HomeMy WebLinkAboutFDP202100009 Plan - Approved 2021-10-28PROPOSED CUT (18"t A
SECTION #1) TO ALLOW
LINED OUTLET PROTECTIOf
FLAT AT 0% GRADE
MINIMUM VESCH REQUIREMEN
OF RIPRAP LINED
PROTECTION ELEVATION N
STREAM's TOP OF BANK ELI
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CROSS
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-EXISTING PROPOSED FLAT VDOT CLASS Al, EC-1 RIPRAP OUTLET PROTECI
GRADE ELEV.=343.00') w/ GEOTEXTILE FILTER FABRIC UNDERLAYMENT. I
BE KEYED INTO EX. GROUND 9' MIN. AT ENDS & ALONG PE
FABRIC TO OVERLAP A MIN. OF 9" (OP L=130% W 1=9', W2=1
--PROPOSED FLAT VDOT CLASS Al, EC-1
RIPRAP OUTLET PROTECTION w/ GEOTEXTILE
FILTER FABRIC UNDERLAYMENT. FABRIC TO
BE KEYED INTO EX. GROUND 9" MIN. AT ENDS
& ALONG PERIMETER. FABRIC TO OVERLAP A
MIN. OF 9" (OP L=64', W1=9% W2=16', D=18")
SWM FACILITY A- X-SEC #i
PROFILE SCALES:
"=S (V)
l..=5o'(T)
350
35o
ION (TOP
ABRICTO
RIMETER.
7', D=18")
345
345
w
'
-XISTING
GRADE
340
340
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PROPOSED CUT ( 12" 18"f AT
CROSS SECTION #1) TO ALLOW
RIPRAP LINED OUTLET PROTECTION
TO BE FLAT AT 0% GRADE MEETING
MINIMUM VESCH REQUIREMENTS. TOP
OF RIPRAP LINED OUTLET
PROTECTION ELEVATION MATCHES
STREAM's TOP OF BANK ELEVATION.
SWM FACILITY B- X-SEC #i
ioo-YEAR FLOODPLAIN NOTES:
1. ALL LAND DISTURBANCES WITHIN THE soo-YEAR FLOODPLAIN ASSOCIATED WITH THIS PERMIT (FDP
2021.00009) SHALL RESULT IN A NO NET CHANGE TO THE FLOODPLAIN.
2. ANY CUT REQUIRED FOR THE 3:3. TIE -BACK GRADES FROM THE PROPOSED FLAT RIPRAP LINED OUTLET
PROTECTIONS TO THE EXISTING GRADES SHALL BE EVENLY SPREAD ADJACENT TO THE RIPRAP WITHIN
THE FLOODPLAIN, WITHOUT CREATING PONDING AREAS. THE DISTURBED AREAS SHALL BE
IMMEDIATELY STABILIZED WITH PERMANENT SEEDING MEETING MINIMUM VESCH REQUIREMENTS. SEE
THE SHEET 3 EXCERPT FROM WPO 2023-00007 FOR PERMANENT SEEDING SCHEDULE.
3. ANY CUT REQUIRED FOR THE 18" DEEP RIPRAP LINED OUTLET PROTECTIONS SHALL BE RELOCATED
OUTSIDE THE LIMITS OF THE ioo-YEAR FLOODPLAIN AND THIS EARTH'S VOLUME SHALL BE REPLACED
WITH THE PROPOSED STONE'S VOLUME. RELOCATED CUT SHALL BE PLACED WITHIN THE PROPOSED
LIMITS OF DISTURBANCE COVERED UNDER WPO 2021-00007's PERMIT.
4. ANY DISTURBANCES WITHIN THE soo-YEAR FLOODPLAIN LIMITS FOR POTENTIAL PROPOSED IMPACTS #3
& #4 SHALL BE BROUGHT BACK TO PRE -CONSTRUCTION GRADES AFTER THE PROPOSED SANITARY
SEWER CONNECTIONS ARE MADE. ANY DISTURBED AREAS WITHIN THE ioo-YEAR FLOODPLAIN FROM
THE UTILITY CONNECTIONS SHALL BE IMMEDIATELY STABILIZED WITH PERMANENT SEEDING, MEETING
THE SEEDING SCHEDULE REQUIREMENTS SET FORTH IN THE SHEET 3 EXCERPT FROM WPO 202100007.
5. CONSTRUCTION EQUIPMENT ASSOCIATED WITH POTENTIAL PROPOSED IMPACTS #3 & #4 SHALL BE
PLACED ON THE UPHILL SIDE WHEN POSSIBLE TO LIMIT POTENTIAL DISTURBANCES BELOW THE
MANHOLES AND WITHIN THE ioo-YEAR FLOODPLAIN.
PROPOSED LAND DISTURBANCE #1 WITHIN
FLOODPLAIN. SEE SHEET 16B EXCERPT
" FROM WPO 202100007 FOR DETAILS.
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' POLO GROUNDS ROAD
(VARIABLE WIDTH)
LOCATION OF PROPOSED DRY DETENTION BASIN
A' & UGD SYSTEM 'A' OUTFALL. SWM FACILITY
OUTFALL WILL GENERATE A LAND DISTURBANCE '
WITHIN THE ioo-YEAR FLOODPLAIN.
PROPOSED LAND DISTURBANCES WITHIN
ioo-YEAR FLOODPLAIN PLAN, SCALE i"=ioo'
i
- PROPOSED DEVELOPMENT OF
BROOKHILL's BLOCKS 16 & 17
POTENTIAL PROPOSED DISTURBANCE #3 TO
FLOODPLAIN. PROPOSED SANITARY SEWER
CONNECTION TO EXISTING MANHOLE
LOCATED OUTSIDE, BUT ON THE FRINGE OF,
THE LIMITS OF THE 100-YEAR FLOODPLAIN.
STREAM LIMITS, TYP.
/ Y
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OTENTIAL PROPOSED DISTURBANCE #4 TO
LOODPLAIN. PROPOSED SANITARY SEWER
ONNECTION TO EXISTING MANHOLE
OCATED OUTSIDE, BUT ON THE FRINGE OF, /\
HE LIMITS OF THE 100-YEAR FLOODPLAIN. //f ��
/
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LOCATION OF PROPOSED DRY DETENTION BASIN /� l
'B' & UGD SYSTEM 'B' OUTFALL. SWM FACILITY //� / 7
f OUTFALL WILL GENERATE A LAND DISTURBANCE
WITHIN THE ioo-YEAR FLOODPLAIN. \ /
/
PROPOSED HALSEY AVENUE CONNECTION TO
PROPOSED POLO GROUNDS ROAD IMPROVEMENTS.
l IMPACTS TO THE ioo-YEAR FLOODPLAIN
ASSOCIATED WITH THESE ROAD IMPROVEMENTS
HAVE BEEN APPROVED UNDER FDP 2o1600004._
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SHEET NO.
1 OF 1
EROSION & SEDIMENT CONTROL MEASURES: EROSION CONTROL NOTES:
STRUCTURAL EROSION AND SEDIMENT CONTROL PRACTICES SHALL BE /N ACCORDANCE WI774
1. THE PLAN APPROVING AUTHORITY MUST BE NOTIFIED ONE WEEK PRIOR TO THE
THE VIRGINIA EROSION AND SEDIMENT CONTROL HANDBOOK. STRUCTURAL PRACTICES USED
PRE -CONSTRUCTION CONFERENCE, ONE WEEK PRIOR TO THE COMMENCEMENT OF LAND
IN THIS SECTION CONSIST OF THE FOLLOWING
DISTURBING ACTIVITY, AND ONE WEEK PRIOR TO THE FINAL INSPECTION.
2. ALL EROSION AND SEDIMENT CONTROL MEASURES WILL BE CONSTRUCTED AND MAINTAINED
3.01 SAFETY FENCE:
ACCORDING TO MINIMUM STANDARDS AND SPECIFICATIONS OF THE ORGINIA EROSION AND
A PR07EC77VE BARRIER INSTALLED TO PREVENT ACCESS TO AN EROSION CONTROL MEASURE. TO
SEDIMENT CONTROL HANDBOOK AND VIRGINIA REGULATIONS VR 625-02-00 EROSION AND
PROHIBIT THE UNDESIRABLE USE OF AN EROSION CONTROL MEASURE BY THE PUBLIC. APPLICABLE
SEDIMENT CONTROL REGULATIONS.
TO ANY CONTROL MEASURE OR SERIES OF MEASURES WHICH CAN BE CONSIDERED UNSAFE BY
J. ALL EROSION AND SEDIMENT CONTROL MEASURES ARE TO BE PLACED PRIOR TO OR AS THE
OR77JE OF P07EN77AL ACCESS BY 7HE PUBLIC.
FIRST STEP IN CLEARING.
3.02 CONS7RUC77ON ENTRANCE:
4. A COPY OF THE APPROVED EROSION AND SEDIMENT CONTROL PLAN SHALL BE MAINTAINED ON
A STABILIZED CONSTRUCTION ENTRANCE LOCATED AT POINTS OF VEHICULAR INGRESS AND EGRESS
THE S/7E AT ALL TIMES.
ON A CONSTRUCTION SITE TO REDUCE 7HE AMOUNT OF MUD TRANSPORTED ONTO PAVED PUBLIC
5. PRIOR TO COMMENCING LAND DISTURBING ACTIVITIES IN AREAS 07HER THAN INDICATED ON
ROADS BY MOTOR VEHICLES OR RUNOFF. CONSTRUCTION ENTRANCES SHALL BE INSTALLED AS
THESE PLANS (INCLUDING, BUT NOT LIMITED TO, OFF -SITE BORROW OR WASTE AREAS), 7N£
SHOWN ON THE PLANS TO REDUCE THE AMOUNT SEDIMENT 7RANSPORTED ONTO PUBLIC ROADWAYS.
CONTRACTOR SHALL SUBMIT A SUPPLEMENTARY EROSION CONTROL PLAN TO THE OWNER FOR
REVIEW AND APPROVAL BY THE PLAN APPROVING AUTHORITY.
303 CONSTRUCTION ROAD STABILIZATION
6. THE CONTRACTOR IS RESPONSIBLE FOR INSTALLA77ON OF ANY ADDITIONAL EROSION CONTROL
THE TEMPORARY STABILIZATION OF ACCESS ROADS, SUBDIVISION ROADS, PARKING AREAS, AND
MEASURES NECESSARY TO PREVENT EROSION AND SEDIMENTATION AS DETERMINED BY THE PLAN
OTHER S17E VEHICLE 7RANSPORTA77ON ROUTES WITH STONE IMMEDIATELY AFTER GRADING. TO
APPROVING AU774ORITY.
REDUCE EROSION OF TEMPORARY ROADBEDS BY CONS77?UCT70N 7RAFF7C DURING WET WEATHER AND
TO REDUCE EROSION AND SUBSEQUENT REGRADING OF PERMANENT ROADBEDS BETWEEN THE 77ME
7. ALL DISTURBED AREAS ARE TO DRAIN TO APPROVED SEDIMENT CONTROL MEASURES AT ALL
OF INITIAL GRADING AND FINAL STABILIZATION. USE WHEREVER STONE -BASE ROADS OR PARKING
77MES DURING LAND DISTURBING ACTIVITIES AND DURING SITE DEVELOPMENT UN77L FINAL
AREAS ARE CONSTRUCTED, WHETHER PERMANENT OR TEMPORARY, FOR USE BY CONS7RUCTION
STABILIZATION IS ACHIEVED.
TRAFFIC.
8. DURING DEWATERING OPERATIONS, WATER WILL BE PUMPED INTO AN APPROVED FILTERING
DEVICE.
3.05 SILT FENCE & SUPER SILT FENCE:
9. THE CONTRACTOR SHALL INSPECT ALL EROSION CONTROL MEASURES PERIODICALLY AND AFTER
A TEMPORARY SEDIMENT BARRIER CONSISTING OF A SYN7HE77C FILTER FABRIC STRETCHED ACROSS
EACH RUNOFF -PRODUCING RAINFALL EVENT. ANY NECESSARY REPAIRS OR CLEANUP TO
AND ATTACHED TO SUPPOR77NG POSTS AND ENTRENCHED, TO INTERCEPT AND DETAIN SMALL
MAINTAIN THE EFFECTIVENESS OF THE EROSION CONTROL DEVICES SHALL BE MADE IMMEDIATELY.
AMOUNTS OF SEDIMENT FROM DISTURBED AREAS DURING CONS7RUCT0N OPERATIONS IN ORDER TO
10. ALL FILL MATERIAL TO BE TAKEN FROM AN APPROVED, DESIGNATED BORROW AREA.
PREVENT SEDIMENT FROM LEAVING THE SITE AND TDECREASE THE VELOCITY OF SHEET FLOWS
AND LOW -TO -MODERATE LEVEL CHANNEL FLOWS. THE SILT FENCE BARRIERS SHALL BE INSTALLED
11. ALL WASTE MATERIALS SHALL BE TAKEN TO AN APPROVED WASTE AREA. EARTH FILL SHALL BE
DOWN SLOPE OF AREAS WITH MINIMAL GRADES TO FILTER SEDIMENT LADEN RUNOFF FROM SHEET
INERT MATERIALS ONLY FREE OF ROOTS STUMPS WOOD RUBBISH AND 07HER DEBRIS.
FLOW AS INDICATED. THEY SHALL BE INSPECTED IMMEDIATELY AFTER EACH RAINFALL AND
12. BORROW OR WASTE AREAS ARE TO BE RECLAIMED WITHIN 7 DAYS OF COMPLETION PER ZONING
MAINTAINED IN ACCORDANCE WITH THE 14RGINIA EROSION & SEDIMENT CONTROL HANDBOOK
ORDINANCE SECTION 5.1.28.
(VESCH).
13. ALL INERT MATERIALS SHALL BE TRANSPORTED IN COMPLIANCE WITH SECT70N 13-301 OF THE
CODE OF ALBEMARLE.
3.07 STORM DRAIN INLET PROTEC770N:
14. BORROW, FILL OR WASTE AC77VITY INVOLVING INDUSTRIAL -TYPE POWER EQUIPMENT SHALL BE
A SEDIMENT FILTER OR AN EXCAVATED IMPOUNDING AREA AROUND A STORM DRAIN DROP INLET OR
LIMITED TO THE HOURS OF 7.•00 AM TO 9.,00 PM.
CURB INLET. TO PREVENT SEDIMENT FROM ENTERING STORM DRAINAGE SYSTEMS PRIOR TO
15. BORROW, FILL OR WASTE ACTIVITY SHALL BE CONDUCTED IN A SAFE MANNER THAT MAINTAINS
PERMANENT STABILIZATION OF THE DISTURBED AREA. INLET PR07EC77ON APPLIES WHERE STORM
LATERAL SUPPORT, OR ORDER TO MINIMIZE ANY HAZARD TO PERSONS, PHYSICAL DAMAGE TO
DRAIN INLETS ARE TO BE MADE OPERATIONAL BEFORE PERMANENT STABILIZATION OF THE
ADJACENT LAND AND IMPROVEMENTS, AND DAMAGE TO ANY PUBLIC STREET BECAUSE OF SLIDES,
CORRESPONDING DISTURBED DRAINAGE AREA.
SINKING, OR COLLAPSE.
3.09 TEMPORARY DIVERSION DIKE:
16. THE DEVELOPER SHALL RESERVE THE RIGHT TO INSTALL, MAINTAIN, REMOVE OR CONVERT TO
A TEMPORARY RIDGE OF COMPACTED SOIL CONSTRUCTED AT THE TOP OR BASE OF A SLOPING
PERMANENT STORMWATER MANAGEMENT FACILITIES WHERE APPLICABLE ALL EROSION CONTROL
DISTURBED AREA. TO DIVERT STORM RUNOFF FROM UPSLOPE DRAINAGE AREAS AWAY FROM
MEASURES REQUIRED BY THIS PLAN REGARDLESS OF THE SALE OF ANY LOT, UNIT, BUILDING OR
UNPROTECTED DISTURBED AREAS AND SLOPES TO A STABILIZED OUTLET. TO DIVERT
OTHER PORTION OF THE PROPERTY.
SEDIMENT -LADEN RUNOFF FROM A DISTURBED AREA TO A SEDIMENT -TRAPPING FACILITY SUCH AS
17. TEMPORARY STABILIZATION SHALL BE TEMPORARY SEEDING AND MULCHING. SEEDING IS TO BE
A SEDIMENT TRAP OR SEDIMENT BASIN. USE WHEREVER STORMWATER RUNOFF MUST BE
AT 75 LBS/ACRE, AND IN THE MONTHS OF SEPTEMBER TO FEBRUARY TO CONSIST A 50/50 MIX
TEMPORARILY DIVERTED TO PR07ECT DISTURBED AREAS AND SLOPES OR RETAIN SEDIMENT ON S17E
OF ANNUAL RYGRASS AND CEREAL WINTER RYE, OR IN MARCH AND APRIL TO CONSIST OF
DURING CONSTRUCTION THESE STRUCTURES GENERALLY HAVE A LIFE EXPECTANCY OF 18 MONTHS
ANNUAL RYE, OR MAY THROUGH AUGUST TO CONSIST OF GERMAN MILLET. STRAW MULCH IS TO
OR LESS, WHICH CAN BE PROLONGED WITH PROPER MAINTENANCE.
BE APPLIED AT 80LBS f00SF. ALTERNATIVES ARE SUBJECT TO APPROVAL BY THE EROSION
3.11 TEMPORARY RIGHT-OF-WAY DIVERSION:
CONTROL INSPECTOR.
A RIDGE OF COMPACTED SOIL OR LOOSE ROCK OR GRAVEL CONSTRUCTED ACROSS DISTURBED
18. PERMANENT STABILIZA 77ON SHALL BE LIME AND FERTILIZER, PERMANENT SEEDING, AND MULCH.
RIGHTS -OF -WAY AND SIMILAR SLOPING AREAS. TO SHORTEN 7HE FLOW LENGTH WITHIN A SLOPING
AGRICULTURAL GRADE LIMESTONE SHALL BE APPLIED AT 1000SF, INCORPORATED INTO
RIGHT-OF-WAY, THEREBY REDUCING THE EROSION P07EN77AL BY DIVER77NG STORM RUNOFF TO A
THE TOP 4-6 INCHES OF SOIL. FERTILIZER SHALL BE APPLIEDLIED AT 1000LBS ACRE AND CONSIST
STABILIZED OUTLET. GENERALLY, EARTHEN DIVERSIONS ARE APPLICABLE WHERE THERE WILL BE
OF A 10-20-10 NUTRIENT MIX. PERMANENT SEEDING SHALL BE APPLIED AT 180LBS ACRE AND
LITTLE OR NO CONSTRUCTION TRAFFIC WI1HlN 174E RIGHT-OF-WAY. GRAVEL STRUCTURES ARE
MORE APPLICABLE TO ROADS AND OTHER RIGHTS -OF -WAY WHICH ACCOMMODATE VEHICULAR
CONSIST OF 95Z KENTUCKY 31 OR TALL FESCUE AND 0-57 PERENNIAL RYGRASS OR KENTUCKY
TRAFFIC.
BLUEGRASS STRAW MULCH IS TO BE APPLIED AT 80LBS1100SF. ALTERNA77VES ARE SUBJECT TO
APPROVAL BY THE EROSION CONTROL INSPECTOR.
313 TEMPORARY SEDIMENT TRAP:
19. MAINTENANCE ALL MEASURES ARE TO BE INSPECTED WEEKLY AND AFTER EACH RAINFALL. ANY
A TEMPORARY PONDING AREA FORMED BY CONSTRUC77NO AN EARTHEN EMBANKMENT WI7H A STONE
DAMAGE OR CLOGGING TO STRUCTURAL MEASURES IS TO BE REPAIRED IMMEDIATELY. SILT TRAPS
OUTLET. TO DETAIN SEDIMENT -LADEN RUNOFF FROM SMALL DISTURBED AREAS LONG ENOUGH TO
ARE TO BE CLEANED WHEN 50% OF THE WET STORAGE VOLUME IS FILLED K17H SEDIMENT. ALL
ALLOW THE MAJORITY OF THE SEDIMENT TO SETTLE OUT. USE BELOW DISTURBED AREAS WHERE
SEEDED AREAS ARE TO BE RESEEDED WHEN NECESSARY TO ACHIEVE A GOOD STAND OF GRASS.
THE TOTAL CONTRIBUTING DRAINAGE AREA IS LESS THAN 3 ACRES, WHERE THE SEDIMENT TRAP
SILT FENCE AND DIVERSION DYKES WHICH ARE COLLEC77NG SEDIMENT TO HALF THEIR HEIGHT
WILL BE USED NO LONGER THAN 18 MONTHS, AND IT MAYBE CONSTRUCTED EITHER
INDEPENDENTLY OR IN CONJUNCTION WITH A TEMPORARY DIVERSION DIKE.
MUST BE CLEANED AND REPAIRED IMMEDIATELY.
20. ALL TEMPORARY EROSION AND SEDIMENT CONTROL MEASURES ARE TO BE REMOVED WITHIN 30
314 TEMPORARY SEDIMENT BASIN:
DAYS OF FINAL SITE STABILIZATION, WHEN MEASURES ARE NO LONGER NEEDED, SUBJECT TO
A TEMPORARY BARRIER OR DAM WITH A CONTROLLED STORMWATER RELEASE S7RUCTURE FORMED
APPROVAL BY THE EROSION CONTROL INSPECTOR.
BY CONSTRUCTING AN EMBANKMENT OF COMPACTED SOIL ACROSS A DRAINAGEWAY. TO DETAIL
21. THE £&S INSPECTOR HAS THE AUTHORITY TO ADD OR DELETE £&S CONTROLS AS NECESSARY IN
SEDIMENT -LADEN RUNOFF FROM DISTURBED AREAS IN "WET" AND 'DRY" STORAGE LONG ENOUGH
THE FIELD AS SITE CONDITIONS CHANGE. IN ADDITION, NO SEDIMENT BASIN OR TRAP CAN BE
FOR THE MAJORITY OF 7HE SEDIMENT TO SETTLE OUT. APPLIES BELOW DISTURBED AREAS WHERE
REMOVED WITHOUT WRITTEN AUTHORIZATION.
THE TOTAL CONTRIBUTING DRAINAGE AREA IS EQUAL TO OR GREATER THAN THREE ACRES. ]HERE
MUST BE SUFFICIENT SPACE AND APPROPRIATE TOPOGRAPHY FOR THE CONSTRUCTION OF A
SOIL DESCRIPTION.•
TEMPORARY IMPOUNDMENT.
SOILS ON -SITE ARE CURRENTLY AS FOLLOWS:
3.18 OUTLET PROTECTION:
S7RUCTURALLY LINED APRONS OR 07HER ACCEPTABLE ENERGY DISSIPATING DEVICES PLACED AT
16-CODORUS SILT LOAM-2 TO 29 SLOPES. SOIL IS SOMEWHAT POORLY DRAINED WITH A VERY HIGH
7HE OUTLETS OF PIPES OR PAVED CHANNEL SECTIONS TO PREVENT SCOUR AT STORMWATER
RUNOFF CLASSIFICATION. SURFACE LAYER IS TYPICALLY SILT LOAM AND ABOUT 0-8" THICK.
OUTLETS, TO PR07ECT THE OUTLET STRUCTURE, AND TO MINIMIZE 7HE P07EN77AL FOR
THE DEPTH TO THE WATER TABLE IS GENERALLY 9-18".
DOWNSTREAM EROSION BY REDUCING THE VELOCITY AND ENERGY OF CONCENTRATED STORMWA TER
28D3-ELIOAK CLAY LOAM-15 TO 257 SLOPES. SOIL /S TYPICALLY WELL DRAINED WITH A HIGH
FLOWS. APPLICABLE TO THE OUTLETS OF ALL PIPES AND ENGINEERED CHANNEL SECTIONS.
RUNOFF CLASSIFICATION. SURFACE LAYER IS TYPICALLY CLAY LOAM AND ABOUT 0-8" THICK.
319 RIPRAP:
THE DEPTH TO THE WATER TABLE IS GENERALLY MORE THAN 80".
A PERMANENT, EROSION -RESISTANT GROUND COVER OF LARGE, LOOSE, ANGULAR STONE WITH
278-ELIOAK LOAM-2 TO 79 SLOPES. SOIL /S TYPICALLY WELL DRAINED WITH A MEDIUM RUNOFF
FILTER FABRIC OR GRANULAR UNDERLINING. TO PR07ECT 7HE SOIL FROM 7HE EROSIVE FORCES OF
-
CLASSIFICATION. SURFACE LAYER IS TYPICALLY LOAM AND ABOUT 0 8' THICK THE DEPTH TO
CONCEN7RATED RUNOFF, SLOW 7HE VELOCITY OF CONCEN7RATED RUNOFF WHILE ENHANCING THE
THE WATER TABLE IS GENERALLY MORE THAN 80".
P07EN77AL FOR INFILTRATION AND TO STABILIZE SLOPES WI7H SEEPAGE PROBLEMS AND OR
27C-SLOPES. SOIL IS TYPICALLY WELL DRAINED WITH A MEDIUM RUNOFF
L LOAM 7 TOFICATION.
NON-COHESIVE SOILS USE WHEREVER SOIL AND WATER INTERFACE AND THE SOIL CONDITIONS
CSURFACE LAYER IS TYPICALLY LOAM AND ABOUT 0-8" THICK THE DEPTH TO
CLASSIFICATION.
WATER TURBULENCE AND VELOCITY, EXPECTED VEGETATIVE COVER, ETC., ARE SUCH THAT THE SOIL
THE WATER TABLE IS GENERALLY MORE THAN 80".
MAY ERODE UNDER THE DESIGN FLOW CONDITIONS
34B-GLENELG LOAM-2 TO 79 SLOPES. SOIL IS TYPICALLY WELL DRAINED WITH A MEDIUM RUNOFF
3.31 TEMPORARY SEEDING:
CLASSIFICATION. SURFACE LAYER IS TYPICALLY LOAM AND ABOUT O 8" THICK. THE DEPTH TO
7HE ESTABLISHMENT OF A TEMPORARY VEGETATIVE COVER ON DISTURBED AREAS BY SEEDING WITH
THE WATER TABLE IS GENERALLY MORE THAN 80".
APPROPRIATE RAPIDLY GROWING ANNUAL PLANTS. TO REDUCE EROSION AND SEDIMENTATION BY
34C-GLENELG LOAM-7 TO 157 SLOPES. SOIL /S TYPICALLY WELL DRAINED WITH A MEDIUM RUNOFF
STABILIZING DISTURBED AREAS THAT WILL NOT BE BROUGHT TO FINAL GRADE FOR A PERIOD OF
CLASSIFICATION. SURFACE LAYER IS TYPICALLY LOAM AND ABOUT 0-8" THICK. THE DEPTH TO
MORE THAN 30 DAYS TO REDUCE DAMAGE FROM SEDIMENT AND RUNOFF TO DOWNS7REAM OR
THE WATER TABLE IS GENERALLY MORE THAN 80".
F
OFSITE AREAS, AND TO PROVIDE PR07EC77ON TO BARE SOILS EXPOSED DURING CONSTRUCTION
UN77L PERMANENT VEGETATION OR OTHER EROSION CONTROL MEASURES CAN BE ESTABLISHED.
34D-GLENELG LOAM-15 TO 25% SLOPES. SOIL IS TYPICALLY WELL DRAINED WITH A HIGH RUNOFF
CLASSIFICATION. SURFACE LAYER IS TYPICALLY LOAM AND ABOUT 0-6" THICK. THE DEPTH TO
3.32 PERMANENT STABILIZATION:
THE WATER TABLE IS GENERALLY MORE THAN 80".
THE ESTABLISHMENT OF PERENNIAL VEGETA FIVE COVER ON DISTURBED AREAS BY PLAN77NG SEED.
39D-HAZEL LOAM-15 TO 259 SLOPES. SOIL IS TYPICALLY EXCESSIVELY DRAINED WITH A MEDIUM
TO REDUCE EROSION AND DECREASE SEDIMENT YIELD FROM DISTURBED AREAS. TO PERMANENTLY
RUNOFF CLASSIFICATION. SURFACE LAYER IS TYPICALLY LOAM AND ABOUT 0-10" THICK. THE
STABILIZE DISTURBED AREAS IN A MANNER 77-IAT IS ECONOMICAL, ADAPTABLE TO S17E CONDITIONS,
DEPTH TO THE WATER TABLE IS GENERALLY MORE THAN 80".
AND ALLOWS SELECTION OF THE MOST APPROPRIATE PLANT MATERIALS. TO IMPROVE WILDLIFE
39E-HAZEL LOAM-25 TO 45% SLOPES. SOIL IS TYPICALLY EXCESSIVELY DRAINED WITH A MEDIUM
HABITAT. TO ENHANCE NATURAL BEAUTY. UPON COMPLETION OF CONSTRUCTION ACTIVITIES, ALL
AREAS WILL RECEIVE A PERMANENT VEGETATIVE COVER.
RUNOFF CLASSIFICATION. SURFACE LAYER IS TYPICALLY LOAM AND ABOUT 0-10" THICK. THE
DEPTH TO THE WATER TABLE IS GENERALLY MORE THAN 80".
3.38 TREE PRESERVA77ON AND PRO7EC7ON
- - 95 HATBORO SILT LOAM-0 70 29 SLOPES. SOIL IS TYPICALLY POORLY DRAINED WITH A VERY HIGH
PR07EC77ON OF DESIRABLE TREES FROM MECHANICAL OR OTHER INJURY DURING LAND DISTURBING
RUNOFF CLASSIFICATION. SURFACE LAYER IS TYPICALLY SILT LOAM AND ABOUT 0-10" THICK.
AND CONSTRUCTION ACTIVITY. TO ENSURE THE SURVIVAL OF DESIRABLE TREES WHERE THEY WILL
THE DEPTH TO THE WATER TABLE IS GENERALLY 0-30".
BE EFFECTIVE FOR EROSION AND SEDIMENT CONTROL WATERSHED PROTECTION LANDSCAPE
BEAU7IFICA770N, DUST AND POLLUTION CONTROL, NOISE REDUCTION, SHADE AND OTHER
REFERENCE: WEB SOIL SURVEY ONLINE DATABASE, FOUND A7
ENVIRONMENTAL BENEFITS WHILE THE LAND IS BEING CONVERTED FROM FOREST TO URBAN -TYPE
USES APPLIES IN 7REE-INHAB17ED AREAS SUBJECT TO LAND DISTURBING ACTIVITIES
http://websoilsurvey.nres.usda.govlappIWebSoilSurvey.aspx
3.39 DUST CONTROL:
1992
REDUCING SURFACE AND AIR MOVEMENT OF DUST DURING LAND DISTURBING, DEMOLITION AND
CONSTRUCTION ACTIVITIES TO PREVENT SURFACE AND AIR MOVEMENT OF DUST FROM EXPOSED
SOIL SURFACES AND REDUCE THE PRESENCE OF AIRBORNE SUBSTANCES WHICH MAY PRESENT
HEALTH HAZARDS, TRAFFIC SAFETY PROBLEMS OR HARM ANIMAL OR PLANT LIFE. DUST CONTROL
MEASURES SHALL BE EMPLOYED TO PREVENT SURFACE AND AIR MOVEMENT OF DUST DURING
CONSTRUCTION. MEASURES EMPLOYED SHALL BE /N ACCORDANCE WTH THE VESCH.
SEDIMENT BASIN BAFFLE DETAIL
NO SCALE N07E.
BAFFLES SHALL EXTEND FROM THE
SHEETS OF 4'x8i}' EXTERIOR BOTTOM TO 6" ABOVE THE OVERFLOW.
PLYWOOD OR EQUIVALENT � 1. SET POSTS AND EXCAVATE A 4"X4" 2. STAPLE WIRE FENCING TO
I
I II
I II
1 11
II
4' 11
11
1
1
CREST
TRENCH UPSLOPE ALONG THE LINE THE POSTS.
OF POSTS.
77ON
MIN. SIZE
IT�0!�,rs.�
�, S�!ill j���l` I1
GROUND -Ii�1141111. Q_ � `�� N �,��I VII`1- VA ��
TABLE 3.31-B
ACCEPTABLE TEMPORARY SEEDING PLANT MATERIALS
"QUICK REFERENCE FOR ALL REGIONS"
Rate
PlantinE Dates 54mcies
lbs. acre
Sept. 1 - Feb. 15 50/50 Mix of
Annual Ryegrass
(Lolium multi-floruml
&
50 - 100
Cereal (Winter) Rye
(S(�ale�reale)
Feb. 16 - Apr. 30 Annual Ryegrass
60 - 100
(Lolium multi-florum)
May 1 - Aug 31 German Millet
(Setaria italics)
50
Source: Va. DSWC
-III-III
FLOW !77t�;1 � I I I-
4
J. ATTACH THE FILTER FABRIC TO
THE WIRE FENCE AND EXTEND
IT INTO THE TRENCH.
4. BACKFILL AND COMPACT THE
EXCAVATED SOIL.
�/
- - - 1 /
�_ �11r
-11
�l IIIII1 I III'
FLOW / `�/
EXTENSION OF FABRIC AND WIRE INTO THE TRENCH.
SUPER SILT ssF FENC5 (WITH WIRE -BACK o5-
NO SCALE
EROSION CONTROL NOTES & NARRATIVE.
DESCRIPTION OF EROSION & SEDIMENT
CONTROL
MEASURES:
PROJECT DESCRIPTION:
THE PURPOSE OF THIS LAND DISTURBANCE ACTIVITY IS TO CONSTRUCT A RESIDENTIAL SUBDIVISION. THIS PLAN PROPOSES 26.25 cc. OF LAND
EROSION AND SEDIMENT CONTROL MEASURES:
DISTURBANCE. THE PROJECT WILL BEGIN ITS CONSTRUCTION WITH THE PROPOSED ESC MEASURES FOLLOWING PLAN APPROVAL, WHICH IS
IT IS ANTICIPATED TO USE A CONSTRUCTION ENTRANCE, RIPRAP, OUTLET PROTECTION,
ANTICIPATED TO BE IN THE SUMMER OF 2021. THE WORK IS ANTICIPATED TO BE COMPLETED WITHIN 24 MONTHS AND TO CONCLUDE IN THE
DIVERSIONS, TWO SEDIMENT BASINS, A SEDIMENT TRAP AND SILT FENCES TO CONTROL
SUMMER OF 2023.
SURFACE DRAINAGE TEMPORARY SEEDING WILL BE USED IMMEDIATELY FOLLOWING ALL
EXISTING S17E CONDITIONS:
LAND DISTURBANCE ACTIVITIES. TEMPORARY STOCKPILE AREAS SHALL BE DISCUSSED WISH
THE PROPOSED DEVELOPMENT IS LOCATED ON A PARCEL WITH EXISTING WOODS AND GRASSY LAWNS THIS SITE IS GENERALLY WELL SLOPED WITH
THE ESC INSPECTOR AHEAD OF 77ME & WILL NEED TO BE MAINTAINED AND STORED FOR
A RIDGE RUNNING NORTHEAST THROUGH THE PROPERTY, WITH POLO GROUNDS ROAD TO THE SOUTH AND THE STREAM TO THE WEST BEING THE
LOWER AREAS
LATER SPREADING. STOCKPILE LOCATIONS SHALL BE ON SITE AND SHALL BE STABILIZED
ADJACENT AREAS:
K17H A TEMPORARY VEGETATIVE COVER. PERMANENT SEEDING WILL BE PERFORMED FOR
THIS SITE IS SURROUNDED TO THE NORTH OPEN SPACES TREES AND LIGHT UNDERBRUSH. TO THE WEST OF THE PROPERTY IS A STREAM.
ALL AREAS WHICH WILL NO LONGER BE EXCAVATED AND WHERE CONSTRUCTION ACTIVITIES
THE SOUTHERN PORTION OF THE SITE IS BORDERED GROUNDS BY POLO GROUNDS ROAD, AND THE RESIDENTIAL SUBDIVISION MONTGOMERY RIDGE IS LOCATED
HAVE CEASED. PERMANENT SEEDING SHALL ALSO BE PERFORMED FOR ALL DENUDED
TO THE EAST. SILT FENCE WITH WIRE BACKING, DIVERSIONS, TWO SEDIMENT BASINS, A SEDIMENT TRAP, INLET CONTROLS AND VARIOUS 07HER ESC
AREAS WHICH WILL BE LEFT DORMANT FOR A YEAR OR MORE. SELECT70N OF SEED
MEASURES ARE PROPOSED TO LIMIT THE POTEN77AL FOR CONTAMINATION OF THESE ADJACENT PROPER77ES AND WATERWAYS.
MIXTURE WILL DEPEND ON THE 77ME OF YEAR APPLIED. TEMPORARY SEEDING WILL BE
OFFSITE LAND DISTURBANCE.•
PERFORMED FOR ALL DENUDED AREAS WHICH WILL BE LEFT DORMANT FOR MORE THAN
OFFSITE LAND DIS7URBANCE /S LIMITED TO PUBLIC RIGHT-OF-WAY AND EASEMENTS.
SEVEN DAYS. THESE AREAS SHALL BE SEEDED WITH FAST GERMINATING VEGETATION
SOILS,•
IMMEDIATELY FOLLOWING GRADING OF THOSE AREAS. SELECT70N OF SEED MIXTURE WILL
SEE SOIL DESCRIPTIONS ON THIS PAGE, AND THE PHASE l ESC PLAN FOR THE BOUNDARIES.
DEPEND ON THE TIME OF YEAR APPLIED. THESE MEASURES, AND THE FOLLOWING, ARE
CRI77CAL AREAS:
PROPOSED:
EXISTING STEEP SLOPES, A STREAM AND A GREENWAY ARE LOCATED AROUND THE PERIMETER OF THIS SITE. THE STEEP SLOPES ARE A MIXTURE
OF PRESERVED AND MANAGED STEEP SLOPES THESE AREAS ARE CONSIDERED TO BE CRITICAL AREAS THE CONTRACTOR SHALL GIVE EXTRA
ATTENTION AND CAUTION IN AND AROUND THESE AREAS TO ENSURE SEDIMENT IS NOT DEPOS17ED ON THEM OUTSIDE THE SCOPE OF THE
3.01 SAFETY FENCE- TO DISCOURAGE ACCESS TO A PAR77CULAR AREA.
PROPOSED PLAN. TREE PR07ECT70N FENCING, SILT FENCING, DIVERSIONS AND SEDIMENT TRAPPING DEVICES SHALL ALSO BE INSTALLED AS A FIRST
3.02 CONSTRUCTION ENTRANCE - TO REDUCE THE AMOUNT OF MUD TRANSPORTED ONTO
STEP IN LAND DISTURBANCE TO ENSURE 774ESE CRI77CAL AREAS ARE MAINTAINED.
PAVED PUBLIC ROADS BY MOTOR VEHICLES OR RUNOFF.
SEQUENCE OF CONS77?UC770N:
3.03 CONSTRUCTION ROAD STABILIZATION - TO REDUCE THE EROSION OF TEMPORARY
1. CONTRACTOR SHALL NOTIFY THE ALBEMARLE COUNTY COMMUNITY DEVELOPMENT ENGINEERING DEPARTMENT TO SCHEDULE A
ROADBEDS BY CONSTRUCTION TRAFFIC AND TO REDUCE THE EROSION AND SUBSEQUENT
PRE- CONS 7RUC77ON MEETING.
REGRADING OF PERMANENT ROADBEDS BETWEEN THE 77ME OF 1N177AL GRADING AND FINAL
2• PRIOR TO DISTURBANCES, THE LIMITS OF DISTURBANCE SHALL BE FLAGGED AND THE TREE PR07ECTION FENCING SHALL BE INSTALLED.
ADDITIONALLY, THE PRESERVED SLOPES & GREENWAY SHALL BE FLAGGED OR MARKED BEFORE LAND DISTURBANCE CAN START.
STABILIZATION. CONSTRUCTION ROAD STABILIZATION WILL BE APPLIED TO THE
J. NO EROSION CONTROL MEASURES MAY BE REMOVED DURING THE CONSTRUCTION PROCESS WITHOUT THE APPROVAL FROM THE INSPECTOR ON
CONTRACTOR PARKING & STAGING AREAS AS NEEDED.
774E PROJECT.
3.05 SILT FENCE- SILT FENCE IS PROPOSED, WHERE SHOWN ON THE PLANS.
4. INSTALLA7ION OF THE PROPOSED CONSTRUCTION ENTRANCE SHALL OCCUR NEXT. THE CONTRACTOR SHALL MODIFY THE EXISTING PAVED
3.07 STORM DRAIN INLET PROTECTION- INLET PR07ECTION IS PROPOSED ON INLETS,
ENTRANCE TO MEET THE MINIMUM CONSTRUC770N ENTRANCE REQUIREMENTS SHOWN ON THE THE DETAIL ON THIS SHEET. THE CONTRACTOR
WHERE SHOWN ON THE PLANS
SHALL ALSO GRADE, WITH THE APPLICA77ON OF CONSTRUCTION ROAD STABILIZATION, IMMEDIATELY BEYOND THE CONSTRUCTION ENTRANCE TO
M177GATE THE SHARP INCLINE IMMEDIATELY BEHIND THE EXIS77NG ENTRANCE BEING MODIFIED. THE CONTRACTOR SHALL ALSO PROVIDE
3.09 DIVERSION- PERIMETER DIVERSIONS ARE PROPOSED WHERE SHOWN ON THE PLANS TO
CONSTRUCTION ROAD STABILIZATION TO THE SURROUNDING AREA ENVISIONED FOR THE CONTRACTOR PARKING & STAGING AREA. CONTRACTOR
DIRECT RUNOFF INTO A SEDIMENT TRAPPING DEVICE.
SHALL ENSURE 774E CONSTRUCTION ENTRANCE AND PARKING AREA ARE PROPERLY GRADED AND DRAIN TO AN ADEQUATE E&S MEASURE. THE
3.11 RIGHT OF WAY DIVERSION- A RIGHT OF WAY DIVERSION IS PROPOSED AT THE
CONTRACTOR SHALL INSTALL A SMALL NEARBY SEDIMENT TRAP FOR VEHICULAR FLASH WASH OFF, WITH A PAVED RIGHT-OF-WAY DIVERSION
CONSTRUCTION ENTRANCE.
DISCHARGING INTO IT. CONSTRUCTION ENTRANCES ARE TO BE INSTALLED WHERE CONSTRUCTION VEHICLE ROUTES INTERSECT PAVED PUBLIC
3.13 SEDIMENT TRAP- A SEDIMENT TRAP IS PROPOSED WHERE SHOWN ON THE PLANS.
ROADS, PROVISIONS SHALL BE MADE TO MINIMIZE THE TRANSPORT OF SEDIMENT BY (VEHICULAR) TRACKING ONTO THE PAVED SURFACE.
3.14 SEDIMENT BASIN- TWO SEDIMENT BASINS ARE PROPOSED WHERE SHOWN ON THE
WHERE SEDIMENT IS TRANSPORTED ONTO A PUBLIC ROAD SURFACE, THE ROAD SHALL BE CLEANED THOROUGHLY AT THE END OF EACH DAY.
PLANS.
SEDIMENT SHALL BE REMOVED FROM THE ROADS BY SHOVELING OR SWEEPING AND 7RANSPOR77NG TO A SEDIMENT CONTROL DISPOSAL AREA.
STREET WASHING SHALL BE ALLOWED ONLY AFTER SEDIMENT IS REMOVED IN THIS MANNER.
3.18 OUTLET PROTECTION -OUTLET PROTECTION IS PROPOSED AT THE OUTLET OF PIPES.
5. 774E 1N177AL ESC CONSTRUCTION MEASURES, AS SHOWN ON THE PHASE l EROSION & SEDIMENT CONTROL PLAN, SHALL BE INSTALLED NEXT.
3.19 RIPRAP- RIPRAP IS PROPOSED AT THE OUTLET OF PIPES.
774E CONTRACTOR SHALL BEGIN BY INSTALLING THE PERIMETER SILT FENCE. PERIMETER MEASURES INTENDED TO TRAP SEDIMENT SHALL BE
3.32 PERMANENT SEEDING -PERMANENT SEEDING IS REQUIRED AND PROPOSED KITH THIS
CONSTRUCTED AS A FIRST STEP WITH ANY LAND DISTURBANCE ACTIVITY AND SHALL BE MADE FUNCTIONAL BEFORE UPSLOPE LAND
PLAN.
DISTURBANCE TAKES PLACE.
3.38 TREE PRESERVATION AND PROTECTION- TREE PROTECTION IS PROPOSED WITH THIS
6. ONCE THE PERIMETER EROSION CONTROL MEASURES HAVE BEEN INSTALLED, AND THE COUNTY INSPECTOR HAS APPROVED THESE MEASURES,
774E CONTRACTOR SHALL PROCEED TO LIGHT CLEARING OF THE SITE. THE CONTRACTOR SHALL BEGIN BY CLEARING THE AREAS REQUIRED TO
PLAN. SEE THE ESC PLAN FOR THE REQUIRED LOCATIONS
ACCESS THE LOCATIONS OF SEDIMENT BASIN A, SEDIMENT BASIN B' AND THE AREAS DESIGNATED AND/OR APPROVED BY THE INSPECTOR
PLAN DUST CONTROL -DUST CONTROL IS REQUIRED AND PROPOSED WITH THIS PLAN.
FOR CUT REQUIRED FOR THE BASINS' INSTALLATIONS. INSTALLATION OF SEDIMENT BASIN A' & SEDIMENT BASIN B' SHALL IMMEDIATELY
FOLLOW THE SELECTIVE CLEARING. FOLLOWING THE INSTALLATION OF THESE MEASURES THE CONTRACTOR SHALL INSTALL THE DIVERSIONS. THE
MAINTENANCE.
DIVERSIONS SHALL MAINTAIN POSITIVE DRAINAGE TO THE SEDIMENT TRAPPING DEVICES AT ALL TIMES 774ROUGHOUT CONSTRUCTION. ANY
REMAINING EROSION CONTROL ITEMS AS SHOWN ON 774E PHASE I EROSION CONTROL PLAN SHALL ALSO BE CONSTRUCTED AT THIS TIME.
IN GENERAL, DURING CONSTRUCTION THE RLD OR CONTRACTOR ON -SITE WILL CHECK ALL
7 ONCE ALL THE PHASE I EROSION CONTROL ITEMS HAVE BEEN INSTALLED & ARE OPERATIONAL, DRAINAGE IS PROPERLY CONVEYED TO THESE
EROSION AND SEDIMENT CONTROL MEASURES DAILY AND AFTER EACH SIGNIFICANT
MEASURES, AND THE ESC INSPECTOR HAS GRANTED APPROVAL, THE CONTRACTOR CAN BEGIN CLEARING THE REMAINDER OF THE SITE.
RAINFALL. MONITORING REPORTS WILL BE REQUIRED FROM THE RLD IF NEEDED. SPECIFIC
TEMPORARY SEEDING, PERMANENT SEEDING AND DUST CONTROL SHALL BE IMPLEMENTED AS REQUIRED.
ATTENTION WILL BE GIVEN SHE FOLLOWING ITEMS
aAFTER CLEARING THE PROPOSED AREAS, THE CONTRACTOR CAN PROCEED TO PHASE 11 OF THE EROSION &SEDIMENT CONTROL PLAN. UPON
a.SEDIMENT BASINS AND/OR TRAPS WILL BE CLEANED AND MAINTAINED IN ACCORDANCE
INSPECTOR APPROVAL, THE CONTRACTOR SHALL BEGIN ROUGH GRADING THE SITE TO THE CONTOURS SHOWN ON THE PHASE ll EROSION &
WITH THE VIRGINIA EROSION & SEDIMENT CONTROL HANDBOOK.
b.ALL GRAVEL OUTLETS WILL BE CHECKED REGULARLY FOR SEDIMENT BUILDUP THAT WILL
SEDIMENT CONTROL PLAN. ANY RETAINING WALL CONSTRUCTION THAT OCCURS IN ESC PHASE Il WITH THE GRADING OPERATIONS SHALL FILL THE AREAS
PREVENT PROPER DRAINAGE. IF THE GRAVEL IS CLOGGED BY SEDIMENT, THE GRAVEL
SURROUNDING THE RETAINING WALLS IN A MANNER THAT ENSURES THE FILL LOCATIONS ARE LEVEL VERTICALLY AT THE END OF EACH WORK DAY. SUCH A
WILL BE REMOVED AND CLEANED, OR IT WILL BE REPLACED.
PRACTICE WILL LIMIT CHANNEL FLOW AND PROMOTE SHEET FLOW. WORK ASSOCIATED WIN ANY RETAINING WALLS NEAR A GREENWAY SHALL OCCUR ON THE
c. ALL SILT FENCE BARRIERS WILL BE CHECKED REGULARLY FOR UNDERMINING OR
TOP SIDE TO REDUCE P07EN77AL IMPACTS TO THE DOWNSTREAM AREA. MEASURES INTENDED TO TRAP SEDIMENT SHALL BE CONSTRUCTED AS A
DETERIORATION OF THE FABRIC AND REPAIRED AS REQUIRED. SEDIMENT SHALL BE
FIRST STEP KITH ANY LAND DISTURBANCE ACTIVITY AND SHALL BE MADE FUNCTIONAL BEFORE UPSLOPE LAND DISTURBANCE TAKES PLACE.
REMOVED WHEN THE LEVEL OF SEDIMENT DEPOS177ON REACHED HALF WAY TO THE TOP
9. 774E CONTRACTOR SHALL INSTALL ANY REMAINING EROSION CONTROL ITEMS AS SHOWN ON THE PHASE ll EROSION CONTROL PLAN. TEMPORARY
OF THE BARRIER.
SEEDING PERMANENT SEEDING AND DUST CONTROL SHALL BE IMPLEMENTED AS REQUIRED.
d.ALL SEEDED AREAS WILL BE CHECKED REGULARLY TO SEE THAT A GOOD STAND IS
10. ONCE ALL THE PHASE Y EROSION CONTROL ITEMS HAVE BEEN INSTALLED & ARE OPERATIONAL, THE S17E /S ROUGH GRADED, DRAINAGE IS
MAINTAINED. AREAS SHOULD BE FER77LIZED AND RESEEDED AS NEEDED.
PROPERLY CONVEYED TO THESE MEASURES, AND 774E ESC INSPECTOR HAS GRANTED APPROVAL, THE CONTRACTOR CAN BEGIN PHASE Ill OF
IN CASE OF EMERGENCY, THE PRIMARY CONTACT FOR THE PROJECT WILL BE THE RLD OR
774E EROSION & SEDIMENT CONTROL PLAN.
CONTRACTOR ON -SITE 774E RLD's CONTACT INFORMATION CAN BE FOUND IN THE SWPPP,
12. 774E CONTRACTOR CAN BEGIN INSTALLATION OF THE UTILITIES, CURB AND GUTTER, AND PAVED ROADS INLET PR07EC77ON SHALL ALSO BE
WHICH IS TO BE LOCATED ONS17E AT ALL 77MES DURING CONSTRUC770N. IN ADDITION, THE
INSTALLED AS THE STORM SEWER IS CONSTRUCTED. INLET PR07EC77ON SHALL BE INSPECTED AFTER EACH RAINFALL EVENT AND REPAIRS
OWNER MAY BE CONTACTED. UPON COMPLETION OF THE PROJECT, THE OWNER WILL BE
SHALL BE MADE AS NEEDED. IF THE STONE FILTER BECOMES CLOGGED WITH SEDIMENT SO THAT IT NO LONGER ADEQUATELY PERFORMS ITS
RESPONSIBLE FOR SI7F MAINTENANCE.
FUNCTION, THE STONE MUST BE PULLED AWAY AND CLEANED AND/OR REPLACED. TO PROLONG THE LIFE OF TEMPORARY SEDIMENT BASIN A;
THE FINAL CONSTRUCTION OF COTS 124-127 & UNDERGROUND DETENTION SYSTEM A' SHALL BE DELAYED. TO FURTHER PROLONG THE LIFE
EROSION CONTROL NOTES:
OF SEDIMENT BASIN A', AND TO PROLONG THE LIFE OF SEDIMENT BASIN B; THE PERMANENT STORM SEWER OUTFALLING INTO THE
UNDERGROUND DETENTION SYSTEMS (AND ITS NEARBY MANHOLES) SHALL BE TEMPORARILY MODIFIED TO DIRECT UPLAND RUNOFF INTO THE
BASINS VIA THE TEMPORARY OUTFALLS SHOWN ON THE ESC PHASE 111 SHEETS. SEE SHEETS 10 & 12's NOTES FOR ADDITIONAL GUIDANCE.
ES-1: UNLESS OTHERWISE INDICATED, ALL VEGETATIVE AND STRUCTURAL EROSION AND
13 AFTER ALL OTHER PHASE 111 ESC MEASURES HAVE BEEN INSTALLED THE CONTRACTOR SHALL COORDINATE THE TIMING OF THE FINAL STORM SEWER
SEDIMENT CONTROL PRACTCES WILL BE CONSTRUCTED AND MAINTAINED ACCORDING TO
TO PERMANENT STRUCTURES, THE FINAL GRADING LOTS &THE INSTALLATION OF THE TWO UNDERGROUND
MODIFl770N
MINIMUM STANDARDS AND SPECIFICATIONS OF THE VIRGINIA EROSION AND SEDIMENT
SYSTEMS INS 'A'
DETENTION SYSTEMS KITH THE ESC INSPECTOR. AT THIS TIME SEDIMENT BASINS :4' AND B' SHALL BE CONVERTED TO PERMANENT SWIM
IM
CONTROL HANDBOOK AND VIRGINIA
N. REGULATIONS VR 625-02-00 EROSION AND
SEDIMENT CONTROL REGULATIO
FACIL177ES AND THE RETAINING WALLS ADJACENT TO SWM FACILITIES A' SHALL BE INSTALLED. PRIOR TO CONVER77NG SEDIMENT BASINS 'A'
ES-2: 774E PLAN APPROVING AUTHORITY MUST BE NOTIFIED ONE WEEK PRIOR TO THE
AND B' THE CONTRACTOR SHALL ENSURE THE UPLAND WATERSHEDS ARE STABILIZED. THE CONTRACTOR SHALL ALSO OBTAIN APPROVALS
PRE-CONS7RUC770N CONFERENCE, ONE WEEK PRIOR TO THE COMMENCEMENT OF LAND
FROM THE INSPECTOR TO INSTALL THE TWO UNDERGROUND DETENTION SYSTEMS AND FINALIZE 7HE CONS7RUC770N OF THE PERMANENT STORMW47ER
DISTURBING ACTIVITY, AND ONE WEEK PRIOR TO THE FINAL INSPEC770N
MANAGEMENT FACILITIES. AT THE TIME OF 7HE BASINS' CONVERSIONS, 7HE CONTRACTOR SHALL REMOVE SEDIMENT LADEN MATERIAL & BACKFILL THE AREAS
ES-3-ALL EROSION AND SEDIMENT CONTROL MEASURES ARE TO BE PLACED PRIOR TO OR AS
WITH STRUCTURAL FILL TO THE GRADES SHOWN ON THE STORMWATER MANAGEMENT SHEETS THE CONTRACTOR SHALL PAY SPECIAL AT7EN770N TO THE
THE FIRST STEP IN CLEARING.
SILT FENCE BENEATH THESE AREAS AT THIS TIME AND ENSURE THE FENCING CON77NUES TO BE EFFECTIVE. THE CONVERSIONS OF SEDIMENT
ES-4: A COPY OF THE APPROVED EROSION AND SEDIMENT CONTROL PLAN SHALL BE
BASINS 'A' & B' SHALL ONLY OCCUR AFTER ESC INSPECTOR APPROVAL.
MAINTAINED ON 774E SITE AT ALL TIMES.
14. FOLLOWING 774E CONVERSIONS OF THE SEDIMENT BASINS TO PERMANENT SWIM FACILITIES, AND 774E INSTALLATION OF UNDERGROUND DETENTION
ES-5. PRIOR TO COMMENCING LAND DISTURBING ACTIVITIES IN AREAS OTHER THAN INDICATED
SYSTEMS A' AND 'B', SHE CONTRACTOR CAN REMOVE THE REMAINDER OF THE EROSION & SEDIMENT CONTROL MEASURES NO ITEM SHALL BE
ON THESE PLANS (INCLUDING BUT NOT LIM17ED TO, OFF -SITE BORROW OR WASTE
REMOVED, THROUGHOUT ALL PHASES OF CONSTRUCTION, UNLESS THE UPS7REAM AREAS ARE STABILIZED AND SHE INSPECTOR GIVES
AREAS), THE CONTRACTOR SHALL SUBMIT A SUPPLEMENTARY EROSION CONTROL PLAN
PERMISSION.
TO THE OWNER FOR REVIEW AND APPROVAL BY THE PLAN APPROVING AUTHORITY.
15. PERMANENT OR TEMPORARY SOIL STABILIZATION SHALL BE APPLIED TO DENUDED AREAS W774IN SEVEN DAYS AFTER FINAL GRADE IS REACHED
ES-6: 774E CONTRACTOR IS RESPONSIBLE FOR INSTALLA77ON OF ANY ADDITIONAL EROSION
ON ANY PORTION OF THE SITE TEMPORARY SOIL STABILIZATION SHALL BE APPLIED W774IN SEVEN DAYS TO DENUDED AREAS THAT MAY NOT
CONTROL MEASURES NECESSARY TO PREVENT EROSION AND SEDIMENTATION AS
DETERMINED BY THE PLAN APPROVING AUTHORITY.
BE AT FINAL GRADE BUT KILL REMAIN DORMANT (UNDISTURBED) FOR LONGER THAN 30 DAYS. PERMANENT STABILIZATION SHALL BE APPLIED
ES -].•ALL DISTURBED AREAS ARE TO DRAIN TO APPROVED SEDIMENT CONTROL MEASURES AT
TO AREAS THAT ARE TO BE LEFT DORMANT FOR MORE THAN ONE YEAR.
ALL TIMES DURING LAND DISTURBING ACTIVITIES AND DURING SITE DEVELOPMENT UNTIL
16. THE CONTRACTOR SHALL MAINTAIN ALL EROSION CONTROL MEASURES AS SPECIFIED IN THE VIRGINIA EROSION AND SEDIMENT CONTROL
FINAL STABILIZATION IS ACHIEVED.
HANDBOOK REMOVING ONLY WHEN APPROVED BY THE LOCAL PROGRAM ADMINISTRATOR IN ACCORDANCE WITH THE VIRGINIA EROSION AND
-
ES 8: DURING DEWATERING OPERATIONS, WATER WILL BE PUMPED INTO AN APPROVED WATER
K.
SEDIMENT CONTROL HANDBOOK.
FILTERING DEVICE.
17. ALL TEMPORARY EROSION AND SEDIMENT CONTROL MEASURES SHALL BE REMOVED WITHIN 30 DAYS AFTER FINAL S17E STABILIZA7ON OR
ES-9: THE CONTRACTOR SHALL INSPECT ALL EROSION CONTROL MEASURES PERIODICALLY AND
AFTER THE TEMPORARY MEASURES ARE NO LONGER NEEDED, UNLESS OTHERWISE AUTHORIZED BY THE LOCAL PROGRAM ADMINISTRATOR.
AFTER EACH RUNOFF -PRODUCING RAINFALL EVENT. ANY NECESSARY REPAIRS OR
TRAPPED SEDIMENT AND THE DISTURBED SOIL AREAS RESUL77NG FROM THE DISPOS177ON OF TEMPORARY MEASURES SHALL BE PERMANENTLY
CLEANUP TO MAINTAIN THE EFFECTIVENESS OF THE EROSION CONTROL DEVICES SHALL
STABILIZED TO PREVENT FURTHER EROSION AND SEDIMENTATION.
BE MADE IMMEDIATELY.
3.05 1992
3.11 Pared construction entrance for erosion control plans 1992
CONSTRUCTION OF A SILT FENCE
(WITHOUT WIRE SUPPORT)
1. SET THE STAKES. 2. EXCAVATE A 47X 4" TRENCH
UPSLOPE ALONG THE LINE OF
STAKES.
6'MAX. / 'e�jrpl
I
/1 /�.1
FLOW -
3. STAPLE FILTER MATERIAL
TO STAKES AND EXTEND
IT INTO THE TRENCH.
4. BACKFILL AND COMPACT
THE EXCAVATED SOIL.
SHEET FLOW INSTALLATION
(PERSPECTIVE VIEW)
POINTS A SHOULD BE HIGHER THAN POINT B.
DRAINAGEWAY INSTALLATION
(FRONT ELEVATION)
Source: Adapted from Installation of Straw and Fabric Filter
Barriers for Sediment Control Sherwood and Wyant
TEMPORARY RIGHT-OF-WAY
DIVERSIONS
VDOT #1
COARSE AGGREGATE I11, Mt. I
g• MINIMUM
TYPICAL GRAVEL STRUCTURE
COMPACTED SOIL
/
- ---------------
-- _
10. Mlrt
I
6, MINIMUM
TYPICAL EARTHEN STRUCTURE
Plate 3.05-2
Source: Va. DSWC
Plate 3.11-1
CONSTRUCTION
Vi`�ii`�i\`Nci`�9`�xi\�i�Xi\.�,A-�.P:i .i:: i.:i .:i::i::i::i •:i �.
PROFIL
J..''
....... Y
i�POSITNE DRAINAGE
•MUST EXTEND FULL WIDTH L-.-0 TO SEDIMENT
]F INGRESS AND EGRESS DPERATION I TRAPPING, DEVICE
ELM
12' MIN.
rILTER CLO'H
(HIVE DRAINA01
SEDIMENT
RPING DEVICE
A ulummmt walat lap of I Much iuI be msWlcd wtlh a uutwmou 1 Much balko.l
,hutoti cah a supphniu a wash Is"e NTth a t1 ainc'In ut 1 ' mLhc� lol ;I(IC c
LOWA2111 pleS'Sltte. WaAl Walel Must be canietlawi% liom the elh ince to an
appl o%,etl ..aeNlule ai ea to I eaoce Aetluuetd .all ..<e,]I AhaO be pl eveated 8xm
calcimu Etotm dean,-. dttch6 of waterc MuFe9
PAVED WASH RAC4C
CONTRACTOR MAY SELECT A
RETAINING WALL MATERIAL/
DESIGN EQUIVALENT TO
ANCHOR DIAMOND
BEVBLED UNITS lloo ,,,,,
mwR.M.�.THE w� FF IF1 . ,w<-I F
�/�/�\\ Mchor- Diamond®
aEBJPORCBMENT CONNECTION
WX INarro.ca.E1 '-"""-wWm_..
E_..-FF1
I
06v�MEW L'NQ
Y I
�>nN
a
.o.E ..E�",,T,��a._ Em
wa
�Mc- O'_ "°
1:1 EXCAVATION OVBRSIZWO
WX $ E:1." VCF • "•"w.w."mmvm
X TYPICAL BASE PREPARATTON
WX (NOT TO SCALD -
�.
FB,TER FABRIC
ENTRENCHED 6-
COMPACTED SOIL3,tTM s' Imtnl
I �III
_-IIrII�IIH _7ItT1tTIII=III
1 �T-ITT-m-TI T�T�l
ta' �. - II-II-II�II�I =III-III=llrll-II-II�II�II-III=1
II Ildll=III-III=I �II II TIII-�II�II III-III=I --- -
IF�IIdILIIL=I - -
1 ll� - L
Id =III=1 -1 -I -1 L- -
�L�1' _--
e wNluou
DD TEMPORARY 113" DIVERSION BERM
GENERAL SLOPE (11 OR LESS) PER ACRE
TOTAL LBS
KENTUCKY 31 FESCUE 128 LBS.
RED TOP GRASS 2 LBS.
SEASONAL NURSE CROP 20 LBS.
SEASONAL NURSE CROP 50 LBS
FEBRUARY 16 THROUGH APRIL ANNUAL RYE
MAY 1 THROUGH AUGUST 15 FOXTAIL MILLET
AUGUST 16 THROUGH OCTOBER ANNUAL RYE
NOVEMBER THROUGH FEBRUARY 15 WINTER RYE
NOTES:
1. LIME AND FERTILIZER NEEDS SHALL BE DETERMINED BY SOIL
TESTS AND APPLIED IN ACCORDANCE WITH VESCH STD. 3.32.
2. SEEDINGS TO BE MULCHED IMMEDIATELY UPON COMPLETION
OF SEED APPLICATION IN ACCORDANCE W VESCH STD 3.35.
OPS
PERMANENT SEEDING SCHEDULE
NO SCALE
STD. & SPEC. 3.32 OF VIRGINIA EROSION &
SEDIMENT CONTROL HANDBOOK, 3RD ED.)
TABLE 331-A
LIMING REQUIREMENTS
FOR TEMPORARY SITES
Recommended Application
PH Test of Agricultural Limestone
below 42 3 tons per acre
4.2 to 5.2 2 tons per acre
52 to 6 1 ton per acre
Source: Va. DSWC
3.38
Source: Va. DSWC Plate 3.38-2
iCOTT/R. CbLLINSZ_
Lic. No. 035791�
L.
10/15/21 ,,'j
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SHEET NO.
3
DRY DETENTION BASIN CONSTRUCTION NOTES:
FACILITY PLANTING SPECIFICATIONS:
1. THE DETENTION BASIN SHALL HAVE TURF GROUND COVER, SUCH AS GRASS OR SOME OTHER FORM OF A VEGETATIVE GROUNDCOVER. LANDSCAPING BEYOND THIS IS OPTIONAL
AND IS NOT REQUIRED.
2. THE PROPOSED FLOOR SLOPES SHALL BE GRADED TO PROVIDE POSITIVE DRAINAGE AT ALL TIMES TO THE RISER STRUCTURE.
3. WOODY VEGETATION SHALL NOT BE PLANTED OR ALLOWED TO GROW WITHIN 15 FEET OF THE TOE OF THE EMBANKMENT NOR WITHIN 25 FEET OF THE PRINCIPAL SPILLWAY
STRUCTURE.
4. THE SOILS IN THE STORMWATER BUFFER AREA ARE OFTEN SEVERELY COMPACTED DURING THE CONSTRUCTION PROCESS, TO ENSURE STABILITY THE DENSITY OF THESE
COMPACTED SOILS CAN BE SO GREAT THAT IT EFFECTIVELY PREVENTS ROOT PENETRATION AND, THEREFORE, MAY LEAD TO PREMATURE MORTALITY OR LOSS OF VIGOR. AS A
RULE OF THUMB, PLANTING HOLES SHOULD BE THREE TIMES DEEPER AND WIDER THAN THE DIAMETER OF THE ROOTBALL FOR BALL -AND -BURLAP STOCK, AND FIVE TIMES DEEPER
AND WIDER FOR CONTAINER -GROWN STOCK.
5. AVOID SPECIES THAT REQUIRE FULL SHADE, OR ARE PRONE TO WIND DAMAGE. EXTRA MULCHING AROUND THE BASE OF TREES AND SHRUBS IS STRONGLY RECOMMENDED AS
MEANS OF CONSERVING MOISTURE AND SUPPRESSING WEEDS.
1. THE CONTRACTOR SHALL BE RESPONSIBLE FOR LAYOUT OF ALL WORK COVERED UNDER THESE PLANS.
2. LANDSCAPE CONTRACTOR SHALL REFER TO THE STANDARDIZED LANDSCAPE SPECIFICATIONS FOR THE STATE OF VIRGINIA FOR ADDITIONAL INFORMATION. THE CONTRACTOR
SHALL ABIDE BY ITS CONTENTS; HOWEVER ANY NOTES OR SPECIFICATIONS ON THE PLANS SHALL SUPERSEDE THOSE OUTLINED IN THE SPECIFICATIONS MANUAL (COPIES ARE
AVAILABLE FORA FEE FROM THE VIRGINIA CHAPTER OF THE AMERICAN SOCIETY OF LANDSCAPE ARCHITECTS, VIRGINIA NURSERYMEN'S ASSOCIATION, INC. AND THE VIRGINIA
SOCIETY OF LANDSCAPE DESIGNERS). ALL DISCREPANCIES SHALL BE BROUGHT TO THE ATTENTION OF COLLINS ENGINEERING PRIOR TO THE CORRESPONDING CONSTRUCTION
ACTIVITY.
3. ALL PLANT MATERIAL SHALL MEET THE MINIMUM SPECIFICATIONS AND STANDARDS DESCRIBED IN THE CURRENT ISSUE OFTHE AMERICAN STANDARD FOR NURSERY STOCK,
PUBLISHED BY THE AMERICAN ASSOCIATION OF NURSERYMEN, 1250 STREET, NW, SUITE 500, WASHINGTON, DC 20005.
4. THE CONTRACTOR SHALL VERIFY ALL DIMENSIONS IN THE FIELD AND NOTIFY THE DESIGNER OF ANY VARIANCE FROM THE PLAN.
5. THE LANDSCAPE CONTRACTOR IS RESPONSIBLE FOR VERIFYING THE LOCATION OF ANY ONSITE UTILITIES (CALL MISS UTILITY AT 1-800-552-7001 BEFORE ANY EXCAVATION).
6. REFER TO THE APPROVED FINAL SITE PLANS FOR ANY DETAILED SITE INFORMATION.
7. ALL WORK SHALL BE COORDINATED WITH OTHER PARTIES.
8. PLANTS WILL BE PREPARED FOR SHIPMENT IN A MANNER THAT WILL NOT CAUSE DAMAGE TO THE BARK, BUDS, BRANCHES, STEMS, OR OVERALL SHAPE OF THE STOCK.
CONTAINER GROWN PLANTS WILL BE TRANSPORTED IN THE CONTAINERS IN WHICH THEY HAVE GROWN.
9. ALL PLANT MATERIAL, UNLESS OTHERWISE SPECIFIED, SHALL BE UNIFORMLY BRANCHED AND HAVE A VIGOROUS ROOT SYSTEM. PLANT MATERIAL SHALL BE HEALTHY, VIGOROUS,
AND FREE FROM DEFECTS DECAY DISEASES INSECT PEST EGGS AND ALL FORMS OF INFESTATION. ALL PLANT MATERIAL SHALL BE FRESH FREE FROM TRANSPLANT SHOCK OR
VISIBLE WILT. PLANTS DEEMED UNHEALTHY WILL BE REJECTED.
10. ALL CONTAINER STOCK SHALL HAVE BEEN PROPAGATED IN A CONTAINER LONG ENOUGH FOR THE ROOT SYSTEM TO HAVE DEVELOPED SUFFICIENTLY TO HOLD ITS SOIL.
CONTAINER STOCK WITH POORLY DEVELOPED ROOT SYSTEMS WILL NOT BE ACCEPTED.
11. PLANTS NOT INSTALLED ON THE DAY OF ARRIVAL ON SITE SHALL BE STORED AND PROTECTED BY THE CONTAINER. OUTSIDE STORAGE AREAS WILL BE SHADED AND PROTECTED
FROM THE WIND AND SUN. PLANTS STORED ON SITE SHALL BE PROTECTED FROM ANY DRYING AT ALL TIMES BY COVERING THE BALLS OR ROOTS WITH MOIST SAWDUST, WET
BURLAP, WOOD CHIPS, SHREDDED BARK, PEAT MOSS, OR OTHER SIMILAR MULCHING MATERIAL.
12. THE OWNER RESERVES THE RIGHT TO SUBSTITUTE PLANT MATERIAL TYPE, SIZE AND/OR QUANTITY. ANY SUBSTITUTIONS MUST BE APPROVED BY THE INSPECTOR INITIALLY, AND
THEN THE DESIGNER.
13. MINOR FIELD ADJUSTMENTS MAYBE NECESSARY DUE TO SITE CONDITIONS (EX: ROOTBALL AND UTILITY CONFLICT). MAJOR ADJUSTMENTS MUST BE APPROVED BY THE DESIGNER.
14. NO PLANTING SHALL OCCUR WHEN THE SOIL IS FROZEN.
15. PLANT MATERIAL SHALL BE PLACED IN EXISTING SOIL WITH EACH PLANTING PIT EXCAVATED TO A SIZE SUFFICIENT TO CONTAIN THE ENTIRE ROOT BALL OR ROOT MASS, WITHOUT
CRAMPING ROOTSTOCK.
16. THE CONTRACTOR SHALL MAINTAIN A ONE (1) CALENDAR YEAR 90°%CARE AND REPLACEMENT WARRANTY FOR ALL PLANTINGS. THE PERIOD OF CARE AND REPLACEMENT SHALL
BEGIN AFTER INSPECTION AND APPROVAL OF THE COMPLETE INSTALLATION OF ALL PLANTS AND CONTINUE FOR ONE CALENDAR YEAR.
17. THE CONTRACTOR IS RESPONSIBLE FOR REMOVAL AND DISPOSAL OF TRASH AND DEBRIS WITHIN THE LIMITS OF THE PLANTING ON A DAILY BASIS.
18. THE CONTRACTOR WILL NOT BE RESPONSIBLE FOR PLANT MATERIAL THAT HAS BEEN DAMAGED BY VANDALISM, FIRE, OR OTHER ACTIVITIES BEYOND THE CONTRACTOR'S
CONTROL.
FACILITY CONSTRUCTION
1. DETENTION BASINS MAY SERVE AS SEDIMENT BASINS AND/OR TRAPS DURING PROJECT CONSTRUCTION. IF THIS IS DONE, THE VOLUME SHALL BE BASED ON THE MORE STRINGENT
SIZING RULE EROSION AND SEDIMENT CONTROL REQUIREMENTS VS. STORMWATER TREATMENT REQUIREMENTS). INSTALLATION OF THE PERMANENT RISER SHALL BE INITIATED
( Q
DURING THE CONSTRUCTION PHASE, AND DESIGN ELEVATIONS SHALL BESET WITH FINAL CLEANOUT OF THE SEDIMENT BASIN AND CONVERSION TO THE POST -CONSTRUCTION
POND IN MIND. APPROPRIATE PROCEDURES SHALL BE IMPLEMENTED TO PREVENT DISCHARGE OF TURBULENT WATERS WHEN THE BASIN IS BEING CONVERTED TO AN DETENTION
BASIN.
2. THE DETENTION BASIN SHALL ONLY BE CONSTRUCTED AFTER THE CONTRIBUTING DRAINAGE AREA TO THE POND IS COMPLETELY STABILIZED. IF THE PROPOSED POND SITE WILL BE
USED AS A SEDIMENT TRAP OR BASIN DURING THE CONSTRUCTION PHASE THEN THE FACILITY WILL BE DEWATERED DREDGED AND RE -GRADED TO DESIGN DIMENSIONS AFTER
THE ORIGINAL SITE CONSTRUCTION IS COMPLETE. MODIFICATIONS SHALL BE MADE TO THE RISER ORIFICES AND BARRELS AS REQUIRED SO THAT THEY ARE CONSISTENT WITH THE
FINAL CONSTRUCTION SPECIFICATIONS.
3. THE CONTRACTOR SHALL ASSEMBLE CONSTRUCTION MATERIALS ON -SITE MAKING SURE THEY MEET DESIGN SPECIFICATIONS AND ARE PREPARED AT STAGING AREAS WHEN
POSSIBLE.
4. THE CONTRACTOR SHALL CLEAR AND STRIP THE PROJECT AREA IF REQUIRED TO THE DESIRED SUB -GRADE.
5. INSTALL E&S CONTROLS PRIOR TO CONSTRUCTION OFTHE BASIN, INCLUDING TEMPORARY DE -WATERING DEVICES AND STORMWATER DIVERSION PRACTICES. ALL AREAS
SURROUNDING THE BASIN THAT ARE GRADED OR DENUDED DURING CONSTRUCTION SHALL BE PLANTED WITH TURF GRASS, NATIVE PLANTINGS, OR OTHER APPROVED METHODS
OF SOIL STABILIZATION.
6. CONTRACTOR SHALL EXCAVATE THE CORE TRENCH AND INSTALL THE SPILLWAY PIPE DURING THE ESC PHASE.
7. CONTRACTOR SHALL ALSO INSTALLTHE RISER OUTFLOW STRUCTURE AND/OR THE BARREL s WITH PERMANENT COLLARS DURING THE ESC PHASE. CONTRACTOR SHALL ENSURE
THE TOP INVERT OF THE OVERFLOW WEIR IS CONSTRUCTED LEVEL AT THE DESIGN ELEVATION.
8. THE CONTRACTOR SHALL CONSTRUCT THE EMBANKMENT AND ANY INTERNAL BERMS IN 8-TO 12-INCH LIFTS, COMPACTION SHALL BE COMPLETED IN LIFTS WITH APPROPRIATE
EQUIPMENT. THE CONTRACTOR SHALL ALSO ADHERE TO THE CLAY LINER SPECIFICATIONS OUTLINED IN TABLE 14.4 BELOW:
Table 14.4. Clay Liner Specmcations
Pro
Test Method
Unk
swillication
Permeability
ASTM D-2434
Cmtsec
1 x 1
Plasticity Index of Clay
ASTM D-4231424
%
Not less than 15
Liquid Limit of Clay
ASTM D-2216
%
Not less than 30
Clay ParlI Pass"
ASTM D422
%
Not less than 30
Clay Compaction
ASTM D-2216
%
95%ol standard pfotlordens
Source: Virginia Stormwaler Management. Handbook (1999)
9. UPON COMPLETION OF THE EMBANKMENT GRADING THE CONTRACTOR SHALL EXCAVATEGRADE UNTIL THE APPROPRIATE ELEVATION AND DESIRED CONTOURS ARE ACHIEVED
FOR THE BOTTOM AND SIDE SLOPES OF THE BASIN.
10. CONTRACTOR SHALL THEN CONSTRUCT THE EMERGENCY SPILLWAY IN CUT OR STRUCTURALLY STABILIZED SOILS.
11. THE CONTRACTOR SHALLTHEN FINISH CONSTRUCTION OF ALL OUTLET STRUCTURES, INCLUDING DOWNSTREAM RIP -RAP PROTECTION IF APPLICABLE.
12. THE CONTRACTOR SHALL NEXT STABILIZE EXPOSED SOILS BY HYDROSEEDING OR SEEDING OVER STRAW.
13. THE CONTRACTOR SHALL THEN INSTALL THE APPROPRIATE BASIN LANDSCAPING IN ACCORDANCE WITH THE APPROVED PLANS, IF APPLICABLE.
FACILITY MAINTENANCE:
MAINTENANCE OF THE DETENTION BASIN IS DRIVEN BY ANNUAL INSPECTIONS THAT EVALUATE THE CONDITION AND PERFORMANCE OF THE FACILITIES. DURING THESE INSPECTIONS
THE FOLLOWING TASKS SHALL BE PERFORMED BY THE CONTRACTOR IN THE FIRST YEAR FOLLOWING INSTALLATION, AND THE OWNER THEREAFTER:
1. MEASURE SEDIMENT ACCUMULATION LEVELS IN THE BASIN.
2. MONITOR THE GROWTH OF THE GROUNDCOVER AND ANY TREES AND SHRUBS PLANTED, AS APPLICABLE. RECORD THE SPECIES AND THEIR APPROXIMATE COVERAGE, AND NOTE
THE PRESENCE OF ANY INVASIVE PLANT SPECIES, AS APPLICABLE.
3. INSPECTTHE CONDITION OF STORMWATER INLETS TO THE BASIN FOR MATERIAL DAMAGE EROSION OR UNDERCUTTING.
4. INSPECTTHE BANKS OF UPSTREAM AND DOWNSTREAM CHANNELS FOR EVIDENCE OF SLOUGHING, ANIMAL BURROWS, BOGGY AREAS, WOODY GROWTH, OR GULLY EROSION
THAT MAY UNDERMINE EMBANKMENT INTEGRITY.
5. INSPECT BASIN OUTFALL CHANNEL FOR EROSION, UNDERCUTTING, RIP -RAP DISPLACEMENT, WOODY GROWTH, etc.
6. INSPECT CONDITION OF PRINCIPAL SPILLWAY AND RISER FOR EVIDENCE OF SPALLING, JOINT FAILURE, LEAKAGE, CORROSION OR OTHER FAILURES.
7. INSPECT CONDITION OF ALL TRASH RACKS, REVERSE SLOPED PIPES OR FLASHBOARD RISERS AS APPLICABLE FOR EVIDENCE OF CLOGGING, LEAKAGE, DEBRIS ACCUMULATION OR
OTHER FAILURES.
8. INSPECT MAINTENANCE ACCESS TO ENSURE IT IS FREE OF WOODY VEGETATION, AND CHECK TO SEE WHETHER VALVES, MANHOLES AND LOCKS CAN BE OPENED AND OPERATED.
9. INSPECT INTERNAL AND EXTERNAL SIDE SLOPES OF THE BASIN FOR EVIDENCE OF SPARSE VEGETATIVE COVER, EROSION, OR SLUMPING.
10. OWNER OR CONTRACTOR SHALL MAKE NEEDED REPAIRS IMMEDIATELY.
FACILITY INSPECTION:
MULTIPLE INSPECTIONS ARE CRITICALTO ENSURE THE BASIN(s) ARE PROPERLY CONSTRUCTED. BECAUSE THE TIMING OF THE INSTALLATION IS DICTATED BY THE CONTRACTOR, THE
CONTRACTOR SHALL BE RESPONSIBLE FOR CONTACTING THE ENGINEER AND INSPECTOR PRIOR TO INSTALLATION. MULTIPLE SITE VISITS AND INSPECTIONS ARE REQUIRED TO BE
SCHEDULED BY THE CONTRACTOR WITH THE ENGINEER AND INSPECTOR DURING THE FOLLOWING STAGES OF THE DETENTION BASIN's CONSTRUCTION PROCESS:
1. PRE -CONSTRUCTION MEETING
2. INITIAL SITE PREPARATION (INCLUDING INSTALLATION OF PROJECT E&S CONTROLS)
3. EXCAVATION/GRADING (e.g., INTERIM/FINAL ELEVATIONS)
4. INSTALLATION OF THE EMBANKMENT, THE RISER/PRIMARY SPILLWAY, AND THE OUTLET STRUCTURE(s).
4. DETENTION BASIN INSTALLATION (e.g., INTERIM AND FINAL ELEVATIONS)
5. PLANTING PHASE (WITH AN EXPERIENCED LANDSCAPE ARCHITECT PRESENT/DIRECTING IF APPLICABLE)
6. FINAL INSPECTION (DEVELOP A PUNCH LIST FOR FACILITY ACCEPTANCE)
400 400
PR POSED
FADE
®--m m®
PROPOSED RETAINING
WALL, TYP.
390
390
FOUNDATION,
-PROPOSED
TYP.
SEE RETAINING WALL
DESIGN, BY OTHERS,
FOR CONSTRUCTION
385
385
DETAILS TYPICAL.
Di4
400
395
PROPOSED RETAINING
WALL, TYP.
39 PROPOSED
FOUNDATION, TYP.
385
380 GRADE
PROPOSED STORMTECH
--XISTINC CHAMBERS TO BE
GRADE SURROUNDED WITH STONE &
FILTER FABRIC CLOTH. A 30
mil LINER SHALL BE
NSTALLED ON THE WEST SIDE 375 375 375
OF THE SYSTEM.
.0' MIP
COVER
370 370 1 370
PROPOSED ADS 6" DUAL WALL PERFORATED HDPE UNDERDRAIN
STORMTECH - 1Z BENEATH EACH ROW OF STORMTECH CHAMBERS,
CHAMBERS, TYP. TYPICAL. UNDERDRAIN TO BE SLOPED AT 0.50%,
DOWNSTREAM INV. AT STR. Al2=363.50
CHAMBER BOTTOM= 366.50'
6 6 6
5 3 5 3 5 3
WESTERN
/
UNDERDRAIN
RAL
INV. AT CROSS
UNDE DRAIN
SECTION
INV. AT CROSS
36o
SECTION 363.6
r6
00
01
It
J J
W LU10
11 N
O W
6
w0
m
M ^�
Dm ^�
m
0+50 0+75
UNDERDRAII
INV. AT CROS
SECTION=364.1
STONE BOTTOM= 363.50' -
360 INV. AT
crrTl I
UNDERDRAIN w w n
NV. AT CROSS w w
SECTION=363.56 M
W LL
)OSED
ADE 395
390
P OPOSE
0-GRIE
TYP.
385
TG
5
38o
375
O PROPOSED ADS
STORMTECH
CHAMBERS TYP
365
ASTERN
UNDERDRAIN
INV. AT CROSS
SECTION=364.02
\IN
oS
360
0)
IN
P.,
Do 00
rn
m
m
0+50 0+75
U G D A- X-SEC # 1 PROFILE SCALES U G D A- X-SEC # 2
1"=5' (V)
VAA6114'IDLO STORMWATER DESIGN SPECIFICATION NO. 2 SHEET FLOW TO FILTER OR OPEN SPACE
KEY LEVEL SPREADER
INTO EXISTING GRADE
RIPRAPPLUNaE POOL STORMWATER MANAGEMENT FACILITY STORAGE TABLE
(D)
AIPRAPAPAON `�� (A) (B) (C) (B+c)
6' X6"TREATED UGD S stem Facilit Area of StormTech D Basin Area Total Facility
.1 TIMBERS OR Y Y Dry Y
�� wCONCRETE LIP Elevations (ft) System (sf) (Sf) Area (sf)
LENG0_01% LIP TORE BASEDOF ` ONDESIiGGNN FLOW 363.00 0 304 304
AND ALLOWABLE VE LOCITY 363.50 1,726 442 2,168
1 TOP
BL.EVEL SPREADER 364.00 1,726 598 2,324
E FLAT 364.50 1,726 778 2,504
365.00 1,726 979 2,705
1-3 IN. COURSE AGGREGATE 365.50 1,726 1200 2,926
OR OTHER LJNING AS
DESIGNED FOR STABILITY 366.00 1,726 1441 3,167
PLAN VIEW 366.50 1,726 1703 3,429
DIMENSION BASED ON Unnr6TVRBED EXIT W E 367.00 3,274 1985 5,259
DESIGN DISCHARGE S% C20I OR LEES. IF VECfTATSD
FLTER S'rP1P OR CONSERVED
2'MIN OPEFR4TiOFEETLFe6 367.50 3,229 2195 5,424
3 TMMBJeP4CMIN 368.00 3,167 2391 5,558
19 MIN 3 IN
368.50 3,087 2608 5,695
M
I 369.00 2,987 2835 5,822
12 369.50 2,861 3073 5,934
f MIN. oEvrH aASEOo I 370.00 2,702 3320 6,022
/ REQUIRED STONE SIZE ) I.
370.50 2,488 3577 6,065
II II 371.00 2,135 3844 5,979
371.50 1,749 4122 5,871
SECTIONA A 372.00 1,726 4,410 6,136
Figure 2.4: Level Spreader: Pipe or Channel Flow to Filter Ship or Ffese~4 Con Served 372.50 1,726 4,708 6,434
Op
en Space 373.00 0 5,017 5,017
375
375
Q
�
K
370
30'
370
P
OPOSED
FADE
P
R
S
FI
365
365 c
XISTIN
GRADE
362
362
ao
o u1
0NDm
ELIOUJOL�u
lDm
^'�
m ^'�
m
NOTE, AFTER AN EVALUATION OF THE SITE'S HYDRAULICS IT IS
BELIEVED THAT LEVEL SPREADER UPLAND OF THE
WETLANDS TO REMAIN IS A SUITABLE DESIGN. THE
WETLANDS ARE RELATIVELY LEVEL WITH GENTLE SLOPES,
AND HAVE A HIGH INFILTRATION RATE. THESE
.�
W
CHARACTERISTICS ARE SUITABLE FOR THE SWM CONSERVED
W
OPEN SPACE EASEMENT BELOW THE LEVEL SPREADER. ALSO,
THE RUNOFF ENTERING THE WETLANDS WILL NOT BE
ALTERED DRASTICALLY. THE SMALLER/ LOWER OUTFALL
DIRECTING RUNOFFTOTHE LEVEL SPREADER WILL ENSURE ,� W
s
MORE FREQUENT AND LESS SIGNIFICANT RAINFALL EVENTS S J
DRAIN TO THE WETLANDS. AND THE LARGER/UPPER J
OUTFALL DIRECTING RUNOFF AWAY FROM THE WETLANDS W \
WILL ENSURE LESS FREQUENT AND MORE SIGNIFICANT
RAINFALL EVENTS DO NOT BURDEN THE WETLANDS.
/ S
's DRY DETENTION BASIN'A' & UNDERGROUND DETENTION SYSTEM'A' DETAIL:
SCALE 1"=30'
PROPOSED 30' WIDE VDOT CL. Al RIPRAP LINED EMERGENCY/ 0000
SPILLWAY w/4:2 SIDE SLOPES & FILTER FABRIC UNDERLAYMENT
\ (STONE DEPTH=22"). SPILLWAY CREST ELEV.=372.75'. U
\ / l it
PROPOSED 20' WIDE EMBANKMENT &
HANDRAILS ALONG RETAINING WALL
/ - - SURROUND THE DRY BASIN &SERVE
/ j AS A SAFETY BENCH/ MEASURE.
PROPOSED ELEVATED 030" OUTFALL CARRYING LARGER
STORM EVENTS TO THE OUTLE
T PROTECTION /
SEE THIS SHEET FOR SCALED PROFILES
-j. .. .. ..........
OF THE SWM FACILITY, TYP. / \ -
io'WIDE GRADED, GRASS LINED ---
ACCESS ROAD TO SWM FACILITIES / STR, q) ul -
FOR POTENTIAL MAINTENANCE. 2+0O37�`_
ACCESS ROAD ENCASED IN VAR. /
--- \ WIDTH SWM &ACCESS ESMT. / 1 -
0 / R. A10
17
�Q-' / uluu
'1_\
PROPOSED FLAT VOOT CLASS At, EC-1 RIPRAP
PROPOSED STIR. T(/ A4 TO SERVE -
OUTLET PROTECTION w/ GEOTEXTILE FILTER /
AS THE RISER STRUCTURE
P
1
FABRIC UNDERLAYMENT. FABRIC TO BE KEYED
I
\ O � 1 h
INTO EX. GROUND FABRIC
9OOVERLAP ENDS
MI ALONG
PERIMETER. FABRIC TO OVERLAP A MIN. OF 9"
i 1
W E W
I
(OP L-64', W1-9', W2-16', D-18") / \ !LI
r PROP SED VAR. H \_ iiJ- + O
ISWM WAC( E55. T �I
PROPOSED zo' WIDE TOP
1
OF DAM ELEVATION=373..0'
PROPOSED LOWER OUTFALL(78.6o LF OF 01.5"HDPE_ i.
/ @o.5o0%) CARRYING THE TREATMENT VOLUME =u Q
FLOW TO LEVEL SPREADER W. 11=36z.8o', 10=362.4z) 7= \
0 ti
/ PROPOSED STIR. Ai, A 030" HDPE, TO >+�
�\ / CONVEY RUNOFF FROM UGD SYSTEM Jk \
�'�\v / WTO DRY DETENTION BASIN'A'.
COUNTY DEFINED-n�'J \\ +00 _ W STR=�A2 V
-
' PRESERVED STEEP f
'SLOPES TYP. k
i \ 0
I
360.0 50
LIMITS ,LlllOF I I W 362.1
FEMA 10(p-YR LIMITS OF
LO DPLIIAIN \ STREAM,TYP. 3622 w--
\ Q W W V I OT O
A
r
l
W D
G I
I I E
PROPOSED 94' LONG FLAT LEVEL SPREADER W. LS TO HAVE A 12" MIN. DEEP X
PLUNGE POOL&6"WIDE RIGID LIP. LS TO INCLUDE AVDOT CL. Al RIPRAP LINING I �I
AND SLOPED 3( )MIN. VDOT CL. Al RIPRAPLINED EMBANKMENT
DOWNSTREAM FROM THE RIGID LIP EXTENDING TO THE EXISTING GRADE. ALL � /
RIPRAP TO INCLUDE FILTER FABRIC UNDERLAYMENTS&BE A MIN. OF 12" DEEP. _� J
3:1 W
1
1
1
PROPOSED 5o'x94'SWM CONSERVED WIW W W W W W I 1
OPEN SPACE EASEMENT. AREA I
WITHIN EASEMENTTO REMAIN
UNDISTURBED & TO BE LOCATED 362.32-TOP OF LEVEL SPREADE
OUTSIDE THE LIMITS OF -
DISTURBANCE. EASEMENT PREVENTS
FUTURE DEVELOPMENT, I 361..31 BOTTOM OF LEVEL SPREADER I
DISTURBANCES & SITE CLEARING. +II PROPOSED VAR. WIDT
v I 1 I SWM&ACCESS ES \ I
PROPERTY LINE, TYP N PROPOSED STORMTECH +O X G.#2
r ,SE
CONTRACTOR SHALL CALL THE COUNTY INSPECTOR& ISOLATOR ROW TO PROVIDE,
PROPOSED STORMWATER QUALITY & \ I
ENGINEERING DEPARTMENT z -HOURS BEFOREANY
4 4EENWAY, TYP. 0 QUANTITY TREATMENT, TYP. II
ANTICIPATED CONSTRUCTION ACTIVITIES FOR THE BMPs. THIS \ - �
IS INCLUSIVE OF WHEN THE UNDERGROUND DETENTION \ 6" DUAL WALL PERFORATED HDPE UNDERDRAIN BENEATH EACH
SYSTEM SUBGRADE IS READY FOR PIPE CONSTRUCTION, BUT ROW OF STORMTECH CHAMBERS, TYPICAL. UNDERDRAIN TO BE
BEFORE STONE BEDDING IS INSTALLED.I I I ' ' \ X SLOPED AT 0.50%, DOWNSTREAM INV. AT STR. Alt=363.50
SWM CONSERVED OPEN SPACE EASEMENT & LEVEL SPREADER REQUIREMENTS:
MAINTENANCE INSPECTIONS:
ANNUAL INSPECTIONS SHALL BE CONDUCTED IN THE NON -GROWING SEASON DURING THE FALL AND WINTER MONTHS.
INSPECTIONS SHALL TRIGGER MAINTENANCE OPERATIONS, AS REQUIRED. MAINTENANCE OPERATIONS MAY INCLUDE,
BUT IS NOT LIMITED TO, SEDIMENT REMOVAL, PERIODIC MOWING, REPAIR OFTHE LEVEL SPREADER AND ENSURING A
DENSE, HEALTHY VEGETATED GROUNDCOVER. MOWING SHALL BE COMPLETED AT LEAST TW ICE A YEAR TO PREVENT
FURTHER WOODY GROWTH AND SPOT RE -VEGETATION OFTHE CONSERVATION AREA, BUTSHALL NOT EXCEED 4TIMES
A YEAR. THIS MOWING 15 REQUIRED IN ORDER TO MAINTAIN Ago% MINIMUM COVERAGE RATE. THE CONTRACTOR SHALL
CONDUCT THE INSPECTIONS FOLLOWING THE FIRST YEAR THE PROJECT 15 COMPLETED, AND THE OWNER SHALL
CONDUCTTHE INSPECTIONS THEREAFTER.
INSPECTIONS SHALL INCLUDE THE FOLLOWING ATA MINIMUM:
2. ENSURE FLOW PATHSARE NOTSHORT-CIRCUITED INTHE LEVEL SPREADER AND THROUGH THE SWM CONSERVED
OPEN SPACE EASEMENT.
2. ENSURE DEBRIS AND SEDIMENT HAS NOTACCUMULATED.
3. CHECK FOR SCOUR AND EROSION WITHIN THE LEVEL SPREADER SYSTEM AND CONSERVATION AREA.
4. CHECK FOR FOOT OR VEHICULAR TRAFFIC DAMAGE IN THE STONE.
5. ENSURE VEGETATIVE DENSITY MEETS OR EXCEEDS go% OF THE SWM CONSERVED OPEN SPACE EASEMENT.
IN THE EVENT MAINTENANCE IS REQUIRED DURING THE ABOVE NOTED INSPECTIONS, CORRECTIVE MEASURES SHALL BE
COMPLETED IMMEDIATELY.
PROPOSED BASIN's FLOOR SHALL BE SLOPED TO DRAIN TO THE RISER (o.5%MIN.) WITH
POSITIVE SLOPES THROUGHOUT. BASIN FLOOR TO BE LINED WITH VDOT CL. At STONE
380 (1.8" DEPTH) & FILTER FABRIC UNDERLAYMENTTO REDUCE THE RISK OF CLOGGING.
PROPOSED id
WIDE TOP OF DAM
ELEVATION=373.0'
ZOPOSED 30' WIDE VDOT CL. A
PRAP LINED EMERGENCY
'ILLWAY w/ 4:1 SIDE SLOPES &
-TER FABRIC UNDERLAYMENT
TONE DEPTH=12"). SPILLWAY
ZEST ELEV.=372.75'.
0+50
BASIN A SPILLWAY
i
_J
r 373- iil„
_-
O
/
TO PREVENT FLOTATION THE RISER
/
/ BASE SHALL BE FIRMLY EMBEDDED 6"
INTOA36"THICK REINFORCED
CONCRETE FOUNDATION THAT IS
l
idxio', AND BURIED BELOW GROUND.
�J
J
O
/ V �
PROPOSED BASIN's FLOOR SHALL BE
SLOPED TO DRAIN TO THE RISER (o.5% MIN.) /
WITH POSITIVE SLOPES THROUGHOUT.
�
/ / III„Ro f.
PROPOSED MANHOLE (A22)TO PROVIDE -
/ ACCESS TO STORMTECH SYSTEM FOR
/ INSPECTION & MAINTENANCE.
MANHOLE TO ACCEPT 6"UNDERDRAINS
FROM STONES' BOTTOM (11=363.50') &
THE 28" PIPES FROM THE CHAMBERS.
5 MANHOLE TO INCLUDE A 2' SUMP, WITH
AN ELEV. SET 2' BELOW THE ISOLATOR iI
ROW FOR CLEANOUT.
I \ 1 A
PROPOSED FLAT VDOT STD. CLASS AI
-1
RIPRAP LINED OUTLET PROTECTION WITH
FILTER FABRIC UNDERLAYMENT(L=8', �\ I
W1=3', W2=9, D=28", TOP ELEV.=362.4i') II
PROPOSED VAR. WIDTH SWM 4Q\A---
`, & ACCESS ESMT. COINCIDES \
WITH PROPERTY LINE \ :.
1
12 4
PROPOSED STORMTECH CHAMBERS TO
BE SURROUNDED WITH STONE & FILTER
FABRIC CLOTH. A 30 mil LINER SHALL
BE INSTALLED ON THE WEST SIDE OF
THE SYSTEM. SEE SHEET 19 FOR
ADDITIONAL DETAILS.
PROPOSED MANHOLE TO PROVIDE
ACCESS TO STORMTECH SYSTEM FOR
INSPECTION & MAINTENANCE. MANHOLE
TO INCLUDE A WEIR TO DIVERT INITIAL
TREATMENT VOLUME RUNOFF TO THE
i + I SOLATOR ROW. TOP OF WEI R(367.50')
TO BESET 12" ABOVETHE BOTTOM OF
THE CHAMBER TO ALLOW
(366.5o),
GREATER STORM EVENTS TO OVERFLOW
'INTO THE ADDITIONAL CHAMBERS ROWS.
8
I COUNTY DEFINED MANAGED
STEEP SLOPES, TYP.11
SWM CONSERVED OPEN SPACE EASEMENT LANDSCAPING REQUIREMENTS:
IN ACCORDANCE WITH VA DEQ SPECIFICATION #2, NO GRADING OR CLEARING OF NATIVE VEGETATION IS
ALLOWED WITHIN THE SWM CONSERVED OPEN SPACE EASEMENT. THE CONTRACTOR IS HOWEVER REQUIRED TO
REFORESTTHE EASEMENT's AREA WITH NATIVE TREES AND SHRUBS WHERE VEGETATION IS SPARSE.
THE LANDSCAPER SHALL INITIALLY REMOVE ANY INVASIVE SPECIES WITHIN THE SWM CONSERVED OPEN SPACE
EASEMENT. FOLLOWING THIS THE CONTRACTOR SHALL PLANTTREES io' ON -CENTER OUTSIDE OFTHE SANITARY
SEWER EASEMENT AND SHRUBS 5' ON -CENTER WITHIN THE SANITARY SEWER EASEMENT WHERE NATIVE SPECIES
ARE NOTALREADY PRESENT. THIS OVER -PLANTING WILLASSIST IN THEAREA's FAST ESTABLISHMENT AND WILL
ACCOUNT FOR MORTALITY. TREES AND SHRUBS WITH DEEP ROOTING CAPABILITIES ARE REQUIRED FOR PLANTING
TO MAXIMIZE SOIL INFILTRATION CAPACITY. THETREES SHALL BE A COMBINATION OF 2" CAL. ROTUNDILOBA
AMERICAN SWEETGUMS (LIQUIDAMBAR STYRACIFLUA'ROTUNDILOBA') AND 2" CAL. PINCETON ELMS (ULMUS
AMERICANA'PRINCETON'). THE SHRUBS SHALL BEA COMBINATION OF 2" CAL. BUFORD HOLLIES (ILLEXCORNUTA
'BURFORDII')AND 2"' CAL. NELLIE R. STEVENS HOLLIES ILLEXX'NELLIE R. STEVENS). ATTHE COMPLETION OFTHE
TREE AND SHRUB PLANTINGS THE CONTRACTOR SHALL APPLY A NATIVE SLOPE MIXTOTHE GROUNDCOVER WITH
AN ANNUAL RYEGRASS BY ERNST CONSERVATION SEEDS ATA RATE OF 6o LBS. PER ACRE OR 2 LB. PER 2 000sf
UNLESS OTHERWISE SPECIFIED. THIS GROUNDCOVER WILL HELP TO ENSURE RAPID VEGETATIVE COVER OFTHE
SWM CONSERVED OPEN SPACE EASEMENT.
PROPOSED MANHOLE (A22) TO PROVIDE
ACCESS TO STORMTECH SYSTEM FOR
INSPECTION & MAINTENANCE. MANHOLE TO
ACCEPT 6" UNDERDRAINS FROM STONES'
BOTTOM (11=16i.so') & THE 28" PIPES FROM
100-yr PEAK WSE=371.7
10-yr PEAK WSE=371.36
2-yr PEAK WSE=370.73
1-yr PEAK WSE=369.69
PROPOSED 06" HDPE STUB PIPE, 19.50 LF @ 0.50% WITH VDOT STD. EW-12 HEADWALL. CONTRACTOR
TO INSTALL A MANUFACTURED STEEL WEIR PLATE IN LIEU OF THE SPECIFIED TYPICAL FLATTENED
'EXPANDED STEEL MESH'. WEIR PLATE TO INCLUDE A 1-16" LOW -FLOW ORIFICE OPENING DIRECTING
RUNOFF INTO THE 06" STUB PIPE. ALTERNATIVELY, A 1-,6" x 1-,6" SQUARE LOW -FLOW ORIFICE CAN BE
CUT INTO THE WEIR PLATE. EW-12 HEADWALL OPENING TO BE COVERED WITH A LANE ENTERPRISES
TRASHRACK, OR EQUIVALENT. SEE SHEET 19B FOR EW-12 HEADWALL & TRASHRACK DETAIL.
SEPARATION
OF 1.5' IS REQ'D
W W
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a
rn
n
m
N
r�
01
00 p
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Doi
17 0
M
M
M
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11, m
m m
r,
W LL
0+50 1+00
PROPOSED FLAT VDOT CLASS Al, EC-1
RIPRAP OUTLET PROTECTIONw/GEOTEXTILE
FILTER FABRIC UN DERLAYM ENT. FABRIC TO
BE KEYED INTO EX. GROUND 9" MIN. AT ENDS
& ALONG PERIMETER. FABRIC TO OVERLAP A
MIN. OF 9" (OP L=64', W1=9', W2=16', D=18")
1+50 2+00 2+50 3+00 3+50
FUGD SYSTEM A AND BASIN A
4+00
PROFILE SCALES
1"=5' (V)
1"=50'(H)
4+50 5+00
SCOTT/R. CD•LLINSZ
ti
Lic. No. 035791,'
p 10/15/21 �41
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JOB NO.
182150
SCALE
AS SHOWN
SHEET NO.
168
r
UNDERGROUND DETENTION SYSTEM (UGD) U REQUIREMENTS
CONTRACTOR REQUIREMENTS:
i. THE CONTRACTOR SHALL BE RESPONSIBLE FOR LAYOUT OF ALL WORK COVERED UNDER THESE PLANS.
z. THE CONTRACTOR SHALL VERIFY ALL DIMENSIONS IN THE FIELD AND NOTIFY THE DESIGNER OF ANY VARIANCE FROM THE PLAN.
3. REFER TOTH E APPROVED FINALS ITE PLAN FOR ANY DETAILED SITE INFORMATION.
4 ALL WORK SHALL BE COORDINATED WITH OTHER PARTIES.
5. MINOR FIELD ADJUSTMENTS MAYBE NECESSARY DUE TO SITE CONDITIONS. MAJOR ADJUSTMENTS MUST BE APPROVED BY THE DESIGNER.
GENERAL CONSTRUCTION SEQUENCE NARRATIVE
i. THE CONTRACTOR SHALL ASSEMBLE CONSTRUCTION MATERIALS ON -SITE, MAKING SURE THEY MEET DESIGN SPECIFICATIONS AND ARE PREPARED AT
STAGING AREAS WHEN POSSIBLE.
z. THE CONTRACTOR SHALL CLEAR AND STRIP THE PROJECT AREA IF REQUIRED TOTH E DESIRED SUB -GRADE.
3. CONTRACTOR SHALL EXCAVATE THE TRENCH.
4. THE TRENCH FOR THE UGD SYSTEM SHALL EXTEND 3' BEYOND THE PIPES' SPRINGLINES.
5. CONTRACTOR SHALL WRAP THE EXCAVATED TRENCH WITH A 6 OUNCE FILTER FABRIC CLOTH. A SUITABLE FOUNDATIONS SHALL BE BENEATH THE TRENCH's
FILTER CLOTHS.
6. TRENCH TO INCLUDE A 6"#57 STONE BED AT 95% COMPACTION BENEATH THE STORM PIPES.
7. CONTRACTOR SHALL INSTALL THE UGD DETENTION SYSTEM, INCLUSIVE OF THE OUTFALLS AND ALL OF THE ASSOCIATED STRUCTURES.
8. TRENCH SHALL BE BACKFILLED WITH COMPACTED #57 STONE IN 8" LIFTS AND SHALL EXTEND 6" VERTICALLY ABOVE THE CROWNS OF THE PIPES.
9. THE TOP OF THE #57 STONE SHALL BE COVERED WITH A 6 OUNCE FILTER FABRIC CLOTH, OVERLAPPING THE PREVIOUSLY INSTALLED CLOTH THAT
SURROUNDS THE BOTTOM AND SIDES OF THE TRENCH.
io. SUITABLE FILL REACHING THE FINISHED GRADE SHALL BE APPLIED ABOVE THE TOP LAYER'S FILTER CLOTHES, MEETING MINIMUM PIPE MANUFACTURER'S
REQUIREMENTS TO PREVENT FLOATATION AND ENSURING PIPE INTEGRITY IS MAINTAINED.
ii. A MINIMUM COVER OF 18" IS REQUIRED ABOVE THE CROWN OF THE DETENTION SYSTEM's PIPES. THE MINIMUM 6"OF#57 STONE ABOVE THE CROWN OF THE
PIPES CAN BE PART OF THE MINIMUM 18" OF COVER.
12. SEE THE MANUFACTURER'S SPECIFICATIONS FOR ADDITIONAL UNDERGROUND DETENTION SYSTEM REQUIREMENTS.
INSPECTIONS DURING CONSTRUCTION:
CONSTRUCTION INSPECTIONS ARE CRITICAL TO ENSURE THE UNDERGROUND DETENTION SYSTEM IS PROPERLY BUILT. BECAUSE THE TIMING OF THE
INSTALLATION IS DICTATED BY THE CONTRACTOR THE CONTRACTOR SHALL BE RESPONSIBLE FOR CONTACTING THE ENGINEER COUNTY INSPECTOR AND
CONTECH REPRESENTATIVE PRIOR TO INSTALLATION. CONTECH OR AN EQUIVALENT PIPE MANUFACTURER SHALL BE CONTACTED WELL AHEAD OF THE
CONSTRUCTION START DATE TO ENSURE ADEQUATE LEAD TIME FOR MATERIALS AND DELIVERY. MULTIPLE SITE VISITS AND INSPECTIONS ARE REQUIRED TO BE
SCHEDULED BY THE CONTRACTOR, WITH THE ENGINEER, COUNTY INSPECTOR & PIPE MANUFACTURER, DURING THE FOLLOWING STAGES OF THE UNDERGROUND
DETENTION SYSTEM CONSTRUCTION PROCESS:
i. PRE -CONSTRUCTION MEETING
z. INITIAL SITE PREPARATION (INCLUDING INSTALLATION OF PROJECT E&S CONTROLS)
3. EXCAVATION/GRADING(E.G., INTERIM/FINAL ELEVATIONS).
4. WHEN THE DETENTION PIPE SUBGRADE IS READY FOR PIPE CONSTRUCTION, BUT BEFORE STONE BEDDING IS INSTALLED.
5. AFTER STONE BEDDING IS PLACED AND COMPACTED, BUT PRIOR TO PIPE INSTALLATION.
6. ATTHE TIME OF THE PIPE INSTALLATION.
7. AFTER PIPE INSTALLATION, BUT PRIOR TO PLACING BACKFILL & FILL OVER THE SYSTEM.
8. FINAL INSPECTION (DEVELOP A PUNCH LIST FOR FACILITY ACCEPTANCE)
PLEASE ALSO SEE BELOW, UNDER FACILITY MAINTENANCE, FOR REQUIRED INSPECTIONS AFTER INSTALLATION IS COMPLETE.
INSPECTIONS & MAINTENANCE AFTER CONSTRUCTION:
THE FOLLOWING MAINTENANCE TASKS SHALL BE PERFORMED BY THE CONTRACTOR IN THE FIRST YEAR FOLLOWING THE INSTALLATION OF THE UNDERGROUND
DETENTION SYSTEM.
i. FOR THE FIRSTYEAR FOLLOWING CONSTRUCTION THE SITE SHALL BE INSPECTED BY THE CONTRACTOR QUARTERLY AND AFTER STORM EVENTS THAT
EXCEED 3/2 INCH OF RAINFALL.
2. THE CONTRACTOR SHALL LOOK FOR BARE OR ERODING AREAS IN THE CONTRIBUTING DRAINAGE AREA AND AROUND THE UNDERGROUND DETENTION
SYSTEM AND MAKE SURE THEY ARE IMMEDIATELY STABILIZED. CONTRACTOR SHALL SPOT RESEED AS NECESSARYAND ENSURE ADEQUATE SITE COVERAGE
IS PROVIDED WITHIN THE FIRSTYEAR. AT THE QUARTERLY INSPECTIONS, AND AFTER EACH RAINFALL EVENT IN EXCESS OF"', THE CONTRACTOR SHALL
PERFORM THE ANNUAL MAINTENANCE TASKS DESCRIBED BELOW IN #3.
AFTER THE FIRSTYEAR THE OWNER SHALL PERFORM FOLLOW-UP INSPECTIONS ANNUALLY, AND AFTER EACH SIGNIFICANT RAINFALL EVENT:
3. A SPRING MAINTENANCE INSPECTION AND CLEANUP SHALL BE CONDUCTED ANNUALLY. THE MAINTENANCE PROGRAM FOR THE UNDERGROUND DETENTION
SYSTEM SHALL INCLUDE CLEANING ITANNUALLY OFTRASH, DEBRIS & SEDIMENTAND ENSURING THE INTEGRITY OF THE TRASH RACKS AND OUTFALL &
INFLOW PIPES. THE OWNER SHALL ENSURE THE SYSTEM IS OPERATING AS INTENDED AND IS NOT CLOGGED OR DAMAGED. THE OWNER SHALL IMMEDIATELY
CLEAN & REPAIR THE FACILITY AS NECESSARY AND SHALL PAY SPECIAL ATTENTION TO THE INLETAND OUTLET LOCATIONS. THE ACCESS MANHOLES SHALL
BE USED FOR INSPECTION AND MAINTENANCE.
390
GENERAL SWM NOTES:
i. STATE APPROVED TRASH RACKS SHALL BE INSTALLED ON ALL ORIFICE OPENINGS. SEE DETAILS IN THIS PLAN SET OR
EQUIVALENT, FOR DESIGN.
z. CONCRETE FOUNDATIONS SHALL BE INSTALLED ON ALL RISER STRUCTURES MEETING MINIMUM VESCH .i SPECIFICATIONS.
3 4
3. CONTRACTOR SHALL HIRE ATHIRD PARTY GEOTECHNICAL ENGINEER TO ENSURE THE EMBANKMENTS ARE STRUCTURALLY
SOUND. THE EMBANKMENTS SHALL HAVE A COMPACTED CLAY CORE WITH A CUTOFFTRENCH & BE IN ACCORDANCE WITH THE
DETAILS SHOWN IN THIS PLAN SET. ALL EXISTING AND PROPOSED FILL MATERIAL AND PROPOSED CONSTRUCTION SHALL BE
APPROVED BYAN ONSITE GEOTECHNICAL ENGINEER PRESENT DURING THE CONSTRUCTION OF THE EMBANKMENTS AND FILL
AREAS AND PRESENT DURING THE CORE SAMPLING.
4. THE DOWNSTREAM EMBANKMENT SIDE SLOPES OF ALL PERMANENT FACILITIES SHALL HAVE A MAXIMUM 3:1 SLOPE.
S. THE GENERAL CONTRACTOR, 3RD PARTY GEOTECHNICAL ENGINEER AND STRUCTURAL ENGINEER DESIGNING THE RETAINING
WALLS SHALL WORK TOGETHER TO ENSURE THE SWM FACILITIES AND RETAINING WALLS DO NOT UNDERMINE EACH OTHER.
THESE PARTIES SHALL ENSURE THE STRUCTURAL INTEGRITY OF THE WALLS AND SWM FACILITIES ARE MAINTAINED.
0120" WEIR PLATE DETAIL
NOTE: (UNDERGROUND DETENTION SYSTEM 'B'
SCALE:i"=5' )
WEIR PLATE TO BE SECURELY
BOLTED, OR SIMILARLY FASTENED,
TO THE DETENTION SYSTEM.
9.01' ELEV.=379.50'
(TOP OF PIPE;
OVERFLOW WEIR IS HYDRAULICALLY ELEV.=377.67'
EQUIVALENTTO AN ORIFICE WITH AN
APPROX. DIAMETER OF 021.24"
INSTALLTRASH RACKS ON ALL -
ORIFICES, TYP. SEE SHEET i9B
FOR THE WEIR PLATE's
TRASHRACK ON THE LOW -FLOW
ORIFICE, OR EQUIVALENT.
NFORCED 12 GA.
STEEL PLATE
ELEV.=369.5'
(BOTTOM OF F
MANUFACTURE / INSTALL ONE l 0za" LOW -FLOW
ORIFICE IN THE STEEL WEIR PLATE AT THE LOW POINT OF
THE DETENTION SYSTEM (INVERT ELEVATION 369.50')
390
NOTE:
PROP
SEDACC
SS MHw
f STAIRS
ANY DRAINAGE
STRUCTURE
WITH
k DROP IM
EXCES
3 OF 4'
ERTICAL
Y SHALL
HAVE
FOR INSPECTION
& MAINTENANCE
A 1" THI
K STEEL
PLATE ATTHE
BOTTOM
017
THE ST
ZUCTURE,
TYPICA
.
385
385
60" MH
z
RI
=388.55
I
=369.37
IC
=369.27
38o
STIR.
BBIl
38o
RIN
=387.22
I/I
I
=368.14
III
IC
=366.64
III I
030" F
DPE
° ELEVATE
CY BYP
EMERGE
SS
375
PIPES,
V.=377.
0'
375
STIR.
Bab TO SERVE
AS A RISER
STR. BB
z
TOP
OF WEIR
PLATE=
77.67'
STIR
UCTURE.
SEE DETAILS ON
P
OPOSE
6 8 0
5 3
0 6
3 "
SHE
19B. RISER
TO INCLUDE
RADE
HOPE
z.00%
A 60"
NER DI
METER WITH A
OPEN TOP
& TRASHRACK
TR. BB8
RIM-361.33
60" MH
370
II=349.
5 (06" RIFICE)
RI
=366.5
370
I0=3
6.50 l
36
II
360.79
IO
357.04
01
" LOW-
LOW
FICE INV
OR
IN
WEIR
P
10
-yr PEAK
WSE
362.56
1
-yr P
AK WSE
361.64
030" INV.
OUT=
69.47'
365
ROPOS
SoSPILD
IDESRI.
EMERGEICY
PEAK
WSE
359.57
365
AYw
zSIzVDOT
OPESN&DILTERFA
FABRIC
_�
UNDI
RLAYME
4T (STONE
DEPTH
iz ). SPILLWAY
CIR
EST
STIR. BBi
PROPOSED
LOWER
LEV.=362
33'. (10'
IDE TOP
F DAM
LEV. 364
00)
PROPOS
D VDOT
030HD
,
E PRIMA
Y OUTF
LL
S
D. EW-1
_
(io.o6
LF
II 36g.4
10 36g.
7)
CON
RACTOR SHALL
INSTALL
/
`�'
STR. BB
EMBAN<MENTII
w/ THE
54-54'O
036"
3ROPOSE
DOizo
ERFORA
ED CMP
ACCORDANCE
DI
SIGN S
OWN ON THESE
PLANS.
4RI
HDPE@10.70%
NDERGR
UNDO
TENTIO
SYSTEM
o.5o%
31
TR. BB4
360
-357.33
(MH2-M
1A). A
I
=345.40
MIN. SEI
1ARATIOI
I
=344.65
OF 1. 0' IS
RE 'D
APPROX.
LOCA
ION OF I
X. 021"
STR. BB7
DIPS
IL (INV=
50.42t
. A MIN.
r?
20.00' O
036"
355
SEP
RATION
OF 1.0'
S REQ'D
'
HOPE Qa
.5o%
355
INV. OU
=356.14'
EXISTING-
STR. BBz
FADE
`�
So" MH
CONTRA
OR SH
LL REP
CE STE
L WEIR
LATE A
ACHED
O THE
ISER
WIT
A
TEEL
RI
=348.0o
E
IN V
=343.66
STABILIZED,
OR
HEN T
E ESC INSPECTO
DIRECT
THE O
NER (W
ICHEVE
INV
T=343.16
COMES
IRST). P
OPOSE
WEIR P
-ATE BEL
W IS S ZED
FO
BLOCKS
16 & 17
NEW
350
WEIR P
TE IS S
ZED FOF
BLOCKE
16 & 17
AND THE
PORTIO
OF FUl
URE BLC
CK 18
350
SHOWN
DIN THESE
PLANS.
NEW WEIR
PLATE
TO INCIIUDE
A 1
16" LOW
FLOW ORIFICE
PROPOSED
VDOT
(INVERT
350.00
, OR A 1
a" x 1-a"
SQUARE
OPENIN
WITH
N INVER
OF 350
00.
D. ES-1
sFEDUFFiHALLBE
INV. OU
343.00'
SLOPED
ODRAI
TOTHE
ISER(o.5
MIN.)
345
WITHPO
ITIVESL
PESTH
OUGHO
T.
345
STR. BB
CONTRA
OR SH
LL INST
LL A 12
x12" MA14UFACTL
RED STEEL
WEIR
8z.8o' O
036" :`
PLATE O
ER THE
ISER's
6" LOW
FLOW DRIFT
EO
ENING.
EIR PLATE
STR. BB
HDPE Le11.30%
TO INCLUDE
A 1 4"
LOW-F
OW ORI
ICE (IN
ERT=35
.00), O
A 1-L6"
1-I6"
48-05'OF
036"
RE
OPENING
WITH A
IN
350.00.
-PLATE
OPENHV
STR. BB
HOPE dal
z. o%
WILL DI
ECT RU
OFF INT
THE R RISER
0
" ORIFI
E. A LAN
ENTER
RISE
7.85' OF
036"
TRASH
CK, OR
EQUIVALENT,
SH
ILL BE IN
TALLIED
OVER T
E WEIR
LATE
340
HOPE
z.o%
&AFFIX
D TO THEE
RISER.
SEE LAN
ENTER
RISE T
SHRAC
DETAIL
N
340
TO IF
REVENTIFLOTATIC
N THE RISER
BASE
SHALL BE
FIRMLY
SHEET 1
B. NOTE,
TO RE
UCE THE
RISK OF
CLOGGI
4G THE
ONTRACrOR
EIV
BEDDED
"INTO
36"THI
K REINF
RCED C
NCRETE
SHALL IP
STALL A
10'Lx10'
x12"D i.L.
AI RIPRAP
LINED
STON
PIT WI
H A
FOUNDATION
HAT IS i
'xio', AN
BURIED
BELOW GROUND.
FILTER F
NBRIC Ul
IDERLAYMENT
AT
THE RIS
R's LOW
HFILOW O
IFICE
PROPOSE
DFLAT V
OTCLASS
ET PROTECTION
(T0
1, EC-1 RIF
RAP OUT
LOW-FLC
W ORIFI
E, WHE14
DIRECT
LY BELOW
THE L(
&
ELEV: 34
.00')w/G
OTEXTILE
ILTERFA
RICUNDE
LAYMENT
FABRICT
TRASH
CK.
335
BE KEYED
NTO EX. GROUND
9"
MIN. ATENDS
& ALC
NG PERIM
TER.
335
FABRICT
OVERLAPA
MIN. OF9"
OPL=
30' W1=9
W2=17'
=18"
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l0
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rl06
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lDkD
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w w
0+50 1+00 1+50 2+00
PROFILE SCALES
1"=5' (V)
1"=50'(H)
2+50 3+00 3+50 4+00 4+50 5+00
UGD SYSTEM B AND BASIN B
5+50 6+oo 6+5o 6+75
UNDERGROUND DETENTION SYSTEM'B' i
& DRY DETENTION BASIN'B' DETAIL:
SCALE 1"=30' j I - PROPOSED ACCESS MH w/ STAIRS FOR
INSPECTION & MAINTENANCE, TYP.
1
W I
'0120"- INV. 370.16'
(� \ 0120" INV. 370.09'
0120" INV. 370,03'
0120" INV. 369.96'
to
-\ 2
�z / I " 0120" INV. 3I9.90' 1
I• / / \ \ I I I 0120" INV. 369,83'
II \ I 10120" INV. 369.77'
0120" INV. 369.70'
I \\ \ \ 1 I I 0120" INV. 369.64'
I
1 ,
00
I M
IV' I IO
I
22.00m OF 0120"
CMP 0 0.50%, TYP.
/ I I PROPOSED ELEVATED !o" LE
I \�„ EMERGENCY OUTFALL
(14.75 LF, 11=377.00, 10=376.5o)
■ 1
W PROPOSED ELEVATED 030" HOPE
EMERGENCY OUTFALL
(22.5o LF, 11=377.00, 10=372.00)
\ \ \ 1 " ■ 1 I
PROPOSED 06oMH WITH;" I
STEEL PLATE, RIM=386.50'
PROPOSED 036"HDPE I
EMERGENCY OUTFALL
W W W W I\ \' (4.85 LF, 11=3693o, 10=36937) \
I
l/ � W .W.WW 1 I / EXISTING WETLANDS TO--!' \
„ W ,��U,(J�Y DE�INF�W
/ ISTEEP, I I REMAIN UNDISTURBED,PRESE13VEQ
' \W TYP. ", SLOPES TYP.". W I I I 11 \ II
I
I 1 /pWWWWW�W\a1I �1` "I�
X I) 1I S I s
PROPOSED io'WIDE TOP I 'I �IIT
w W OF DAM ELEVATION- 6
PROPOSED 4.0' J m
GREENWAY, TYP. IW W W W W W W I I IDIIEIIEITIITI TI
PROPOSED VARIABLE
WIDTH SWM"& IDTI=ITI
IS � ACCESSESMT:",-
PROPOSED FLAT VDOT CLASS Al, EC-1
RIPRAP OUTLET PROTECTION (TOP
III
ELEV: 343.00') w/ GEOTEXTILE FILTER
FABRIC UNDERLAYMENT. FABRIC TO BE
KEYED INTO EX. GROUND 9" MIN. AT
\\ I ENDSOV RLAP A`MIN OF 9" (OP D i 0O STIR. Bz ' I / " +00 I�i -111
1 / 3
PROPOSED 60"X60" BOX CULVERT
(UNDER SEPARATE SET OF PLANS)
340 -
PROPOSED 5o' WIDE VDOT CL. Al
RIPRAP LINED EMERGENCY SPILLWAY
& FILTER FABRIC UNDERLAYMENT
(STONE DEPTH=12"). SPILLWAY
365 CREST ELEV.=362.33'. 365
Q
360
360
r5O'
DROPOSIED
EXISTNG
GRADE
GRACE
355
355
MN OM
Eouujjou�j
N
ILI
M Min
PROPOSED id
WIDE TOP OF DAM
ELEVATION=364.0'
0+50 0+75
BASIN B SPILLWAY
r �
SEE THIS SHEET FOR
PROPOSED VDOT SCALED PROFILES OF
1 STD. ES-1 \ THE ALIGNMENTS (TYP.) " 1
1
I
V
B ` PROPR SPL\WI� VDOTCL.AI I II
NED RGE CY
SPILL AYE�''/4 SI SLOP&
FILTER FABRIC UD YMENT0+7�
(STONE EPT�i3"). ILLW Y
T E 6z3�'.
I�
xS
\ \ CONTRACTOR SHALLCALLTHE COUNTY INSPECTOR&
\ \\ \ \ ENGINEERING DEPARTMENT 24-HOURS BEFORE ANY
Y\ ANTICIPATED CONSTRUCTION ACTIVITIES FOR THE BMPs. THIS
IS INCLUSIVE OF WHEN THE UNDERGROUND DETENTION
SYSTEM SUBGRADE IS READY FOR PIPE CONSTRUCTION BUT
J BEFORE STONE BEDDING IS INSTALLED.
i
4,6
I
0 7 120" INV. 3 005'
0120" INV. 369.98' I__ _ 3
0120 11INV. 36992
0120 INV. 369.85'
0120" INV. 3 69.79'
I I /
109.00' OF 0120"
CMP @ 0.50%
I/ I \
0120" INV. 369.72'
0120" INV. 369.66'
- 0120" INV: 369.59'
0120" INV:--369.53'
I 1 0120" INV. 369.52'
I\ 030" INV. 376.50'
1
0120" INV. 369.50'
/ STIR. BB13, PROPOSED LOWER \: \
/ '<R BBiz 03o" HOPE PRIMARY OUTFALL `\ \
\ (a0.06 LF, 11=369-47, 10=36937)
m/ 5+00
1 \
3.�0 \
5
STR. BB1�' \ \ 384 1 \ LOT \ I \
/ 1 \
I L
PROPOSED VDOT SWM&-CCESS E _ T.
STD. EW-1
PROPOSE VDOT STD. -1
-� '...:. 5�
zo' WIDE GRADED, GRASS LINED ACCESS ROAD
C. FOR POTENTIAL MAINTENANCE. ACCESS s�
_ v ROAD ENCASED IN VAR. WIDTH SWM &
= ACCESS EASEMENT. ROAD TO EXTEND FROM
r ` PUBLIC RIGHT-OF-WAY TO THE SYSTEM.
UNDERGROUND DETENTION SYSTEM 'B'STORAGE TABLE
i
a
PROPOSED BASIN's FLOOR
SHALL BE SLOPED TO DRAIN TO
THE RISER (o.5% MIN.) WITH
POSITIVE SLOPES THROUGHOUT.
J-PROPOSED STIR. BB6 TO SERVE AS THE
_ RISER STRUCTURE. RISER TO INCLUDE A
TOP TRASHRACK AND A LOW -FLOW ORIFICE
THAT CONTAINS A STEEL WEIR PLATE &
TRASHRACK. SEE THE PROFILE ON THIS
SHEET FOR ADDITIONAL INFORMATION.
1-n4 Y
TO PREVENT FLOTATION THE RISER
BASE SHALL BE FIRMLY EMBEDDED 6 /
INTO A 36" THICK REINFORCED
CONCRETE FOUNDATION THAT IS
io'xi0', AND BURIED BELOW GROUND.
36 .
(E)
(F)
(G)
(A)
(B)
(C)
(D)
C-B
DxE
B+F
Facility Elevations
Area of 120"
UGD System
Void Space of
Area of Stone
Storage Area in
Total UGD System
(ft)
Perforated CMP (sf)
Footprint (sf)
Stone (%)
(sf)
Stone (cf)
Storage Area (sf)
369.00
0
3,960
40%
3,960
1,584
1,584
369.50
0
3,960
40%
3,960
1,584
1,584
370.50
11842
3,960
40%
2,118
847
2,689
371.50
2,456
3,960
40%
1,504
602
3,058
372.50
2,814
3,960
40%
1,146
459
3,272
373.50
3,008
3,960
40%
952
381
3,389
374.50
3,070
3,960
40%
890
356
3,426
375.50
3,008
3,960
40%
952
381
3,389
376.50
2,814
3,960
40%
1,146
459
3,272
377.50
2,456
3,960
40%
1,504
602
3,058
378.50
1,842
3,960
40%
2,118
847
2,689
379.50
0
3,960
40%
3,960
1,584
1,584
380.50
0
3,960
40%
3,960
1,584
1,584
DRY BASIN 'B' STORAGE TABLE
(H)
(1)
Facility Elevations
Area of Contours
(ft)
(sf)
350
2,672
352
3,816
354
5,127
356
6,609
358
8,268
360
10,105
362
12,089
364
14,178
FAP
SCOTT7 R. CD'LLINS'Z
Lic. No. 035791,E
p 10/15/21 �41
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SCALE
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SHEET NO.
17
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