 656.0 4 656.0000 5 657.0 M HIGH EL PER PLAN SEAM FLOW INEL PER :K, JCI� I IVIV t5 - CS' NITS 20 FT WIDE EMERGENCY SPILLWAY CREST ELEV. = 656.20 FT PROVIDE 880 SF OF LANDLOK 450 TURF REINFORCEMENT MATTING OR EQUIVALENT. BERM CREST ELEVATION = 657.20 FT STANDARD VDOT SWM-1 RISER CREST ELEV. = 655.25 FT 1-10 INCH ORIFICE @ 651.35 FT 2-9 INCH ORIFICES @ 654.15 FT CHANNEL GS3-1 REMOVE EXISTING RISER AND EXTEND - EXISTING RCP APPROXIMATELY 32 FT. INV UP = 651.32 FT ` PLUNGE POOL LINED WITH CLASS Al RIPRAP (14.1 CY) rns s� HIGH FLOW BYPASS STRUCTURE \ CREST ELEVATION = 656.0 FT (SEE DETAIL THIS SHEET) \ \ EXISTING 36 INCH RCP INV UP = 650.83 FT INVERT DOWN = 649.97 FT ° Ir ' A / OUTLET I------- CO z PROTECTION S-3-3 h J D D Cp LU LU O) O� Q\ rn � w TOP OF ENDWALL = 656.00 FT 30 INCH RCP LENGTH = 50 FT INV UP = 656.30 FT INV DOWN = 656.00 FT OUTLET PROTECTION S-3-1 z 664 662 660 NOTES: 1. EMBANKMENT BACKFILL MATERIALS SHALL CONSIST OF GC, SC, CL, CH, AND/OR MH SOILS. 2. CONTRACTOR SHALL PLACE SIGNS EVERY 150 FEET ALONG THE PERIMETER OF THE FACILITY. CONTRACTOR SHALL SUBMIT SHOP DRAWINGS/INFORMATION TO THE OWNER FOR APPROVAL PRIOR TO PURCHASE AND INSTALLATION. SIGNS SHALL READ: "NOTICE: STORMWATER MANAGMENT FACILITY - AREA EXPERIENCES WATER SURFACE FLUCTUATION AND STANDING WATER. NO TRESPASSING." 1 06/28/16 REVISED PER COUNTY COMMENTS EV DATE DESCRIPTION S-3 SUMMARY: LEGEND . ' PROJECT LIMITS EXISTING CONTOURS 010 APPROXIMATE LOCATION OF 100 EXISTING STREAM BUFFER PROPOSED GRADES PROPOSED BIORETENTION FOOTPRINT PROPOSED STORM SEWER NETWORK COUNTY CRITICAL SLOPES (2007) CROSS SECTION MINIMUM MAINTENANCE ACCESS LIMITS LAP RAIL FENCE PRE -DEVELOPMENT: TOTAL DRAINAGE AREA = 9.65 ACRES ESTIMATED IMPERVIOUS AREA = 0.00 ACRES CURVE NUMBER = 61.00 POST -DEVELOPMENT: TOTAL DRAINAGE AREA = 6.32 ACRES ESTIMATED IMPERVIOUS AREA = 3.51 ACRES CURVE NUMBER = 81.54 BIORETENTION SIZING: REQUIRED AREA = 2.5% * IMPERVIOUS ACREAGE = 0.025 * 3.51 AC * 43560 SF / AC = 3,822 S.F. PROVIDED AREA = 3,905 S.F. WATER QUALITY TREATMENT: POST -DEVELOPMENT POLLUTANT LOAD = 7.89 (LBS-TP/YR) POLLUTANT REMOVAL EFFICIENCY = 50% TOTAL ESTIMATED POLLUTANT REMOVAL = 3.95 (LBS-TP/YR) HYnRn1 nGIC; Sl JMMARY- 2-YEAR 10-YEAR 100-YEAR PRE -DEVELOPMENT POST -DEVELOPMENT (UNROUTED) POST -DEVELOPMENT (ROUTED) POST -DEVELOPMENT (COMPLIANCE NODE) ROUTED PEAK ELEVATIONS: BIORETENTION FILTER DETENTION BASIN AJT I JGM I JGM 3.65 11.52 30.66 15.09 27.94 52.63 3.60 11.48 41.41 3.60 11.48 41.41 2-YEAR 10-YEAR 100-YEAR FT FT FT 656.21 656.34 656.58 654.03 655.44 656.16 PREPARED BY: itantec 5209 Center Street Williamsburg, VA 23188 PHONE: (757) 220-6869 FAX: (757) 229-4507 FOR: TITLE: OLD TRAIL VILLAGE CROZET,VA S-3 BIORETENTION GRADING AND LAYOUT DRAWN BY: DESIGNED BY: �A �I H D� AJT JGM CHECKED BY: APPROVED BY: JGM JGM f PROJECT NUMBER: SCALE: o J. GLENN MUCKLEY Lic. No. 038970 203400430 1" = 25' DATE: FILE PATH: SSIONAL O� 05/20/2016 U:/203400430 SHEET: 4 DSN I CHK I APP NEI ..:�1-1 ..: ..•BERM MOMMEMEMEME DEPTH = ..� 55.5 FT No CREST ,BIMMEMMWAMMMMMMMMMMMMMMMMMMEMWJ P OF END WWO MENNEN MMMMMMMMMMMMMMM ..1 ..1Mi INV DO P . .�: •,1 ••• 11 1 1 1 •1 1 .1 1 :1 11 1 •1 .1 :1 11 1 •1 .1 � � � 1 11 1 1 1 1 11 1 • 1 .1 1\1■■■1 �iL1�.-1.��•r.,:.....����r��.�..®.®.®..®.......�.®.®a.��--p�,�•I..9.:riN►��::��������� 1 - �■■�J�I�I���:����!��\`�i\\►�%/./I - 17.%�\S�\I���i'!�'�i►//I/.%%%►►�'//,%%��■'./1%�%%■"®i■■■�%�!®'.%�I�B►��/J'�:��■■■■■■■■■ i�■I��t�■��i�\�1_I/J'\��!I//i 1\I■■■1 ' � I irl�-s'��; �.►���i � I r ' ' rI ►��®®®- �--®®®-ter®®���®� �i■■��\\1 ■■■■■■■■■■■■■■ .. - •STANDARD II■I��■■��■�i������► ��� 1■■■■1 'I�'\r1II�\r/.i\►r1►�\►"/II/.%'/.'/.%//%%I���.�y{�.��_�K_����..��';,`'�P.���\Il\�■■■■ ■■III■IlJi�9lJ��I�7■■■■■■■■■\I I■1\■■1 \`\�\\�1�\\�1J\���1/J'\\17.��;\�\\�1�\\�1J\\�1/J'\\17.�\`\�\\�1�!"I \�1J\\�1/J1'���,•�i�17s\`\ ' • RISER �\�II�!����■I■1�■■■■■■■■■�111■\\■■ li :�:��!Ir?�►iiris.��'�����i • - .. • . �� �JI�11i%�►7IIJ1�l�%�,,I� ' _ I_�'.11i%�►7IIJ1�l�%��11L - '- -� �►7_!ri��%��11I�'�..�' 1■!1■■� PROPOSED .. • . �1��'LI��.r1����������rl���'LI��.r1��� • -. • � PROPOSED -. . - • - • • �►�'LI��.r1��� � � � ► � . DIAMETER gy P.4 FLOW REACH STORM FLOW DEPTH VELOCITY ADEQUATE EROSIVE? QUANTITY (CFS) (FT/S) CHANNEL? (CY) 1 2-YR 9.59 0.44 5.26 YES NO 22.3 2 2-YR 9.59 0.64 2.88 YES NO TIE INTO PRO SED DEVELOPMENPTOG3RADES PER RGA PLANS -7-PROPOSED NONNI R EFER TO GRADING PLAN FOR ACTUAL PROPOSED GRADED SLOPES, AS LABELS ARE SKEWED DUE TO SECTION ORIENTATION. ONE OEM- GRADE 20 FT WIDE EMERGENCY SPILLWAY CREST ELEV. = 656.20 FT REINFORCEMENT ��i%���■■■■■■■■■■■■■■■■■■■■TURF ■■■■■■■■■■■■■■■■ BERM ELEVATION 657.2 F� ' %2!� - a� . I • i - . . , : .. - J/II1i�%2l�I/.�%�I�G/%��II ►■'%%2l�►/�%�I�G/%��I►■'%%2 ' ��1►i ��=i�il�l�l►i�/.i�'\vll�\�ii\►rIG�.\`�G�►�/.iL\vG�\�ii\�G�.\`�G�\ ■■■■ ■■■I0110■■■■■■■■■■■■■■■■►■■■■■■■ i " '' �!i%%l1III� ■■■►■■■I. III'' !i/'/.�iIII�''%�/I�111'/�J►7.�IJ1Jli%%IIIII�''%�JI�II 1 11 1 1 1 •1 1 .1 1 :1 11 1 •1 .1 :1 11 1 •1 .1 :1 • 0.5 0 d W 0 -1 -1.5 -6 -3 0 3 6 DISTANCE (FT.) DETAIL: CHANNEL C-S3-2 VERTICAL SCALE: 1 " = 1' HORIZONTAL SCALE: 1 " = 3' i�I��i►.\ -;:.-. I%o��C� �.• tea- .�:� .�i•-,.. FLOW STORM FLOW DEPTH VELOCITY ADEQUATE EROSIVE? QUANTITY (CFS) (FT/S) CHANNEL? (CY) 2-YR 3.65 0.48 4.40 YES NO 7.7 NOTES: t (thickness) = 4.0" 1) CONCRETE SHALL BE CLASS A3 2) CONTRACTOR MAY SUBMIT ALTERNATE BID WITH PLOWABLE FILL INSTEAD OF CONCRETE, PENDING APPROVAL BY DESIGN 8 ENGINEER D = 36" d d d� FLOTATION CALCILATIOrIS FOR RISER BASE WEIGHT Y12 D = 3.0" '` SIDE WALLS MAY CONFORM %4 D OR 9.0" ** J TO THE SHAPE OF EXCAVATED TRENCH * SHALL NOT BE LESS THAN 6" DETAIL: OUTFACE CULVERT CONCRETE CRADLE NTS �! J40�t;=tea OF WATER 62.40 WEIGHT OF CONCRETE = 150.00 C . �������❑��r���� TOP INVERT OF RISER = 655.25 FT, NAVD88 L INVERT OF 10" ORIFICE = 651.35 FT, NAVD88 111111��INVERT OF 2-9" ORIFICES = 654.15 FT, NAVD88 INVERT OF CULVERT = 651.32 FT, NAVD88 3 BOTTOM INVERT OF RISER = 651.32 FT, NAVD88 HEIGHT OF RISER = 4.42 FT RISER INSIDE DIAMETER = 4.0 FT WALL THICKNESS = 5 INCHES RISER INSIDE AREA = 12.57 SF RISER OUTER AREA = 18.35 SF 2 - SEE RISER FOOTPRINT = 5.78 SF NOTE 6 RISER BASE: METAL 4.42' RISER BASE AREA = 18.35 SF PLATE BASE DEPTH = 2.50 FT RISER OPENINGS: 36" DIAMETER 1 DEBRIS WQ ORIFICE (10" DIAMETER) = 0.55 "Dr - CULVERT RACK 2 ORIFICES (9" DIAMETER) = 0.88 SF 10 INCH WATER OUTFACE CULVERT (44" OUTER DIAMETER) _ QUALITY ORIFICE 10.56 SF SEE NOTE 8 TOTAL AREA = 11.99 SF TOTAL VOLUME (AREA X 5") = 5.00 CU-FT WEIGHT OF DISPLACED WATER: ° VOLUME OF RISER = 81.11 CU-FT 45.88 CU-FT 21_01811 1 VOLUME OF BASE MIN. TOTAL DISPLACED VOLUME = 126.99 CU-FT ° WEIGHT OF DISPLACED WATER = 7,924 LBS CLASS A-3 CONCRETE TO BE WEIGHT OF RISER: USED TO FILL SWM VOLUME OF RISER CONCRETE = 25.55 CU-FT DRAINAGE VOLUME OF OPENINGS = 5.00 CU-FT STRUCTURE TO � TOTAL VOLUME OF RISER = 20.55 CU-FT INVERT OF WEIGHT OF RISER = 3,082 LBS OUTLET PIPE. 511 4'-0" DIA. 5„ WEIGHT OF BASE: = 45 88 CU-FT SIDE VIEW SWM DRAINAGE STRUCTURE %" DIA. X 6" LG. ADHESIVE BOLTS W/FLAT WASHERS AND SELF LOCKING NUTS TYPICAL 8PCACES-EQUALLY r� ri n o r r-� � n i n n i u r u r� i n VOLUME OF BASE WEIGHT OF BASE TOTAL DOWNWARD WEIGHT FACTOR OF SAFETY 3LE ACCESS WHINGE TE 1 X /4" STEEL RING D TO RISER TYP. RISER DIMENSION APPROX. WT. (CBS.) I.D. O.D. A B C D E SEGMEN 48 58 55 9 13 20 53 29 120 METAL DETAIL: S-3 BIORETENTION VDOT STORMWATER MANAGEMENT (SWM-1) RISER AND TRASH RACK NTS = 6,882 LBS = 9,964 LBS = 1 .26 NOTES: 1 . COST OF TRASH RACK AND DEBRIS RACK ARE TO BE INCLUDED IN THE PRICE BID FOR THE STORMWATER MANAGEMENT DRAINAGE STRUCTURE. 2. STRUCTURE MAY BE PRECAST OR CAST IN PLACE. 3. WEEP HOLES SHALL NOT BE PROVIDED. ANY LIFT HOLES SHALL BE PLUGGED. 4. STEPS ARE TO BE PROVIDED WHEN HEIGHT OF STRUCTURE IS 4'-0" OR GREATER ABOVE INVERT OF OUTLET PIPE. FOR STEP DETAILS SEE STANDARD ST-1 . 5. SEE STANDARD SWM-DR FOR ADDITIONAL DETAILS ON PLATE, DEBRIS RACK AND TRASH RACK. 6. MARK HEIGHT OF STRUCTURE, IN BLACK, WITH 4" HIGH NUMERALS AND 1 "WIDE HORIZONTAL STRIPES AT 1' INTERVALS FROM INVERT OF WATER QUALITY ORIFICE (ALL VISIBLE SIDES). 7. THE PERMANENT STORMWATER MANAGEMENT DRAINAGE STRUCTURE, STANDARD SWM-1 MAY BE MODIFIED WHERE THE STORMWATER MANAGEMENT BASIN IS TO BE USED AS A TEMPORARY SEDIMENT BASIN DURING PROJECT CONSTRUCTION. SEE STANDARD SWM-DR, SHEET 1 OF 5 FOR TEMPORARY MODIFICATION DETAILS. 8. THE SIZE OF THE WATER QUALITY ORIFICE SHALL BE 10 INCHES. un SILL SHALL BE LLFI BANK A FLOW SECTION A - Al STRUCTURE ELEVATIONS POINT ELEVATION (FT) 1 649.5 2 648.5 3 648.5 4 648.50 5 649.5 SILL SHALL BE CONSTRUCTION NOTES IN MIN. 4 FEET 2 1. MINIMUM STONE SIZE SHALL BE 2 FT X 2 FT X 2 FT. SEE IMBRICATED BOULDER ROCK SIZING DEFINITION DETAIL ON SHEET 14. 2. ALL STRUCTURE CREST WIDTHS (BETWEEN POINTS 2 AND 4) SHALL BE AS SHOWN. 5 3. SEE SHEET 15 FOR ADDITIONAL CONSTRUCTION SPECIFICATIONS. 4. CONTRACTOR IS RESPONSIBLE FOR CLEAN UP. 5. MAXIMUM ALLOWABLE FOOTER ELEVATION SHALL BE 646.50 FT. SHOULD THIS BE ABOVE THE BOTTOM OF THE INSTALLED TOP ROCK, NO ADDITIONAL FOOTER ROCK -_- SHALL BE NECESSARY. 6. STEP HEIGHT = 0.00 FEET. CREST ON GRADE WITH DOWNSTREAM CHANNEL. 7. CONTRACTOR SHALL SUBMIT SHOP DRAWINGS FOR OWNER & ENGINEER APPROVAL SHOULD ALTERNATE METHOD OF BYPASS (TREATED TIMBER OR CONCRETE) BE PROPOSED. A' f1filill 0 N HIGH FLOW BYPASS � 22 STRUCTURE PLUNGE POOL LINED WITH CREST ELEVATION I CLASS Al RIPRAP (25.5 CY) APPROXIMATE -648.5 FT FEMA FLOODPLAIN OUTLET W W LIMITS PROTECTION S-12-1 `�' `�' `I' CHANNEL C-S12-1 3 BERM ELEV -650.20 FT STANDARD VDOT SWM-1 RISER z CREST -646.0 FT DOWNSTREAM HIGH \ ��s�s� 1-4 INCH ORIFICE @ 640 FT mom STEP HEIGHT Flow CHANNEL PER �.0 Pp PLAN IN 1-6 INCH ORIFICE @ 644.9 FTgoo ll� S',v HEADER ROCK LENGTH = 45.5 FT son too INV UP = 651.60 o UPSTREA OUTLET 00 HIGH FLOW INV DOWN = 649.10 FT _ 9AA ;9 PROTECTION S-12-3 CHANNEL PER /9 r' PLAN PRETREATMENT I / CELL SPLASH/FOOTER ROCK, LEVEL SPREADER NON -WOVEN IF NECESSARY / GEOTEXTILE FABRIC ELEVATION = 648 FT I /00 (6.7 CY) N MAXIMUM ALLOWABLE FOOTER ELEVATION = 646.50 FT SECTION B - B' �, - �, r/ DETAIL: S-12 HIGH FLOW BYPASS STRUCTURE cotO , Lw NTS 2 2,857 SF BIORETENTION FACILITY _ I -1 /� °� CHANNEL C-S12-2 �u J BIOFILTER FLOOR - 648 FT TOP OF END WALL \ - - 632.5 FT / / ROWCROSS ST. 24 INCH RCP LENGTH = 96.5 FT - - -r0ro-On o _ _ INV UP = 640.0 FT 658 656 INV DOWN = 629.5 FT 654 652 ' 5 OUTLET64. / 646 3�650 / , PROTECTION S-12-2 / -644 642 650 _ 640 648 6 646 / 644 MAINTENANCE ACCESS ' DI-1 RISER 2 MINIMUM 10' WIDE 64 �QG3 CREST ELEVATION 638 MAX GRADE 20% ♦ = 648.5 FT - 636 634 / C 7- �( -100 FT STREAM BUFFER 100, sTEaM _ - 630 / b J L _ 628 6 3 12 INCH RCP 626 628 LENGTH = 48 FT ------------ ---- _ - _ INV UP=645.25FT 7- INV INV DOWN = 640.0 FTtoo S -------- -- / NOTES: 1. EMBANKMENT BACKFILL MATERIALS SHALL CONSIST OF GC, SC, CL, CH, AND/OR MH SOILS. N 2. CONTRACTOR SHALL PLACE SIGNS EVERY 150 FEET ALONG THE PERIMETER OF THE FACILITY. CONTRACTOR SHALL SUBMIT SHOP DRAWINGS/INFORMATION TO THE OWNER FOR APPROVAL PRIOR TO PURCHASE AND INSTALLATION. SIGNS SHALL READ: "NOTICE: STORMWATER MANAGMENT FACILITY - AREA EXPERIENCES WATER SURFACE FLUCTUATION AND STANDING WATER. NO TRESPASSING." 0 40 80 APPROXIMATE SCALE (FEET) FILEPATH:U:\ 5 report e ro was eslan ca as desicin 20160627.dwalatiefenbacklJun 28. 2016 at avout -12 GRADING & LAYOUT 6 LEGEND PROJECT LIMITS /.' EXISTING CONTOURS APPROXIMATE LOCATION OF EXISTING STREAM BUFFER PROPOSED GRADES PROPOSED BIORETENTION -8 ,.I...I... ' FOOTPRINT PROPOSED STORM SEWER NETWORK COUNTY CRITICAL SLOPES (2007) CROSS SECTION MINIMUM MAINTENANCE ACCESS LIMITS LAP RAIL FENCE S-12 SUMMARY: PRE -DEVELOPMENT: TOTAL DRAINAGE AREA = 1.86 ACRES ESTIMATED IMPERVIOUS AREA = 0.00 ACRES CURVE NUMBER = 60.71 POST -DEVELOPMENT: TOTAL DRAINAGE AREA = 4.36 ACRES ESTIMATED IMPERVIOUS AREA = 2.61 ACRES CURVE NUMBER = 83.13 BIORETENTION SIZING. REQUIRED AREA = 2.5% * IMPERVIOUS ACREAGE = 0.025 * 2.61 AC * 43560 SF / AC = 2,842 S.F. PROVIDED AREA = 2,857 S.F. WATER QUALITY TREATMENT: POST -DEVELOPMENT POLLUTANT LOAD = 5.38 (LBS-TP/YR) POLLUTANT REMOVAL EFFICIENCY = 50% TOTAL ESTIMATED POLLUTANT REMOVAL = 2.69 (LBS-TP/YR) HYDROLOGIC SUMMARY: 2-YEAR 10-YEAR 100-YEAR CFS CFS CFS PRE -DEVELOPMENT 1.17 3.63 9.48 POST -DEVELOPMENT (UNROUTED) 8.53 16.63 32.55 POST -DEVELOPMENT (ROUTED) 0.81 2.24 22.50 POST -DEVELOPMENT (COMPLIANCE NODE) 0.81 2.26 22.61 ROUTED PEAK ELEVATIONS: 2-YEAR 10-YEAR 100-YEAR FT FT FT BIORETENTION FILTER 648.64 648.71 648.82 DETENTION BASIN 644.13 646.03 646.67 PREPARED BY: Stantec I ` / 5209 Center Street Williamsburg, VA 23188 PHONE: (757) 220-6869 FAX: (757) 229-4507 FOR: OLD TRAIL VILLAGE CROZET,VA 1 TITLE: S-12 BIORETENTION GRADING AND LAYOUT DRAWN BY: DESIGNED BY: ALTH Op j AJT JGM CHECKED BY: APPROVED BY: JGM JGM PROJECT NUMBER: SCALE: J. GLENN MUCKLEY a 203400430 1" = 40' Lic. No. 038970 DATE: FILE PATH: 1 06/28/16 AJT JGM JGM *Po U-/� W� 05/20/2016 U:/203400430 REVISED PER COUNTY COMMENTS �� SHEET: ""'YIONAL E��1 6 EV DATE DESCRIPTION DSN CHK APP DIAMETER COBBLE, um • ..ice_ • • • .� o .�_.i�_ • • • �� o - -10 -5 0 5 10 DISTANCE (FT.) DETAIL: C-S12-2 (OUTFALL CHANNEL) VERTICAL SCALE: 1 " = 2' HORIZONTAL SCALE: 1 " = 5' FLOW FLOW VELOCITY ADEQUATE QUANTITY REACH STORM (CFS) DEPTH (FT/S) CHANNEL? EROSIVE? (CY) (FT) 1 2-YR 0.81 0.06 3.02 YES NO 1 10-YR 2.24 0.12 4.40 YES NO 30.6 2 2-YR 0.81 0.08 2.45 YES NO 2 10-YR 2.24 0.13 3.56 YES NO 664 664 TIE INTO PROPOSED STANDARD VDOT SWM-1 EVELOPMENT GRADES PER RGA PLANS 2,857 SF BIORETENTION FACILITY RISER CREST -646.0 FT ROPOSED GRADE BIOFILTER FLOOR = 648 FT 1-4 INCH ORIFICE @ 640 FT 660 1-6 INCH ORIFICE @ 644.9 FT 660 30 INCH RCP NV UP = 651.60 XISTING GRADE INV DOWN = 649.10 FT 656 �� DI-1 RISER ERM ELEV -650.2 FT 656 TOP OF WALL = 651.90 FT CREST ELEVATION = 648.5 FT \ 652 ERM ELEV-•650.2 FT 652 100 YR. WSE 648 . 648 100 YR. WSE 10 YR. WSE 24 INCH RCP NV UP = 640.0 FT 644 INV DOWN = 629.5 FT 644 SZZ� EVEL SPREADER 2 YR. WSE RISER BASE ELEVATION 640 = 643.25 FT \ n • 640 12 INCH RCP s •� INV UP = 645.25 FT r • PROPOSED RIPRAP INV DOWN = 640.0 FT r• s •� 636 OUTLET PROTECTION S-12-1 ' PROPOSED RIPRAP r / y .TOP OF END WALL 632.5 FT 636 CLASS I RIPRAP MIN. DEPTH = 2.2 FT OUTLET PROTECTION S-12-2 r s • •� CLASS I RIPRAP n r MIN. DEPTH = 2.2 FT DETENTION BASIN FLOOR ELEVATIO PROPOSED RIPRAP 632 = 640 FT OUTLET PROTECTION S-12-3 632 CLASS I RIPRAP RISER BASE ELEVATION / MIN. DEPTH = 2.2 FT = 637 FT J 628 PROPOSED CULVERT 628 \ \ , / PROPOSED CONCRETE / DRAINAGE BLANKET SEE DETAIL THIS SHEET CRADLE 4 ' Zz SEE DETAIL THIS SHEET t PROPOSED 4" PERFORATED ' 624 PVC DRAIN WRAPPED IN \ 624 NON -WOVEN GEOTEXTI- FILTER FABRIC \ CHANNEL C-S12-2 REACH 1 620 620 �. CHANNEL C-S12-2 REACH 2 PROPOSED 12" SS LINE 616 NOTE:7,7 41 TOP-614.38' 616 REFER TO GRADING PLAN FOR ACTUAL PROPOSED GRADED coNTRACTOR SHALL BE RESPONSIBLE FOR_ SLOPES, AS LABELS ARE SKEWED DUE TO SECTION ORIENTATION. FIELD LOCATION 612 612 0+00 0+20 0+40 0+60 0+80 1+00 1+20 1+40 1+60 1+80 2+00 2+20 2+40 2+60 2+80 3+00 3+20 3+40 3+60 3+80 4+00 4+20 4+40 4+60 4+80 5+00 S 12A - S 12AI pjvl4b!wjv'4jjw PI '�'% III%�;%�■■■■��j,��,�;. • OR ful. gnomon DIAMETER kh..aCdW ■ ■■■,�/�',■■■■■■■■ ■ r ■■■■■■■■■■■■■■■ ■■■■■■■■■■■■■■■■■■■■ 0. FLOW STORM FLOW D(FT)H VELOCITY ADEQUATE EROSIVE? QUANTITY (CFS) (FT/S) CHANNEL? (CY) 2-YR 7.06 0.39 4.55 YES NO 38.5 NOTES: 1) CONCRETE SHALL BE CLASS A3 2) CONTRACTOR MAY SUBMIT ALTERNATE BID WITH PLOWABLE FILL INSTEAD OF CONCRETE, PENDING APPROVAL BY DESIGN ENGINEER t (thickness) = 3.0" 8" D=24" 12" %2 D = 2. 0" * --wI �-- '` SIDE WALLS MAY CONFORM %4 D OR 6.0" ** TO THE SHAPE OF EXCAVATED TRENCH '`* SHALL NOT BE LESS THAN 6" DETAIL: OUTFACE CULVERT CONCRETE CRADLE AND GRAVEL DRAINAGE BLANKET NTs 12" / 12 INCH D = 24" DRAINAGE o � boo` BLANKET (VDOT #78) og��oc 0000�oo 4 INCH DIAMETER )o 0 0 �oU SLOTTED PVC PIPES 1211, (MIN. 5 FEET LONG) DAYLIGHTED THROUGH WEEPHOLE IN HEADWALL Y T • r S���F �T 24" DIAMETER CULVERT 3 2 1 4 INCH WATER QUALITY ORIFICE SEE NOTE 8 FLOTATION CALCULATIONS FOR RISER BASE GIVEN: WEIGHT OF WATER = 62.40 LBS/CU-FT WEIGHT OF CONCRETE = 150.00 LBS/CU-FT TOP INVERT OF RISER = 347.2 FT, NAVD88 INVERT OF 4.5" ORIFICE = 340.0 FT, NAVD88 INVERT OF 6" ORIFICE = 344.9 FT, NAVD88 INVERT OF CULVERT = 340.0 FT, NAVD88 BOTTOM INVERT OF RISER = 340.0 FT, NAVD88 HEIGHT OF RISER = 6.0 FT RISER INSIDE DIAMETER = 4.0 FT WALL THICKNESS = 5 INCHES RISER INSIDE AREA = 12.57 SF RISER OUTER AREA = 18.35 SF -SEE RISER FOOTPRINT = 5.78 SF NOTE 6 RISER BASE: METAL 1 1 .2' RISER BASE AREA = 18.35 SF PLATE BASE DEPTH = 3.00 FT RISER OPENINGS: -DEBRIS ORIFICE (4" DIAMETER) = 0.09 SF RACK ORIFICE (6" DIAMETER) = 0.20 SF OUTFACE CULVERT (30" OUTER DIAMETER) = 4.91 SF TOTAL AREA = 5.20 SF TOTAL VOLUME (AREA X 511) = 2.17 CU-FT WEIGHT OF DISPLACED WATER: `•d' ' �' � �'�"�'' � •�' ' �'`•' " '' •':''•; ':'' VOLUME OF RISER = 1 10.10 CU-FT • • � � • • � • � � �3-6 1811 1 VOLUME OF BASE = 55.05 CU-FT 165.15 CU-FT "`• °� •'"`• •''• • � •'' MIN. TOTAL DISPLACED VOLUME ��•��°•�':�����•�':���•�•�':���•����: � ����•°��': WEIGHT OF DISPLACED WATER = 10,305 LBS CLASS A-3 . ;,...° , ; ... • :,., o , :. •.:.•.. CONCRETE TO BE WEIGHT OF RISER: USED TO FILL SWM VOLUME OF RISER CONCRETE = 34.68 CU-FT DRAINAGE VOLUME OF OPENINGS = 2.17 CU-FT STRUCTURE TO � TOTAL VOLUME OF RISER = 32.51 CU-FT INVERT OF WEIGHT OF RISER = 4,877 LBS OUTLET PIPE. 5" 4'-0" DIA. 511 WEIGHT OF BASE: VOLUME OF BASE = 55.05 CU-FT WEIGHT OF BASE = 8,258 LBS SIDE VIEW TOTAL DOWNWARD WEIGHT = 13,135 LBS SWM DRAINAGE STRUCTURE FACTOR OF SAFETY = 1.27 "DIA.X6"LG. ADHESIVE BOLTS W/FLAT WASHERS AND SELF LOCKING NUTS TYPICAL 8PCACES-EQUALLY n n n � r r-� � n i ANI u r u I n r-i � BILE ACCESS WHINGE TE 1 X %" STEEL RING D TO RISER TYP. RISER DIMENSION APPROX. WT. (CBS.) 1. D. O.D. A B C D E SEGMEN 48 58 55 9 13 20 53 29 120 METAL DETAIL: S-12 BIORETENTION VDOT STORMWATER MANAGEMENT (SWM-1) RISER AND TRASH RACK NTS NOTES: 1 . COST OF TRASH RACK AND DEBRIS RACK ARE TO BE INCLUDED IN THE PRICE BID FOR THE STORMWATER MANAGEMENT DRAINAGE STRUCTURE. 2. STRUCTURE MAY BE PRECAST OR CAST IN PLACE. 3. WEEP HOLES SHALL NOT BE PROVIDED. ANY LIFT HOLES SHALL BE PLUGGED. 4. STEPS ARE TO BE PROVIDED WHEN HEIGHT OF STRUCTURE IS 4'-0" OR GREATER ABOVE INVERT OF OUTLET PIPE. FOR STEP DETAILS SEE STANDARD ST-1 . 5. SEE STANDARD SWM-DR FOR ADDITIONAL DETAILS ON PLATE, DEBRIS RACK AND TRASH RACK. 6. MARK HEIGHT OF STRUCTURE, IN BLACK, WITH 4" HIGH NUMERALS AND 1 "WIDE HORIZONTAL STRIPES AT 1' INTERVALS FROM INVERT OF WATER QUALITY ORIFICE (ALL VISIBLE SIDES). 7. THE PERMANENT STORMWATER MANAGEMENT DRAINAGE STRUCTURE, STANDARD SWM-1 MAY BE MODIFIED WHERE THE STORMWATER MANAGEMENT BASIN IS TO BE USED AS A TEMPORARY SEDIMENT BASIN DURING PROJECT CONSTRUCTION. SEE STANDARD SWM-DR, SHEET 1 OF 5 FOR TEMPORARY MODIFICATION DETAILS. 8. THE SIZE OF THE WATER QUALITY ORIFICE SHALL BE 4.5 INCHES. SILL SHALL BE KEYED IN MIN. 4 FEET SECTION A -A' m; 111111II�111= - 2 4 3 1I- n=i a-1 HEADER ROCKS '�-III=III-III-_ FOOTER ROCKS=_- I- - - LEFT -1-111-111-111= -- BANK 4 FT SILL SHALL BE CONSTRUCTION NOTES / KEYED IN MIN. 4 FEET UPGRADES ON ALBEMARLE COUNTY PARKS 1. MINIMUM STONE SIZE FOR S-1 SHALL BE 2.5 FT X 2.5 FT X 2.5 FT. MINIMUM STONE DEPARTMENT AND ADMINISTRATION PROPERTY, SIZE FOR STRUCTURES S-2, S-3, S-4, AND S-5 SHALL BE 2 FT X 2 FT X 2 FT. SEE IMBRICATED BOULDER ROCK SIZING DEFINITION DETAIL ON SHEET14. INCLUDING EMBANKMENT ENCROACHMENT AND 2. ALL STRUCTURE CREST WIDTHS (BETWEEN POINTS 2 AND 4) SHALL BE 4 FEET WIDE. CHANNEL IMPROVEMENTS AS NECESSARY SHALL a 3. SEE SHEET 15 FOR ADDITIONAL CONSTRUCTION SPECIFICATIONS. fl/1I V V C LB�EV� PERFORMED VIMPROVEMENTS CS V�7T/'1HJROV CU G� CH�7AGREEMENT L 4. CONTRACTOR IS RESPONSIBLE FOR CLEAN UP. -1 FEET DEEP TRAPAZOIDAL 5. SEE PROFILE FOR MAXIMUM FOOTER ELEVATIONS. TRANSITION CHANNEL FEET BOTTOM WIDT / 5H RIGHT BANK \/ 2:1 IDE L P S S O ES APPROXIMATE CHANNEL SLOPE _ RIGHT ARM LENGTH (L) A\ RIGHT BANK SILL SHALL BE 4 KEYED MIN. 4 FEET UNLESS OTHERWISE g, SPECIFIED A' HEADER ROCKS FOOTER ROCKS SPLASH ROCKS B SCODU ' - 'POOL / � I\ ` LEGEND ' PROJECT LIMITS PROPOSED STORM SEWER NETWORK CHANNEL C-1-2-1 COORDINATION ONGOING REGARDING COUNTYCRITICALSLOPES / EXISTING CONTOURS OUTLET USE OF PARKS PROPERTY _- Soo EXISTING APPROXIMATE LOCATION OF ► 1 CROSS SECTION PROTECTION L-2-1 RESOLUTION TO BE PROVIDED -- EXISTING STREAM BUFFER L� �' PROPOSED GRADES MINIMUM MAINTENANCE THROUGH EASEMENTS ACCESS LIMITS � PROPOSED BIORETENTION I-b 12-- �o� LAP RAIL FENCE ` ■ ■ �,-�-�FOOTPRINT 8°13'53" .92' LINED WITH 2.2 FEET OF CLASS I RIPRAP UNDERLAIN WITH / sa2 GEOTEXTILE FABRIC 644" 10 FEET WIDE EMERGENCY SPILLWAY --- 646 CREST ELEVATION = 663.25 MODIFY EXISTING -- 658 NON -ACTIVATED IN THE 100-YEAR STORM A EMBANKMENT - - - s5z MATTED WITH LANDLOK 450 TRM RAISE CREST / 654 ELEVATION TO = / 656 664.40 FT sso 15 FEET WIDE TOP -------- 662 zo / 664 -�- WIDTH NO GAPS G� BETWEEN - ROCKS -__- 664 ' � A LEFT ARM LENGTH (L) LEFT BANK SCOUR POOL TO BE CONSTRUCTED DURING SILL SHALL BE INSTALLATION OF STRUCTURE. KEYED IN MIN. 4 FEET SEE PLAN VIEW AND PROFILE FOR POOL SIZES HEADER SPLASH STREAM FLOW ROCKS WATER ROCKS E- SURFACE SCOUR ELEVATION POOL 3 - PROPOSED CHANNEL THALWEG = - -_ COMPACTED CLAY OR FINES - MATERIALWULCH STRUCTURE ELEVATIONS POINT ELEVATION 1 CREST +1 FT 2 CREST PER PLAN 3 CREST PER PLAN 4 CREST PER PLAN 5 CREST + 1 FT 0' \ \ •�yDAM HEIGHT APPROXIMATELY 25.4 FEET, .: DAM SAFETY REGULATIONS SHALL NOT . • �►��� �� ,11�. APPLY - pam= WAR A 42 INCH RCP �,�� ♦ �el INV . • 11 FT 1 � � ROCKS L NON -WOVEN GEOTEXTILE FABRIC SECTION B-13' (STD. AND SPEC. 3.19 TABLE D) INSTALL NEW STANDARD VDOT SWM-1 RISER DETAIL: L-2 DROP STRUCTURES (TYP) STRUCTURE NITS WITH 8 INCH DRAIN VALVE AT ELEV = 645.50 FT CREST ELEVATION -661.25 FT CLASS I RIPRAP •3-6 INCH CIRCULAR ORIFICES @ 655.50 FT 012, INSET (1" = 201) N 0 40 80 APPROXIMATE SCALE (FEET) FILEPATH:U:\ 5 report e ro wns eslan ca es desicin STRUCTURE DIMENSIONS STRUCTURE MIN. LEFT ARM L (FT) MIN. RIGHT ARM L (FT) 1 10 10 2 15 15 3 15 15 4 15 15 5 15 25 Z `I STRUCTURE S5 CREST = 656.00 FT \ \ \ �, o N (� Nco co r O \ 1 0 PLUNGE POOL LINED WITH EXISTING PEDESTRIAN/ \ _ 1 CLASS I RIPRAP (17.5 CY) I I MAINTENANCE ACCESS PATH - PLUNGE POOL LINED WITH \ CLASS I RIPRAP (28.9 CY) STEP POOL STRUCTURE 1 (SEE INSET) PLUNGE POOL LINED WITH / CLASS I RIPRAP (24.0 CY) INSET I \ I 0 EXISTING 12 INCH DIP WATERLINE TOP STRUCTURE S2 ,C OF PIPE ELEVATION-665.75 FT CREST = 659.00 FT �/ � / CONTRACTOR SHALL LOCATE VIA I41.� � � � � �� ? � �1 ��POTHOLING (25 FEET ON CENTER) i DURING CONSTRUCTION O-) \ -) DOUBLE STEP - CREST = 659.00 FT L� L-2 RETENTION BASIN SUMMARY: PRE -DEVELOPMENT: TOTAL DRAINAGE AREA = 14.19 APPROXIMATE IMPERVIOUS AREA = 0.21 ACRES CURVE NUMBER = 61.54 POST -DEVELOPMENT: TOTAL FACILITY DRAINAGE AREA = 23.81 ACRES (23.91 ACRES TO DOWNSTREAM COMPLIANCE NODE) APPROXIMATE IMPERVIOUS AREA = 16.22 ACRES CURVE NUMBER = 86.94 RETENTION BASIN SIZING: REQUIRED VOLUME = IMPERVIOUS AREA * 0.5 IN / 12 IN/FT * 4 = 2.70 AC -FT (4*WQv WITH AQUATIC BENCH) PROVIDED VOLUME = 2.73 AC -FT WATER QUALITY TREATMENT: POST -DEVELOPMENT POLLUTANT LOAD = 36.01 (LBS-TP/YR) POLLUTANT REMOVAL EFFICIENCY = 65% TOTAL ESTIMATED POLLUTANT REMOVAL = 23.41 (LBS-TP/YR) HYDROLOGIC SUMMARY: 2-YEAR 10-YEAR 100-YEAR CFS CFS CFS PRE -DEVELOPMENT (UNROUTED) 6.04 18.69 48.54 CURRENT DEVELOPMENT (ROUTED) 5.49 9.27 44.64 POST -DEVELOPMENT (UNROUTED) 68.87 114.60 198.99 POST -DEVELOPMENT (ROUTED) 5.34 16.98 108.76 POST -DEVELOPMENT (COMPLIANCE NODE) 5.35 17.02 108.91 ROUTED PEAK ELEVATIONS: 2-YEAR 10-YEAR 100-YEAR FT FT FT POST -DEVELOPMENT 659.63 661.38 663.01 (7) 670 o 00 nl � S6a�y1� PREPARED BY: / REMOVE EXISTING 36 \ L,� INCH HDPE PIPE AND tJ/ j INSTALL NEW MANHOLE Stantec UPSTREAM MANHOLE INSTALL NEW MANHOLE AND NEW 30 INCH RCP 5209 Center Street AND 42 INCH RCP WITH PER RGA APPROVED 1 Williamsburg, VA23188 DEVELOPMENT PLAN _ PHONE: (757) 220-6869 FAX: (757) 229-4507 VDOT EW-1 / INV DOWN = 660.00 FT FOR: L' O 63o INSTALL PER ACCESS FROM 2 OLD TRAIL VILLAGE 7 �< GOLF DRIVE / APPROVED RGA \ CROZET, VA 10' DEVELOPMENT PLAN L� 670 / NOTES: 1. MAINTENANCE ACCESS IS PROVIDED PER ORIGINAL APPROVED AND CONSTRUCTED PLAN FROM GOLF DRIVE VIA EXISTING PEDESTRIAN/MAINTENANCE ACCESS PATH. 2. EMBANKMENT BACKFILL MATERIALS SHALL CONSIST OF GC, SC, CL, CH, AND/OR MH SOILS. 3. CONTRACTOR SHALL PLACE SIGNS EVERY 150 FEET ALONG THE PERIMETER OF THE FACILITY. CONTRACTOR SHALL SUBMIT SHOP DRAWINGS/INFORMATION TO THE OWNER FOR APPROVAL PRIOR TO PURCHASE AND INSTALLATION. SIGNS SHALL READ: "NOTICE: STORMWATER MANAGMENT FACILITY - AREA EXPERIENCES WATER SURFACE FLUCTUATION AND STANDING WATER. NO TRESPASSING." TITLE: L-2 RETENTION BASIN GRADING AND LAYOUT DRAWN BY: DESIGNED BY: ALTH Op j AJT JGM CHECKED BY: APPROVED BY: JGM JGM PROJECT NUMBER: SCALE: J. GLENN MUCKLEY a 203400430 1" = 40' Lic. No. 038970 DATE: FILE PATH: 1 06/28/16 AJT JGM JGM *PO U'/� W� 05/20/2016 U:/203400430 REVISED PER COUNTY COMMENTS �� SHEET: sIONAL E8 EV DATE DESCRIPTION DSN CHK APP 672 Ip \ REMOVE EXISTING INSTALL NEW STANDARD DAM HEIGHT APPROXIMATELY 25.4 FEET, MPOUNDMENT VOLUME -9.49 ACRE-FEET RISER AND BARREL DAM SAFETY REGULATIONS SHALL NOT APPLY VDOT SWM-1 RISER 672 668 78; STRUCTURE 51 XISTING GRADE WITH 8 INCH DRAIN CREST = 660.00 FT CREST DOUBLE STEP 3-6 INCH CIRCULAR Tr CREST = 659.00 FT 5-8 INCH CIRCULAR STRUCTURE VALVE AT ELEV = 645.50 FT MODIFY EXISTING EMBANKMENT ELEVATION-661.25 FT AISE CREST ELEVATION TO = 664.40 FT ORIFICES @ 655.50 FT 5 FEET WIDE TOP WIDTH ORIFICES @ 659.35 FT 668 STRUCTURE S2 664 °REST = 659.00 FT STRUCTURE S3 4' 664 CREST=658.00FT 100YR. WSE STRUCTURE 54 10 YR. WSE 660 CREST = 651.00 FT STRUCTURE S5 2 YR. WSE CHANNEL SHALL NOT EXTENDINTO 660 CREST = 656.00 FT 42 INCH RCP DOWNSTREAM 361NCH RCP WITH VDOT EW-1 NV UP = 547.50 FT WETLANDS INV DOWN = 539.00 FT WSE = 655.50 FT 656 INV DOWN - 660.00 FT -1 FEET DEEP TRAPAZOIDAL TRANSITION CHANNEL 5 FEET BOTTOM WIDTH 656 652 STRUCTURE S1 ROCK\ / SIZE 2.5 ' X 2.5' X 2.5' ` ALL OTHER STRUCTURES 2' X 2• X FLOOR ELEVATION UNLESS OTHERWISE = 658.00 FT 21 SAFETY/AQUATIC APPROXIMATE CHANNEL SLOPE LOPES CONTRACTOR TO PROVIDE BENCH DRAWING RELATED TO / LINED WITH 2.2 FEET OF CLASS I RIPRAP UNDERLAIN WITH GEOTEXTILE FABRIC DRAIN VALVE FOR- APPROVAL PRIOR TO INSTALLATION PROPOSED RIPRAP 652 SHOP ENGINEER/OWNER -PROPOSED GRADE 648 644 NOTED \FLOOR ELEVATION = 656.00 FT / / . FLOOR ELEVATIONAI /r =655.00 FT \ FLOOR ELEVATION =651.00 FT \ OUTLET PROTECTION L-2-1 r P PER VESCH STD. AND SPEC. 3.18 � v _ ° r v v ° \ CLASS I RIPRAP o • vr•a r e MIN. DEPTH=2.2 FT \ °+ i v+ r A v A• r • • a r v + / r • v r° a r+ a a v °p ► A v o 6-INCH DRAIN PIPE ° r 648 644 FLOOR ELEVATION OREBAY WSE = 656.00 FT INV. = 647.50 FT 640 640 PROPOSED CONCRETE CADL SEE DETAIL THIS SHEET 636 NOTE: REFER TO GRADING PLAN FOR ACTUAL PROPOSED GRADED SLOPES, AS LABELS ARE SKEWED DUE TO SECTION ORIENTATION. PROPOSED CULVERT PROPOSED 4" PERFORATED SEEo'E'q�°HssHEET v PVC DRAIN WRAPPED IN w��%lil X ��/ NON -WOVEN GEOTEXTILE FILTER FABRIC 636 717 632 632 0+00 0+20 0+40 0+60 0+80 1+00 1+20 1+40 1+60 1+80 2+00 2+20 2+40 2+60 2+80 3+00 3+20 3+40 3+60 3+80 4+00 4+20 4+40 4+60 4+80 5+00 5+20 5+40 5+60 5+80 6+00 6+20 L2A - L2AI ■ommoI.CmolE ICm11ommom n -IN N 2- • �� fir. �I•fir•���•�.�.��:•�r•�y�.e.,•I•��r.�ll% • 11=•i��•�•�ili iii li•� i•,mROM! •� lii i•,r ��i•�•N�I��ii�li•��i•!i�illi�ii lii% CLASS,•�, ��'+�l�_•:�••�•41�'+may' .._.rFABRIC FLOW STORM FLOW DEPTH VELOCITY ADEQUATE EROSIVE? QUANTITY (CPS) (FT) (FT/S) CHANNEL? (CY) 2-YR 5.34 0.45 2.03 YES NO 10-YR 13.83 0.77 2.76 YES NO 46.4 r\InTF(Z- 1) CONCRETE SHALL BE CLASS A3 2) CONTRACTOR MAY SUBMIT ALTERNATE BID WITH PLOWABLE FILL INSTEAD OF CONCRETE, PENDING APPROVAL BY DESIGN ENGINEER I 672 668 664 660 TIE INTO PROPOSED ROPOSED GRADE DEVELOPMENT GRADES PER RGA PLANS �: BERM ELEVATION 664.4 FT ti^ 672 668 664 660 / 10 FEET WIDE EMERGENCY CREST -ACTIVATED IN MATTED WITH SPILLWAY ELEVATION = THE 100-YEAR LANDLOK 450 663.25 STORM TRM / NON 7z 7Z EXISTING GRADE. 656 652 652 648 42 INCH RCP NV UP = 644.00 INV DOWN FT - 639.00 FT 648 644 644 4� 640 640 0+00 0+20 0+40 0+60 0+80 1+00 1+20 1+40 1+60 1+80 2+00 2+20 2+40 2+60 NOTE: REFER TO GRADING PLAN FOR ACTUAL PROPOSED GRADED SLOPES, AS LABELS ARE SKEWED DUE TO SECTION ORIENTATION. L2 B - L2 B' t (thickness) = 5.25" 8" D = 42" 12" %2 D = 3.5" * � [,,*- * SIDE WALLS MAY CONFORM %4 D OR 10.5" ** TO THE SHAPE OF EXCAVATED TRENCH *'` SHALL NOT BE LESS THAN 6" DETAIL: OUTFACE CULVERT CONCRETE CRADLE AND GRAVEL DRAINAGE BLANKET NTS 12" Y2 (D + 2t) = 26.25") 8" D=42" 12 INCH DRAINAGE BLANKET (VDOT #78) F �4 INCH DIAMETER 10 0 0°�°ono°ter SLOTTED PVC PIPES 12" (MIN. 5 FEET LONG) DAYLIGHTED THROUGH WEEPHOLE IN HEADWALL ��6�y7Oi u?y0��� �T 42" DIAMETER CULVERT CLASS A-3 CONCRETE TO BE USED TO FILL SWM DRAINAGE STRUCTURE TO INVERT OF OUTLET PIPE. 3 2 METAL 3.0' PLATE I DEBRIS RACK 6 INCH WATER QUALITY ORIFICE `•a�•' � � MIN A 8" 511 4'-0" DIA. 5„ SIDE VIEW SWIM DRAINAGE STRUCTURE %" DIA. X 6" LG. ADHESIVE BOLTS W/FLAT WASHERS AND SELF LOCKING NUTS TYPICAL 8PCACES-EQUALLY n 1 ANI uru -A r-i i-+ FLOTATION CALCULATIONS FOR RISER BASE GIVEN WEIGHT OF WATER = 62.40 LBS/CU-FT WEIGHT OF CONCRETE = 150.00 LBS/CU-FT TOP INVERT OF RISER = 661.25 FT, NAVD88 INVERT OF 8 INCH DRAIN VALVE = 647.50 FT, NAVD88 INVERT OF 3-6 INCH ORIFICES = 655.50 FT, NAVD88 INVERT OF 5-8 INCH ORIFICES = 659.35 FT, NAVD88 INVERT OF CULVERT = 647.50 FT, NAVD88 BOTTOM INVERT OF RISER = 647.50 FT, NAVD88 HEIGHT OF RISER = 13.75 FT RISER INSIDE DIAMETER = 4.0 FT WALL THICKNESS = 5 INCHES RISER INSIDE AREA = 12.57 SF RISER OUTER AREA = 18.35 SF RISER FOOTPRINT = 5.78 SF QICCQ C24CC• RISER BASE AREA = 18.35 SF BASE DEPTH = 6.5 FT RISER OPENINGS: DRAIN VALVE (8" DIAMETER) = 0.35 SF 3 ORIFICES (6" DIAMETER) = 0.59 SF 5 ORIFICES (8" DIAMETER) = 1 .75 SF OUTFACE CULVERT (42" OUTER DIAMETER) TOTAL AREA = 12.30 SF TOTAL VOLUME (AREA X 5") = 5.13 CU-FT WEIGHT OF DISPLACED WATER: VOLUME OF RISER = 252.31 CU-FT VOLUME OF BASE = 119.28 CU-FT TOTAL DISPLACED VOLUME = 371.59 CU-FT WEIGHT OF DISPLACED WATER = 23,187 LBS WEIGHT OF RISER: VOLUME OF RISER CONCRETE = 79.48 CU-FT VOLUME OF OPENINGS = 5.13 CU-FT TOTAL VOLUME OF RISER = 74.35 CU-FT WEIGHT OF RISER = 11 ,153 LBS WEIGHT OF BASE: VOLUME OF BASE = 119.28 CU-FT WEIGHT OF BASE = 17,891 LBS TOTAL DOWNWARD WEIGHT = 29,044 LBS FACTOR OF SAFETY = 1.25 NOTES: 1 . COST OF TRASH RACK AND DEBRIS RACK ARE TO BE INCLUDED IN THE PRICE BID FOR THE STORMWATER MANAGEMENT DRAINAGE STRUCTURE. 3LE ACCESS 2. STRUCTURE MAY BE PRECAST OR CAST WHINGE IN PLACE. TE 1 3. WEEP HOLES SHALL NOT BE PROVIDED. ANY LIFT HOLES SHALL BE PLUGGED. 4. STEPS ARE TO BE PROVIDED WHEN HEIGHT OF STRUCTURE IS 4'-0" OR GREATER ABOVE INVERT OF OUTLET PIPE. FOR STEP DETAILS SEE STANDARD ST-1 . 5. SEE STANDARD SWM-DR FOR ADDITIONAL DETAILS ON PLATE, DEBRIS RACK AND TRASH RACK. 6. MARK HEIGHT OF STRUCTURE, IN BLACK, WITH 4" HIGH NUMERALS AND 1 "WIDE HORIZONTAL STRIPES AT 1' INTERVALS FROM INVERT OF WATER QUALITY X %" ORIFICE (ALL VISIBLE SIDES). STEEL RING 7. THE PERMANENT STORMWATER D TO RISER MANAGEMENT DRAINAGE STRUCTURE, STANDARD SWM-1 MAY BE MODIFIED WHERE THE STORMWATER MANAGEMENT BASIN IS TO BE USED AS A TEMPORARY SEDIMENT BASIN DURING PROJECT CONSTRUCTION. SEE STANDARD SWM-DR, SHEET 1 OF 5 FOR TEMPORARY MODIFICATION DETAILS. TYP. RISER METAL DIMENSION APPROX. WT. (CBS.) I.D. O.D. A B C D E SEGMEN 48 58 55 9 13 20 53 29 120 DETAIL: L-2 RETENTION BASIN VDOT STORMWATER MANAGEMENT (SWM-1) RISER AND TRASH RACK NTS -I Ian I Ate, , APPROXIMATE- ��, FEMA FLOODPLAIN LIMITS 30 INCH RCP �4 LENGTH = 93 FT TOP OF WALL = 626 FT %.� 4ft ,INV UP = 628.00 INV DOWN = 622.00 INTEGRATE FUTURE TRAIL - 8 INCH HDPE 12 INCH NYOBLAST\ PIPE (TYP) - • ss DRAINAGE BASIN 632 2 6' RIM = 633.50 FT' - - \ so S \ 11 o1z _ INV IN = 631.20 - 640 ♦ s�o INV OUT = 631 A U 12 INCH NYOBLAST s - As DRAINAGE BASIN RIM = 641.50 FT - INV IN = 638.50 INV OUT = 638.40 i ROWCROSS ST. 12 INCH NYOBLAST� DRAINAGE BASIN RIM = 645.50 FT INV IN = 642.50 INV OUT = 642.40 6 s �.. 12 INCH NYOBLAST DRAINAGE BASIN RIM =647FT� INV OUT = 644.0 FT � STANDARD VDOT MH-1 RIM ELEVATION - 662.00 FT 36 INCH RCP OUT INV. = 657.00 FT 30 INCH RCP IN INV. = 656.50 FT 18 INCH RCP OUT INV. = 656.40 FT CONCRETE FOOTING DETAIL: HIGH FLOW BYPASS NTS E 36 INCH \\\RCP s6 LENGTH = 110 FEET INV UP = 657.00 FT INV DOWN = 648.00 FT 10 FOOT WIDE MAINTENANCE ACCESS MAX GRADE = 20% 30 INCH RCP LENGTH = 18 FEET � j INV UP = 656.60 FT X INV DOWN = 656.50 FT STANDARD VDOT MH-1 `., RIM ELEVATION = rt�� 662.00 FT'� per• � 18 INCH RCP GO\-F LENGTH = 8 FEET _ � INV UP = 656.40 FT INV DOWN = 656.30 FT 4 FT HIGH WOODEN � LAP RAIL FENCE z N - CHANNEL C-L3-1 OUTLET �\� 40 PROTECTION L-3-2 622 - - am own 624 626 Y -f- 62a / ho h� / 0 0 LEGEND PROJECT LIMITS /.' EXISTING CONTOURS APPROXIMATE LOCATION OF EXISTING STREAM BUFFER PROPOSED GRADES PROPOSED BIORETENTION -8 ,.I...I... ' FOOTPRINT PROPOSED STORM SEWER NETWORK COUNTY CRITICAL SLOPES (2007) CROSS SECTION MINIMUM MAINTENANCE ACCESS LIMITS LAP RAIL FENCE �f COORDINATION ONGOING REGARDING USE OF PARKS PROPERTY RESOLUTION TO BE PROVIDED THROUGH EASEMENTS 6� ro ro STANDARD VDOT SWM-1 RISER CREST -636.50 FT 1-6 INCH ORIFICE @ 630.00 FT 14* 01�, 1-6 INCH ORIFICE @ 635.00 FT OUTLET - PROTECTION L-3-1 36 INCH RCP , LENGTH = 83 FEET INV UP=647.00FT� j INV DOWN = 631.00 FT STANDARD VDOT MH-1 RIM ELEVATION = 654.00 FT 12 INCH RCP LENGTH = 32 FEET INV UP = 652.00 FT INV DOWN = 648.00 FT _ DI-1 CREST ELEVATION = 656.80 FT 41746 SF BIORETENTION FACILITY FLOOR ELEVATION = 656.3 FT LEVEL SPREADER ELEVATION = 656.3 (5.7 CY) STRUCTURAL WALL CONTRACTOR SHALL - PROVIDE SEALED SHOP DRAWINGS FOR OWNER REVIEW L-3 SUMMARY: PRE -DEVELOPMENT: TOTAL DRAINAGE AREA = 6.90 ACRES ESTIMATED IMPERVIOUS AREA = 0.00 ACRES CURVE NUMBER = 60.90 POST -DEVELOPMENT: TOTAL DRAINAGE AREA = 6.88 ACRES ESTIMATED IMPERVIOUS AREA = 3.69 ACRES CURVE NUMBER = 80.10* BIORETENTION SIZING: REQUIRED AREA = 2.5% * IMPERVIOUS ACREAGE = 0.025 * 3.69 AC * 43560 SF / AC = 4,019 S.F. PROVIDED AREA = 4,746 S.F. WATER QUALITY TREATMENT: POST -DEVELOPMENT POLLUTANT LOAD = 8.36 (LBS-TP/YR) POLLUTANT REMOVAL EFFICIENCY = 50% TOTAL ESTIMATED POLLUTANT REMOVAL = 4.18 (LBS-TP/YR) i IX/r1rIf-NI �r+ir+ n1 1n A A A MX/. ')_VGOC? 10 Vr:AD 1(1()_VpAR PRE -DEVELOPMENT POST -DEVELOPMENT (UNROUTED) POST -DEVELOPMENT (ROUTED) POST -DEVELOPMENT (COMPLIANCE NODE) ROUTED PEAK ELEVATIONS: BIORETENTION FILTER DETENTION BASIN NOTES: 1. EMBANKMENT BACKFILL MATERIALS SHALL CONSIST OF GC, SC, CL, CH, AND/OR MH SOILS. 2. CONTRACTOR SHALL PLACE SIGNS EVERY 150 FEET ALONG THE PERIMETER OF THE FACILITY. CONTRACTOR SHALL SUBMIT SHOP DRAWINGS/INFORMATION TO THE OWNER FOR APPROVAL PRIOR TO PURCHASE AND INSTALLATION. SIGNS SHALL READ: "NOTICE: STORMWATER MANAGMENT FACILITY - AREA EXPERIENCES WATER SURFACE FLUCTUATION AND STANDING WATER. NO TRESPASSING." 4.71 14.32 36.64 17.94 32.51 60.35 1.91 7.14 45.03 1.94 7.24 45.47 ''-YEAR 10-YEAR 100-YEAR FT FT FT 657.44 657.62 657.90 634.34 636.61 637.40 PREPARED BY: itantec 5209 Center Street Williamsburg, VA 23188 PHONE: (757) 220-6869 FAX: (757) 229-4507 FOR: TITLE: OLD TRAIL VILLAGE CROZET,VA L-3 BIORETENTION GRADING AND LAYOUT N ALTH �F � j DRAWN BY: AJT DESIGNED BY: JGM CHECKED BY: JGM APPROVED BY: JGM PROJECT NUMBER: SCALE: REVISED PER COUNTY 0 30 60 1 06/28/16 COMMENTS AJT JGM JGM APPROXIMATE SCALE (FEET) J. GLENN MUCKLEY a Lic. No. 038970 � �� � y S 1 `sI6NAL ��� 203400430 1" = 30' DATE: 05/20/2016 FILE PATH: U:/203400430 SHEET: 1 0 REV DATE DESCRIPTION DSN CHK APP FILEPATH:C:\Users\atiefenback\appdata\local\temi)\AcPublish 2524\00430 es desiqn 20160627.dwglatiefenbacklJun 28, 2016 at 14:481Lavout: L-3 GRADING & LAYOUT 10 672 668 664 660 656 652 648 TIE INTO PROPOSED EVELOPMENT GRADES 4,746 SF BIORETENTION FACILITY PER RGA PLANS \ BIOFILTER FLOOR = 656.3 FT -PROPOSED GRADE / STANDARD VDOT MH-1 EXISTING GRADE \ RIM ELEVATION = 662.00 FT DI-1 RISER 'ala, CREST ELEVATION = 656.8 FT T ERM ELEtt 100YR. WSE STANDARD VDOT MH-1 RIM ELEVATION = 654.00 FT EVEL SPREADER 18 INCH RCP LENGTH = 8 FEET RISER BASE ELEVATION INV UP = 656.40 FT = 650.0 FT' V DOWN = 656.30 FT 672 668 664 660 656 652 648 STANDARD VDOT SWM-1 RISER CREST-636.50 FT 1-6 INCH ORIFICE @ 630.00 FT 1-6 INCH ORIFICE @ 635.00 FT MH-1 BASE ELEVATION 644 64O 636 632 62$ 624AA 620 616 = 655.40 FT 30 INCH RCP LENGTH = 18 FEET INV UP = 656.60 FT INV DOWN = 656.50 FT ERM ELEVATION = 640 FT PROPOSED CULVERT SE-DRE BLANKET DETAIL \ i,� sEe DErAIL rNIs SHEET 100 YR. WSE 10 YR. WSE 2 YR. WSE ro \ PROPOSED RIPRAP \ OUTLET PROTECTION L-3-2 EEI CLASS 8 IHZIP AND SPEC. 3.18 - - MIN. DEPTH = 2.2 FT a r PROPOSED RIPRAP ° • r OUTLET PROTECTION L-3-1 0 o CLASS I RIPRAP MIN. DEPTH = 2.2 FT _ r p .vl RISER BASE ELEVATION r r \ = 624.0 FT \ PROPOSED CONCRETE \ CRADLE \ SEE DETAIL THIS SHEET 301NCHRCP PROOSED4"PERFORATED LENGTH = 93 FT PVC DRAIN WRAPPED IN INV UP = 628.00 NON -WOVEN GEOTEXTILE INV DOWN=622.00 FILTER FABRIC CHANNEL C-L2- 644 640 636 632 628 624 620 616 / 12 INCH RCP LENGTH = 32 FEET INV UP = 652.00 FT INV DOWN = 648.00 FT MH-1 BASE ELEVATION = 646.0 FT k 36 INCH RCP LENGTH = 83 FEET INV UP = 647.00 FT INV DOWN = 6 31.00 FT _ .. NOTE: REFER SLOPES, TO GRADING AS LABELS PLAN ARE FOR SKEWED ACTUAL DUE PROPOSED GRADED TO SECTION ORIENTATION. 612 0+00 0+20 0+40 0+60 0+80 1+00 1+20 1+40 1+60 1+80 2+00 2+20 2+40 2+60 2+80 3+00 3+20 3+40 3+60 L3A - L3AI 3+80 4+00 4+20 4+40 4+60 4+80 5+00 612 5+20 2 _ 0 MEN DEPTH _ -2 d w 6" DEPTH -4 620 -10 0 10 20 DISTANCE (FT.) DETAIL: C-1-3-1 (OUTFALL CHANNEL) VERTICAL SCALE: 1 " = 2' HORIZONTAL SCALE: 1 " = 10 . FLOW FLOW VELOCITY ADEQUATE QUANTITY STORM (CPS) D(FT)H (FT/S) CHANNEL? EROSIVE? (CY) 2-YR 1.91 0.24 1.65 YES NO 19.5 10-YR 7.14 0.51 2.52 YES NO NInTF(:Z• 1) CONCRETE SHALL BE CLASS A3 2) CONTRACTOR MAY SUBMIT ALTERNATE BID WITH PLOWABLE FILL INSTEAD OF CONCRETE, PENDING APPROVAL BY DESIGN ENGINEER t (thickness) = 3.5" D=30" 81, 12" %2 D = 2.5" *SIDE WALLS MAY CONFORM %4 D OR 7.5" ** TO THE SHAPE OF EXCAVATED TRENCH *'` SHALL NOT BE LESS THAN 6" DETAIL: OUTFACE CULVERT CONCRETE CRADLE AND GRAVEL DRAINAGE BLANKET NTS 12" D=30" 12 INCH DRAINAGE BLANKET (VDOT #78) 4 INCH DIAMETER �oop000c SLOTTED PVC PIPES one 0�0 Qo� Qo�On� (MIN. 5 FEET LONG) 12" or 0�9°00�- DAYLIGHTED THROUGH WEEPHOLE IN HEADWALL 30" DIAMETER CULVERT CLASS A-3 CONCRETE TO BE USED TO FILL SWIM DRAINAGE STRUCTURE TO INVERT OF OUTLET PIPE. 5 3 2 1 6 INCH WATER QUALITY ORIFICE SEE NOTE 8 FLOTATION CALCULATIONS FOR RISER BASE WEIGHT OF WATER WEIGHT OF CONCRETE TOP INVERT OF RISER INVERT OF UPPER 6" ORIFICE INVERT OF LOWER 6" ORIFICE INVERT OF CULVERT BOTTOM INVERT OF RISER HEIGHT OF RISER RISER INSIDE DIAMETER WALL THICKNESS RISER INSIDE AREA RISER OUTER AREA RISER FOOTPRINT C21CII=C2 C20CG• METAL 3.0' RISER BASE AREA PLATE BASE DEPTH RISER OPENINGS: DEBRIS RACK ., o•.,... MIN. 8° 4'-0" DIA. 511 SIDE VIEW SWIM DRAINAGE STRUCTURE %" DIA. X 6" LG. ADHESIVE BOLTS W/FLAT WASHERS AND SELF LOCKING NUTS TYPICAL 8 ^PLACES -EQUALLY = 62.40 LBS/CU-FT = 150.00 LBS/CU-FT = 636.5 FT, NAVD88 = 635.0 FT, NAVD88 = 630.0 FT, NAVD88 = 628.0 FT, NAVD88 = 628.0 FT, NAVD88 =4.OFT = 5 INCHES = 12.57 SF = 18.35 SF = 5.78 SF = 18.35 SF = 4.0 FT UPPER ORIFICE (6" DIAMETER) = 0.20 SF LOWER ORIFICE (6" DIAMETER) = 0.20 SF OUTFACE CULVERT (30" OUTER DIAMETER) = 4.91 SF TOTAL AREA = 5.31 SF TOTAL VOLUME (AREA X 5") = 2.21 CU-FT WEIGHT OF DISPLACED WATER: VOLUME OF RISER = 155.98 CU-FT VOLUME OF BASE = 73.40 CU-FT TOTAL DISPLACED VOLUME = 229.38 CU-FT WEIGHT OF DISPLACED WATER = 14,313 LBS WEIGHT OF RISER: VOLUME OF RISER CONCRETE = 49.13 CU-FT VOLUME OF OPENINGS = 2.21 CU-FT TOTAL VOLUME OF RISER = 46.92 CU-FT WEIGHT OF RISER = 7,038 LBS WEIGHT OF BASE: VOLUME OF BASE = 73.40 CU-FT WEIGHT OF BASE = 1 1 ,010 LBS TOTAL DOWNWARD WEIGHT = 18,048 LBS FACTOR OF SAFETY = 1 .26 3LE ACCESS WHINGE TE 1 X %II STEEL RING ) TO RISER TYP. RISER DIMENSION APPROX. I.D. 0. D. A B C D E SEGMEN WT. (CBS.) 48 58 55 9 13 20 53 29 120 METAL DETAIL: L-3 DETENTION BASIN VDOT STORMWATER MANAGEMENT (SWM-1) RISER AND TRASH RACK NTS NOTES: 1 . COST OF TRASH RACK AND DEBRIS RACK ARE TO BE INCLUDED IN THE PRICE BID FOR THE STORMWATER MANAGEMENT DRAINAGE STRUCTURE. 2. STRUCTURE MAY BE PRECAST OR CAST IN PLACE. 3. WEEP HOLES SHALL NOT BE PROVIDED. ANY LIFT HOLES SHALL BE PLUGGED. 4. STEPS ARE TO BE PROVIDED WHEN HEIGHT OF STRUCTURE IS 4'-0" OR GREATER ABOVE INVERT OF OUTLET PIPE. FOR STEP DETAILS SEE STANDARD ST-1 . 5. SEE STANDARD SWM-DR FOR ADDITIONAL DETAILS ON PLATE, DEBRIS RACK AND TRASH RACK. 6. MARK HEIGHT OF STRUCTURE, IN BLACK, WITH 4" HIGH NUMERALS AND 1 "WIDE HORIZONTAL STRIPES AT 1' INTERVALS FROM INVERT OF WATER QUALITY ORIFICE (ALL VISIBLE SIDES). 7. THE PERMANENT STORMWATER MANAGEMENT DRAINAGE STRUCTURE, STANDARD SWM-1 MAY BE MODIFIED WHERE THE STORMWATER MANAGEMENT BASIN IS TO BE USED AS A TEMPORARY SEDIMENT BASIN DURING PROJECT CONSTRUCTION. SEE STANDARD SWM-DR, SHEET 1 OF 5 FOR TEMPORARY MODIFICATION DETAILS. 8. THE SIZE OF THE WATER QUALITY ORIFICE SHALL BE 6 INCHES. NInTF(:Z• 1) CONCRETE SHALL BE CLASS A3 2) CONTRACTOR MAY SUBMIT ALTERNATE BID WITH PLOWABLE FILL INSTEAD OF CONCRETE, PENDING APPROVAL BY DESIGN ENGINEER t (thickness) = 3.5" D=30" 81, 12" %2 D = 2.5" *SIDE WALLS MAY CONFORM %4 D OR 7.5" ** TO THE SHAPE OF EXCAVATED TRENCH *'` SHALL NOT BE LESS THAN 6" DETAIL: OUTFACE CULVERT CONCRETE CRADLE AND GRAVEL DRAINAGE BLANKET NTS 12" D=30" 12 INCH DRAINAGE BLANKET (VDOT #78) 4 INCH DIAMETER �oop000c SLOTTED PVC PIPES one 0�0 Qo� Qo�On� (MIN. 5 FEET LONG) 12" or 0�9°00�- DAYLIGHTED THROUGH WEEPHOLE IN HEADWALL 30" DIAMETER CULVERT CLASS A-3 CONCRETE TO BE USED TO FILL SWIM DRAINAGE STRUCTURE TO INVERT OF OUTLET PIPE. 5 3 2 1 6 INCH WATER QUALITY ORIFICE SEE NOTE 8 FLOTATION CALCULATIONS FOR RISER BASE WEIGHT OF WATER WEIGHT OF CONCRETE TOP INVERT OF RISER INVERT OF UPPER 6" ORIFICE INVERT OF LOWER 6" ORIFICE INVERT OF CULVERT BOTTOM INVERT OF RISER HEIGHT OF RISER RISER INSIDE DIAMETER WALL THICKNESS RISER INSIDE AREA RISER OUTER AREA RISER FOOTPRINT C21CII=C2 C20CG• METAL 3.0' RISER BASE AREA PLATE BASE DEPTH RISER OPENINGS: DEBRIS RACK ., o•.,... MIN. 8° 4'-0" DIA. 511 SIDE VIEW SWIM DRAINAGE STRUCTURE %" DIA. X 6" LG. ADHESIVE BOLTS W/FLAT WASHERS AND SELF LOCKING NUTS TYPICAL 8 ^PLACES -EQUALLY = 62.40 LBS/CU-FT = 150.00 LBS/CU-FT = 636.5 FT, NAVD88 = 635.0 FT, NAVD88 = 630.0 FT, NAVD88 = 628.0 FT, NAVD88 = 628.0 FT, NAVD88 =4.OFT = 5 INCHES = 12.57 SF = 18.35 SF = 5.78 SF = 18.35 SF = 4.0 FT UPPER ORIFICE (6" DIAMETER) = 0.20 SF LOWER ORIFICE (6" DIAMETER) = 0.20 SF OUTFACE CULVERT (30" OUTER DIAMETER) = 4.91 SF TOTAL AREA = 5.31 SF TOTAL VOLUME (AREA X 5") = 2.21 CU-FT WEIGHT OF DISPLACED WATER: VOLUME OF RISER = 155.98 CU-FT VOLUME OF BASE = 73.40 CU-FT TOTAL DISPLACED VOLUME = 229.38 CU-FT WEIGHT OF DISPLACED WATER = 14,313 LBS WEIGHT OF RISER: VOLUME OF RISER CONCRETE = 49.13 CU-FT VOLUME OF OPENINGS = 2.21 CU-FT TOTAL VOLUME OF RISER = 46.92 CU-FT WEIGHT OF RISER = 7,038 LBS WEIGHT OF BASE: VOLUME OF BASE = 73.40 CU-FT WEIGHT OF BASE = 1 1 ,010 LBS TOTAL DOWNWARD WEIGHT = 18,048 LBS FACTOR OF SAFETY = 1 .26 3LE ACCESS WHINGE TE 1 X %II STEEL RING ) TO RISER TYP. RISER DIMENSION APPROX. I.D. 0. D. A B C D E SEGMEN WT. (CBS.) 48 58 55 9 13 20 53 29 120 METAL DETAIL: L-3 DETENTION BASIN VDOT STORMWATER MANAGEMENT (SWM-1) RISER AND TRASH RACK NTS NOTES: 1 . COST OF TRASH RACK AND DEBRIS RACK ARE TO BE INCLUDED IN THE PRICE BID FOR THE STORMWATER MANAGEMENT DRAINAGE STRUCTURE. 2. STRUCTURE MAY BE PRECAST OR CAST IN PLACE. 3. WEEP HOLES SHALL NOT BE PROVIDED. ANY LIFT HOLES SHALL BE PLUGGED. 4. STEPS ARE TO BE PROVIDED WHEN HEIGHT OF STRUCTURE IS 4'-0" OR GREATER ABOVE INVERT OF OUTLET PIPE. FOR STEP DETAILS SEE STANDARD ST-1 . 5. SEE STANDARD SWM-DR FOR ADDITIONAL DETAILS ON PLATE, DEBRIS RACK AND TRASH RACK. 6. MARK HEIGHT OF STRUCTURE, IN BLACK, WITH 4" HIGH NUMERALS AND 1 "WIDE HORIZONTAL STRIPES AT 1' INTERVALS FROM INVERT OF WATER QUALITY ORIFICE (ALL VISIBLE SIDES). 7. THE PERMANENT STORMWATER MANAGEMENT DRAINAGE STRUCTURE, STANDARD SWM-1 MAY BE MODIFIED WHERE THE STORMWATER MANAGEMENT BASIN IS TO BE USED AS A TEMPORARY SEDIMENT BASIN DURING PROJECT CONSTRUCTION. SEE STANDARD SWM-DR, SHEET 1 OF 5 FOR TEMPORARY MODIFICATION DETAILS. 8. THE SIZE OF THE WATER QUALITY ORIFICE SHALL BE 6 INCHES. 30" DIAMETER CULVERT CLASS A-3 CONCRETE TO BE USED TO FILL SWIM DRAINAGE STRUCTURE TO INVERT OF OUTLET PIPE. 5 3 2 1 6 INCH WATER QUALITY ORIFICE SEE NOTE 8 FLOTATION CALCULATIONS FOR RISER BASE WEIGHT OF WATER WEIGHT OF CONCRETE TOP INVERT OF RISER INVERT OF UPPER 6" ORIFICE INVERT OF LOWER 6" ORIFICE INVERT OF CULVERT BOTTOM INVERT OF RISER HEIGHT OF RISER RISER INSIDE DIAMETER WALL THICKNESS RISER INSIDE AREA RISER OUTER AREA RISER FOOTPRINT C21CII=C2 C20CG• METAL 3.0' RISER BASE AREA PLATE BASE DEPTH RISER OPENINGS: DEBRIS RACK ., o•.,... MIN. 8° 4'-0" DIA. 511 SIDE VIEW SWIM DRAINAGE STRUCTURE %" DIA. X 6" LG. ADHESIVE BOLTS W/FLAT WASHERS AND SELF LOCKING NUTS TYPICAL 8 ^PLACES -EQUALLY = 62.40 LBS/CU-FT = 150.00 LBS/CU-FT = 636.5 FT, NAVD88 = 635.0 FT, NAVD88 = 630.0 FT, NAVD88 = 628.0 FT, NAVD88 = 628.0 FT, NAVD88 =4.OFT = 5 INCHES = 12.57 SF = 18.35 SF = 5.78 SF = 18.35 SF = 4.0 FT UPPER ORIFICE (6" DIAMETER) = 0.20 SF LOWER ORIFICE (6" DIAMETER) = 0.20 SF OUTFACE CULVERT (30" OUTER DIAMETER) = 4.91 SF TOTAL AREA = 5.31 SF TOTAL VOLUME (AREA X 5") = 2.21 CU-FT WEIGHT OF DISPLACED WATER: VOLUME OF RISER = 155.98 CU-FT VOLUME OF BASE = 73.40 CU-FT TOTAL DISPLACED VOLUME = 229.38 CU-FT WEIGHT OF DISPLACED WATER = 14,313 LBS WEIGHT OF RISER: VOLUME OF RISER CONCRETE = 49.13 CU-FT VOLUME OF OPENINGS = 2.21 CU-FT TOTAL VOLUME OF RISER = 46.92 CU-FT WEIGHT OF RISER = 7,038 LBS WEIGHT OF BASE: VOLUME OF BASE = 73.40 CU-FT WEIGHT OF BASE = 1 1 ,010 LBS TOTAL DOWNWARD WEIGHT = 18,048 LBS FACTOR OF SAFETY = 1 .26 3LE ACCESS WHINGE TE 1 X %II STEEL RING ) TO RISER TYP. RISER DIMENSION APPROX. I.D. 0. D. A B C D E SEGMEN WT. (CBS.) 48 58 55 9 13 20 53 29 120 METAL DETAIL: L-3 DETENTION BASIN VDOT STORMWATER MANAGEMENT (SWM-1) RISER AND TRASH RACK NTS NOTES: 1 . COST OF TRASH RACK AND DEBRIS RACK ARE TO BE INCLUDED IN THE PRICE BID FOR THE STORMWATER MANAGEMENT DRAINAGE STRUCTURE. 2. STRUCTURE MAY BE PRECAST OR CAST IN PLACE. 3. WEEP HOLES SHALL NOT BE PROVIDED. ANY LIFT HOLES SHALL BE PLUGGED. 4. STEPS ARE TO BE PROVIDED WHEN HEIGHT OF STRUCTURE IS 4'-0" OR GREATER ABOVE INVERT OF OUTLET PIPE. FOR STEP DETAILS SEE STANDARD ST-1 . 5. SEE STANDARD SWM-DR FOR ADDITIONAL DETAILS ON PLATE, DEBRIS RACK AND TRASH RACK. 6. MARK HEIGHT OF STRUCTURE, IN BLACK, WITH 4" HIGH NUMERALS AND 1 "WIDE HORIZONTAL STRIPES AT 1' INTERVALS FROM INVERT OF WATER QUALITY ORIFICE (ALL VISIBLE SIDES). 7. THE PERMANENT STORMWATER MANAGEMENT DRAINAGE STRUCTURE, STANDARD SWM-1 MAY BE MODIFIED WHERE THE STORMWATER MANAGEMENT BASIN IS TO BE USED AS A TEMPORARY SEDIMENT BASIN DURING PROJECT CONSTRUCTION. SEE STANDARD SWM-DR, SHEET 1 OF 5 FOR TEMPORARY MODIFICATION DETAILS. 8. THE SIZE OF THE WATER QUALITY ORIFICE SHALL BE 6 INCHES. 3LE ACCESS WHINGE TE 1 X %II STEEL RING ) TO RISER TYP. RISER DIMENSION APPROX. I.D. 0. D. A B C D E SEGMEN WT. (CBS.) 48 58 55 9 13 20 53 29 120 METAL DETAIL: L-3 DETENTION BASIN VDOT STORMWATER MANAGEMENT (SWM-1) RISER AND TRASH RACK NTS NOTES: 1 . COST OF TRASH RACK AND DEBRIS RACK ARE TO BE INCLUDED IN THE PRICE BID FOR THE STORMWATER MANAGEMENT DRAINAGE STRUCTURE. 2. STRUCTURE MAY BE PRECAST OR CAST IN PLACE. 3. WEEP HOLES SHALL NOT BE PROVIDED. ANY LIFT HOLES SHALL BE PLUGGED. 4. STEPS ARE TO BE PROVIDED WHEN HEIGHT OF STRUCTURE IS 4'-0" OR GREATER ABOVE INVERT OF OUTLET PIPE. FOR STEP DETAILS SEE STANDARD ST-1 . 5. SEE STANDARD SWM-DR FOR ADDITIONAL DETAILS ON PLATE, DEBRIS RACK AND TRASH RACK. 6. MARK HEIGHT OF STRUCTURE, IN BLACK, WITH 4" HIGH NUMERALS AND 1 "WIDE HORIZONTAL STRIPES AT 1' INTERVALS FROM INVERT OF WATER QUALITY ORIFICE (ALL VISIBLE SIDES). 7. THE PERMANENT STORMWATER MANAGEMENT DRAINAGE STRUCTURE, STANDARD SWM-1 MAY BE MODIFIED WHERE THE STORMWATER MANAGEMENT BASIN IS TO BE USED AS A TEMPORARY SEDIMENT BASIN DURING PROJECT CONSTRUCTION. SEE STANDARD SWM-DR, SHEET 1 OF 5 FOR TEMPORARY MODIFICATION DETAILS. 8. THE SIZE OF THE WATER QUALITY ORIFICE SHALL BE 6 INCHES. METAL DETAIL: L-3 DETENTION BASIN VDOT STORMWATER MANAGEMENT (SWM-1) RISER AND TRASH RACK NTS NOTES: 1 . COST OF TRASH RACK AND DEBRIS RACK ARE TO BE INCLUDED IN THE PRICE BID FOR THE STORMWATER MANAGEMENT DRAINAGE STRUCTURE. 2. STRUCTURE MAY BE PRECAST OR CAST IN PLACE. 3. WEEP HOLES SHALL NOT BE PROVIDED. ANY LIFT HOLES SHALL BE PLUGGED. 4. STEPS ARE TO BE PROVIDED WHEN HEIGHT OF STRUCTURE IS 4'-0" OR GREATER ABOVE INVERT OF OUTLET PIPE. FOR STEP DETAILS SEE STANDARD ST-1 . 5. SEE STANDARD SWM-DR FOR ADDITIONAL DETAILS ON PLATE, DEBRIS RACK AND TRASH RACK. 6. MARK HEIGHT OF STRUCTURE, IN BLACK, WITH 4" HIGH NUMERALS AND 1 "WIDE HORIZONTAL STRIPES AT 1' INTERVALS FROM INVERT OF WATER QUALITY ORIFICE (ALL VISIBLE SIDES). 7. THE PERMANENT STORMWATER MANAGEMENT DRAINAGE STRUCTURE, STANDARD SWM-1 MAY BE MODIFIED WHERE THE STORMWATER MANAGEMENT BASIN IS TO BE USED AS A TEMPORARY SEDIMENT BASIN DURING PROJECT CONSTRUCTION. SEE STANDARD SWM-DR, SHEET 1 OF 5 FOR TEMPORARY MODIFICATION DETAILS. 8. THE SIZE OF THE WATER QUALITY ORIFICE SHALL BE 6 INCHES. OTOP OF SEDIMENT TRAP SURROUNDING GRADE (3:1 OR GENTLER SLOPE) DEPTH SEDIMENT TRAP CONVERSION SEQUENCE: 1. GRADE SEDIMENT TRAP. a SURROUNDING GRADE (3:1 OR GENTLER SLOPE 6" DEPTH (TYP.) BIORETENTION FILTER 2 BED ELEVATION STABILIZE SLOPE BEFORE EXCAVATING NATIVE SOIL TO BIORETENTION FILTER TEMPORARY FLOOR ELEVATION SEDIMENT BED FTRAP ELEVATION SURROUNDING GRADE (3:1 OR GENTLER SLOPE) DEPTH NATIVE SOIL 6" PEA GRAVEL (#7 STONE) OVERLAYING UNDERDRAIN NETWORK ON 6" DEPTH (TYP.) - 10' MAX. FILTER FABRIC AT TOP OF PEA GRAVEL OVER UNDERDRAIN ONLY (EXTEND 1-1.5' EACH SIDE) SEDIMENT TRAP CONVERSION SEQUENCE: 4. PROVIDE PEA GRAVEL OVERLAYING UNDERDRAIN NETWORK AND INSTALL FILTER FABRIC 1-1 .5 FEET ON TOP OF PEA GRAVEL ON EITHER SIDE OF THE UNDERDRAIN PIPE. O PVC SCREW CAP ON GRADE PVC NON -PERFORATED STANDPIPE GEOTEXTILE FABRIC URROUNDING GRADE (3:1 OR GENTLER SLOPE) BIORETENTION FILTER SURFACE EXCAVATE SEDIMENT TRAP TO PROPOSED ELEVATION SEDIMENT TRAP CONVERSION SEQUENCE: 2. AFTER THE CONTRIBUTING AREA IS STABILIZED, EXCAVATE THE SEDIMENT TRAP TO AN ELEVATION CORRESPONDING TO THE BIORETENTION FILTER FLOOR ELEVATION, AND DISPOSE OF EXCAVATED SOIL. O 3-INCHES SHREDDED )LCH SEDIMENT TRAP CONVERSION SEQUENCE: 5. INSTALL BIOFILTER SOIL MEDIA (AS SPECIFIED IN DESIGN PLANS) ENSURING THAT ABOVE SPECIFICATIONS ARE OBSERVED. LIGHTLY TAMP BIORETENTION FILTER SOIL MEDIA. ONCE BIORETENTION FILTER SOIL MEDIA IS INSTALLED, INSTALL A 3-INCH LAYER OF SHREDDED HARDWOOD MULCH OVERLYING THE BIORETENTION FILTER SOIL MEDIA. DETAIL: SEDIMENT TRAP TO BIOFILTER CONVERSION SEQUENCE NTS ENGINEERED SOIL MEDIA SPECIFICATIONS: BIOFILTER SIDESLOPE EXCAVATION 1:1 OR GENTLER WATERTIGHT CAP ON TERMINAL END F P(J IPE PERFORATED P.V.0 + UNDERDRAIN (MAX. 12" DEPTH (TYP.) 10 FT SPACING) 12'' #57 6" NON -PERFORATED STONE (TYP.) P.V.C. PIPE TO PROPOSED SEDIMENT TRAP CONVERSION SEQUENCE: OUTFALL LOCATION 3. PROVIDE A 12 INCH LAYER OF VDOT #57 STONE (TYP.). INSTALL UNDERDRAIN NETWORK WITH A MAXIMUM OF 10-FOOT SPACING BETWEEN UNDERDRAIN BRANCHES AND NEST 3-INCHES WITHIN THE #57 STONE LAYER ENSURING THAT PERFORATED PIPES WITH A WATERTIGHT CAP ON TERMINAL END ARE USED FOR UNDERDRAIN BRANCHES AND NON -PERFORATED PIPES ARE USED FOR PRIMARY UNDERDRAIN PIPE WITHIN 5 FT OF MANHOLE. INSTALL NON -PERFORATED CLEANOUT PIPE PER DETAIL. 6 PONDING DEPTH VEGETATION (SEE PROPOSED VARIES (6-12" TYP.) PLANTING PLAN SURROUNDING GRADE (3:1 OR GENTLER SLOPE SEDIMENT TRAP CONVERSION SEQUENCE: 6. SEED AND PLANT BIORETENTION FILTER SURFACE AREA ACCORDING TO THE PROVIDED PLANTING PLAN. GENERAL NOTES: 1) CONSTRUCTION OF THE BIORETENTION FILTERS SHALL NOT BE FINISHED UNTIL THE CONTRIBUTING DRAINAGE AREAS HAVE BEEN STABILIZED AND APPROVED BY THE COUNTY. UPON WHICH, THE BASINS SHALL FIRST BE CLEANED AND BROUGHT TO DESIGN GRADE. 2) CONTRACTOR SHALL CONTACT THE COUNTY INSPECTOR AND ENGINEER 24 HOURS PRIOR TO BACKFILLING THE BIORETENTION FILTERS, AND REQUEST AN INSPECTION AND APPROVAL OF THE UNDER -DRAIN INSTALLATION AND THE SOIL MIX. ENGINEERED SOIL MEDIA SHALL CONSIST OF A MIXTURE OF 80-90% SAND, 10-20% SOIL FINES, AND 3-5% ORGANIC MATTER THAT SHALL HAVE POROSITY ADEQUATE TO MAINTAIN THE DESIRED PERMEABILITY, PROVIDE LIMITED SOIL FINES, AND SUFFICIENT ORGANIC MATTER TO SUPPORT PLANT GROWTH AND ADSORB PHOSPHORUS (P) AND OTHER STORMWATER CONTAMINANTS IN A BIORETENTION FILTER. THE MEDIA SHALL BE LOOSE AND NON -COMPACTED TO ALLOW FOR ADEQUATE INTERCONNECTED POROSITY TO MEET THE REQUIRED PERMEABILITY (KSAT) SPECIFICATION. A. SAND USED SHALL CONSIST OF SILICA BASED COARSE AGGREGATE, ANGULAR OR ROUND IN SHAPE AND MEET THE MIXTURE GRAIN SIZE REPORTED IN THE TABLE BELOW. NO SUBSTITUTIONS OF ALTERNATE MATERIALS SUCH AS DIABASE, CALCIUM CARBONATE, ROCK DUST OR DOLOMITIC SANDS ARE ACCEPTED. IN PARTICULAR, MICA CAN MAKE UP NO MORE THAN 5% OF THE TOTAL SAND FRACTION. THE SAND FRACTION MAY ALSO CONTAIN A LIMITED QUANTITY OF PARTICLES > 2.0 MM AND < 9.5 MM PER THE TABLE BELOW, BUT THE OVERALL SAND FRACTION MUST MEET THE REQUIREMENT OF > 75% BEING COARSE OR VERY COARSE SAND. Fine ALYareLmte — Engineered Soil '-\Iedia Amounts Finer Than Each Laboratory Sieve (Square Opening.) (.P--b by Weight] Application 3. 9 in- No. 4 No. 8 No- 16 No- 30 No- 50 No- 100 No. 200 Type 1 95-11"10 80-100 4--85 1-�-60 3-15 0-4 Effective particle size I;'D10) > 0.3 rnm. Unitortn n7 Coefficient (_D60.`D10) <4.0 B. TOPSOIL MATERIALS USED SHALL CONFORM TO THE REQUIREMENTS OF SECTION 244.02 (B) OF THE VDOT ROAD AND BRIDGE SPECIFICATIONS. C. ORGANIC MATTER MATERIALS USED SHALL CONSIST OF WELL -DECOMPOSED NATURAL CARBON -CONTAINING ORGANIC MATERIALS SUCH AS PEAT MOSS, HUMUS, COMPOST (CONSISTENT WITH THE REQUIREMENTS FOR ORGANIC MATTER DESCRIBED IN II(B)A. OF SPECIAL PROVISION FOR SOIL COMPOST AMENDMENT, JULY 1, 2014), PINE BARK FINES OR OTHER ORGANIC SOIL CONDITIONING MATERIAL. D. THE TEXTURE OF NON -ORGANIC COMPONENTS SHOULD BE LOAMY, COARSE SAND WITH NO MORE THAN 10% CLAY, NO MORE THAN 20% SILT AND CLAY (CUMULATIVELY), AND AT LEAST 75% OF THE SAND FRACTION SHOULD BE COARSE OR VERY COARSE SAND. IT SHALL BE FREE OF VIABLE NOXIOUS WEED SEED, PLANT PROPAGULES, BRUSH, ROCKS OR OTHER LITTER, AND OBJECTS GREATER THAN 3 INCHES IN ANY DIMENSION. PRIOR TO DELIVERY, THE CONTRACTOR SHALL SUBMIT TO THE ENGINEER FOR APPROVAL, A SAMPLE OF THE ENGINEERED SOIL MEDIA AND TEST RESULTS FROM AN INDEPENDENT LABORATORY VERIFYING THAT THE MATERIAL CONFORMS TO THE FOLLOWING ANALYSIS: L NON -ORGANIC SOIL TEXTURE = LOAMY, COARSE SAND WITH NO MORE THAN 10% CLAY, NO MORE THAN 20% SILT + CLAY, AND A MINIMUM OF 75% OF THE SAND FRACTION AS COARSE OR VERY COARSE SAND. ALL CLASSIFICATIONS SHALL BE DONE IN ACCORDANCE WITH THE USDA-NRCS SOIL TEXTURAL TRIANGLE. ii. FINES CONTENT = A MINIMUM OF 10% SOIL FINES (SILT + CLAY). THE PARTICLE SIZE ANALYSIS SHALL BE CONDUCTED ON THE MINERAL FRACTION ONLY, OR FOLLOWING REMOVAL OF ORGANIC MATTER PRIOR TO PARTICLE SIZE ANALYSIS. iii. ORGANIC MATTER CONTENT = BETWEEN 3% AND 5% OF THE ENGINEERED SOIL MEDIA SHALL BE ORGANIC MATTER, AS DETERMINED BY THE CONVENTIONAL WALKLEY-BLACK SOIL ORGANIC MATTER DETERMINATION METHOD OR SIMILAR ANALYSIS. ORGANIC MATTER IS EXPRESSED ON A DRY WEIGHT BASIS AND DOES NOT INCLUDE COARSE PARTICULATE COMPONENTS. iv. BULK DENSITY = 1.6-1.7 G/CM3 v. SOIL PERMEABILITY OR HYDRAULIC CONDUCTIVITY (KSAT) = MINIMUM 1-2 IN/HR (30-60 CM/DAY). THE INITIAL MIX WILL HAVE AN INITIAL RATE SIGNIFICANTLY HIGHER. vi. AVAILABLE SOIL PHOSPHORUS (P) = LOW+ (L+) TO MEDIUM (M) PER TABLE 2.2 OF DCR (2005) VIRGINIA NUTRIENT MANAGEMENT STANDARDS AND CRITERIA. THIS IS EQUIVALENT TO 5-15 MG/KG P FOR THE MEHLICH I EXTRACTION PROCEDURE OR 10-40 MG/KG P FOR THE MEHLICH III PROCEDURE. vii.ACETATE, CE AHN EXCHANGE TE, SUMMATION CAOF CATIONSITY OR EFFECTIVE)/CHEC TECH NIQUEOS+(SUGMNEOR AND MILLERS 1996)DETERMINED BY SIMI AR THE METHODS UNBUFFERED THAT DONOT AONIUM UTILIZE STRONGLY ACIDIC EXTRACTING SOLUTIONS. BIORETENTION CONSTRUCTION SPECIFICATIONS I. MATERIALS CONDITIONS, THE CONTRACTOR SHALL NOTIFY THE ENGINEER DESIRED TOP ELEVATION OF THE FACILITY IS ACHIEVED. THE -DURING THE FIRST TWO MONTHS FOLLOWING PLANT IMMEDIATELY FOR INSPECTION. THE PROPOSED SITE SHOULD MEDIA SHOULD BE PLACED AND SPREAD BY HAND WITH INSTALLATION, THE CONTRACTOR WILL BE RESPONSIBLE FOR (A)EXCAVATION SHALL CONSIST OF THE DESIGN SUB -GRADE BE CHECKED FOR ANY EXISTING UTILITIES IN THAT AREA PRIOR MINIMAL COMPACTION, IN ORDER TO AVOID COMPACTION AND WATERING AT LEAST ONCE A WEEK AND THEN AS NEEDED FOR THE FACILITY AS WELL AS THE GRADING REQUIRED TO TO ANY EXCAVATION. MAINTAIN THE POROSITY OF THE MEDIA. LIFTS SHOULD BE DURING FIRST GROWING SEASON (APRIL-OCTOBER). ACHIEVE DESIGN SLOPES. ALL EXCAVATION SHALL CONFORM LIGHTLY WATERED TO ENCOURAGE SETTLING AND ROLLED TO SECTION 303. B)EROSION AND SEDIMENT CONTROL MEASURES -- WITH A LANDSCAPE ROLLER TO CONSOLIDATE. AFTER THE TEMPORARY E&S CONTROLS MAY BE NEEDED DURING FINAL LIFT IS PLACED, THE MEDIA SHOULD BE RAKED LEVEL, (B)MATERIALS FOR TEMPORARY SILT FENCES, GEOTEXTILE CONSTRUCTION TO DIVERT STORMWATER AWAY FROM SATURATED, AND ALLOWED TO SETTLE FOR AT LEAST ONE FABRIC SILT BARRIERS, AND FILTER BARRIERS SHALL FACILITIES UNTIL IT IS COMPLETED AND STABILIZED. SPECIAL WEEK PRIOR TO INSTALLATION OF PLANT MATERIALS. CONFORM TO THE REQUIREMENTS OF SECTIONS 242.02(C) AND PROTECTION MEASURES SUCH AS EROSION CONTROL 245.03(A). FABRICS MAY BE NEEDED TO PROTECT VULNERABLE SIDE AFTER A MINIMUM OF SEVEN DAYS, THE CONTRACTOR SHALL SLOPES FROM EROSION DURING THE CONSTRUCTION CHECK FOR CONTAMINATION, SUCH AS EXCESSIVE (C)ALL DRAINAGE STRUCTURES AND PIPE SHALL CONFORM TO PROCESS. ACCUMULATED FINE SEDIMENT OR TRASH, AND REMOVE IF SECTION 232, UNLESS OTHERWISE SPECIFIED. PRESENT. C)ALL DRAINAGE STRUCTURES SHALL BE INSTALLED (D)UNDERDRAIN, CLEANOUTS, INSPECTION PORTS, WYES, CONFORMANCE WITH SECTION 302 AND ALL OTHER TEES, AND OTHER ACCESSORIES ASSOCIATED WITH THE APPLICABLE SPECIFICATIONS. UNDERDRAIN SYSTEM SHALL CONFORM TO DETAILS DEFINED HEREIN. (E)GRAVEL AND AGGREGATE REQUIRED FOR, UNDERDRAINS, CHOKER LAYER, AND SUMP LAYER, SHALL CONSIST OF CLEAN, WASHED STONE MEETING THE APPROPRIATE SIZE CLASSIFICATION, AND BE IN CONFORMANCE WITH SECTION 203 UNLESS OTHERWISE SPECIFIED THE FOLLOWING SHALL APPLY D)UNDERDRAIN, CLEANOUTS, AND OBSERVATION WELLS - FOR FACILITIES WHERE UNDERDRAIN SYSTEMS WILL BE INSTALLED, POSITION EACH UNDERDRAIN NO MORE THAN 20 FEET FROM THE NEXT PIPE. LAY THE PERFORATED PIPE UNDER THE LENGTH OF THE FACILITY AND INSTALL NON -PERFORATED PIPES AS NEEDED TO CONNECT WITH THE STORM DRAIN SYSTEM OR TO DAYLIGHT AT ULTIMATE OUTFALL LOCATION. INSTALL ELBOWS, TEES, AND WYES AS NEEDED, DEPENDING -CONDUCT MAINTENANCE INSPECTION WITHIN SIX MONTHS OF COMPLETION AT EACH BIORETENTION AREA. CHECK TO SEE IF 75% TO 90% COVER (MULCH IF INSTALLED PLUS VEGETATIVE COVER) HAS BEEN ACHIEVED IN THE BED. -CHECK FOR SEDIMENT BUILDUP AT CURB CUTS, PRETREATMENT PRACTICES SUCH AS GRAVEL DIAPHRAGMS OR PAVEMENT EDGES THAT PREVENTS FLOW FROM GETTING INTO THE BED, AND CHECK FOR OTHER SIGNS OF BYPASSING FLOW. ONCE DESIGN GRADES ARE ACHIEVED FOR THE ENGINEERED SOIL MEDIA, IF EXPOSED TO CONSTRUCTION SEDIMENT, THE -CHECK FOR ANY WINTER OR SALT -KILLED VEGETATION, AND CONTRACTOR SHALL COVER THE ENTIRETY OF THE FACILITY REPLACE IT WITH HARDIER SPECIES IN CONSULTATION WITH WITH NON -WOVEN GEOTEXTILE FILTER FABRIC OR OTHERWISE THE ENGINEER. TAKING MEASURES TO PRECLUDE SEDIMENT FROM ENTERING THE FACILITY TO PROTECT AGAINST ANY CONTAMINATION -VEGETATION MANAGEMENT - TRIM AND PRUNE VEGETATION PRIOR TO ANY MULCHING. ANY CONTAMINATION, SUCH AS AS NEEDED. CHECK FOR PRESENCE OF INVASIVE PLANTS AND EXCESSIVE ACCUMULATED FINE SEDIMENT OR TRASH, SHALL WEEDS AND REMOVE. ANY HERBICIDE SPRAYING, IF BE REMOVED PRIOR TO COMMENCING WITH SUBSEQUENT NECESSARY, SHALL CONFORM WITH SECTION 607. LAYER INSTALLATION. -INSPECT FACILITY SIDE SLOPES AND GRASS FILTER STRIPS 1.CHOKER LAYER STONE SHALL CONFORM TO #8 AGGREGATE ON THE UNDERDRAIN CONFIGURATION. EXTEND CLEANOUT J)SURFACE LAYER, PLANTING, SEEDING, STABILIZATION AND FOR EVIDENCE OF ANY RILL OR GULLY EROSION, AND REPAIR OR ALTERNATE AS APPROVED BY THE ENGINEER. PIPES TO THE SURFACE WITH VENTED CAPS AT THE TEE'S AND MULCH - PREPARE PLANTING HOLES FOR ANY TREES AND IT, IN CONSULTATION WITH THE ENGINEER. 2.SUMP LAYER / UNDERDRAIN STONE SHALL CONFORM TO #57 WYE'S. SHRUBS, INSTALL VEGETATION AND MULCH IF REQUIRED, AND AGGREGATE OR ALTERNATE APPROVED BY THE ENGINEER. WATER THE VEGETATION ACCORDINGLY. INSTALL PIPE JOINTS AND STORM DRAIN STRUCTURE CONNECTIONS VEGETATION AND GROUND COVER SPECIFIED IN THE PLANTING -CHECK THE FACILITY BED FOR EVIDENCE OF MULCH (F)NON-WOVEN GEOTEXTILE FILTER FABRICS SHALL BE USED. MUST BE ADEQUATELY SEALED TO AVOID PIPING CONDITIONS PLAN FOR THE FACILITY. INSTALL A THREE (3) INCH MULCH FLOTATION, EXCESSIVE PONDING, DEAD PLANTS OR (WATER SEEPING THROUGH PIPE OR STRUCTURE JOINTS). PIPE LAYER TO THE SURFACE OF BIORETENTION CELLS IF CALLED CONCENTRATED FLOWS, AND TAKE APPROPRIATE REMEDIAL (G)GEOSYTHETICS USED AS BEDDING MATERIAL UNDER RIP SECTIONS SHALL BE COUPLED USING SUITABLE CONNECTION FOR IN THE DESIGN. PLACE SOD, FABRIC, OR NON EROSIVE ACTION. CHECK INFLOW POINTS FOR CLOGGING, AND REMOVE RAP, FOR SILT FENCES, SILT BARRIERS, FILTER BARRIERS, OR RINGS AND FLANGES. FIELD CONNECTIONS TO STORM DRAIN LINING (DEPENDING ON INFLOW SHEAR STRESSES) IN THE ANY SEDIMENT, AS DIRECTED BY THE ENGINEER. STABILIZATION SHALL CONFORM TO THE REQUIREMENTS OF STRUCTURES AND PIPES SHALL BE SEALED WITH POLYMER INLET CHANNEL AND/OR FILTER STRIPS. SECTIONS 245.03(A), 245.03(B), AND 245.03(D), AS APPROPRIATE. GROUT MATERIAL THAT IS CAPABLE OF ADHERING TO -LOOK FOR ANY BARE SOIL OR SEDIMENT SOURCES IN THE SURFACES. UNDERDRAIN PIPE SHALL BE CAPPED (AT K)ACCEPTANCE PROCEDURE UPON COMPLETION - ONCE THE CONTRIBUTING DRAINAGE AREA, AND STABILIZE THEM THE SOIL MEDIA FOR BIORETENTION SYSTEMS AND DRY STRUCTURE) UNTIL COMPLETION OF SITE. UNDERDRAINS FACILITY HAS BEEN COMPLETED, THE CONTRACTOR SHALL IMMEDIATELY IN ACCORDANCE WITH SPECIFICATIONS. SWALES SHALL CONFORM WITH ENGINEERED SOIL MEDIA CONNECTED DIRECTLY TO A STORM DRAINAGE STRUCTURE NOTIFY THE ENGINEER TO INSPECT THE FACILITY. ANY ITEMS SPECIFICATIONS HEREIN. SHALL BE NON -PERFORATED FOR A DISTANCE OF AT LEAST 5 THAT ARE NOTED AS UNACCEPTABLE SHALL BE CORRECTED. -CHECK FOR CLOGGED OR SLOW -DRAINING SOIL MEDIA, A FEET FROM THE STRUCTURE INTERFACE TO AVOID POSSIBLE ONCE THE INSPECTOR HAS APPROVED THE FACILITY, CRUST FORMED ON THE TOP LAYER, INAPPROPRIATE SOIL (H)THE ENGINEER MAY TO REJECT ANY ENGINEERED SOIL PIPING PROBLEMS. STABILIZE ALL DISTURBED AREAS AND THEN REMOVE ALL MEDIA, OR OTHER CAUSES OF INSUFFICIENT FILTERING TIME, MEDIA MATERIAL NOT COMPLYING WITH THE REQUIREMENTS SEDIMENT CONTROLS. UNBLOCK CURB OPENINGS OR ANY AND RESTORE PROPER FILTRATION CHARACTERISTICS IN OIF THESE PLANS. E)INSPECTION AND APPROVAL -- PLACE NON -WOVEN OTHER UPSTREAM DIVERSION METHODS, PROVIDING ACCORDANCE WITH DESIGN METHODOLOGY AND GEOTEXTILE FILTER FABRIC ON THE SIDES OF THE FACILITY DRAINAGE TO THE FACILITIES ONLY UPON APPROVAL FROM SPECIFICATIONS. TESTING MAY BE REQUIRED FOR (I)ANY COMPOST AMENDED SOIL (AS REQUIRED) SHALL CAVITY AND AS SPECIFIED ON DESIGN PLANS. PLACE THE THE ENGINEER. VERIFICATION OF INFILTRATION RATES. CONFORM SPECIFICATIONS HEREIN. APPROPRIATE DEPTH OF SUMP LAYER AGGREGATE ON THE BOTTOM, INSTALL THE PERFORATED UNDERDRAIN PIPE ALONG -IF WATER REMAINS ON THE SURFACE FOR MORE THAN 24 (J)TOPSOIL, SOIL RETENTION, PLANTING, SEEDING, SODDING, WITH INSPECTION PORTS. PRIOR TO INSTALLATION OF CHOKER IV.TOLERANCES HOURS AFTER A STORM, ADJUSTMENTS TO THE GRADING MAY STABILIZATION, AS SHOWN ON THE DESIGN DRAWINGS SHALL LAYER AND AGGREGATE AND WHILE THE INSTALLED AND BE NEEDED OR UNDERDRAIN REPAIRS MAY BE NEEDED. THE CONFORM TO SECTIONS 242, 244, 601, 602, 603, 604, 605, AND CONNECTED DRAIN SYSTEM IS STILL VISIBLE, CONTRACTOR TO (A)FINISHED GRADE OF SUBGRADE SHALL CONFORM TO THE SURFACE OF THE FILTER BED SHOULD ALSO BE CHECKED FOR 606, AND 607. SCHEDULE A MEETING WITH SITE INSPECTOR TO REVIEW REQUIREMENTS OF SECTION 305.03(C). ACCUMULATED SEDIMENT OR A FINE CRUST THAT BUILDS UP DRAINAGE CONNECTIONS TO STRUCTURES, SUBGRADE AFTER THE FIRST SEVERAL STORM EVENTS. IF THERE IS (K)RIPRAP SHALL CONFORM WITH SECTION 414 AND BE OF SIZE CONDITIONS, ETC. CONTRACTOR TO VERIFY UNDERDRAIN (B)SLOPES SURROUNDING BIORETENTION FACILITIES SHALL BE STANDING WATER, OPEN THE UNDERDRAIN OBSERVATION AND DIMENSION AS SPECIFIED IN DESIGN PLANS. LAYOUT AND INVERTS OF DRAIN SYSTEM, PROVIDING GRADED TO 3:1 OR FLATTER, UNLESS OTHERWISE SPECIFIED. WELL OR CLEANOUT AND POUR IN WATER TO VERIFY THAT THE CONSTRUCTED ELEVATIONS MARKED ON THE RECORD ALL TOLERANCES SHALL CONFORM TO SECTION 303.05(B). UNDERDRAINS ARE FUNCTIONING AND NOT CLOGGED OR (L)A THREE (3) INCH MULCH LAYER SHALL BE APPLIED TO THE DRAWINGS. CONTRACTOR SHALL BE RESPONSIBLE FOR OTHERWISE IN NEED OF REPAIR. IF THERE IS STANDING SURFACE OF THE BIORETENTION FACILITY. MULCH SHALL PHOTO -DOCUMENTING THE FACILITY, INCLUDING SUBGRADE (C)ALL DRAINAGE PIPE SLOPES AND INVERTS SHALL BE AS WATER ON TOP, BUT NOT IN THE UNDERDRAIN, THEN THERE IS CONFORM TO THE REQUIREMENTS OF SECTION 244.02(G.4) PRIOR TO AGGREGATE INSTALLATION AND UPON INSTALLATION DEFINED ON PLANS. NO BUBBLES, BULGES, OR SIGNIFICANT LIKLEY A CLOGGED SOIL LAYER. IF THE UNDERDRAIN AND AND BE FREE OF FOREIGN MATERIAL INCLUDING PLANT OF SUB -SURFACE DRAINAGE SYSTEM ONCE INSTALLED. ONCE DEFECTIONS PERMITTED. STAND PIPE INDICATES STANDING WATER, THEN THE MATERIAL. THE ENGINEER ISSUES APPROVAL, ANY REMAINING SUMP UNDERDRAIN MUST BE CLOGGED AND WILL NEED TO BE LAYER AGGREGATE MAY BE ADDED. ALL APPROVALS SHALL BE REHABILITATED. III.FACILITY CONSTRUCTION SEQUENCE & PROCEDURES ON AN INDIVIDUAL FACILITY BASIS. V. INSPECTION AND MAINTENANCE -IN THE EVENT THAT THE SURFACE OR FILTER IS CLOGGED, THE CONTRACTOR SHALL MEET WITH THE ENGINEER PRIOR TO PACK THE SUMP LAYER STONE TO 3 INCHES ABOVE THE DURING CONSTRUCTION, THE CONTRACTOR SHALL MAINTAIN REMOVE AND REPLACE SOME OR ALL OF THE ENGINEERED STARTING WORK ON THE FACILITIES. AT THAT TIME, THE UNDERDRAIN PIPE. PLACE THE CHOKER LAYER AT THE ANY AREAS OR FACILITIES IN TEMPORARY OR FINAL CONDITION SOIL MEDIA AND REHABILITATE AS REQUIRED, IN ACCORDANCE CONTRACTOR SHALL PREPARE A CONSTRUCTION AND APPROPRIATE DEPTH ON TOP OF THE SUMP LAYER. UNTIL FINAL APPROVAL AND ACCEPTANCE OF THE ENTIRE WITH DESIGN SPECIFICATIONS AND METHODOLOGY. TESTING MAINTENANCE SCHEDULE FOR EACH FACILITY. ITEMS TO BE PROJECT BY THE OWNER. PRIOR TO THIS, THE CONTRACTOR MAY BE REQUIRED BY THE OWNER TO CONFIRM FILTRATION INCLUDED IN THE SCHEDULE ARE INTENDED ONCE DESIGN SUB -GRADES ARE ACHIEVED FOR ANY SHALL ENSURE THAT ALL REGULAR MAINTENANCE IS AND DRAIN TIME CHARACTERISTICS. DOCUMENTED DRAIN DATES/MILESTONES OF FEATURE/MATERIAL INSTALLATION IN INTERMEDIATE STONE LAYER, IF EXPOSED TO CONSTRUCTION PERFORMED SO AS TO NOT DEGRADE THE NEWLY TIMES SHALL BE VERIFIED TO THE OWNER TO BE LESS THAN 24 ACCORDANCE WITH THE PLANS AND SPECIFICATIONS, SEDIMENT, THE CONTRACTOR SHALL COVER THE ENTIRETY OF CONSTRUCTED FACILITY AND ITS EFFICACY. ANY HOURS AFTER A ONE (1) INCH OR GREATER STORM EVENT, FREQUENCY OF MOWING GRASS, EROSION REPAIR, REMOVAL THE FACILITY WITH NON -WOVEN GEOTEXTILE FILTER FABRIC DEFICIENCIES OR DAMAGE SHALL BE RECTIFIED AT THE AFTER THE 1-YEAR CARE AND MAINTENANCE PERIOD, AND OF INVASIVE PLANTS, TRASH REMOVAL AND CHECKING THE OR OTHERWISE TAKING MEASURES TO PRECLUDE FINE CONTRACTOR'S EXPENSE. PRIOR TO FINAL ACCEPTANCE OF PRIOR TO ACCEPTANCE. FUNCTIONALITY OF THE FACILITY. PROPER WORKMANSHIP SEDIMENT FROM ENTERING THE FACILITY TO PROTECT THE ENTIRE PROJECT BY THE OWNER, THE CONTRACTOR SHALL BE PROVIDED CONSISTENT WITH PLANS, AGAINST ANY CONTAMINATION, SUCH AS EXCESSIVE SHALL ENSURE THAT THE FACILITIES MEET THE FOLLOWING COMPLETION OF ALL CONSTRUCTION ON THE SITE, SPECIFICATIONS, AND REFERENCE STANDARDS, TO THE ACCUMULATED FINE SEDIMENT OR TRASH, UNTIL MATERIALS SPECIFICATIONS REFERENCED ON THE PLANS. THE CONTRACTOR SHALL CONDUCT A JOINT INSPECTION WITH SATISFACTION OF THE ENGINEER. AND TIMING SHOULD ALLOW THE CONSTRUCTION OF THE ENGINEER AND, UPON PROPER FUNCTION AND OWNER SUBSEQUENT LAYERS. ANY CONTAMINATION SHALL BE THE CONTACTOR SHALL WARRANTY ALL PLANT MATERIAL FOR APPROVAL, THE FACILITIES MAY BE TRANSFER TO THE OWNER. A)EXCAVATION - CONTRACTOR SHALL GENERALLY VERIFY THE REMOVED PRIOR TO COMMENCING WITH SUBSEQUENT LAYER THE FIRST YEAR FOLLOWING FACILITY COMPLETION. THE PROVIDE AN ITEMIZED LIST OF MAINTENANCE ACTIVITIES BOUNDARIES OF THE CONTRIBUTING DRAINAGE AREA AND THE INSTALLATION. COMPLETION DATE SHALL BE THE DATE THE FACILITY IS CONDUCTED, REFERENCED WARRANTY SURVEY AND ACTUAL (AS -BUILT) INLET ELEVATIONS TO ENSURE THEY APPROVED BY THE OWNER FOLLOWING CONSTRUCTION. THE PLANTING INFORMATION, AND DOCUMENTATION OF DRAIN CONFORM TO ORIGINAL DESIGN. SINCE OTHER F)NON-WOVEN GEOTEXTILE FILTER FABRIC -- THE NON -WOVEN WARRANTY SHALL INCLUDE CARE AND REPLACEMENT TO TIMES DURING A ONE (1) INCH OR GREATER STORM EVENT. SUBCONTRACTORS MAY BE RESPONSIBLE FOR GEOTEXTILE FILTER FABRIC SHALL BE INSTALLED AS PER PLAN. ENSURE THAT VEGETATION IS PROPERLY ESTABLISHED AND CONSTRUCTING PORTIONS OF THE SITE, SUBTLE DIFFERENCES A TWO (2) FOOT STRIP OF GEOTEXTILE SHOULD BE LAIN AT THE SURVIVES DURING THE FIRST GROWING SEASON FOLLOWING PREPARED BY: IN SITE GRADING, DRAINAGE AND PAVING ELEVATIONS MAY BE TOP OF THE AGGREGATE CHOKER LAYER (DIRECTLY BENEATH CONSTRUCTION. THRESHOLDS BELOW WHICH REPLACEMENT OBSERVED THAT CAN PRODUCE HYDRAULICALLY IMPORTANT THE ENGINEERED SOIL MEDIA) CENTERED ON EACH IS REQUIRED ARE 85% SURVIVAL OF PLANT MATERIAL AND DIFFERENCES FOR THE PROPOSED FACILITIES. THE PERFORATED SEGMENT OF UNDERDRAIN, TO ENCOURAGE A 100% SURVIVAL OF TREES. ANY REMEDIAL WORK ASSOCIATED Stantec CONTRACTOR AND THE ENGINEER SHOULD CLEARLY CIRCUITOUS FLOW PATH FOR FLOW DIRECTED TROUGH THE WITH RE -PLANTING SHALL BE PERFORMED. CONTRACTOR COMMUNICATE, IN WRITING, ANY NEEDED MODIFICATIONS FILTER AND REDUCE POTENTIAL FOR SOIL LOSS. SHALL PROVIDE TO THE ENGINEER THE PRE -WARRANTY DETERMINED DURING THE PRECONSTRUCTION MEETING AND PLANT SURVEY (COMPLETED AFTER A FULL GROWING SEASON) 5209 Center Street ANY MODIFICATIONS BASED ON FIELD CONDITIONS. I SOIL MEDIA - PRIOR TO INSTALLATION OF SOIL MEDIA, ) AND EVIDENCE OF THE WARRANTED PLANT REPLACEMENT, Williamsburg, VA 23188 PHONE: (757) 220-6869 FAX: (757) 229-4507 CONTRACTOR SHALL VERIFY THROUGH PRIOR TO ACCEPTANCE BY THE ENGINEER. CONSTRUCTION OF THE FACILITIES SHALL ONLY BEGIN AFTER PHOTO -DOCUMENTATION AND RECORDED ELEVATIONS, THE THE ENTIRE CONTRIBUTING DRAINAGE AREA HAS BEEN DEPTH OF SUMP LAYER AND CHOKER LAYER AND UNDERDRAIN ROUTINE MAINTENANCE WHICH MAY BE REQUIRED INCLUDES: STABILIZED WITH VEGETATION. IT MAY BE NECESSARY TO LAYOUT. -CONTRACTOR ALONG WITH THE INSPECTORS SHOULD LOOK BLOCK CERTAIN CURB OR OTHER INLETS WHILE THE FOR BARE OR ERODING AREAS IN THE CONTRIBUTING BIORETENTION AREA IS BEING CONSTRUCTED. DURING PRIOR TO DELIVERY OF ENGINEERED SOIL MEDIA TO THE SITE, DRAINAGE AREA OR AROUND THE FACILITIES, AND ASSURE EXCAVATION, USE LIGHT, TRACKED EQUIPMENT TO AVOID PROVIDE EVIDENCE TO SITE INSPECTOR THAT THE SOIL THEY ARE IMMEDIATELY STABILIZED WITH GRASS COVER OR COMPACTION OF THE BASIN FLOOR. AFTER FINAL GRADING IS SUPPLIER HAS PROVIDED APPROPRIATE TESTING OF THE OTHER APPROPRIATE LINING (RIPRAP, BLANKETING/MATTING, COMPLETE, DEEPLY TILL THE BASIN FLOOR WITH ROTARY MEDIA AND PROPER BATCHING AND QUALITY CONTROL ETC.). FERTILIZERS, IN ACCORDANCE WITH REGULATIONS AND TILLERS OR DISC HARROWS TO PROVIDE A WELL -AERATED, PROCEDURES TO SATISFY THE SPECIAL PROVISION FOR SPECIFICATIONS MAY BE REQUIRED. HIGHLY POROUS SURFACE TEXTURE. BOTTOM AND SIDES OF ENGINEERED SOIL MEDIA. FAILURE TO DELIVER THE EXCAVATED AREA SHALL BE SCARIFIED WITH EXCAVATING APPROPRIATE TESTING, VERIFICATION AND VENDOR EQUIPMENT HAVING A TOOTHED BUCKET. THE FACILITY AREAS CERTIFICATION MAY RESULT IN REJECTION OF THE MATERIAL SHALL BE CLEANED OF ALL DEBRIS AND RE-ESTABLISHED TO PRIOR TO OR AFTER INSTALLATION, AND REPLACEMENT AT DESIGN SUB -GRADES PRIOR TO FINAL STABILIZATION OF THE THE CONTRACTOR'S EXPENSE. SURROUNDING AREAS. ALA STORE THE ENGINEERED SOIL MEDIA ON AN ADJACENT O ONCE ALL EFFORTS HAVE BEEN MADE TO ISOLATE DRAINAGE INTO THE FACILITY AND THE AREA HAS BEEN ALLOWED TO DRY, IMPERVIOUS AREA OR PLASTIC SHEETING. APPLY TWO (2) FEET STRIP OF GEOTEXTILE OVER GRAVEL CHOKER LAYER IF THE CONTRACTOR STILL OBSERVES EXCESSIVE SEEPAGE, CENTERED ON PERFORATED UNDERDRAINS, AND THEN APPLY J. GLD STANDING WATER OR OTHER ADVERSE DRAINAGE THE ENGINEERED SOIL MEDIA IN 8-INCH LIFTS UNTIL THE LIC. T RETENTION BASIN L-2 CONVERSION NARRATIVE: OTHERWISE WAIVED OR APPROVED BY A VARIANCE, IN WRITING. OR PERMANENT CHANNEL LINING SHALL BE INSTALLED. GENERAL CONVERSION NOTES 1. SAFETY FENCE - STD. & SPEC. 3.01 MS-12 WORK IN LIVE WATERCOURSE - NO WORK WITHIN A LIVE WATERCOURSE AS A PART OF THE PROJECT. THE 1. THE PURPOSE OF THE EROSION CONTROL MEASURES SHOWN ON THESE PLANS SHALL BE TO PRECLUDE THE SAFETY FENCE WILL BE PROVIDED TO SEPARATE THE ADJACENT SITE USES FROM THE LAND DISTURBING AND UPLAND SWM MANAGEMENT FACILITY L-2 BMP FOOTPRINTIS THE ONLY WET AREA ENVISIONED TO BE DISTURBED. TRANSPORT OF ALL WATERBORNE SEDIMENTS RESULTING FROM CONSTRUCTION ACTIVITIES FROM ENTERING ONTO CONSTRUCTION ACTIVITIES. ADJACENT PROPERTIES OR STATE WATERS. IF FIELD INSPECTION REVEALS THE INADEQUACY OF THE PLAN TO CONFINE SEDIMENT TO THE PROJECT SITE, APPROPRIATE MODIFICATIONS SHALL BE MADE TO CORRECT ANY PLAN MS-13 CROSSING LIVE WATERCOURSE - NO CROSSINGS OF LIVE WATERCOURSES ARE ENVISIONED AS PART OF THE DEFICIENCIES. IN ADDITION TO THESE NOTES, ALL PROVISIONS OF THE VIRGINIA EROSION AND SEDIMENT CONTROL 2. TEMPORARY CONSTRUCTION ENTRANCE - STD. & SPEC. 3.02 PROJECT. REGULATION SHALL APPLY TO THIS PROJECT. IT IS UNDERSTOOD THAT THE CONVERSION ACTIVITY WILL UTILIZE THE EAST SIDE DEVELOPMENT APPROVED CONSTRUCTINO ENTRANCE (BY OTHERS). CONSTRUCTION ACCESS SHALL BE FROM THE EXISTING PAVED SURFACES MS-14 REGULATION OF WATERCOURSE CROSSING - NO IMPACTS TO LIVE WATERCOURSES ARE ENVISIONED AS PART 2. WHERE CONSTRUCTION VEHICLE ACCESS ROUTES INTERSECT PAVED PUBLIC ROADS, PROVISIONS SHALL BE MADE AND SHALL BE KEPT CLEAN ON A DAILY BASIS IN ACCORDANCE WITH STD. & SPEC 3.20. AND TO LIMIT MATERIAL OF THE PROJECT. TO MINIMIZE THE TRANSPORT OF SEDIMENT BY TRACKING ONTO THE PAVED SURFACE. WHERE SEDIMENT IS TRANSPORTED OFF -SITE BY CONSTRUCTION VEHICLES. TRANSPORTED ONTO A PUBLIC ROAD SURFACE, THE ROAD SHALL BE CLEANED THOROUGHLY AT THE END OF EACH 3. SILT FENCE - STD. & SPEC. 3.05 - SILT FENCE SHALL BE INSTALLED AS SHOWN IN ORDER TO INTERCEPT AND MS-15 STABILIZATION OF WATERCOURSE - NOT APPLICABLE. DAY. SEDIMENT SHALL BE REMOVED FROM THE ROADS BY SHOVELING OR SWEEPING AND TRANSPORTED TO A DETAIN SMALL AMOUNTS OF SEDIMENT FROM THE DISTURBED AREAS DURING CONSTRUCTION OPERATIONS. DISPOSAL AREA. MS-16 UNDERGROUND UTILITY LINE INSTALLATION - NO UNDERGROUND UTILITY LINES SHALL BE INSTALLED IN THIS 3. ALL APPLICABLE MEASURES SHALL BE INSTALLED AND MAINTAINED IN ACCORDANCE WITH THE VIRGINIA EROSION 4. OUTLET PROTECTION - STD. & SPEC. 3.18 - OUTLET PROTECTION SHALL BE INSTALLED PER PLAN AND IN PLAN. AND SEDIMENT CONTROL HANDBOOK, THIRD EDITION, 1992 (VESCH) . THE CONTRACTOR SHALL BE THOROUGHLY ACCORDANCE WITH VESCH. FAMILIAR WITH ALL APPLICABLE MEASURES CONTAINED THEREIN WHICH MAY BE PERTINENT TO THIS PROJECT. MS-17 VEHICULAR SEDIMENT TRACKING - WHERE CONSTRUCTION VEHICLE ACCESS ROUTES INTERSECT PAVED OR 5. STORM DRAIN INLET PROTECTION - STD. & SPEC. 3.07 - INLET PROTECTION SHALL BE PROVIDED AS NECESSARY ON PUBLIC ROADS, PROVISIONS SHALL BE MADE TO MINIMIZE THE TRANSPORT OF SEDIMENT BY VEHICULAR TRACKING 4. ALL APPLICABLE FEDERAL, STATE AND LOCAL REGULATIONS PERTAINING TO WORKING IN OR CROSSING A LIVE THE DROP INLETS ADJACENT TO OR IN THE PROJECT AREAS AND ACCESS WAYS TO PREVENT SEDIMENT FROM ONTO THE ROADWAY. WHERE SEDIMENT IS TRANSPORTED INTO A PAVED OR PUBLIC ROAD SURFACE, THE ROAD WATERCOURSE SHALL BE MET. ENTERING THE STORMWATER SYSTEM. SURFACE SHALL BE CLEANED THOROUGHLY AT THE END OF EACH DAY. SEDIMENT SHALL BE REMOVED FROM THE ROADS BY SHOVELING OR SWEEPING AND TRANSPORTED TO A SEDIMENT CONTROL 5. PERIODIC INSPECTIONS OF ALL EROSION CONTROL MEASURES SHALL BE MADE BY THE CONTRACTOR TO ASSESS THEIR CONDITION. INSPECTIONS SHALL BE CONDUCTED IN ACCORDANCE WITH THE PROJECT STORMWATER 6. TEMPORARY DIVERSION DIKE - STD & SPEC 3.09 - DIVERSION DIKE OR SIMILAR BERM CONTAINMENT SHALL BE USED DISPOSAL AREA. STREET WASHING SHALL BE ALLOWED ONLY AFTER SEDIMENT IS REMOVED IN THIS MANNER. POLLUTION PREVENTION PLAN (SWPPP). THIS INCLUDES INSPECTION AFTER EVERY MEASURABLE RAINFALL EVENT TO ISOLATE INFLOWS FOR CONTAINMENT AND DEWATERING EARLY IN THE CONSTRUCTION SEQUENCE. SEE AND THE REPAIR OF MEASURES DAMAGED BY SUB -CONTRACTORS. ANY NECESSARY REPAIRS OR CLEAN UP TO SEQUENCE THIS SHEET. MS-18 REMOVAL OF TEMPORARY MEASURES - ALL TEMPORARY EROSION AND SEDIMENT CONTROL MEASURES SHALL MAINTAIN THE EFFECTIVENESS OF THE EROSION CONTROL DEVICES SHALL BE MADE IMMEDIATELY. BE REMOVED WITHIN 30 DAYS AFTER THE FINAL SITE STABILIZATION OR WHEN TEMPORARY MEASURES ARE NO 6. ROCK CHECK DAMS - STD. & SPEC. 3.20 - TEMPORARY ROCK CHECK DAMS SHALL BE UTILIZED TO REDUCE LONGER NEEDED, ONLY UPON APPROVAL OF THE COUNTY INSPECTOR. 6. SEDIMENT CONTROL MEASURES MAY REQUIRE MINOR FIELD ADJUSTMENTS AT THE TIME OF CONSTRUCTION TO VELOCITIES IN SWALES, DITCHES, AND/OR TEMPORARY OUTFALL AREAS USED FOR DEWATERING. INSURE THEIR INTENDED PURPOSE IS ACCOMPLISHED. APPROVAL BY THE ENGINEER WILL BE REQUIRED FOR ANY DEVIATIONS FROM THE APPROVED PLANS. MS-19 STORMWATER MANAGEMENT - PROPERTIES AND WATERWAYS DOWNSTREAM FROM DEVELOPMENT SITES 7. DEWATERING - STD. & SPEC. 3.26 - ALL DEWATERING SHALL BE IN ACCORDANCE WITH VESCH. A PUMP AROUND SHALL BE PROTECTED FROM SEDIMENT DEPOSITION, EROSION, AND DAMAGE DUE TO INCREASES IN VOLUME, 7. ADDITIONAL EROSION CONTROL DEVICES MAY BE REQUIRED BY THE COUNTY INSPECTOR, THE STATE DIVERSION / DEWATERING SYSTEM SHALL BE USED TO ISOLATE CONSTRUCTION ACTIVITIES DURING LOW OR NO VELOCITY, AND PEAK FLOW RUNOFF. CONCENTRATED STORMWATER RUNOFF LEAVING THE PROJECT SHALL BE INSPECTOR,OR ENGINEER IF DEEMED NECESSARY. FLOW CONDITIONS PER SEQUENCE. CONTROLLED IN THE MANNER DEFINED UNDER THE STORMWATER MANAGEMENT PLAN. 8. ALL EROSION CONTROL DEVICES SHALL BE IN PLACE AND FUNCTIONAL AT ALL TIMES AND IF REMOVED FOR NON-STRUCTURAL PRACTICES SWPPP EROSION AND SEDIMENT CONTROL PLAN REQUIREMENTS: CONSTRUCTION PROGRESS, SHALL BE REPLACED BY THE CLOSE OF EACH WORKDAY. THE STORMWATER POLLUTION PREVENTION PLAN (SWPPP) SHALL INCLUDE AN EROSION AND SEDIMENT CONTROL 9. SURFACE FLOWS OVER CUT AND FILL SLOPES SHALL BE CONTROLLED BY EITHER REDIRECTING FLOWS FROM 1. TEMPORARY SEEDING - STD. & SPEC. 3.31 - ALL EXPOSED SOIL SURFACES THAT ARE NOT TO BE FINE -GRADED FOR PLAN APPROVED BY THE VESCP AUTHORITY AS AUTHORIZED UNDER THE EROSION AND SEDIMENT CONTROL TRANSVERSING THE SLOPES OR BY INSTALLING MECHANICAL DEVICES TO SAFELY LOWER WATER DOWNSLOPE PERIODS LONGER THAN 30 DAYS SHALL RECEIVE TEMPORARY SEEDING. SELECTION OF THE TEMPORARY SEED REGULATIONS (9VAC25-840). THE PROJECT DISTURBANCE IS GREATER THAN 1 ACRE AND REQUIRES CGP COVERAGE. MIXTURE SHALL BE IN ACCORDANCE WITH THE VIRGINIA EROSION AND SEDIMENT CONTROL HANDBOOK, THIRD WITHOUT CAUSING EROSION. EDITION, 1992 AND APPROVED BY THE ENGINEER. L-2 CONVERSION SEQUENCE: 10. THE CONTRACTOR SHALL PLACE SOIL STOCKPILES AT THE LOCATIONS SHOWN ON THIS PLAN OR AS DIRECTED BY THE ENGINEER. SOIL STOCKPILES SHALL BE STABILIZED OR PROTECTED WITH SEDIMENT TRAPPING MEASURES. 2. PERMANENT SEEDING - STD. & SPEC. 3.32 - PERMANENT SEEDING SHALL BE USED TO STABILIZE DISTURBED AREAS OFF -SITE WASTE OR BORROW AREAS SHALL BE APPROVED PRIOR TO THE IMPORT OF ANY BORROW OR EXPORT OF BROUGHT TO FINAL GRADE BY ESTABLISHING PERENNIAL VEGETATIVE COVER. THE PROJECT IS ENVISIONED TO BE COMPLETED INCREMENTALLY AS TO ADDRESS THE CONSTRUCTION OF ANY WASTE TO OR FROM THE PROJECT SITE. VARIOUS COMPONENTS AND ACCOMODATE TEMPORARY ONSITE FLOWS, AS NECESSARY. THE FOLLOWING REPRESENTS THE GENERAL PHASED SEQUENCE OF CONSTRUCTION; HOWEVER, ADDITIONAL MEASURES OR 11. ALL SLOPES SHALL REQUIRE THE USE OF EROSION CONTROL BLANKETS TO AID IN THE ESTABLISHMENT OF A 3. TOPSOILING - STD. & SPEC. 3.30 - TOPSOIL WILL BE STRIPPED FROM AREAS TO BE GRADED AND STOCKPILED STEPS MAY BE REQUIRED AS NECESSARY IN THE FIELD BY THE COUNTY INSPECTOR, OWNER, OR ENGINEER: SEPARATELY FOR LATER USE WHERE APPLICABLE VEGETATIVE COVER. INSTALLATION SHALL BE IN ACCORDANCE WITH SPECIFICATION 3.36 (B/M) AND MANUFACTURER'S INSTRUCTIONS. NO SLOPES SHALL BE CREATED STEEPER THAN 2:1. 1 . CONTRACTOR SHALL SCHEDULE AN ON -SITE PRE -CONSTRUCTION MEETING WITH THE COUNTY, AS 4. MULCHING -STD. &SPEC. 3.35 -AREAS WHICH HAVE BEEN PERMANENTLY OR TEMPORARILY SEEDED SHOULD BE 12. THE CONTRACTOR SHALL COMPLETE DRAINAGE FACILITIES WITHIN 30 DAYS FOLLOWING COMPLETION OF ROUGH MULCHED IMMEDIATELY FOLLOWING SEEDING. MULCHING SHALL BE USED IN FALL FOR WINTER COVER AND DURING NECESSARY, THE OWNER, AND THE ENGINEER. GRADING AT ANY POINT WITHIN THE PROJECT. OUTFALL CHANNELS FROM DRAINAGE STRUCTURES SHALL BE HOT AND DRY SUMMER MONTHS. 2. INSTALL ALL PERIMETER CONTROLS AT THE DOWNSTREAM TOE OF THE PROPOSED EMBANKMENT. STABILIZED IMMEDIATELY AFTER CONSTRUCTION OF SAME. THIS INCLUDES INSTALLATION OF EROSION CONTROL STONE OR PAVED DITCHES WHERE REQUIRED. 5. BLANKETING AND MATTING - STD. & SPEC3.36 - ALL AREAS OUTSIDE OF NORMAL POOLS, UNLESS OTHERWISE 3. CONSTRUCTION THE DOWNSTREAM CHANNEL IMPROVEMENTS, INCLUSIVE OF TEMPORARY CHECK SPECIFIED FOR SURFACE TREATMENT SHALL RECEIVE EC-2 MATTING AT MINIMUM. DAMS SHALL COMMENCE IN DRY WEATHER. CONTRACTOR SHALL TAKE PARTICULAR CARE TO AVOID ANY 13. PERMANENT OR TEMPORARY SOIL STABILIZATION MUST BE APPLIED TO ALL DENUDED AREAS WITHIN 7 DAYS DISTURBANCE OF DOWNSTREAM WETLANDS. SILT FENCE SHALL BE INSTALLED AT THE PROPOSED AFTER FINAL GRADE IS REACHED ON ANY PORTION OF THE SITE. SOIL STABILIZATION MUST ALSO BE APPLIED TO DENUDED AREAS WHICH MAY NOT BE AT FINAL GRADE BUT WILL REMAIN DORMANT (UNDISTURBED) FOR LONGER 6. PUMP AROUND DIVERSION - A PUMP AROUND DIVERSION / DEWATERING SYSTEM SHALL BE USED TO ISOLATE CHANNEL TERMINUS TO AVOID DEPOSITION IN THE DOWNSTREAM WETLANDS. THAN 14 DAYS. SOIL STABILIZATION MEASURES INCLUDE VEGETATIVE ESTABLISHMENT OR MULCHING. CONSTRUCTION ACTIVITIES DURING LOW OR NO FLOW CONDITIONS PER SEQUENCE. 4. DEWATERING OF THE WET POOLS SHALL COMMENCE PER APPROVED METHODS. 14. IF DISTURBED AREA STABILIZATION IS TO BE ACCOMPLISHED DURING THE MONTHS OF DECEMBER, JANUARY, OR MAINTENANCE PRACTICES 5. ONCE SUFFICIENTLY DRY IN APPLICABLE AREAS, COMMENCE CONSTRUCTION OF THE TEMPORARY FEBRUARY, STABILIZATION SHALL CONSIST OF MULCHING IN ACCORDANCE WITH SPECIFICATION 3.35 OF THE DIVERSION DIKE OR SIMILAR APPROVED DIVERSION IN THE FIELD TO ISOLATE INFLOWS FOR DEWATERING VIRGINIA EROSION AND SEDIMENT CONTROL HANDBOOK THIRD EDITION, 1992 . SEEDING WILL THEN TAKE PLACE AS SOON AS THE SEASON PERMITS. IN GENERAL, ALL EROSION AND SEDIMENT CONTROL MEASURES SHALL BE CHECKED DAILY AND AFTER EACH PER PLAN. PROVIDE TEMPORARY SEEDING OF THE TEMPORARY BERM FEATURES. SIGNIFICANT RAINFALL BY THE CONTRACTOR. ALL PRACTICES SHALL BE MAINTAINED IN PROPER WORKING ORDER 15. THE TERM SEEDING, FINAL VEGETATIVE COVER OR STABILIZATION, ON THIS PLAN SHALL MEAN THE SUCCESSFUL AND MAY REQUIRE REPAIR REPLACEMENT PER THE COUNTY INSPECTOR, ENGINEER, OR OWNER. 6. BULK EARTHWORK SHALL THEN COMMENCE. STAGING AND STOCKPILING OF MATERIALS SHALL OCCUR ONSITE. TEMPORARY STABILIZATION SHALL BE APPLIED TO ALL SOIL STOCKPILES THAT WILL REMAIN GERMINATION AND ESTABLISHMENT OF A STABLE COVER FROM A PROPERLY PREPARED SEEDBED CONTAINING THE SPECIFIED AMOUNTS OF SEED AND FERTILIZER IN ACCORDANCE WITH THE SEEDING SCHEDULE LOCATED ON SHEET EROSION AND SEDIMENT CONTROL MINIMUM STANDARDS UNPROTECTED FOR MORE THAN 14 DAYS AND ALL DENUDED/DISTURBED AREAS THAT WILL NOT REACH 5. FINAL GRADE WITHIN 14 DAYS. 16. TEMPORARY EROSION CONTROL MEASURES ARE NOT TO BE REMOVED UNTIL ALL DISTURBED AREAS ARE THE INTENT OF THIS SECTION IS TO SUMMARIZE HOW THE EROSION AND SEDIMENT CONTROL MEASURES PROPOSED 7. EXCAVATE EASTERN BASIN GRADES AND IMITATE DAM RECONSTRUCTION UNDER DIRECTION OF A STABILIZED AND ONLY WITH APPROVAL OF JCC ERP DIVISION SITE INSPECTOR. TRAPPED SEDIMENT SHALL BE IN THE CONVERSION PLAN SATISFY THE 19 MINIMUM STANDARDS SET FORTH IN THE VIRGINIA EROSION AND LICENSED GEOTECHNICAL ENGINEER. ALL CONSTRUCTION CONSTRUCTION OF DAM KEY AND CORE, IF SPREAD AND SEEDED. SEDIMENT CONTROL REGULATIONS (4VAC50-30-40). THE FOLLOWING IS A BRIEF SYNOPSIS OF THE MINIMUM APPLICABLE SHALL BE PERFORMED IN ACCORDANCE WITH THE GEOTECHNICAL ENGINEER. STANDARDS (MS) AND HOW THEY ARE ADDRESSED IN THE PLAN. THE CONTRACTOR MUST ABIDE BY ALL CONDITIONS 17. WHEN ANY MEASURE OR PRACTICE IS DEEMED BY LAW, REGULATION, CONTRACT DOCUMENT, SWPPP, OR CGP; AND STANDARDS. 8. REMOVE EXISTING SPILLWAY PIPE DEWATERING THE BASIN FLOOR AS NECESSARY AND PREPARE THE THE MORE STRINGENT SHALL APPLY. EMBANKMENT AND SPILLWAY SUBGRADE PER THE GEOTECHNICAL ENGINEER'S DIRECTION. MS-1 STABILIZATION OF DENUDED AREAS - WITHIN SEVEN DAYS, PERMANENT OR TEMPORARY SOIL STABILIZATION PROJECT DESCRIPTION SHALL BE APPLIED TO DENUDED AREAS THAT MAY REMAIN DORMANT FOR LONGER THAN 30 DAYS. TEMPORARY AND 9. INSTALL PROPOSED SPILLWAY STRUCTURE AND APPURTENANCES IN ACCORDANCE WITH PERMANENT SEEDING, MULCHING, BLANKETS AND MATTING, AND RIPRAP ARE SPECIFIED IN THE PLAN FOR MANUFACTURERS RECOMMENDATIONS. WHILE THESE PLANS DO NOT REPRESENT EROSION AND SEDIMENT CONTROL (ESC) DESIGN FOR THE DEVELOPMENT, STABILIZATION OF DENUDED AREAS. 10. DAM EMBANKMENT MAY BE BROUGHT INCREMENTALLY UP TO PROPOSED ELEVATIONS PER PLAN IN THE FOLLOWING IS INTENDED TO PROVIDE CLARITY ON THE REQUIREMENTS FOR RESPONSIBLE CONVERSION OF FACILITY L-2. ADDITIONALLY, ALL OTHER BMP CONVERSIONS SHALL BE CARRIED OUT IN ACCORDANCE THE MS-2 STABILIZATION OF SOIL STOCKPILES - DURING CONSTRUCTION, SOIL STOCKPILES AND BORROW AREAS SHALL ACCORDANCE WITH THIS PLAN AND GEOTECHNICAL ENGINEER DIRECTION. APPROVED PROJECT ESC PLANS AND VESCH. BE STABILIZED OR PROTECTED WITH SEDIMENT TRAPPING MEASURES (I.E. SILT FENCE). 1 1 . ONCE EMBANKMENT IS IN PLACE THE REMAINDER OF THE BASIN FLOOR MAY BE COMPLETED IN THE AREA NEAR THE PROPOSED STRUCTURE. THIS AREA MAY NOW SERVE AS COLLECTION FOR DEWATERING MS-3 ESTABLISHMENT OF PERMANENT VEGETATION - A PERMANENT VEGETATIVE COVER SHALL BE ESTABLISHED ON PRACTICES. EXISTING CONDITIONS DENUDED AREAS NOT OTHERWISE PERMANENTLY STABILIZED. PERMANENT VEGETATION SHALL NOT BE CONSIDERED ESTABLISHED UNTIL A GROUND COVER IS ACHIEVED THAT IS UNIFORM, MATURE ENOUGH TO SURVIVE, 12. REMOVE TEMPORARY DIVERSION DIKE ANDN INSTALL FOREBAY STEP POOL SYSTEM PER PLAN. THE EXISTING CONDITION IS AN UPLAND CONSTRUCTED RETENTION BASIN THAT IS SCHEDULE FOR RETROFIT UNDER AND WILL INHIBIT EROSION. IMPROVEMENTS SHALL STAY OFFLINE UNTIL COMPLETE AND APPROVED BY THE ENGINEER. THE MASTER PLAN. THE BMP IS SITED WITHIN A MODERATE DRAW WITH SIDESLOPES ON EITHER SIDE THAT REACH TO THE UPSTREAM EXISTING DEVELOPMENT ON THE WEST AND THE PROPOSED RESIDENTIAL DEVELOPMENT ON THE MS-4 TIMING AND STABILIZATION OF SEDIMENT TRAPPING MEASURES - ALL SEDIMENT TRAPPING MEASURES 13. UPON APPROVAL OF THE FOREBAY AND STEP POOL SYSTEM, THE CONTRACTOR SHALL INSTALL THE EAST. (INCLUDING SEDIMENT BASINS) SHALL BE CONSTRUCTED AS A FIRST STEP IN ANY LAND -DISTURBING ACTIVITY AND UPSTREAM PIPE IMPROVEMENTS PER THE APPROVED RGA DEVELOPMENT PLANS. IF NECESSARY SAND SHALL BE MADE FUNCTIONAL BEFORE UPSLOPE LAND DISTURBANCE TAKES PLACE. BAGS MAY BE PLACED IN UPSTREAM STORM SEWER STRUCTURES TO FACILITATE TEMPORARY PUMP ADJACENT AREAS AROUND OF THIS AREA. MS-5 STABILIZATION OF EARTHEN STRUCTURES - STABILIZATION MEASURES SHALL BE APPLIED TO EARTHEN 5. THE CONTRACTOR SHALL ENSURE THAT ALL FINAL GRADES ARE MET AND DRAINAGE PATTERNS ALIGN DOWSTREAM PARK AREA, FLOODPLAIN, AND ASSOCIATED WETLANDS SHALL BE PROTECTED AT ALL TIMES. UP[PER STRUCTURES IMMEDIATELY AFTER INSTALLATION AS SPECIFIED IN THE PLAN. SLOPES SHOULD ALSO BE RESPECTED AND REMAIN IN STABLE CONDITION THROUGHOUT CONSTRUCTION. WITH WHAT IS SHOWN ON THE PLAN. ONCE FINAL GRADE HAS BEEN REACHED FOR THE BMP'S PERMANENT SEEDING, AND STABILIZATION SHALL OCCUR. MS-6 SEDIMENT TRAP AND BASINS - SEDIMENT TRAPS AND BASINS ARE NOT USED IN THIS PLAN. CRITICAL EROSION AREAS: 6. UPON COMPLETION OF ALL PROPOSED WORK THE CONTRACTOR SHALL NOTIFY THE ENGINEER TO MS-7 DESIGN, CONSTRUCTION, AND STABILIZATION OF CUT AND FILL SLOPES - CUT AND FILL SLOPES SHALL BE ARRANGE A SUBSTANTIAL COMPLETION SITE WALKOVER. CRITICAL EROSION AREAS INCLUDE SIDESLOPES ABOVE THE EXISTING BMP ENTERING FROM THE SOUTH, WEST, AND DESIGNED AND CONSTRUCTED IN A MANNER THAT WILL MINIMIZE EROSION. MOST SLOPES ARE PROPOSED TO BE EAST. THE OUTFALL GRADING IN CLOSE PROXIMITY TO THE DOWNSTREAM WETLAND SYSTEM IS ALSO A CRITICAL STABILIZED WITH BLANKETING AND MATTING AS SHOWN ON THE E&S PLAN. SLOPES FOUND TO BE ERODING 7 UPON COMPLETION OF ALL PROPOSED WORK ACTIVITIES AND APPROVAL BY THE COUNTY INSPECTOR, AREA THAT MUST BE AVOIDED AND PROTECTED DURING CONSTRUCTION. EXCESSIVELY WITHIN ONE YEAR OF PERMANENT STABILIZATION SHALL BE PROVIDED WITH ADDITIONAL SLOPE ALL TEMPORARY EROSION AND SEDIMENT CONTROL MEASURES SHALL BE REMOVED WITHIN 30 DAYS. ANY STABILIZING MEASURES UNTIL THE PROBLEM IS CORRECTED. CONCENTRATED SEDIMENT ALONG THE EROSION AND SEDIMENT CONTROL MEASURES SHALL BE SEEPAGE ALONG SLOPES: RESPREAD AND STABILIZED WITH SEED/MULCH IN UPLANDS. MS-8 CONCENTRATED RUNOFF DOWN SLOPES - CONCENTRATED RUNOFF SHALL NOT FLOW DOWN CUT OR FILL SLOPES UNLESS CONTAINED WITHIN AN ADEQUATE TEMPORARY OR PERMANENT CHANNEL, FLUME, OR SLOPE DRAIN 8 NOTIFY ENGINEER UPON COMPLETION OF CLEANUP ACTIVITIES TO ARRANGE AN FINAL SITE INSPECTION. PROPOSED SLOPE STABILIZATION CONSISTS OF BLANKETING AND MATTING IMMEDIATELY FOLLOWING GRADING STRUCTURE. OPERATIONS IN AREAS OF BMP CONSTRUCTION. NO OTHER CONCERNS, SUCH AS SEEPAGE, ARE ANTICIPATED AT 9. THE CONTRACTOR SHALL COORDINATE WITH THE ENGINEER TO SCHEDULE INSTALLATION OF WOODY THIS TIME. HOWEVER, IF EXCESSIVE GROUNDWATER SEEPAGE IS IDENTIFIED WITHIN A PARTICULAR AREA DURING VEGETATION INCLUDING TREES AND SHRUBS. AS THE PLANTING WINDOW FOR THIS VEGETATION MAY NOT CONSTRUCTION, PREVENTING ADEQUATE STABILIZATION, THE CONTRACTOR SHALL EMPLOY SEEPAGE CONTROL MS-9 ADEQUATE DRAINAGE PROTECTION FROM WATER SEEPS - IF THE CONTRACTOR IDENTIFIES WATER SEEPAGE FALL WITHIN THE CONSTRUCTION WINDOW, THE PLANTING SHALL BE SCHEDULED AT THE EARLIEST TIME MEASURES SUCH AS A SUBSURFACE DRAIN PER VESCH 3.28 AS NEEDED. FROM A SLOPE FACE, ADEQUATE DRAINAGE PER VESCH 3.28 OR OTHER APPROPRIATE PROTECTION SHALL BE POSSIBLE AS SHOWN IN SPECIFICATIONS OR AS APPROVED BY ENGINEER. PROVIDED. STRUCTURAL PRACTICES MS-10 STORM SEWER INLET PROTECTION - ALL STORM SEWER INLETS SHALL BE PROVIDED INLET UNLESS OTHERWISE INDICATED, ALL VEGETATIVE AND STRUCTURAL EROSION AND SEDIMENT CONTROL PRACTICES PROTECTION. SHALL BE CONSTRUCTED AND MAINTAINED ACCORDING TO MINIMUM STANDARDS AND SPECIFICATIONS OF THE VIRGINIA EROSION AND SEDIMENT CONTROL HANDBOOK, THIRD EDITION, 1992. THE MINIMUM STANDARDS OF THE MS-11 STORMWATER CONVEYANCE PROTECTION - BEFORE NEWLY CONSTRUCTED STORMWATER CONVEYANCE VIRGINIA EROSION AND SEDIMENT CONTROL REGULATIONS, LATEST EDITION SHALL BE ADHERED TO UNLESS CHANNELS OR PIPES ARE MADE OPERATIONAL, ADEQUATE OUTLET PROTECTION AND ANY REQUIRED TEMPORARY 1 106/28/16 I REVISED PER COUNTY COMMENTS DATE I DESCRIPTION LEGEND i PROJECT LIMITS - . EXISTING CONTOURS �00 APPROXIMATE LOCATION OF 4000000 � EXISTING STREAM BUFFER PROPOSED GRADES SILT FENCE ��- DEWATERING STRUCTURE PUMP DEWATERING PUMP PROPOSED BIORETENTION ih_"-I FOOTPRINT PROPOSED STORM SEWER NETWORK COUNTY CRITICAL SLOPES (2007) DIVERSION DIKE / ROCK CHECK DAM .00 - •�. lop i1r 1 U Qom;= L�J a 670 I j°4v PREPARED BY: Sta ntec 5209 Center Street Williamsburg, VA 23188 PHONE: (757) 220-6869 FAX: (757) 229-4507 0 60 120 1 FOR: APPROXIMATE SCALE (FEET) TITLE: OLD TRAIL VILLAGE CROZET,VA RETENTION BASIN L-2 CONSTRUCTION PHASING �ALTH of j o J. GLENN MUCKLEY a Lic. No. 038970 `sICNAL �� DRAWN BY: AJT DESIGNED BY: JGM CHECKED BY: JGM APPROVED BY: JGM PROJECT NUMBER: 203400430 SCALE: 1" = 60' DATE: 05/20/2016 FILE PATH: U1203400430 AJT JGM JGM SHEET: 13 DSN CHK APP F1 2 ACRES OR LESS OF DRAINAGE AREA: 6' 5� i i ��i•- 1� 1�• 1�� 1 1 i I�i. I�i Irr �• VDOT #1 2-10 ACRES OF DRAINAGE AREA (DOWNSTREAM VIEW) VDOT #1 COARSE AGGREGATE FLOW- - - -o°C )oU-oCJj 2:1 3' CLASS 1 RIPRAP DETAIL.. ROCK CHECK DAM CROSS SECTION nr)wN]STRFAM RI()RFTFNTinNI FI c)nR INFLOW SURFACE PER PLAN 2:1 OR FLATTER GEOTEXTILE 1 FOOT DEEP SIX (6) INCH COBBLE, UNLESS OTHERWISE SPECIFIED * MIN. PHYSICAL REQUIREMENTS OF FILTER CLOTH NOTED IN STD. & SPEC. 3.19, RIPRAP DETAIL: BIORETENTION INFLOW COBBLE LEVEL SPREADER NTS NTS ® CONSTRUCTION OF A SILT FENCE S F (WITHOUT WIRE SUPPORT) 1. SET THE STAKES. 2. EXCAVATE A 4" x 4" TRENCH UPSLOPE ALONG THE LINE OF STAKES. & MAX. FLOW 4" 3. STAPLE FILTER MATERIAL 4. BACKFILL AND COMPACT TO STAKES AND EXTEND THE EXCAVATED SOIL. IT INTO THE TRENCH. i FLOW SHEET FLOW INSTALLATION (PERSPECTIVE VIEW) FLOW & MAX. AA IA I B I POINTS A SHOULD BE HIGHER THAN POINT B. DRAINAGEWAY INSTALLATION (FRONT ELEVATION) DETAIL: SILT FENCE NTS 1 2„ DIA. T WASHER 10" MIN. n16" 18 3/16" DIA, STEEL PIN 11 GAUGE STEEL 6'x1'x6' STAPLE STAKE STAPLE PIN 1. 1/4 TRIANGLE SURVEY STAKE - MINIMUM 10" IN LENGTH. PLACEMENT OF THE STAKE ACROSS THE FLOW OF WATER IS THOUGHT TO PROVIDE A "PINBALL EFFECT' TO HELP SLOW THE VELOCITY. 2. 11 GAUGE STEEL - MINIMUM 1" WIDE BY 6" IN LENGTH STEEL STAPLE - 2"x8" STAPLE MAY BE REQUIRED IN CERTAIN SOIL CONDITIONS. 3.STEEL PINS - DIAMETER STEEL PIN BY 18" IN LENGTH WITH 2" DIAMETER WASHER ON TOP. (SEE ILLUSTRATION) DETAIL: SOIL MATTING ANCHORS SCHEDULE 40 PVC SCREW CAP ON GRADE NON -PERFORATED SCHEDULE 40 PVC STANDPIPE USE 45 ^ WYE AND FITTING OR EQUIVALENT DIRECTIONAL CONNECTION TO CONNECT UNDERDRAIN TO STANDPIPE WATERTIGHT CAP ON TERMINAL END OF PIPE JVI ILV VLL TV PVC UNDERDRAIN DETAIL: SCHEDULE 40 PVC CLEANOUT NTS W1 W2 a a a C-L3-1 W2 W2 - - >> � W2 W1 a oa 0 W2 W2 a a a o� o L a O W2 W2 W1 W1 a Y W1 L W1 W1 j� W1 OUTLET S-3-1 S-3-2 S-3-3 S-12-1 S-12-2 S-3-3 L-2-1 L-3-1 L-3-2 PROTECTION ID Q10 (CFS) 26.85 7.49 11.48 16.41 3.65 2.24 21.0 7.52 7.14 L (FT) 25.6 9.5 16.0 32.2 6.0 6.0 20.0 13.5 20.0 W1 (FT) 7.5 3.75 9.0 7.5 3.0 6.0 10.5 8.0 9.0 W2 (FT) 24.0 11.0 19.0 27.6 7.0 8.5 21.0 18.6 23.0 RIPRAP CLASS CLASS CLASS CLASS CLASS CLASS CLASS CLASS CLASS MIN. DEPTH (FT) 2.2 2.2 2.2 2.2 2.2 2.2 2.2 2.2 2.2 QUANTITY (CY) 24.4 5.7 18.3 40.7 2.4 3.6 33.9 26.1 16.3 BM mml SHALLOW ►A WHERE THERE IS A BERM AT THE TOP OF THE SLOPE, BRING THE MATERIAL OVER THE BERM AND ANCHOR IT BEHIND THE BERM. ON SHALLOW SLOPES, STRIPS OF NETTING PROTECTIVE COVERINGS MAY BE APPLIED ACROSS THE SLOPE. BERM 1=1 I1=1 I 1=1 1I- 1II- 111=III-III-111=1 11= 1=1 I -III -III -III-III-I 11=1 11=1 11=1 11=1 I -ITI=1 11=1 11=1 11=1 11=1 11=1 11=1 11=1 I ON STEEP SLOPES, APPLY PROTECTIVE COVERING PARALLEL TO THE DIRECTION OF FLOW AND ANCHOR SECURELY. 4"�lowaloft BRING MATERIAL DOWN TO A LEVEL AREA BEFORE TERMINATING THE INSTALLATION. TURN THE END UNDER 4" AND STAPLE AT 12" INTERVALS. T - `\ 12" IN DITCHES, APPLY PROTECTIVE COVERING PARALLEL TO THE DIRECTION OF FLOW. USE CHECK SLOTS AS REQUIRED. AVOID JOINING MATERIAL IN THE CENTER OF THE DITCH IF AT ALL POSSIBLE. DETAIL: E & S CONTROL BLANKET INSTALLATION TAMP FIRMLY ANCHOR SLO NTS T ANCHOR SLOT NOTES APPROXIMATELY 200 STAPLES REQUIRED PER 100 SQ. YDS. OF MATERIAL ROLL. ANCHOR SLOTS, JUNCTION SLOTS & CHECK SLOTS TO BE BURIED 6" TO 12". 12" MAX. 4:1 OR FLATTER 6" MAX. STEEPER THAN 4:1 JUNCTION SLOT f EDGE AND END JOINTS � TO BE SNUGLY ABUTTED CHECK SLOT 1 (JUTE MESH WILL HAVE TERMINAL FOLD STAPLED LAP JOINT IN LIEU OF EDGE JOINT) LAP JOINT 2" MIN. (JUTE MESH ONLY) & MAX. 4:1 OR FLATTER I I I I�II�IIE 3MAX. STEEPER THAN 4:1 T 1 I I 1 1 I II II[ 1 I I 6" TO 12" I I I I I I I I I I I TAMP CHECK SLOT FIRMLY 6' TO 12° JUNCTION SLOT TAMP FIRMLY 12" I I I I I I I xCHECK SLOT JI 1 I 1 1 VAR. VAR. 6"TO8"MIN.-I PLAN VIEW STAPLING DIAGRAM STAPLE FORMED FROM NO.11 STEEL WIRE. CHECK SLOTS AT MIN. 8"STAPLE MIN. LENGTH FOR SANDY SOIL. 5O' RE INTERVALS; NOT R" CTAPI F KAINI I FNI(-'TW F(1P (1TWF=P C(l11 O.'D WITH ALL DETAIL: E & S CONTROL STAPLING DETAIL TERMINAL FOLD TAMP FIRMLY ROCK AXIS DEFINITION X - DIMENSION PERPENDICULAR TO FLOW Y = DIMENSION PARALLEL TO FLOW Z = VERTICAL DIMENSION el 1� T BOULDER/ROCK DEFINITION NOTES 1.) BOULDERS/ROCKS SHALL BE RELATIVELY FLAT, RECTANGULAR SHAPED, AND UNIFORM IN SIZE. Y2.) BOULDERS/ROCKS SHALL BE INSTALLED IN AN OVERLAPPING (IMBRICATED) MANNER WHEN POSSIBLE, WITH STEP BOULDERS OFFSET UPSTREAM. 3.) ROCK SIZING TABLE FOR MODIFIED CROSS VANE, CROSS VANE, AND ROCK SILLS WILL BE PROVIDED WITH FINAL DESIGN. 4) ALL SPLASH ROCK SIZING SHALL BE CONSISTENT WITH TABLE BELOW. STRUCTURE ROCK SIZE SPECIFICATION TABLE STRUCTURE X-AXIS DIMENSION Y-AXIS DIMENSION Z-AXIS DIMENSION S-3 HIGH FLOW 2.0 FT 2 FT 2 FT S-12 HIGH FLOW 2 FT 2 FT 2 FT S-1 2.5 FT 2.5 FT 2.5 FT S-2, S-3, S4, S-5 2.0 FT 2.0 FT 2.0 FT DETAIL: IMBRICATED BOULDER ROCK SIZING DEFINITION NOTE: ALL AREAS SHALL BE MATTED WITH EC-2 AT MINIMUM UNLESS OTHERWISE SPECIFIED. ALL SLOPES 2:1 OR GREATER SHALL RECEIVE EC-3 MATTING. NTS BERM ELEVATION AS AS SHOWN ON NOTED ON CONSTRUCTION CONSTRUCTION PONDING DEPTH BIORETENTIO1 SOIL MEDI) COMPACT SOIL, 1 IIr MAXIMUM 6" LIFTS AND COMPACT TO 95X STANDARD PROCTOR DENSITY PROFILE DETAIL: COMPACTED FILL BERM BIORETENTION NTS OP PUMP DISCHARGE-� CLASS I RIP RAP APRON PLAN VIEW L a J, n d FILTER CLOTH KEY IN &-T; RECOMMENDED FOR ENTIRE PERIMETER SECTION A -A NOTES: 1. APRON LINING MAY BE RIPRAP, GROUTED RIPRAP, GABION BASKET, OR CONCRETE. 2. La IS THE LENGTH OF THE RIPRAP APRON AS CALCULATED USING PLATES 3.18-3 AND 18-4. 3. d = 1.5 TIMES THE MAXIMUM STONE DIAMETER, BUT NOT LESS THAN 6 INCHES. 4. LEVEL SPREADER TRENCH TO BE INSTALLED PARALLEL TO CONTOUR AND TO MATCH THE PROPOSED GRADE. TOP LIP ELEVATION TO BE UNIFORM TO WITHIN 1". DETAIL: OUTFALL PROTECTION NTS Cnmnactc-d Steil DETAIL: DIVERSION DIKE NTS B110RETENT110N MINIMUM MATERIAL STANDARDS BIORETENTION LAYER DIMENSION NOTES //VVVVVVV LAYER DESCRIPTION VA//V// ///A/�A VAjVAj rV�rV\r�A/VA/ A/VA/VA/ O SURFACE 3 DEPTH - - / COVER/MULCH 1\/\MIN.)�\//1\1 O2 ENGINEERED SOIL 24", INCLUDES MEDIA (SEE SPECS) MULCH 3 O O NON -WOVEN FILTER 2' TO EITHER SIDE _ _ 4 FABRIC OF UNDERDRAIN 5 UNDERDRAIN O4 CHOKER LAYER 3" DEPTH CLEAN AND WASHED 6 (1' M .) O5 SUMP LAYER 12" DEPTH, AROUND UNDERDRAIN ONLY CLEAN AND WASHED BIORETENTION CROSS SEC ION (TYP) UNCOMPACTED AVOID COMPACTION OF SUBGRADE; TILLING MAY BE REQUIRED IF NTS © SUBGRADE SOIL COMPACTED; LINER MAY BE REQUIRED OVER STRUCTURAL FILL ��T H OF �jfP C' J. GLENN MUCKLEY a Lic. No. 038970 �SSIONAL E��1 11 106/28/161 REVISED PER COUNTY I AJT I JGM I JGM I COMMENTS REVI DATE I DESCRIPTION DSN CHK APP PREPARED BY: Stantec FOR: TITLE: 5209 Center Street Williamsburg, VA 23188 PHONE: (757) 220-6869 FAX: (757) 229-4507 OLD TRAIL VILLAGE CROZET,VA CONSTRUCTION DETAILS DRAWN BY: AJT CHECKED BY: JGM PROJECT NUMBER: 203400430 DATE: 05/20/2016 SHEET: 14 DESIGNED BY: JGM APPROVED BY: JGM SCALE: FILE PATH: U:/203400430 ALBEMARLE COUNTY FINAL PLAN GENERAL NOTES GENERAL CONSTRUCTION NOTES 1. PRIOR TO ANY CONSTRUCTION WITHIN ANY EXISTING PUBLIC RIGHT-OF-WAY, INCLUDING CONNECTION TO ANY EXISTING ROAD, A PERMIT SHALL BE OBTAINED FROM THE VIRGINIA DEPARTMENT OF TRANSPORTATION (VDOT). THIS PLAN AS DRAWN MAY NOT ACCURATELY REFLECT THE REQUIREMENTS OF THE PERMIT. WHERE ANY DISCREPANCIES OCCUR THE REQUIREMENTS OF THE PERMIT SHALL GOVERN. 2. ALL MATERIALS AND CONSTRUCTION METHODS SHALL CONFORM TO CURRENT SPECIFICATIONS AND STANDARDS OF VDOT UNLESS OTHERWISE NOTED. 3. EROSION AND SILTATION CONTROL MEASURES SHALL BE PROVIDED IN ACCORDANCE WITH THE APPROVED EROSION CONTROL PLAN AND SHALL BE INSTALLED PRIOR TO ANY CLEARING, GRADING OR OTHER CONSTRUCTION. 4. ALL SLOPES AND DISTURBED AREAS ARE TO BE FERTILIZED, SEEDED AND MULCHED. 5. THE MAXIMUM ALLOWABLE SLOPE IS 2:1 (HORIZONTAL:VERTICAL). WHERE REASONABLY OBTAINABLE, LESSER SLOPES OF 3:1 OR BETTER ARE TO BE ACHIEVED. 6. PAVED, RIP -RAP OR STABILIZATION MAT LINED DITCH MAY BE REQUIRED WHEN IN THE OPINION OF THE COUNTY ENGINEER, OR DESIGNEE, IT IS DEEMED NECESSARY IN ORDER TO STABILIZE A DRAINAGE CHANNEL. 7. ALL TRAFFIC CONTROL SIGNS SHALL CONFORM WITH THE VIRGINIA MANUAL FOR UNIFORM TRAFFIC CONTROL DEVICES. 8. UNLESS OTHERWISE NOTED ALL CONCRETE PIPE SHALL BE REINFORCED CONCRETE PIPE - CLASS III. 9. ALL EXCAVATION FOR UNDERGROUND PIPE INSTALLATION MUST COMPLY WITH OSHA STANDARDS FOR THE CONSTRUCTION INDUSTRY (29 CFR PART 1926). GENERAL CONSTRUCTION NOTES FOR EROSION AND SEDIMENT CONTROL PLANS 1. THE PLAN APPROVING AUTHORITY MUST BE NOTIFIED ONE WEEK PRIOR TO THE PRE -CONSTRUCTION CONFERENCE, ONE WEEK PRIOR TO THE COMMENCEMENT OF LAND DISTURBING ACTIVITY, AND ONE WEEK PRIOR TO THE FINAL INSPECTION. 2. ALL EROSION AND SEDIMENT CONTROL MEASURES WILL BE CONSTRUCTED AND MAINTAINED ACCORDING TO MINIMUM STANDARDS AND SPECIFICATIONS OF THE VIRGINIA EROSION AND SEDIMENT CONTROL HANDBOOK AND VIRGINIA REGULATIONS VR 625-02-00 EROSION AND SEDIMENT CONTROL REGULATIONS. 3. ALL EROSION AND SEDIMENT CONTROL MEASURES ARE TO BE PLACED PRIOR TO OR AS THE FIRST STEP IN CLEARING. 4. A COPY OF THE APPROVED EROSION AND SEDIMENT CONTROL PLAN SHALL BE MAINTAINED ON THE SITE AT ALL TIMES. 5. PRIOR TO COMMENCING LAND DISTURBING ACTIVITIES IN AREAS OTHER THAN INDICATED ON THESE PLANS (INCLUDING, BUT NOT LIMITED TO, OFF -SITE BORROW OR WASTE AREAS), THE CONTRACTOR SHALL SUBMIT A SUPPLEMENTARY EROSION CONTROL PLAN TO THE OWNER FOR REVIEW AND APPROVAL BY THE PLAN APPROVING AUTHORITY. 6. THE CONTRACTOR IS RESPONSIBLE FOR INSTALLATION OF ANY ADDITIONAL EROSION CONTROL MEASURES NECESSARY TO PREVENT EROSION AND SEDIMENTATION AS DETERMINED BY THE PLAN APPROVING AUTHORITY. 7. ALL DISTURBED AREAS ARE TO DRAIN TO APPROVED SEDIMENT CONTROL MEASURES AT ALL TIMES DURING LAND DISTURBING ACTIVITIES AND DURING SITE DEVELOPMENT UNTIL FINAL STABILIZATION IS ACHIEVED. 8. DURING DEWATERING OPERATIONS, WATER WILL BE PUMPED INTO AN APPROVED FILTERING DEVICE. 9. THE CONTRACTOR SHALL INSPECT ALL EROSION CONTROL MEASURES PERIODICALLY AND AFTER EACH RUNOFF PRODUCING RAINFALL EVENT. ANY NECESSARY REPAIRS OR CLEANUP TO MAINTAIN THE EFFECTIVENESS OF THE EROSION CONTROL DEVICES SHALL BE MADE IMMEDIATELY. 10. ALL FILL MATERIAL TO BE TAKEN FROM AN APPROVED, DESIGNATED BORROW AREA. 11. ALL WASTE MATERIALS SHALL BE TAKEN TO AN APPROVED WASTE AREA. EARTH FILL SHALL BE INERT MATERIALS ONLY, FREE OF ROOTS, STUMPS, WOOD, RUBBISH, AND OTHER DEBRIS. 12. BORROW OR WASTE AREAS ARE TO BE RECLAIMED WITHIN 7 DAYS OF COMPLETION PER ZONING ORDINANCE SECTION 5.1.28. 13. ALL INERT MATERIALS SHALL BE TRANSPORTED IN COMPLIANCE WITH SECTION 13-301 OF THE CODE OF ALBEMARLE. 14. BORROW, FILL OR WASTE ACTIVITY INVOLVING INDUSTRIAL -TYPE POWER EQUIPMENT SHALL BE LIMITED TO THE HOURS OF 7:OOAM TO 9:OOPM. 15. BORROW, FILL OR WASTE ACTIVITY SHALL BE CONDUCTED IN A SAFE MANNER THAN MAINTAINS LATERAL SUPPORT, OR ORDER TO MINIMIZE ANY HAZARD TO PERSONS, PHYSICAL DAMAGE TO ADJACENT LAND AND IMPROVEMENTS, AND DAMAGE TO ANY PUBLIC STREET BECAUSE OF SLIDES, SINKING, OR COLLAPSE. 16. THE DEVELOPER SHALL RESERVE THE RIGHT TO INSTALL, MAINTAIN, REMOVE OR CONVERT TO PERMANENT STORMWATER MANAGEMENT FACILITIES WHERE APPLICABLE ALL EROSION CONTROL MEASURES REQUIRED BY THIS PLAN REGARDLESS OF THE SALE OF ANY LOT, UNIT, BUILDING OR OTHER PORTION OF THE PROPERTY. 17. TEMPORARY STABILIZATION SHALL BE TEMPORARY SEEDING AND MULCHING. SEEDING IS TO BE AT 75 LBS/ACRE, AND IN THE MONTHS OF SEPTEMBER TO FEBRUARY TO CONSIST A 50/50 MIX OF ANNUAL RYEGRASS AND CEREAL WINTER RYE, OR IN MARCH AND APRIL TO CONSIST OF ANNUAL RYE, OR MAY THROUGH AUGUST TO CONSIST OF GERMAN MILLET. STRAW MULCH IS TO BE APPLIED AT 80LBS/100SF. ALTERNATIVES ARE SUBJECT TO APPROVED BY THE COUNTY EROSION CONTROL INSPECTOR. 18. PERMANENT STABILIZATION SHALL BE LIME AND FERTILIZER, PERMANENT SEEDING, AND MULCH. AGRICULTURAL GRADE LIMESTONE SHALL BE APPLIED AT 90LBS/1000SF, INCORPORATED INTO THE TOP 4-6 INCHES OF SOIL. FERTILIZER SHALL BE APPLIED AT 1000LBS/ACRE AND CONSIST OF A 10-20-10 NUTRIENT MIX. PERMANENT SEEDING SHALL BE APPLIED AT 180LBS/ACRE AND CONSIST OF 95% KENTUCKY 31 OR TALL FESCUE AND 0-5% PERENNIAL RYEGRASS OR KENTUCKY BLUEGRASS. STRAW MULCH IS TO BE APPLIED AT 80LBS/100SF. ALTERNATIVES ARE SUBJECT TO APPROVED BY THE COUNTY EROSION CONTROL INSPECTOR. 19. MAINTENANCE: ALL MEASURES ARE TO BE INSPECTED WEEKLY AND AFTER EACH RAINFALL. ANY DAMAGE OR CLOGGING TO STRUCTURAL MEASURES IS TO BE REPAIRED IMMEDIATELY. SILT TRAPS ARE TO BE CLEANED WHEN 50% OF THE WET STORAGE VOLUME IS FILLED WITH SEDIMENT. ALL SEEDED AREAS ARE TO BE RESEEDED WHEN NECESSARY TO ACHIEVE A GOOD STAND OF GRASS. SILT FENCE AND DIVERSION DIKES WHICH ARE COLLECTING SEDIMENT TO HALF THEIR HEIGHT MUST BE CLEANED AND REPAIRED IMMEDIATELY. 20. ALL TEMPORARY EROSION AND SEDIMENT CONTROL MEASURES ARE TO BE REMOVED WITHIN 30 DAYS OF FINAL SITE STABILIZATION, WHEN MEASURES ARE NO LONGER NEEDED, SUBJECT TO APPROVAL BY THE COUNTY EROSION CONTROL INSPECTOR. 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. 4. SHOP DRAWINGS AND SUBMITTALS SHALL BE REQUIRED FOR ALL STRUCTURES AND MATERIALS. IMBRICATED BOULDER ROCK SPECIFICATIONS 1. MATERIALS A. ROCK SHALL CONSIST OF ANGULAR FLAT ROCK OF APPROPRIATE COLOR (E.G., GREEN/GRAY, BROWN/GRAY, DARK GRAY, AND/OR DARK BROWN IN COLOR) OBTAINED FROM AN APPROVED SOURCE. ROCK SHALL NOT BE HARVESTED FROM STREAMS OR RIVERS OUTSIDE A COMMERCIAL QUARRY OPERATION. ALL ROCK SHALL BE FREE FROM LAMINATIONS, WEAK CLEAVAGES AND SHALL NOT DISINTEGRATE FROM THE ACTION OF AIR, SALT, WATER, AND IN HANDLING AND PLACING. GRANULAR SEDIMENTARY ROCK SHALL GENERALLY BE UNACCEPTABLE. CONCRETE SHALL NOT BE CONSIDERED AS AN ALTERNATIVE FOR ROCK. WHITE ROCK IS NOT ACCEPTABLE. B. ROCK SIZES SHALL BE AS SPECIFIED IN THE CONTRACT DOCUMENTS. ROCK SIZES ARE SHOWN IN THE CONSTRUCTION PLAN. NO PORTION OF THE ROCKS SHALL BE LESS THAN THE SPECIFIED MINIMUM AXIAL DIMENSIONS. THE ROCK SHALL HAVE A MINIMUM UNIT WEIGHT OF 160 LBS. PER CUBIC FOOT. C. CONTRACTOR SHALL OBTAIN FROM THE QUARRY AND SUBMIT TO THE OWNER A CERTIFICATE VERIFYING THE FOLLOWING: 1. ROCK CLASSIFICATION. 2. WEIGHT PER CUBIC FOOT. 3. WEIGHT OF ROCK BEING SUPPLIED. 4. ROCK QUALITY SHALL MEET ALL OF THE ABOVE SPECIFICATIONS. D. SAMPLES SHALL BE DELIVERED TO PROJECT SITE FOR APPROVAL BY THE OWNER, PRIOR TO ITS USE IN THE PROJECT. ANY UNSUITABLE MATERIAL OR ROCK WHICH DOES NOT MEET THE ABOVE SPECIFIED AXIAL DIMENSIONS SHALL BE REMOVED AT THE CONTRACTOR'S EXPENSE. E. FOOTER ROCK - FOOTER ROCK SHALL MEET THE SPECIFICATIONS FOR'ROCK' CONTAINED IN THE CONTRACT DOCUMENTS AND IN SECTION 12. FOOTER ROCK CONSISTS OF ROCK PLACED BELOW THE INVERT OF THE PROPOSED CHANNEL TO PROVIDE SUPPORT FOR THE TOP ROCK AND PREVENT DOWNSTREAM SCOUR. F. TOP ROCK - TOP ROCK SHALL MEET THE SPECIFICATIONS FOR'ROCK' CONTAINED IN THE CONTRACT DOCUMENTS AND IN SECTION 12. TOP ROCK CONSISTS OF ROCK PLACED UPON THE FOOTER ROCK. G. SILL ROCK - SILL ROCK SHALL MEET THE SPECIFICATIONS FOR'ROCK' CONTAINED IN THE CONTRACT DOCUMENTS AND IN SECTION 12. SILL ROCK CONSISTS OF A SINGLE ROW OF ROCK SET AT GRADE AT THE ENDS OF THE STRUCTURE ARMS PERPENDICULAR INTO THE STREAM BANKS. H. SPLASH ROCK - SPLASH ROCK SHALL MEET THE SPECIFICATIONS FOR 'SPLASH ROCK' CONTAINED IN THE CONTRACT DOCUMENTS AND WITHIN THESE SPECIFICATIONS. SPLASH ROCKS CONSIST OF A SINGLE ROW OF ROCKS PLACED ALONG THE BOTTOM OF A POOL FEATURE AND/OR GLIDE FEATURE, AND UP THE STREAMBANKS, AS SHOWN ON THE CONSTRUCTION PLAN. L-2 DROP STRUCTURE SPECIFICATIONS 1. INSTALLATION A. CONTRACTOR SHALL INSTALL THE STRUCTURES AS DESCRIBED IN THE STAKEOUT LOCATION COORDINATES AND ELEVATIONS SPECIFIED IN THE CONTRACT DOCUMENTS, AND AS DIRECTED BY THE OWNER. TOP ROCKS SHALL BE SET SO THAT THE COORDINATES AND ELEVATIONS PROVIDED IN THE CONTRACT DOCUMENTS ARE LOCATED AT THE DOWNSTREAM TOP EDGE OF THE TOP ROCK. B. THE FOOTER ROCKS SHALL BE INSTALLED BY EXCAVATING A TRENCH TO ACCOMMODATE BOTH THE FOOTER ROCKS AND A 2-FOOT AREA UPSTREAM. ALL FOOTER ROCK FOUNDATION SOILS SHALL BE ON IN SITU SOILS OR, IF SPECIFICALLY APPROVED BY THE OWNER ON A CASE BY CASE BASIS, ON SOILS COMPACTED TO 95% STANDARD PROCTOR DENSITY. IN THE EVENT THAT BEDROCK IS PRESENT IN THE AREA OF INSTALLATION, FOOTER ROCK SHALL STILL BE REQUIRED UNLESS APPROVAL FOR ELIMINATION OF FOOTER ROCK IS OBTAINED FROM THE THE OWNER. FOR EXAMPLE, WHERE BEDROCK IS FRIABLE AND WEATHERED AND CAN BE TRENCHED, FOOTER ROCK WILL BE REQUIRED. IN AREAS WHERE BEDROCK IS RESISTANT AND BLASTING WOULD BE REQUIRED, THE THE OWNER SHALL DETERMINE WHETHER OR NOT TO ELIMINATE FOOTER ROCK. C. NON -WOVEN GEOTEXTILE FABRIC SHALL BE PLACED IN THE BOTTOM AND UPSTREAM SIDE OF THE TRENCH ACROSS THE ENTIRE STRUCTURE. FOOTER ROCKS SHALL BE PLACED AT THE BOTTOM AND DOWNSTREAM SIDE OF THE TRENCH SO THAT A MINIMUM OF 1-FOOT OF NON -WOVEN GEOTEXTILE FABRIC LIES UNDER THE ROCK. THE ROCKS SHALL ABUT ONE ANOTHER. THE TOP ELEVATION OF THE FOOTER ROCK PLACED AT THE CENTERLINE OF THE STREAM SHALL BE FLUSH WITH THE PROPOSED STREAM GRADE IMMEDIATELY BELOW THE STEP STRUCTURE. FOOTER ROCKS SHALL BE FIRMLY EMBEDDED INTO THE TRENCH BOTTOM. D. IN THE EVENT WHERE INSTALLATION OF THE DROP STRUCTURE MAY DAMAGE TREE ROOTS, EXCAVATION SHALL BE MINIMIZED, ONLY UPON NOTIFICATION OF, AND APPROVAL BY THE OWNER. THIS MAY INCLUDE REDUCING THE LENGTH OF THE FOOTER ROCK PLACEMENT OR ELIMINATING TRENCHING FOR FOOTER ROCKS. ALTERNATIVELY, THE TREE MAY BE REMOVED, AND THE ROCK CROSS VANE STRUCTURE INSTALLED ACCORDING TO THE CONTRACT DOCUMENTS. THIS DECISION SHALL BE FIELD DETERMINED BY THE OWNER. ANY DEVIATION FROM THE CONTRACT DOCUMENTS MUST BE AUTHORIZED BY THE OWNER. E. THE CONTRACTOR MUST RECEIVE APPROVAL OF ALL FOOTER ROCK PLACEMENT AND ELEVATION BY THE OWNER PRIOR TO PLACEMENT OF TOP ROCKS. TOP ROCKS SHALL BE PLACED SO THAT THEY LEAN ON THE FOOTER ROCKS AND FIT TIGHTLY AGAINST EACH OTHER. WITH FOOTER ROCKS EXTENDING AS LEAST 12" FURTHER DOWNSTREAM THAN HEADER ROCKS. THE SEAMS BETWEEN TOP ROCKS SHALL NOT LINE UP WITH THE SEAMS BETWEEN THE FOOTER ROCKS. TOP ROCK ELEVATIONS AND LOCATIONS SHALL BE SET ACCORDING TO THE STRUCTURE STAKEOUT TABLES, STRUCTURE POINTS, NORTHINGS, EASTINGS, AND ELEVATIONS, AND WITHIN THE VERTICAL AND HORIZONTAL TOLERANCES SPECIFIED IN THE CONTRACT DOCUMENTS. CONTRACTOR SHALL INSTALL THE STRUCTURES AS DESCRIBED IN THE STAKEOUT LOCATIONS AND ELEVATIONS SPECIFIED IN THE CONTRACT DOCUMENTS, AND AS DIRECTED BY THE OWNER. TOP ROCKS SHALL BE SET SO THAT THE COORDINATES AND ELEVATIONS PROVIDED IN THE CONTRACT DOCUMENTS ARE LOCATED AT THE DOWNSTREAM CORNER OF THE TOP AND DOWNSTREAM FACE OF THE TOP ROCK. F. THE OUTERMOST TOP ROCKS ON EACH END OF THE CROSS VANE SHALL BE INSTALLED WITH AT LEAST ONE TOP ROCK BURIED INTO THE STREAM BANK. THE TRENCH BEHIND THE TOP ROCKS SHALL BE BACKFILLED WITH MATERIAL AS SHOWN ON THE PLANS. G. THE TRENCH BEHIND THE TOP ROCKS SHALL BE BACKFILLED WITH MATERIAL AS SHOWN ON THE PLANS WITH THE NON -WOVEN GEOTEXTILE FABRIC BETWEEN THE REINFORCED STREAM BED MATERIAL AND TOP ROCKS. THE NON -WOVEN GEOTEXTILE FABRIC SHALL BE LEFT SO THAT IT IS VISIBLE ABOVE THE TOP ROCKS UNTIL THE ROCKS AND SURFACE BACKFILL MATERIAL SPECIFIED ON THE PLANS HAVE BEEN INSTALLED AND INSPECTED. AFTER INSPECTION AND APPROVAL, TRIM GEOTEXTILE FLUSH WITH FINISHED GRADE. H. SILL ROCK CONSISTS OF A SINGLE ROW OF ROCK, UNDERLAIN BY NON -WOVEN GEOTEXTILE FABRIC, BEGINNING AT THE ENDS OF THE CREST ELEVATION, EXTENDING INTO THE CHANNEL SIDE SLOPES AS NOTED ON THE PLAN SHEETS OR DIRECTED BY THE OWNER. THEY SHALL BE ALIGNED AND EMBEDDED TO THE LIMITS SHOWN ON THE PLANS. EACH ROCK SHALL ABUT TIGHTLY AGAINST EACH OTHER WITH TOPS SET AT PROPOSED GRADE, AND SHALL BE PLACED FOR THE LENGTH SHOWN ON THE GRADING PLAN. ANY DEVIATION TO PROPOSED SILL DIMENSIONS NECESSARY FOR AVOIDANCE OF TREE ROOTS SHALL BE DOCUMENTED IN WRITING AND APPROVED BY THE OWNER AND THE ENGINEER PRIOR TO COMPLETION OF THE RESPECTIVE STRUCTURE INSTALLATION. I. AFTER INSPECTION, TRIM THE GEOTEXTILE FLUSH TO ENSURE NONE IS VISIBLE FROM THE FINISHED SURFACE. HIGH FLOW BYPASS SPECIFICATIONS 1. INSTALLATION A. HIGH FLOW DIVERSION STRUCTURES SHALL BE CONSTRUCTED PERPENDICULAR TO THE CHANNEL ALONG THE ALIGNMENT SHOWN AND ACROSS THE ENTIRE WIDTH AS SHOWN ON THE PLANS, INCLUDING OVER -EXCAVATION BEYOND CHANNEL FLOOR AS SHOWN ON THE PLANS. B. THE ROCKS SHALL BE INSTALLED BY EXCAVATING A TRENCH TO ACCOMMODATE THE ROCK MATERIAL. AS REQUIRED, THE TRENCH SHALL BE EXCAVATED TO ACCOMMODATE THE FOOTER ROCKS (REFER TO DETAILS). THE FOOTER ROCKS SHALL BE INSTALLED BY EXCAVATING A TRENCH TO ACCOMMODATE BOTH THE FOOTER ROCKS AND A 2-FOOT AREA UPSTREAM. ALL FOOTER ROCK FOUNDATION SOILS SHALL BE ON IN SITU SOILS OR, IF SPECIFICALLY APPROVED BY GER ON A CASE BY CASE BASIS, ON SOILS COMPACTED TO 95% STANDARD PROCTOR DENSITY. C. IF BEDROCK IS PRESENT AT THE CHANNEL INVERT OR IN THE EXCAVATED TRENCH, HEADER ROCK OR FOOTER ROCKS SHALL STILL BE REQUIRED UNLESS APPROVAL FOR ELIMINATION IS OBTAINED FROM THE OWNER. FOR EXAMPLE, WHERE BEDROCK IS FRIABLE AND WEATHERED AND CAN BE TRENCHED, FOOTER ROCK WILL BE REQUIRED. IN AREAS WHERE BEDROCK IS RESISTANT AND BLASTING WOULD BE REQUIRED, THE OWNER SHALL DETERMINE WHETHER OR NOT TO ELIMINATE FOOTER ROCK. D. NON -WOVEN GEOTEXTILE FABRIC SHALL BE PLACED IN THE BOTTOM AND UPSTREAM SIDE OF THE TRENCH TO THE WIDTH AS SHOWN ON DETAIL. FOOTER ROCKS SHALL BE PLACED AT THE BOTTOM AND DOWNSTREAM SIDE OF THE TRENCH SO THAT A MINIMUM OF 1-FOOT OF NON -WOVEN GEOTEXTILE FABRIC LIES UNDER THE ROCK SILL. FOOTER ROCKS SHALL BE PLACED AT THE BOTTOM AND DOWNSTREAM SIDE OF THE TRENCH AND SHALL ABUT ONE ANOTHER. THE TOP ELEVATION OF THE FOOTER ROCK PLACED AT THE CENTERLINE OF THE STREAM SHALL BE BELOW THE PROPOSED STREAM GRADE IMMEDIATELY ABOVE AND BELOW THE STRUCTURE. FOOTER ROCKS SHALL BE FIRMLY EMBEDDED INTO THE TRENCH BOTTOM. THE TRENCH BEHIND THE FOOTER ROCKS SHALL BE BACKFILLED WITH STREAM BED MATERIAL TO THE HEIGHT OF THE FOOTER ROCK, WITH THE GEOTEXTILE BETWEEN THE FOOTER ROCK AND BED MATERIAL SPECIFIED ON THE PLANS. E. IN THE EVENT WHERE INSTALLATION OF THE ROCK SILL STRUCTURE MAY DAMAGE TREE ROOTS, EXCAVATION SHALL BE MINIMIZED. THIS MAY INCLUDE REDUCING THE WIDTH OF THE STRUCTURE. THIS DECISION SHALL BE FIELD DETERMINED AND AUTHORIZED BY THE OWNER AND DOCUMENTED IN WRITING FOR APPROVAL BY ENGINEER PRIOR TO COMPLETION OF THE STRUCTURE INSTALLATION. F. HEADER ROCKS SHALL BE PLACED DIRECTLY ON TOP OF PREPARED SUBGRADE AND FIT TIGHTLY AGAINST EACH OTHER. THE TOP ELEVATION OF THE SILL ROCK PLACED AT THE CENTERLINE OF THE STREAM SHALL BE FLUSH WITH THE PROPOSED STREAM GRADE IMMEDIATELY. G. THE TRENCH BEHIND THE HEADER ROCKS SHALL BE BACK -FILLED WITH COMPACTED STRUCTURAL FILL MATERIAL (COMPACTION SPECIFICATIONS SUCH AS 95% STANDARD PROCTOR DO NOT APPLY FOR INSTALLATION OF ROCK EXCEPT FOOTER ROCK AS NOTED). THEN REINFORCED STREAM BED MATERIAL WITH THE NON -WOVEN GEOTEXTILE FABRIC BETWEEN THE STREAM BED MATERIAL AND HEADER ROCKS. THE NON -WOVEN GEOTEXTILE FABRIC SHALL BE KEYED IN A MINIMUM OF 1 FT BELOW THE SILL ROCK OR CUT A MINIMUM OF SIX INCHES BELOW THE SILL ROCK, BEFORE INSTALLING THE STREAM BED MATERIAL TO THE PROPOSED GRADE. STREAM BED MATERIAL SHALL BE PLACED A MINIMUM OF 2 FEET UPSTREAM OF THE SILL ROCKS. THE STREAM BED MATERIAL SHALL BE PLACED TO THE PROPOSED INVERT ELEVATION SHOWN IN THE CONTRACT DOCUMENTS. H. GRADE STREAM BANKS TO FINAL GRADE AS SHOWN ON THE GRADING PLANS. FOR CROSS SECTION DIMENSIONS, REFER TO THE GRADING PLAN AND TYPICAL CROSS SECTIONS. RETENTION BASIN MAINTENANCE PLAN FIRST YEAR MAINTENANCE OPERATIONS: SUCCESSFUL ESTABLISHMENT OF RETENTION BASINS REQUIRES THAT THE FOLLOWING TASKS BE UNDERTAKEN DURING THE FIRST YEAR FOLLOWING CONSTRUCTION. INITIAL INSPECTIONS. FOR THE FIRST SIX MONTHS FOLLOWING CONSTRUCTION, THE SITE SHOULD BE INSPECTED AT LEAST TWICE AFTER STORM EVENTS THAT EXCEED A 1/2-INCH OF RAINFALL. PLANTING OF AQUATIC BENCHES. THE AQUATIC BENCHES SHOULD BE PLANTED WITH EMERGENT WETLAND SPECIES, FOLLOWING THE PLANTING RECOMMENDATIONS CONTAINED IN STORMWATER DESIGN SPECIFICATION NO. 13 (CONSTRUCTED WETLANDS). SPOT RESEEDING. INSPECTORS SHOULD LOOK FOR BARE OR ERODING AREAS IN THE CONTRIBUTING DRAINAGE AREA OR AROUND THE POND BUFFER, AND MAKE SURE THEY ARE IMMEDIATELY STABILIZED WITH GRASS COVER. WATERING. TREES PLANTED IN THE POND BUFFER NEED TO BE WATERED DURING THE FIRST GROWING SEASON. IN GENERAL, CONSIDER WATERING EVERY 3 DAYS FOR FIRST MONTH, AND THEN WEEKLY DURING THE REMAINDER OF THE FIRST GROWING SEASON (APRIL - OCTOBER), DEPENDING ON RAINFALL. INSPECTIONS AND ONGOING MAINTENANCE TASKS MAINTENANCE OF A RETENTION BASIN IS DRIVEN BY ANNUAL INSPECTIONS THAT EVALUATE THE CONDITION AND PERFORMANCE OF THE POND, INCLUDING THE FOLLOWING: 1. MEASURE SEDIMENT ACCUMULATION LEVELS IN THE FOREBAY. 2. MONITOR THE GROWTH OF WETLAND PLANTS, TREES AND SHRUBS PLANTED. RECORD THE SPECIES AND THEIR APPROXIMATE COVERAGE, AND NOTE THE PRESENCE OF ANY INVASIVE PLANT SPECIES. 3. INSPECT THE CONDITION OF STORMWATER INLETS TO THE POND FOR MATERIAL DAMAGE, EROSION OR UNDERCUTTING. 4. INSPECT THE 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 THE POND OUTFALL CHANNEL FOR EROSION, UNDERCUTTING, RIP -RAP DISPLACEMENT, WOODY GROWTH, ETC. 6. INSPECT THE CONDITION OF THE PRINCIPAL SPILLWAY AND RISER FOR EVIDENCE OF SPALLING, JOINT FAILURE, LEAKAGE, CORROSION, ETC. 7. INSPECT THE CONDITION OF ALL TRASH RACKS, REVERSE -SLOPED PIPES, OR FLASHBOARD RISERS FOR EVIDENCE OF CLOGGING, LEAKAGE, DEBRIS ACCUMULATION, ETC. 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 POND FOR EVIDENCE OF SPARSE VEGETATIVE COVER, EROSION, OR SLUMPING, AND MAKE NEEDED REPAIRS IMMEDIATELY. BASIC MAINTENANCE TASKS AND FREQUENCY MAINTENACE ITEMS FREQUENCY • REMOVE DEBRIS AND BLOCKAGES QUARTERLY OR AFTER MAJOR STORMS • REPAIR UNDERCUT, ERODED, AND BARE (>1 INCH OF RAINFALL) SOIL AREAS • MOWING TWICE A YEAR • SHORELINE CLEANUP TO REMOVE ANNUALLY TRASH, DEBRIS AND FLOATABLES • A FULL MAINTENANCE INSPECTION • OPEN UP THE RISER TO ACCESS AND TEST THE VALVES • REPAIR BROKEN MECHANICAL COMPONENTS, IF NEEDED • POND BUFFER AND AQUATIC BENCH ONE TIME - DURING THE SECOND YEAR REINFORCEMENT PLANTINGS FOLLOWING CONSTRUCTION • FOREBAY SEDIMENT REMOVAL EVERY 5 TO 7 YEARS • REPAIR PIPES, THE RISER AND FROM 5 TO 25 YEARS SPILLWAY, AS NEEDED SEDIMENT REMOVAL FREQUENT SEDIMENT REMOVAL FROM THE FOREBAY IS ESSENTIAL TO MAINTAIN THE FUNCTION AND PERFORMANCE OF A RETENTION BASIN. FOREBAY CLEANOUT SHOULD OCCUR APPROXIMATELY EVERY 5 TO 7 YEARS, OR WHEN INSPECTIONS INDICATE THAT 50% OF FOREBAY SEDIMENT STORAGE CAPACITY HAS BEEN FILLED. SEDIMENTS SHALL BE REMOVED FROM THE SITE AND BE DISPOSED OF IN ACCORDANCE WITH ALL APPLICABLE LAWS AND REGULATION. BIORETENTION MAINTENANCE PLAN FIRST YEAR MAINTENANCE OPERATIONS: SUCCESSFUL ESTABLISHMENT OF BIORETENTION AREAS REQUIRES THAT THE FOLLOWING TASKS BE UNDERTAKEN IN THE FIRST YEAR FOLLOWING INSTALLATION. 1. INITIAL INSPECTIONS. FOR THE FIRST 6 MONTHS FOLLOWING CONSTRUCTION, THE SITE SHOULD BE INSPECTED AT LEAST TWICE AFTER STORM EVENTS THAT EXCEED 1/2 INCH OF RAINFALL. 2. SPOT RESEEDING. INSPECTORS SHOULD LOOK FOR BARE OR ERODING AREAS IN THE CONTRIBUTING DRAINAGE AREA OR AROUND THE BIORETENTION AREA, AND MAKE SURE THEY ARE IMMEDIATELY STABILIZED WITH GRASS COVER. 3. FERTILIZATION. ONE-TIME, SPOT FERTILIZATION MAY BE NEEDED FOR INITIAL PLANTINGS. 4. WATERING. WATERING IS NEEDED ONCE A WEEK DURING THE FIRST 2 MONTHS, AND THEN AS NEEDED DURING FIRST GROWING SEASON (APRIL-OCTOBER), DEPENDING ON RAINFALL. 5. REMOVE AND REPLACE DEAD PLANTS. SINCE UP TO 10% OF THE PLANT STOCK MAY DIE OFF IN THE FIRST YEAR, CONSTRUCTION CONTRACTS SHOULD INCLUDE A CARE AND REPLACEMENT WARRANTY TO ENSURE THAT VEGETATION IS PROPERLY ESTABLISHED AND SURVIVES DURING THE FIRST GROWING SEASON FOLLOWING CONSTRUCTION. THE TYPICAL THRESHOLDS BELOW WHICH REPLACEMENT IS REQUIRED ARE 85% SURVIVAL OF PLANT MATERIAL AND 100% SURVIVAL OF TREES. MAINTENANCE INSPECTIONS: IT IS HIGHLY RECOMMENDED THAT A SPRING MAINTENANCE INSPECTION AND CLEANUP BE CONDUCTED AT EACH BIORETENTION AREA. THE FOLLOWING IS A LIST OF SOME OF THE KEY MAINTENANCE PROBLEMS TO LOOK FOR: 1. CHECK TO SEE IF 75% TO 90% COVER (MULCH PLUS VEGETATIVE COVER) HAS BEEN ACHIEVED IN THE BED, AND MEASURE THE DEPTH OF THE REMAINING MULCH. 2. CHECK FOR SEDIMENT BUILDUP AT CURB CUTS, GRAVEL DIAPHRAGMS OR PAVEMENT EDGES THAT PREVENTS FLOW FROM GETTING INTO THE BED, AND CHECK FOR OTHER SIGNS OF BYPASSING. 3. CHECK FOR ANY WINTER- OR SALT -KILLED VEGETATION, AND REPLACE IT WITH HARDIER SPECIES. 4. NOTE PRESENCE OF ACCUMULATED SAND, SEDIMENT AND TRASH IN THE PRE-TREATMENT CELL OR FILTER BEDS, AND REMOVE IT. 5. INSPECT BIORETENTION SIDE SLOPES AND GRASS FILTER STRIPS FOR EVIDENCE OF ANY RILL OR GULLY EROSION, AND REPAIR IT. 6. CHECK THE BIORETENTION BED FOR EVIDENCE OF MULCH FLOTATION, EXCESSIVE PONDING, DEAD PLANTS OR CONCENTRATED FLOWS, AND TAKE APPROPRIATE REMEDIAL ACTION. 7. CHECK INFLOW POINTS FOR CLOGGING, AND REMOVE ANY SEDIMENT. 8. LOOK FOR ANY BARE SOIL OR SEDIMENT SOURCES IN THE CONTRIBUTING DRAINAGE AREA, AND STABILIZE THEM IMMEDIATELY. 9. CHECK FOR CLOGGED OR SLOW -DRAINING SOIL MEDIA, A CRUST FORMED ON THE TOP LAYER, INAPPROPRIATE SOIL MEDIA, OR OTHER CAUSES OF INSUFFICIENT FILTERING TIME, AND RESTORE PROPER FILTRATION CHARACTERISTICS. ROUTINE AND NON -ROUTINE MAINTENANCE TASKS: MAINTENANCE OF BIORETENTION AREAS SHOULD BE INTEGRATED INTO ROUTINE LANDSCAPE MAINTENANCE TASKS. IF LANDSCAPING CONTRACTORS WILL BE EXPECTED TO PERFORM MAINTENANCE, THEIR CONTRACTS SHOULD CONTAIN SPECIFICS ON UNIQUE BIORETENTION LANDSCAPING NEEDS, SUCH AS MAINTAINING ELEVATION DIFFERENCES NEEDED FOR PONDING, PROPER MULCHING, SEDIMENT AND TRASH REMOVAL, AND LIMITED USE OF FERTILIZERS AND PESTICIDES. THE MOST COMMON NON -ROUTINE MAINTENANCE PROBLEM INVOLVES STANDING WATER. IF WATER REMAINS ON THE SURFACE FOR MORE THAN 48 HOURS AFTER A STORM, ADJUSTMENTS TO THE GRADING MAY BE NEEDED OR UNDERDRAIN REPAIRS MAY BE NEEDED. THE SURFACE OF THE FILTER BED SHOULD ALSO BE CHECKED FOR ACCUMULATED SEDIMENT OR A FINE CRUST THAT BUILDS UP AFTER THE FIRST SEVERAL STORM EVENTS. THERE ARE SEVERAL METHODS THAT CAN BE USED TO REHABILITATE THE FILTER (TRY THE EASIEST THINGS FIRST, AS LISTED BELOW): 1. OPEN THE UNDERDRAIN OBSERVATION WELL OR CLEANOUT AND POUR IN WATER TO VERIFY THAT THE UNDERDRAINS ARE FUNCTIONING AND NOT CLOGGED OR OTHERWISE IN NEED OF REPAIR. 2. REMOVE ACCUMULATED SEDIMENT AND TILL 2 TO 3 INCHES OF SAND INTO THE UPPER 8 TO 12 INCHES OF SOIL. 3. INSTALL SAND WICKS FROM 3 INCHES BELOW THE SURFACE TO THE UNDERDRAIN LAYER. SAND WICKS CAN BE INSTALLED BY EXCAVATING OR AUGERING (USING A TREE AUGER OR SIMILAR TOOL) DOWN TO THE GRAVEL STORAGE ZONE TO CREATE VERTICAL COLUMNS WHICH ARE THEN FILLED WITH A CLEAN OPENGRADED COARSE SAND MATERIAL (ASTM C-33 CONCRETE SAND OR SIMILAR APPROVED SAND MIX FOR BIORETENTION MEDIA). 4. REMOVE AND REPLACE SOME OR ALL OF THE SOIL MEDIA. I I I ♦ / / i 069 00 LLI 54LLI \ (o 1 / cea a ° eaa° a(ad C°adaO <aa.d 44 1 \, \ a VD (3) \ BN (1) \ \ \\ a a°n a as as ad ° aaap ° \ 1\ \\ \ a°an ° < °qa a °Aa \ VD (3) / a°n°°d ° ale �°d°°° adna \` \ \\ \ / QA (3) a aaa ° ° a °�° a °° ea ° °e a ea aaaa n ° Qa°ad-- -\� �` (1) `\ \� BN (5) \ \ \ (p a a a \ \ \ VC () aaa5 — 1 ° eaS ° ° a � as ° � V A a aQaQaa a VC (3) a°aa AN (3) 1 A V A / I I AC (1) \ T a°a°aaa °aaa° a°a �\ � / I I \ \ \ \ a°°aaaa ° a°eaaca VD (5)CV a ° 1 CIF (1) \ \ aaa° 1 1 Sc 4 as \ <° I \\ QA (3) \ 1 I \\ \\ \\ IV (3) LU \ CV (1) —�6 / / LLI w VP (9) \ \\ \ \\ \ VP (3) \ I PLANT SCHEDULE LEGEND QUANTITY BOTANICAL NAME COMMON NAME UPLAND MEADOW SEED MIX (0.96 AC.) 2% AGROSTIS HYEMALIS WINTER BENTGRASS 2% ANDROPOGON GERARDII BIG BLUESTEM 4% CHAMAECRISTA FASCICULATA PARTRIDGE PEA LANCELEAF COREOPSIS 2% COREOPSIS LANCEOLATA 15% ELYMUS VIRGINICUS VIRGINIA WILDRYE 1% EUPATORIUM COELESTINUM MISTFLOWER 2% LESPEDEZA VIRGINICA SLENDER BUSHCLOVER 2% LIATRIS SQUARROSA SCALY BLAZING STAR 10% PANICUM ANCEPS BEAKED PANICGRASS 2% PANICUM VIRGATUM SWITCHGRASS 3% PENSTEMON LAEVIGATUS APPALACHIAN BEARDTONGUE 2% RUDBECKIA HIRTA BLACKEYED SUSAN 33% SCHIZACHYRIUM SCOPARIUM LITTLE BLUESTEM 1% SOLIDAGO NEMORALIS GRAY GOLDENROD 10% SORGHASTRUM NUTANS INDIANGRASS 3% TRIDENS FLAVUS PURPLETOP DETENTION BASIN SEED MIX (0.23 AC.) 2% AGROSTIS PERENNANS AUTUMN BENTGRASS 25% CHASMANTHIUM LATIFOLIUM RIVER OATS 20% ELYMUS VIRGINICUS VIRGINIA WILD RYE 2% EUPATORIUM COELESTINUM HELENIUM AUTUMNALE MISTFLOWER FALL SNEEZEWEED 1% 1% HELENIUM FLEXUOSUM PURPLEHEAD SNEEZEWEED 3% JUNCUS EFFUSUS SOFT RUSH 2% JUNCUS TENUIS PATH RUSH 24% PANICUM ANCEPS BEAKED PANIC GRASS 20% PANICUM RIGIDULUM RED -TOP PANIC GRASS BIORETENTION PLANT PALETTE vvvvvvvvvv vvvvvvvvvvv vvvvvvvv 280 AGROSTIS PERENNANS AUTUMN BENTGRASS vvvvvvvvv vv°vvv°vvv°v`v°"vv vvvvvvvvvv 280 CHASMANTHIUM LATIFOLIUM RIVER OATS vvvvvvvvv vv°vvv°v`v°v°v°°`vv vvvvvvvvvv 280 ELYMUS VIRGINICUS VIRGINIA WILD RYE vvvvvvvvv 7v°vvv°vvv°vvv°v°v ° % vvvvvvvvvv vvvvvvvvv 7vvvvvvvvv°vvv°vvv ° %280 vvvvvvvvvv 280 EUPATORIUM COELESTINUM MISTFLOWER BUTTERFLY MILKWEED ASCLEPIAS TUBEROSA vvvvvvvvv vvvvvvvvvv vvvvvvvvv 280 AQUILEGIA CANADENSIS RED COLUMBINE vvvvvvvvvv vvvvvvvvv vvvvvvvvvv vvvAN vvv 280 RUDBECKIA FULGIDA ORANGE CONEFLOWER 3 ACER NEGUNDO ASH -LEAF MAPLE AC 3 AMELANCHIER CANADENSIS CANADIAN SERVICEBERRY Rnl A RFTUI A NIGRA RIVFR BIRCH _ — — — w IV 3 ILEX VERTICILLATA COMMON WINTERBERRY Sc 7 SAMBUCUS CANADENSIS BLACK ELDER VC 13 VACCINIUM CORYMBOSUM HIGHBUSH BLUEBERRY VD 16 VIBURNUM DENTATUM SOUTHERN ARROW -WOOD 111 BUFFER PLANT PALETTE 1 \ CF 1 CORNUS FLORIDA FLOWERING DOGWOOD QA 9 QUERCUS ALBA NORTHERN WHITE OAK N, CV 2 CHIONANTHUS VIRGINICUS WHITE FRINGETREE VP 26 VIBURNUM PRUNIFOLIUM SMOOTH BLACKHAW TEMPORARY STABILIZATION/SEASONAL NURSE CROP 666 \ 0 30 60 APPROXIMATE SCALE (FEET) 1. ANY PLANT SUBSTITUTIONS OR CHANGES MUST BE APPROVED BY THE COUNTY PRIOR TO INSTALLATION. REQUESTS FOR SUBSTITUTIONS OR CHANGES SHALL BE SUBMITTED IN WRITING TO FAIRFAX COUNTY. CONTRACTOR SHOULD ALLOW FAIRFAX COUNTY REVIEW TIME, AND CONTRACTOR SHOULD BE PROACTIVE WITH ALL REQUESTS, IF SUBSTITUTIONS ARE REQUESTED 2. THE CONTRACTOR SHALL BE RESPONSIBLE FOR LAYOUT OF ALL WORK COVERED UNDER THESE PLANS. 3. 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 SHALL BE REJECTED. 4. 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 1 STREET, N.W., SUITE 500, WASHINGTON, D.C. 20005. 5. ALL CONTAINER STOCK SHALL HAVE BEEN PROPAGATED IN A PLANTING NOTES CONTAINER LONG ENOUGH FOR THE ROOT SYSTEM TO HAVE DEVELOPED SUFFICIENTLY TO HOLD ITS SOIL. CONTAINER STOCK WITH POORLY DEVELOPED ROOT SYSTEMS SHALL NOT BE ACCEPTED. 6. PLANTS SHALL BE PREPARED FOR SHIPMENT IN A MANNER THAT SHALL NOT CAUSE DAMAGE TO THE BARK, BUDS, BRANCHES, STEMS, OR OVERALL SHAPE OF THE STOCK. CONTAINER GROWN PLANTS SHALL BE TRANSPORTED IN THE CONTAINERS IN WHICH THEY HAVE BEEN GROWN. 7. PLANTS NOT INSTALLED ON THE DAY OF ARRIVAL AT THE SITE SHALL BE STORED AND PROTECTED BY THE CONTRACTOR. OUTSIDE STORAGE AREAS SHALL 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. 8. NO SUBSTITUTIONS IN SIZE OR VARIETY OF PLANT MATERIAL SHALL OCCUR WITHOUT THE PRIOR APPROVAL OF THE ENGINEER OR LANDSCAPE ARCHITECT. 9. THE CONTRACTOR SHALL VERIFY ALL DIMENSIONS IN THE FIELD AND NOTIFY THE ENGINEER OR LANDSCAPE ARCHITECT OF ANY VARIANCE FROM PLAN. INDICATOR FAC FAC FACU FACU FACW FAC NI NI FAC FAC FACU FACU FACU NI FACU FACU FACU FACU FACW FAC FACW FAC FACW FAC FAC FACW FACU FACU FACW FAC UPL FAC FAC FAC FAC FACW FACW FAC FACW FAC FACU FACU FAC FACU LEGEND QUANTITY BOTANICAL NAME COMMON NAME SEEDING DATE 664 662 660 \ 100% SECALE CEREALE CEREAL RYE NOVEMBER 16 - JANUARY 31 100% LOLIUM MULTIFLORUM ANNUAL RYEGRASS FEBRUARY 1 - APRIL 30 100% UROCHLOA RAMOSA BROWN TOP MILLET MAY 1 - AUGUST 31 100% LOLIUM MULTIFLORUM ANNUAL RYEGRASS SEPTEMBER 1 - NOVEMBER 15 10. NO PLANTING SHALL OCCUR WHEN THE SOIL IS FROZEN. 11. THE CONTRACTOR IS RESPONSIBLE FOR VERIFYING THE LOCATION OF ANY UNDERGROUND AND ABOVEGROUND UTILITIES. ALL PLANTS SHALL BE OFFSET A MINIMUM OF 10 FEET FROM UTILITIES INCLUDING BUT NOT LIMITED TO SANITARY SEWER LINES, ELECTRICAL LINES, GAS LINES, OVERHEAD POWER LINES, AND FIBER OPTIC CABLE LINES. PLANTING SEQUENCE 1. HOLES FOR INDIVIDUAL PLANTINGS SHALL BE EXCAVATED TO PRODUCE VERTICAL SIDES AND FLAT BOTTOMS. ALL PLANTING HOLES SHALL HAVE ROUGHED, SCARIFIED SIDES AND BOTTOMS. 2. THE CONTRACTOR SHALL APPLY AGRIFORM FOREST STARTER TABLETS OR EQUIVALENT PRODUCT TO EACH PLANT AS PER MANUFACTURER'S DIRECTIONS ON LABEL AT TIME OF PLANTING. 3. CONTAINERIZED PLANTS SHALL BE SET IN THE PLANTING PIT AT THE PROPER DEPTH ON TAMPED SOIL. SOIL REMOVED FROM THE PLANTING PIT SHALL THEN BE FILLED AROUND THE ROOTS AND TAMPED. 4. THE CONTRACTOR SHALL RESTORE DISTURBED AREAS TO INDICATED FINAL GRADES IF DISTURBED BY THE INSTALLATION OF SHRUBS AND TREES. PROJECT MAINTENANCE AND WARRANTY 1. CONTRACTOR SHALL MAINTAIN INSTALLED WOODY PLANTS AND SEEDED AREAS WITHIN THE PROJECT LIMITS UNTIL FINAL ACCEPTANCE OF THE PROJECT BY THE ENGINEER. 2. THE CONTRACTOR SHALL NOT BE RESPONSIBLE FOR ANY DAMAGE AS A RESULT FROM HERBIVORY. 3. THE CONTRACTOR SHALL GUARANTEE 100% SURVIVAL FOR ALL PLANT MATERIAL AFTER THE FIRST COMPLETE GROWING SEASON, EXCEPT AS A RESULT FROM HERBIVORY. 4. THE CONTRACTOR SHALL PROVIDE WEED MAINTENANCE THROUGH THE FIRST GROWING SEASON WITH A MINIMUM OF THREE TREATMENTS OF AN APPROVED AQUATIC HERBICIDE WITHIN THE PLANTED AREA. 5. THE CONTRACTOR SHALL PROVIDE WATERING DURING THE FIRST GROWING PERIOD. 6. THE CONTRACTOR IS RESPONSIBLE FOR REMOVING ALL STAKES AND GUY WIRES USED TO SUPPORT TREES AFTER A PERIOD OF ONE YEAR. SPECIFICATION '40:1 SEED SEED SEED SEED SEED SEED SEED SEED SEED SEED SEED SEED SEED SEED SEED SEED SEED SEED SEED SEED SEED SEED SEED SEED SEED REMARKS SEED MIX SHALL BE APPLIED TO LOCATIONS SHOWN ON PLAN AT A RATE OF 20 LBS./AC. APPLY STRAW MULCH AT A RATE OF 2 TONS PER ACRE. SEED MIX SHALL BE APPLIED TO LOCATIONS SHOWN ON PLAN AT A RATE OF 20 LBS./AC. APPLY STRAW MULCH AT A RATE OF 2 TONS PER ACRE. #SP4 CONTAINER 1" CALIPER AND #3 CONTAINER MATERIAL SHALL BE LOCATED AS SHOWN. #SP4 CONTAINER MATERIAL SHALL BE PLANTED 18 INCHES ON CENTER IN GROUPS OF 15 OR MORE BY SPECIES. #SP4 CONTAINER #SP4 CONTAINER #SP4 CONTAINER #SP4 CONTAINER #SP4 CONTAINER #SP4 CONTAINER 1" CALIPER 1" CALIPER 1" CALIPER #3 CONTAINER #3 CONTAINER #3 CONTAINER #3 CONTAINER 3/4" CALIPER 1" CALIPER 1" CALIPER #3 CONTAINER SPECIFICATION SEED SEED SEED SEED LOCATE PLANTS AS SHOWN ON PLAN. REMARKS APPLY TO ALL DISTURBED AREAS OUTSIDE BIORETENTION BASINS IN ACCORDANCE WITH SEEDING DATES SHOWN. PLANTING DETAILS SEE SHEET 17. 'Y II Ql J. GLENN MUCKLEY Lie. No. 038970 �0 LEGEND PROJECT LIMITS ,.' EXISTING CONTOURS APPROXIMATE LOCATION OF 10000 0 EXISTING STREAM BUFFER PROPOSED GRADES PROPOSED STORM SEWER NETWORK 1 06/28/16 REVISED PER COUNTY AJT JGM JGM COMMENTS EV DATE DESCRIPTION DSN CHK APP PREPARED BY: FOR: TITLE: Stantec 5209 Center Street Williamsburg, VA 23188 PHONE: (757) 220-6869 FAX: (757) 229-4507 OLD TRAIL VILLAGE CROZET,VA S-3 BIORETENTION PLANTING PLAN DRAWN BY: DESIGNED BY: JMH JMH CHECKED BY: APPROVED BY: JGM JGM PROJECT NUMBER: SCALE: 203400430 AS SHOWN DATE: FILE PATH: 05/20/2016 U1203400430 SHEET: 16 LEGEND QUANTITY PLANT SCHEDULE BOTANICAL NAME COMMON NAME INDICATOR UPLAND MEADOW SEED MIX (1.61 AC.) SPECIFICATION REMARKS 2% AGROSTIS HYEMALIS WINTER BENTGRASS FAC SEED SEED SEED SEED SEED SEED SEED SEED SEED SEED SEED SEED SEED SEED SEED SEED SEED MIX SHALL BE APPLIED TO LOCATIONS SHOWN ON PLAN AT A RATE OF 20 LBS./AC. APPLY STRAW MULCH AT A RATE OF 2 TONS PER ACRE. 2% ANDROPOGON GERARDII BIG BLUESTEM FAC 4% 2% CHAMAECRISTA FASCICULATA COREOPSIS LANCEOLATA PARTRIDGE PEA LANCELEAF COREOPSIS FACU FACU 15% ELYMUS VIRGINICUS VIRGINIA WILDRYE FACW 1% EUPATORIUM COELESTINUM MISTFLOWER FAC 2% LESPEDEZA VIRGINICA SLENDER BUSHCLOVER NI 2% LIATRIS SQUARROSA SCALY BLAZING STAR NI 10% PANICUM ANCEPS BEAKED PANICGRASS FAC 2% PANICUM VIRGATUM SWITCHGRASS FAC 3% PENSTEMON LAEVIGATUS APPALACHIAN BEARDTONGUE FACU 2% RUDBECKIA HIRTA BLACKEYED SUSAN FACU 33% SCHIZACHYRIUM SCOPARIUM LITTLE BLUESTEM FACU 1% SOLIDAGO NEMORALIS GRAY GOLDENROD NI 10% SORGHASTRUM NUTANS INDIANGRASS FACU 3% TRIDENS FLAVUS PURPLETOP FACU DETENTION BASIN SEED MIX (0.35 AC.) 2% AGROSTIS PERENNANS AUTUMN BENTGRASS FACU SEED SEED MIX SHALL BE APPLIED TO LOCATIONS SHOWN ON PLAN AT A RATE OF 20 LBS./AC. APPLY STRAW MULCH AT A RATE OF 2 TONS PER ACRE. 25% CHASMANTHIUM LATIFOLIUM RIVER OATS FACU SEED 20%D ELYMUS VIRGINICUS VIRGINIA WILD RYE FACW SEED 2% EUPATORIUM COELESTINUM MISTFLOWER FAC SEED 1% HELENIUM AUTUMNALE FALL SNEEZEWEED FACW SEED 1% HELENIUM FLEXUOSUM PURPLEHEAD SNEEZEWEED FAC SEED 3% JUNCUS EFFUSUS SOFT RUSH FACW SEED 2% JUNCUS TENUIS PATH RUSH FAC FAC SEED SEED 24% PANICUM ANCEPS BEAKED PANIC GRASS 20% PANICUM RIGIDULUM RED -TOP PANIC GRASS FACW SEED BIORETENTION PLANT PALETTE °vvvvvvvvv°v°v°v°v ° vvvvvvvvvvvvvvvvvv ° vvvvvvvvv° vvvv vvvvvvvvvv vvvvvvvvv °vvvvvvvvv°v°v°v°v ° °vvvvvvvvv°v°v°v°v ° vvvvvvvvvv vvvvvvvvv vvvvvvvvv vvv°vvv°vvv°v°v°v °v vvvvvvvvv vvvvvvvvv v°v7vO v7vO vpva vav ° vvvvvvvvv vvvvvvvvv v°v°v°°°°�216 vvvvvvvvvvaaaANa3 216 AGROSTIS PERENNANS AUTUMN BENTGRASS FACU #SP4 CONTAINER 1" CALIPER AND #3 CONTAINER MATERIAL SHALL BE LOCATED AS SHOWN. #SP4 CONTAINER MATERIAL SHALL BE PLANTED 18 INCHES ON CENTER IN GROUPS OF 15 OR MORE BY SPECIES. 216 CHASMANTHIUM LATIFOLIUM RIVER OATS FACU #SP4 CONTAINER 216 ELYMUS VIRGINICUS VIRGINIA WILD RYE EUPATORIUM COELESTINUM MISTFLOWER FACW #SP4 CONTAINER 216 FAC UPL #SP4 CONTAINER #SP4 CONTAINER 216 ASCLEPIAS TUBEROSA BUTTERFLY MILKWEED 216 AQUILEGIA CANADENSIS RED COLUMBINE FAC #SP4 CONTAINER RUDBECKIA FULGIDA ORANGE CONEFLOWER FAC #SP4 CONTAINER ACER NEGUNDO ASH -LEAF MAPLE FAC 1" CALIPER AC 3 AMELANCHIER CANADENSIS CANADIAN SERVICEBERRY FAC 1" CALIPER BN 6 BETULA NIGRA RIVER BIRCH FACW 1" CALIPER IV 3 ILEX VERTICILLATA COMMON WINTERBERRY FACW #3 CONTAINER SC 7 SAMBUCUS CANADENSIS BLACK ELDER FAC #3 CONTAINER VC 12 VACCINIUM CORYMBOSUM HIGHBUSH BLUEBERRY FACW #3 CONTAINER VD 19 VIBURNUM DENTATUM SOUTHERN ARROW -WOOD FAC #3 CONTAINER BUFFER PLANT PALETTE CF 1 CORNUS FLORIDA FLOWERING DOGWOOD FACU 3/4" CALIPER LOCATE PLANTS AS SHOWN ON PLAN. QA 6 QUERCUS ALBA NORTHERN WHITE OAK FACU 1" CALIPER CV 4 CHIONANTHUS VIRGINICUS WHITE FRINGETREE FAC 1" CALIPER VP 17 VIBURNUM PRUNIFOLIUM SMOOTH BLACKHAW FACU #3 CONTAINER TEMPORARY STABILIZATION/SEASONAL NURSE CROP LEGEND QUANTITY BOTANICAL NAME SECALE CEREALE COMMON NAME SEEDING DATE NOVEMBER 16 - JANUARY 31 SPECIFICATION REMARKS APPLY TO ALL DISTURBED AREAS OUTSIDE BIORETENTION BASINS IN ACCORDANCE WITH SEEDING DATES SHOWN. 100% CEREAL RYE SEED 100% LOLIUM MULTIFLORUM ANNUAL RYEGRASS FEBRUARY 1 - APRIL 30 SEED 100% UROCHLOA RAMOSA BROWN TOP MILLET MAY 1 - AUGUST 31 SEED 100% LOLIUM MULTIFLORUM ANNUAL RYEGRASS SEPTEMBER 1 - NOVEMBER 15 SEED 15-18" 15-18„15-1O 00 0 #SP4 CONTAINER PLANTING NOTES 1. SEE PLANT SCHEDULE FOR SPACING REQUIREMENTS. 2. REMOVE CONTAINER GROWN PLANTS FROM THEIR CONTAINERS AND CUT ANY CIRCLING ROOTS. QUART PLANTING 3-4" SHREDDED HARDWOOD MULCHTHROUGHOUT PLANTING BED. DO NOT COVER ROOT FLARES. PLANTING SOIL CARIFIED EXISTING SUBSOIL NOT TO SCALE NOTES: 1. PLANT TOP OF ROOTBALL AT FINISH GRADE. 2. REMOVE BURLAP FROM TOP 1/2 OF BALL. REMOVE CONTAINER GROWN PLANTS FROM THEIR CONTAINERS AND CUT ANY CIRCLING ROOTS. SHRU 1.0' MIN. PLANTING SOIL SCARIFY SIDES OF PLANTING. PIT ROOTBALL TO REST ON \ \ COMPACTED EXISTING SUBSOIL TO PREVENT SETTLEMENT \/\\\ I X/l/l\ X//l\ X//l\ X//l NOT TO SCALE NOT TO SCALE #3 CONTAINER PLANTING STD. NO. REV. I / I / I / I / f / 1 / 1 / / I\ I I I I HOSE LINED GUY WIRE ROOT CROWN TO BE AT FINISH GRADE 4" HIGH / 6" WIDE MAXIMUM BERM OUTSIDE OF ROOTBALL 3 - 1"x2" HARDWOOD STAKES EQUALLY SPACED AROUND TREE NOTES: 1. REMOVE WIRE AND NYLON TWINE FROM BALL AND CANOPY. 2. SOAK ROOT BALL AND PLANT PIT IMMEDIATELY AFTER INSTALLATION. 3. STAKING IS REQUIRED FOR ALL TREES. REMOVE EXCESS SOIL FROM / SITE AND DISPOSE OF IN A LEGAL MANNER. / 4. HOSE LINED GUY WIRES SHALL NOT BE TIGHT AROUND TREE, BUT JUST SECURED TO SUFFICIENTLY STABILIZE TREE FROM LARGER MOVEMENTS. FINISH GRADE REMOVE TYPICAL EXCESS SOIL FROM ROOT CROWN \ REMOVE TOP 1/3 BURLAP BACKFILL AS SPECIFIED AND ANY NAILS/PINS, ETC. REMOVE TOP 1/3 OF WIRE BASKET WHERE PRESENT uN�s\/E\\ RAISE PIT BOTTOM TO SET ROOT ROOT BALL DIA. 12" CROWN AT THE CORRECT HEIGHT. FIRM SOIL UNDER ROOT BALL. VARIES 3/4"-l" CALIPER TREE PLANTING NOT TO SCALE (FOR SINGLE AND MULTI -STEM TREES) STD. NO. QA (3) I `Q `9IQ \ 1 \ \ \ \ \ \ \ \ \ \ \ p��iZa � �•�' s LEGEND .' PROJECT LIMITS EXISTING CONTOURS 100 ,00 APPROXIMATE LOCATION OF _ EXISTING STREAM BUFFER PROPOSED GRADES PROPOSED STORM SEWER NETWORK PLANTING AND SEEDING NOTES SEE SHEET 16. \ I / \ \ 1 \ I ( \ ` \ \ c I c J \� L ��9 �10CID- 11 AC (1)' toco c9 i9 \ I Cr Lp VD (7)wr p I Da 1 BN (3) l I I 00 1 BN (3) ► / / I / t VC (5) ,' V(5) / / / / php D 650 648 646 CV 644 --- �/ i 642 ------ / 650`� \ — / 640 648 646 644 642 /� / // // // / / // --— — — — —__ --- \�---� — — — — —— -��y� �� \ 636 /� /� ,/ /% LTH 0/" --------------6�6------- , / — ,— AMIUFFER_ 632 ___ o _ C�- � 0 STRE _ — � � ------6 '� ____--___/ _ _ _--- 630 / L�- � � � /' J. GLENN MUCKLEY � 7 _ 62$ / 0 30 60--------- ---------632------'/ 626/ Lic. No. 038970 APPROXIMATE SCALE (FEET) - - -' - - - - - - - - - - _ - -- - - - - - - - - - - - - -/ // / / / / / / 25 / / / / / / / / / 2 6/' / / i i /G tome r�l / CF (1) o / AC (1) / QA / VP (5) o00 ov° ° vov v ovvvo ovvvo 000 I ° ° v°v v v aaa vv v vvvvvv v vo vvvv v °vvvvv a v aabv vbOvvv vv v °v vvav vavv v I vv vvq o v o vvvv v v ovo vvv v v,d v e vvaav vvo / vvvvv oa vovvvov v vv voa0rw 1 000 oa o0 vov vvvv vvv v °vvvvOO °vvvv v, vo ovvvo a aaaaa as vvvv vvv v �ooao vvvvvv av o v vvvvvv o/ o vv C9 _�99 \ ` / � J / / / / // / I // / Ir L9,\ \ G \ —/ —s_------- 644 \ — — ---- — 646_ __----—___---- 648 650 / — — 652 — 654 ` 658 660 _ _ _ _ / \\ �� —_—_ 662 ,P — 664 / 664 — — —— _ — 662 ----- ----- ----------- 660 p � ----" 658 r / ---- 654.5 - 654 652 /i I I� I / ; SN650 648 - \ \ \ \ I I 1 ttI 1 t IV (7) 1 VC (5) I I I �' M / /LU \ \ \ It \ tt \ I tt 11 I I r 5 VP ( ) IV (3) I I I i t \ \\ \ \ CV (3) It \ \ It \ \ \ \ \ \ 1 tt 1 I t ttt cyl i00 `\ \\\ \ �0N O i i 111 I III I I QA (5)co U \ I C I I I J I ul `1 coy) I o 3 \ \ i J_ I� \\ \ VP (7) \ O) \ \ 01 U, CJI Ui \ c,) \ \`t� OD IV VP(8) 011 �/ � 01) <9-It I I PLANT SCHEDULE LEGEND QUANTITY BOTANICAL NAME COMMON NAME AC.) INDICATOR FAC SPECIFICATION REMARKS UPLAND MEADOW SEED MIX (1.69 2% AGROSTIS HYEMALIS WINTER BENTGRASS SEED SEED MIX SHALL BE APPLIED TO LOCATIONS SHOWN ON PLAN AT A RATE OF 20 LBS./AC. APPLY STRAW MULCH AT A RATE OF 2 TONS PER ACRE. 2% ANDROPOGON GERARDII BIG BLUESTEM FAC SEED 4% CHAMAECRISTA FASCICULATA PARTRIDGE PEA FACU SEED 2% COREOPSIS LANCEOLATA LANCELEAF COREOPSIS FACU SEED 15% ELYMUS VIRGINICUS VIRGINIA WILDRYE FACW SEED 1% EUPATORIUM COELESTINUM MISTFLOWER FAC SEED 2% LESPEDEZA VIRGINICA SLENDER BUSHCLOVER NI SEED 2% LIATRIS SQUARROSA SCALY BLAZING STAR NI SEED 10% PANICUM ANCEPS BEAKED PANICGRASS FAC SEED 2% PANICUM VIRGATUM SWITCHGRASS FAC SEED 3% PENSTEMON LAEVIGATUS APPALACHIAN BEARDTONGUE FACU SEED 2% RUDBECKIA HIRTA BLACKEYED SUSAN FACU SEED 33% SCHIZACHYRIUM SCOPARIUM LITTLE BLUESTEM FACU SEED 1 % SOLIDAGO NEMORALIS GRAY GOLDENROD NI SEED 10% SORGHASTRUM NUTANS INDIANGRASS FACU SEED 3% TRIDENS FLAVUS PURPLETOP FACU SEED AQUATIC BENCH PLANT PALETTE (0.13 AC.) I —I —I —I —I —I —I —I —I— I —I —I —I —I— I —I —I —I —I I —I —I —I —I I I I I I —I —I —I —I— I I I I I —I —I —I —I —I —I —I —I— I —I —I —I —I— I —I —I —I —I 430 ALISMA SUBCORDATUM AMERICAN WATER -PLANTAIN OBL #SP4 CONTAINER #SP4 CONTAINER MATERIAL SHALL BE PLANTED 18 INCHES ON CENTER IN GROUPS OF 15 OR MORE BY SPECIES. LOCATE PLANTS ACCORDING TO INDICATOR STATUS. 430 CAREX VULPINOIDEA COMMON FOX SEDGE OBL #SP4 CONTAINER 430 LEERSIA ORYZOIDES RICE CUT GRASS OBL #SP4 CONTAINER 430 PELTANDRA VIRGINICA GREEN ARROW ARUM OBL #SP4 CONTAINER 430 SAURURUS CERNUUS LIZARD'S -TAIL OBL #SP4 CONTAINER 430 SCIRPUS CYPERINUS WOOLGRASS FACW #SP4 CONTAINER 430 SCHOENOPLECTUS PUNGENS THREE SQUARE OBL #SP4 CONTAINER VC IV 13 VACCINIUM CORYMBOSUM HIGHBUSH BLUEBERRY FACW #3 CONTAINER 18 ILEX VERTICILLATA COMMON WINTERBERRY BLACK WILLOW FACW #3 CONTAINER SN 6 SALIX NIGRA OBL 1" CALIPER BUFFER PLANT PALETTE QA 5 QUERCUS ALBA NORTHERN WHITE OAK FACU 1" CALIPER LOCATE PLANTS AS SHOWN ON PLAN. CV 6 CHIONANTHUS VIRGINICUS WHITE FRINGETREE FAC 1" CALIPER VP 20 VIBURNUM PRUNIFOLIUM SMOOTH BLACKHAW FACU #3 CONTAINER TEMPORARY STABILIZATION/SEASONAL NURSE CROP LEGEND QUANTITY BOTANICAL NAME COMMON NAME SEEDING DATE SPECIFICATION REMARKS 100% SECALE CEREALE CEREAL RYE NOVEMBER 16 - JANUARY 31 SEED APPLY TO ALL DISTURBED AREAS OUTSIDE BIORETENTION BASINS IN ACCORDANCE WITH SEEDING DATES SHOWN. 100% LOLIUM MULTIFLORUM ANNUAL RYEGRASS FEBRUARY 1 - APRIL 30 SEED 100% UROCHLOA RAMOSA BROWN TOP MILLET MAY 1 - AUGUST 31 SEED SEED 100% LOLIUM MULTIFLORUM ANNUAL RYEGRASS SEPTEMBER 1 - NOVEMBER 15 PLANTING AND SEEDING NOTES SEE SHEET 16. PLANTING DETAILS SEE SHEET 17. \ N OF Vv v v v v v vv v 670 rox \ \ / J. GLENN MUCKLEY Lic. No. 038970 \ \\ \ 0 30 60 APPROXIMATE SCALE (FEET) SSIONAL /It z FILEPATH:U: 203400430 05 report delis dwgs design cad 00430 plant plan 20160627.dwg atie enback Jun 28, 2016 at 9:05 Layout: L-2 PLANT-18 LEGEND PROJECT LIMITS ,.' EXISTING CONTOURS APPROXIMATE LOCATION OF 100,00 100 EXISTING STREAM BUFFER PROPOSED GRADES PROPOSED STORM SEWER NETWORK I1 06/28/16 I REVISED PER COUNTY COMMENTS AJT JGM JGM I REV DATE DESCRIPTION DSN I CHK APP PREPARED BY: Stantec 5209 Center Street Williamsburg, VA 23188 PHONE: (757) 220-6869 FAX: (757) 229-4507 FOR: TITLE: OLD TRAIL VILLAGE CROZET,VA L-2 RETENTION BASIN PLANTING PLANS DRAWN BY: DESIGNED BY: JMH JMH CHECKED BY: APPROVED BY: JGM JGM PROJECT NUMBER: SCALE: 203400430 AS SHOWN DATE: FILE PATH: 05/20/2016 U:/203400430 SHEET: 18 _ EX. TREELINE a aloft _ _ — �— 624 632 \ \� vv \ \ \ \ 83 i �� I � I — pBN (11 — / VC (7) 1 ' I� VD (5) / I 6' Off` / 6 / SC (3) _ 1b I / / AN (1) / h O IV (5) o jr / / / / / / avoaavaa aaa vv °O v° v000d 1 aaaaaia 1 / / VC 7 ¢y000voo vo ovobo ■ / a0000000 0 00I ■ \ / o vv°vBN v a vvv 000 VP 5 IV5 av a oaaa _ O Ova° Oa a / \ \ \ / I I/ avaaoa aaa aLaa ° aaaa a o . vov v.J vvvvv \ \ \ \ BN (1) \ / avvv vov / (Q 1 ( ) — - / vvav aaa aaa aaa / VP 3 / vovvvo 0 000 0 \ voov000 / \ � vov00000 v o / (0 n'O I \ \ ovP. IIov pvvvoovo v v0 `YOOOaa Oo000o00 va as dv-ayaR AC (1) / QA (3) 000 ovbvo vovov nova adaa a a IV avovvv VC (3) aaa/ \ \ avvaa 1 v v vvvoavaa vovvvo / aaaaaaaa SC (5) ■ \ o0 ovvaov o asyy,aaaa ' � / o0 00 ovgyovoo \ / o vo vvvo 000va vv ydvvov vvvo • \ VP (3 ) / / v°v°v o v v v v°o v o v ado 00 / ■ 0000o v o 0 — — � _ — \ \ / / vvvo 0 oovoo ov- / ■ vvo v vovvvo w`ov / / \ � ' boa v ovvoovvy- vo / \ ` — / , ,av o vovvvo%° v ` 'AN a ovv / o 000 1 \ _ \ vv \ \ \ \ \ \ \ 666 AC (3) CV (3) I 66 $ / 1 10 30 60 OXIM TE SCALD FEET) sers atie en ack\ap°data oca temp c u is p ant pan 201 6UUt.dwalatiefenbackWun 28. 2016 at 9:1211-avout: L-3 PLANT-19 PLANTING AND SEEDING NOTES SEE SHEET 16. PLANTING DETAILS SEE SHEET 17. PLANT SCHEDULE LEGEND QUANTITY BOTANICAL NAME COMMON NAME INDICATOR SPECIFICATION REMARKS UPLAND MEADOW SEED MIX (2.39 AC.) 2% AGROSTIS HYEMALIS WINTER BENTGRASS FAC SEED SEED MIX SHALL BE 2% ANDROPOGON GERARDII BIG BLUESTEM FAC SEED APPLIED TO LOCATIONS SHOWN ON PLAN AT A 4% CHAMAECRISTA FASCICULATA PARTRIDGE PEA FACU SEED RATE OF 20 LBS./AC. 2% COREOPSIS LANCEOLATA LANCELEAF COREOPSIS FACU SEED APPLY STRAW MULCH 15% ELYMUS VIRGINICUS VIRGINIA WILDRYE FACW SEED AT A RATE OF 2 TONS PER ACRE. 1% EUPATORIUM COELESTINUM MISTFLOWER FAC SEED 2% LESPEDEZA VIRGINICA SLENDER BUSHCLOVER NI SEED 2% LIATRIS SQUARROSA SCALY BLAZING STAR NI SEED 10% PANICUM ANCEPS BEAKED PANICGRASS FAC SEED 2% PANICUM VIRGATUM SWITCHGRASS FAC SEED 3% PENSTEMON LAEVIGATUS APPALACHIAN BEARDTONGUE FACU SEED 2% RUDBECKIA HIRTA BLACKEYED SUSAN FACU SEED 33% SCHIZACHYRIUM SCOPARIUM LITTLE BLUESTEM FACU SEED 1% SOLIDAGO NEMORALIS GRAY GOLDENROD NI SEED 10% SORGHASTRUM NUTANS INDIANGRASS FACU SEED 3% TRIDENS FLAVUS PURPLETOP FACU SEED DETENTION BASIN SEED MIX (0.29 AC.) 2% AGROSTIS PERENNANS AUTUMN BENTGRASS FACU SEED SEED MIX SHALL BE 25% CHASMANTHIUM LATIFOLIUM RIVER OATS FACU SEED APPLIED TO LOCATIONS SHOWN ON PLAN AT A 20% ELYMUS VIRGINICUS VIRGINIA WILD RYE FACW SEED RATE OF 20 LBS./AC. 2% EUPATORIUM COELESTINUM MISTFLOWER FAC SEED APPLY STRAW MULCH 1% HELENIUM AUTUMNALE FALL SNEEZEWEED FACW SEED AT A RATE OF 2 TONS 1% HELENIUM FLEXUOSUM PURPLEHEAD SNEEZEWEED FAC SEED PER ACRE. 3% JUNCUS EFFUSUS SOFT RUSH FACW SEED 2% JUNCUS TENUIS PATH RUSH FAC SEED 24% PANICUM ANCEPS BEAKED PANIC GRASS FAC SEED 20% PANICUM RIGIDULUM RED -TOP PANIC GRASS FACW SEED BIORETENTION PLANT PALETTE vvvvvvvvvv vvvvvvvvvv 326 AGROSTIS PERENNANS AUTUMN BENTGRASS FACU #SP4 CONTAINER 1" CALIPER AND #3 vvvvvvvvv vvvvvvvvvv 326 CHASMANTHIUM LATIFOLIUM RIVER OATS FACU #SP4 CONTAINER CONTAINER MATERIAL SHALL BE LOCATED AS vvvvvvvvv vvvvvvvvv vvvvvvvvvv 326 ELYMUS VIRGINICUS VIRGINIA WILD RYE FACW #SP4 CONTAINER SHOWN. #SP4 vvvvvvvvv vvvvvvvvvv 326 EUPATORIUM COELESTINUM MISTFLOWER FAC #SP4 CONTAINER CONTAINER MATERIAL SHALL BE PLANTED 18 vvvvvvvvv 326 ASCLEPIAS TUBEROSA BUTTERFLY MILKWEED UPL #SP4 CONTAINER INCHES ON CENTER IN vvvvvvvvv vvvvvvvvvv 326 AQUILEGIA CANADENSIS RED COLUMBINE FAC #SP4 CONTAINER GROUPS OF 15 OR MORE BY SPECIES. vvvvvvvvv 326 RUDBECKIA FULGIDA ORANGE CONEFLOWER FAC #SP4 CONTAINER AN4 ACER NEGUNDO ASH -LEAF MAPLE FAC 1" CALIPER AC 4 AMELANCHIER CANADENSIS CANADIAN SERVICEBERRY FAC 1" CALIPER BN 7 BETULA NIGRA RIVER BIRCH FACW 1" CALIPER IV 13 ILEX VERTICILLATA COMMON WINTERBERRY FACW #3 CONTAINER Sc 8 SAMBUCUS CANADENSIS BLACK ELDER FAC #3 CONTAINER VC 17 VACCINIUM CORYMBOSUM HIGHBUSH BLUEBERRY FACW #3 CONTAINER VD 10 VIBURNUM DENTATUM BUFFER PLANALETTE SOUTHERN ARROW -WOOD FAC #3 CONTAINER CV 6 CHIONANTHUS VIRGINICUS WHITE FRINGETREE FAC 1" CALIPER LOCATE PLANTS AS CF 1 CORNUS FLORIDA FLOWERING DOGWOOD FACU 3/4" CALIPER SHOWN ON PLAN. QA 4 QUERCUS ALBA NORTHERN WHITE OAK FACU 1" CALIPER VP 14 VIBURNUM PRUNIFOLIUM SMOOTH BLACKHAW FACU #3 CONTAINER TEMPORARY STABILIZATION/SEASONAL NURSE CROP LEGEND QUANTITY BOTANICAL NAME COMMON NAME SEEDING DATE SPECIFICATION REMARKS 100% SECALE CEREALE CEREAL RYE NOVEMBER 16 - JANUARY 31 SEED APPLY TO ALL DISTURBED AREAS o 100% LOLIUM MULTIFLORUM ANNUAL RYEGRASS FEBRUARY 1 - APRIL 30 SEED OUTSIDE BIORETENTION BASINS IN ACCORDANCE 100% UROCHLOA RAMOSA BROWN TOP MILLET MAY 1 -AUGUST 31 SEED WITH SEEDING DATES SHOWN. 100% LOLIUM MULTIFLORUM ANNUAL RYEGRASS SEPTEMBER 1 - NOVEMBER 15 SEED LEGEND PROJECT LIMITS ,.' EXISTING CONTOURS APPROXIMATE LOCATION OF EXISTING STREAM BUFFER PROPOSED GRADES PROPOSED STORM SEWER NETWORK 1 06/28/16 REVISED PER COUNTY AJT JGM JGM COMMENTS REV DATE DESCRIPTION DSN CHK APP PREPARED BY: Stantec 5209 Center Street Williamsburg, VA 23188 PHONE: (757) 220-6869 FAX: (757) 229-4507 FOR: OLD TRAIL VILLAGE CROZET,VA TITLE: L-3 BIORETENTION PLANTING PLAN DRAWN BY: DESIGNED BY: SALT H Op �r JMH JMH CHECKED BY: APPROVED BY: 4�C.'',/� �,� JGM JGM f PROJECT NUMBER: SCALE: J. GLENN MUCKLEY 203400430 ASSHOWN Lic. No. 038970 DATE: FILE PATH: 160 Co/�1 05/20/2016 U:/203400430 � SHEET: SSIUNAI, ��� 19 VSMP COMPLIANCE SUMMARY THE FOUR (4) BMP DESIGNS ARE IN GENERAL CONFORMANCE WITH THE SWM MASTER PLAN STRATEGY. THE BELOW SUMMARIZES KEY POINTS OF THE HOW THE FACILITIES MEET THE MASTER PLAN AND VSMP REQUIREMENTS. THE PROJECT IS TO BE DESIGN IN ACCORDANCE WITH PART IIC TECHNICAL CRITERIA UNDER THE VIRGINIA STORMWATER MANAGMENT PROGRAM (VSMP): 1.1. PER ALBEMARLE COUNTY (COUNTY) GUIDANCE LETTER OF AUGUST 6, 2015, PART IIC TECHNICAL CRITERIA SHALL APPLY TO OLD TRAIL FOR TWO PERMIT CYCLES, OR UNTIL 2024, PROVIDED CGP COVERAGE IS MAINTAINED. 1.1.1. FACILITIES HAVE BEEN DESIGNED IN ACCORDANCE WITH PART IIC TECHNICAL CRITERIA WITH SOME PRACTICAL ADVANCMENTS OVER THE VIRGINIA STORMWATER MANAGEMENT HANDBOOK, 1999 (BLUEBOOK). 1.2. A COMPREHENSIVE PROJECT -WIDE APPROACH TO WATER QUALITY CENTERING ON BIORETENTION FILTERS IN ACCORDANCE WITH REFINEMENTS TO THE GENERAL DEVELOPMENT PLAN (GDP) SHEET 3 PLAN. COMPLIANCE WITH PART IIC TECHNICAL CRITERIA IS TO BE ACHIEVED PRIMARILY THROUGH ON -SITE TREATMENT IN ORDER TO REDUCE TREATMENT BURDEN ON LICKINGHOLE REGIONAL BASIN (LRB). 1.2.1. ALL FACILITIES ARE IN KEEPING WITH THE TYPE AS DEFINED UNDER THE MASTER PLAN. REGARDING COMPLIANCE WITH 9VAC25-870-96: 2.1. OLD TRAIL VILLAGE FALLS UNDER SITUATION 2, WHICH REQUIRES THAT POLLUTANT DISCHARGE AFTER DISTURBANCE NOT EXCEED EXISTING POLLUTANT DISCHARGE. EXISTING 2.11 % IMPERVIOUS AREA (ZMA) YIELDS LOAD =37.32 LB (TP) PER YEAR. PART IIC APPLIES. PART IIC REQUIRES SWM DESIGN (VIA MASTER PLAN) LIMIT POST -DEVELOPED (DEVELOPMENT -WIDE) DISCHARGE TO THE AVERAGE WATERSHED (16%), OR 104.98 LB TP/YR. PROPOSED IMPERVIOUS AREA (AVE. FOR 237.35 AC.)=43.45%. PROPOSED POLLUTANT LOAD (43.45%)=238.66 LB TP/YR. MASTER PLAN DESIGN REMOVES 133.68 LB TP/YR, TO COMPLY WITH STATE STORMWATER PART IIC (WATER QUALITY) REQUIREMENTS. SEE TABLE 7, MASTER PLAN. 2.2. COMPLIANCE WITH THIS PROVISION WILL BE ACHIEVED THROUGH APPROPRIATE ON -SITE BMPS PER MASTER PLAN, OR APPROVED VARIATION. ACCEPTABLE METHODS TO MEET ALBEMARLE COUNTY GUIDANCE AND MEET VSMP COMPLIANCE REQUIRES OLD TRAIL VILLAGE TO CAPTURE: 2.2.1. BIORETENTION: 92%, OR 51.15, ACRES OF THE TOTAL MAXIMUM MASTER PLAN TARGET ACROSS THE PROJECT BY BIORETENTION FACILITIES (0.5 INCH, 50% EFFICIENCY) AS A MINIMUM. 2.2.1.1. NO DEVIATIONS FROM PROPOSED BIORETENTION FACILITIES ARE PROPOSED UNDER THIS PHASE. L-3, S-3, AND S-12 FACILITIES COLLECTIVELY EXCEED THE MINIMUM BIORETENTION AREA CAPTURE TARGET UNDER PROJECTIONS. 2.2.2. RETENTION BASINS: 100% OF TOTAL MAXIMUM MASTER PLAN TARGET, OR 92.58 ACRES ACROSS THE PROJECT TO RETENTION BASINS AS DEFINED HEREIN. 2.2.2.1. L-2 IS DESIGNED EFFECTIVELYAS PROPOSED UNDER THE MASTER PLAN CONCEPT. AS SUCH, NO VARIATION IS PROPOSED. BASED ON DRAINAGE AREA REFINEMENTS, THE PROPOSED TREATMENT AREA ACTUALLY EXCEEDS THE MASTER PLAN ESTIMATED AREA. AS SUCH, THE RETENTION BASIN TARGET IS PROJECTED WITH A CURRENT SURPLUS. 2.3. REMAINDER TREATMENT REQUIRED FOR VSMP COMPLIANCE WILL BE PROVIDED BY LRB UNDER A TREATMENT TRAIN APPROACH FOR BIORETENTION CAPTURE ONLY. ALTERNATE METHODOLOGY FROM MASTER PLAN REQUIRES ALBEMARLE COUNTY APPROVAL. 2.3.1. NO VARIATION IS PROPOSED FROM MASTER PLAN. 2.4. AS LONG AS APPROVED PLANS MEET OVERALL MINIMUM TOTAL AREA CAPTURE NOTED UNDER MASTER PLAN, THE PROJECT SHALL BE DEEMED TO REMAIN IN COMPLIANCE BY ALBEMARLE COUNTY TO THE MASTER PLAN, COUNTY GUIDANCE, AND VSMP WATER QUALITY REQUIREMENTS. 2.4.1. CURRENTLY, THE PROJECT IS SHOWING A NET SURPLUS OF PROJECTED WATER QUALITY TREATMENT CAPTURE. SEETHE UPDATED TRACKING LEDGER ON THIS SHEET. 2.5. PROOF OF OVERALL COMPLIANCE WILL BE PROVIDED UNDER EACH WPO SUBMITTAL WITH AN UPDATED WATER QUALITY COMPLIANCE TRACKING LEDGER, WHICH IS PROVIDED ON SHEET 20. 2.4.1. CURRENTLY, THE PROJECT IS SHOWING A NET SURPLUS OF PROJECTED WATER QUALITY TREATMENT CAPTURE. SEE THE UPDATED TRACKING LEDGER ON THIS SHEET. AS SUCH, THE PROJECT REMAINS IN COMPLIANCE WITH THE MASTER PLAN AND VSMP WATER QUALITY REQUIREMENTS. REGARDING COMPLIANCE WITH 9VAC25-870-97, 98, COMPLIANCE OF PEAK FLOW ATTENUATION PER BMP ARE PROVIDED HEREIN PER MASTER PLAN. MASTER PLAN DRAINAGE AREAS HAVE BEEN REFINED BASED ON DESIGN; HOWEVER, NOMENCLATURE HAS BEEN KEPT CONSISTENT FOR CLARITY. ADDITIONALLY, TEH DRAINAGE AREAS HAVE BEEN BROKEN INTO SUB -WATERSHEDS WHERE APPLICABLE FOR MODELING PURPOSES. 3.1. FLOW ATTENUATION PER BMP OUTFALL HAS PROVIDED. SEE WATER QUANTITY COMPLIANCE SUMMARY ON THIS SHEET. BASED ON THE ABOVE, THE EAST SIDE DESIGN REMAINS IN COMPLIANCE WITH BOTH THE APPROVED STORMWATER MANAGEMENT MASTER PLAN FOR OLD TRAIL VILLAGE AND THE VIRGINIA STORMWATER MANAGEMENT PROGRAM PART IIC TECHNICAL CRITERIA. Water Quantity Compliance Summary NODE Existing Peak Discharge (cfs) Proposed Peak Discharge (cfs) Percent Difference ID 2-YR 10-YR 100-YR 2-YR 10-YR 100-YR 2-YR 10-YR 100-YR L-2 6.04 18.69 48.54 5.35 17.02 108.91 -11.4% -8.9% 124.4% L-3 4.71 14.32 36.64 1.94 7.24 45.47 -58.8% -49.4% 24.1% S-3 3.65 11.52 30.66 3.60 11.48 41.41 -1.4% -0.3% 35.1% S-12 1.17 3.63 9.48 0.81 2.26 22.61 -30.8% -37.7% 138.5% Water Quality Compliance Tracking Ledger Date: 5/20/2016 Constructed / Planned Facility ID BMP Type (per VSWMH) Master Plan Target Drainage Area Minimum Estimated Required Drainage Area* Design Drainage Area Drainage Area Above Minimum Compliance** Running Compliance (Surplus)** WPO Plan / Approval Date (acres) (acres) (acres) (acres) (acres+/ ) Bioretention Facilities L-3 Biofilter (0.5 inch) 8.96 6.14 6.88 0.14 0.14 Current Submittal S-3 Biofilter (0.5 inch) 6.89 5.18 6.32 1.14 1.27 Current Submittal S-12 Biofilter (0.5 inch) 5.87 4.42 4.36 -0.06 1.22 Current Submittal S-513 Biofilter (0.5 inch) 3.52 2.65 - - Qi S-5A Biofilter (0.5 inch) 4.87 3.66 = S-6 Biofilfer (0.5 inch) 1.40 1.05 S-6A Biofilfer (0.5 inch) 12.50 9.41 S-7 Biofilfer (0.5 inch) 6.66 5.01 S-7A Biofilter (0.5 inch) 1.81 1.36 S-4 Biofilter (0.5 inch) 5.82 4.38 S-13 Biofilter (0.5 inch) 9.68 7.28 - - Sum 67.98 51.15 17.56 1.22 1.22 *Individual BMPs may not meet this requirement as long as the sum of design drainage areas exceeds the sum of estimated minimum drainage areas. **DA above Minimum compliance acreage remains available to offset future areas. Facility ID BMP Type (per VSWMH) Required Minimum Drainage Area* Design Drainage Area Exceedance of Minimum Drainage Area Running Compliance (Surplus/Deficit) WPO Plan / Approval Date (acres) (acres) (acres) (acres) Pond Facilities L-1 Retention Basin II (4xWQV)* 42.54 42.54 0.00 0.00 20140004 (8-26-2014) uGted p(�5 S-2 Ref. Basin III (4xWQV) with Aquatic Bench* 15.30 15.30 0.00 0.00 201500066 (11-17-2015) d L-2 Ref. Basin III (4xWQV) with Aquatic Bench 23.60 23.81 0.21 0.21 Current Submittal Q�ann e S-1 Retention Basin II (4xWQV) 11.14 - - Sum 92.58 81.65 0.21 0.21 Design Submittal: East Side Design - Four Facilities Submittal Notes: In accordance with SWM Master Plan - Three Bioretention and One Retention Basin Compliance as of. 5/20/2016 Retention Basins: Yes Bioretention: z Y Total Site Compliance: 7� Yes Note: Capture areas noted above pertain to water quality capture only. Additional benefit provided from further water quantity capture not included.