HomeMy WebLinkAboutWPO202000034 Plan - VSMP 2021-05-10SITE DATA
OWNER -
DEVELOPER
PLAN PREPARER:
TAX MAP PARCEL No:
PARCEL AREA:
ZONING:
CURRENT USE:
PROPOSED USE
MAGISTERIAL DISTRICT
WATERSHED:
BELVEDERE LAND HOLDINGS LLC
PO BOX 7505
CHARLOTTESVILLE, VA 22906
NEW BELVEDERE, Inc.
610 WEST RIO RD
CHARLOTTESVILLE, VA 22901
ROUDABUSH, GALE, & ASSOCIATES
914 MONTICELLO ROAD
CHARLOTTESVLLE, VA. 22902
(434)-977-0205
%I:Y7/ZIIIIIIIIIIIIIIILY/ZIi
15.00 ACRES
R4 RESIDENTIAL (THIS PARCEL IS NOT PART OF THE BELVEDERE ZMA-2004-0007)
STEEP SLOPES - MANAGED
STEEP SLOPES - PRESERVED
VACANT
RESIDENTIAL DEVELOPMENT
RIO MAGISTERIAL DISTRICT
UPPER RIVANNA RIVER
BOUNDARY SOURCE PLAT DIVISION OF DUNLORA" PREPARED BY WM MORRIS FOSTER, LAND SURVEYOR, DATED NOVEMBER 1,
1985, REVISED DECEMBER 20, 1985, RECORDED AT DB 815 PG 331.
TOPOGRAPHY AERIAL TOPOGRAPHY FLOWN IN 2016 BY BELL LAND SURVEYS LLC. TOPOGRAPHY STILL UNCHANGED BASED
ON A SIFF VISIT AND DESIGN PROFESSIONAL'S OPINION, THE SURVEY IS STILL ACCURATE TO THE EFFECT
THAT THERE ARE NO EVIDENT VARIATIONS
BENCHMARK: FIRE HYDRANT 455.10, RIGHT FRONT BONNET BOLT AT CORNER OF FOWLER SFREET AND FARROW DRIVE
DATUNM. HORZ: NAVD 88, VERL: NAD83
FLOODPLAIN: THIS PROJECT IS LOCATED WITHIN 'ZONE X" AS SHOWN ON FLOOD INSURANCE RATE MAP. COMMUNITY
PANEL NUMBER 510003C 0279 D. EFFECTIVE DA TE FEBRUARY 4. 2005.
NO EVIDENCE OF A BURIAL SITE WAS FOUND ON SUBJECT PARCEL.
NO STREAM BUFFER(S) ARE PRESENT ON THE SUBJECT PARCEL.
THE SUBJECT PROPERTY IS NOT LOCATED WITHIN AN AGRICULTURAL -FORESTAL DISFRICL
THIS SITE IS NOT LOCATED WITHIN THE WATERSHED OF A PUBLIC WATER SUPPLY RESERVOIR.
STORMWATER MANAGEMENT COMPLIANCE SUMMARY
THE DEVELOPMENT OF BELVEDERE PHASE 5, TMP 62-16D, WILL OCCUR IN TWO SEPARATE STAGES OF CONSTRUCTION. THE COMPLETED SUBDIVISION WILL
UTILIZE AN EXTENDED DETENTION FACILITY TO FACILITATE CHANNEL AND FLOOD PROTECTION. STORMWATER RUNOFF WILL BE COLLECTED AND CONVEYED
THROUGH A STORMWATER PIPE NETWORK TO THE FACILITY. NUTRIENT OFFSET CREDIT PURCHASE ROUNDS OFF THE STORMWATER APPROACH.
REGARDING WATER QUALITY ANALYSIS:
9VAC25-870-63. WATER QUALITY DESIGN CRITERIA REQUIREMENTS.
1. NEW DEVELOPMENT, THE TOTAL PHOSPHORUS LOAD OF NEW DEVELOPMENT PROJECTS SHALL NOT EXCEED 0.41 POUNDS PER ACRE PER YEAR, AS
CALCULATED PURSUANT TO 9VAC25-870-65.
CALCULATIONS SHOWN ON THIS PLAN WERE DETERMINED FROM ACCEPTABLE METHODOLOGY "DEQ VRRM FROM NEW DEVELOPMENT COMPLIANCE
SPREADSHEET -VERSION 3.0."
CONCLUSION:
BASED ON NEW DEVELOPMENT OF BELVEDERE PHASE 5 (A AND B), TMP 62-16D, SHOWN HEREON THESE PLANS, THE WATER QUALITY PORTIONS OF THIS
PLAN WILL BE SATISFIED WITH PURCHASING 9.68 IB/YR OF OFFSITE NUTRIENT CREDITS IN THE SAME OF ADJACENT HYDROLOGIC UNIT CODE (02080204).
COMPLIANCE OF 9VAC25-870-65.F: OFFSITE ALTERNATIVE IAW 9VAC25-870-69 PURCHASE OF NUTRIENT OFFSET CREDITS IS PROPOSED AND AFFIRMED.
REGARDING WATER QUANITY ANALYSIS FOR POINT OF DISCHARGE #1:
COMPLIANCE OF 9VAC25-870. III (CHANNEL PROTECTION
IN ACCORDANCE WITH CHANNEL PROTECTION SECTION B.3.A) OF 9VAC25-870-66 OF VIRGINIA LAW; THE MAXIMUM PEAK FLOW RATE FROM THE ONE-YEAR
24-HOUR STORM FOLLOWING THE LAND- DISTURBING ACTIVITY APPEARS TO BE IN ACCORDANCE WITH THE ENERGY BALANCE METHODOLOGY:
QDEVELOPED < I.F.*(QPRE-DEVELOPED* RVPRE-DEVELOPED)/RVDEVELOPED
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WPO 2020 00034
TMP 62 PARCEL 16D
RIO MAGISTERIAL DISTRICT, COUNTY OF ALBEMARLE, VA
L
C
a
VICINITY MAP
SCALE: 1 "=1000 FEET
EXISTING INTERMEDIATE CONTOUR - — --a32
EXISTING INDEX CONTOUR 3ou-
LEGEND
PROPOSED CONTOUR 20
POINT OF ANALYSIS 2: _ _ _ Ex EP
EXISTING EDGE OF PAVEMENT — — — -
1YR QDEVELOPED < I.F.* (1YR QPRE-DEVELOPED * RVPRE- DEVELOPED) /RVDEVELOPED EP
0.772 S 0.80* (1.597 * 0.515)/ 0.680 PROPOSED EDGE OF PAVEMENT
EXISTING CURB AND GUTTER C&G
0.772 < 0.97 cfs - — — — PROPOSED CURB AND GUTTER CG-6
COMPLIANCE OF 9VAC25-870-66.0 (FLOOD PROTECTIONS TRANSITION FROM CG-6 ROLL-TOP CG-6 ROLL-TOP
EX. 15" RCP
EXISTING STORM SEWER
IN REFERENCE TO FLOOD PROTECTION SECTION C.1), THE SITE'S POINT OF DISCHARGE RELEASES CAPTURED STORMWATER INTO A CONVEYANCE SYSTEM PROPOSED STORM SEWER 15" RCP
THAT, FOLLOWING LAND DISTURBING ACTIVITY, CONFINES THE POST -DEVELOPMENT PEAK FLOW RATE FROM THE 10-YEAR 24-HOUR STORM EVENT WITHIN
THE STORMWATER CONVEYANCE SYSTEM. 010POST-DEVELOPED S Q,OPRE-DEVELOPED EXISTING SANITARY SEWER —S —S —S —
'OINT OF ANALYSIS 2:
J10POST-DEVELOPED S Q10PRE-DEVELOPED
5.31 cfs S 7.63 cfs
IIL
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PROPOSED SANITARY SEWER
PROPERTY LINE
EASEMENT LINE
CENTERLINE
LIMITS OF CLEARING AND/OR GRADING
EXISTING SPOT ELEVATION
PROPOSED SPOT ELEVATION +12.0
EXISTING TREE DRIP LINE
EXISTING TREE ?
PROPOSED TREE OAK
EXISTING WATERLINE
PROPOSED WATERLINE
EXISTING FIRE HYDRANT
PROPOSED FIRE HYDRANT
EXISTING WATER VALVE
PROPOSED WATER VALVE
PROPOSED WATER METER
EXISTING REDUCER
PROPOSED REDUCER
HANDICAP RAMP (CG-12)
DENOTES LOCATION OF STD. VDOT
CG-12 AND/OR JURISDICTIONAL
STANDARD RAMP CONSTRUCTION
PARKING INDICATOR
INDICATES THE NUMBER OF TYPICAL PARKING SPACES
BENCHMARK
SOILS BOUNDARY
VEHICLES PER DAY COUNT
PROPOSED STREET NAME SIGN
EXISTING SIGN
PROPOSED SIGN
SANITARY MANHOLE IDENTIFIER
STORM DRAIN STRUCTURE IDENTIFIER
1,2134 VPD
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0
ASSOCIATED PLANS WITH THIS PARCEL:
1. FINAL SITE PLAN SDP-2020-00036
2. ROAD & UTILITY PLAN SUB-2019-00170
3. EASEMENT PLAT SUB-2020-00123
4. RETAINING WALL DESIGN PLANS
APPROVED
by the Albemarle County
Community Development Department
Date 05/10/2021
File WP02020-00034 Amendment #1
SHEET INDEX
Al C SHEET 1 COVER SHEET
2--- ------ I DITIONS, SOILS & DEMOLITION PLAN
SHEET 3--- — --- — EROSION CONTROL NARRATIVE
SHEET 4--- ------ EROSION CONTROL PLAN PHASE 1 - PHASE 5A & TEMPORARY FIRE ROAD
SHEET 5--- ------ EROSION CONTROL PLAN PHASE 1 - PHASE 5113
SHEET 6--- ------ EROSION CONTROL PLAN PHASE 1 - TEMPORARY FIRE ROAD
SHEET 7--- ------ EROSION CONTROL PLAN PHASE 2 - PHASE 5A & TEMPORARY FIRE ROAD
SHEET 8--- ------ EROSION CONTROL PLAN PHASE 2 - PHASE 5113
SHEET 9--- ------ EROSION CONTROL PLAN PHASE 2 - TEMPORARY FIRE ROAD
SHEET 10--------- EROSION CONTROL PLAN PHASE 3 - PHASE 5A & TEMPORARY FIRE ROAD
SHEET 11--------- EROSION CONTROL PLAN PHASE 3 - PHASE 5113
SHE 1 — - rr - - - PORARY FIRE ROAD
SHEET 13 SEDIMENT BASINA DESIGN & DETAILS
SHEET 14--------- EROSION CONTROL NOTES & DETAILS
SHEET 15 ---- T R Q AI I ITY CU TION COMP E
SHEET 16 --- WATER QUANTITY CALCULATIONS & COMPLIANCE
SHEET 17 STORMWATER MANAGEMENT POND CONVERSION
SHEET 18 - -- --- CULVERT DESIGN
VSMP AMENDMENT #1 NARRATIVE
A. THIS AMENDMENT IS TO ADJUST THE GRADING OF THE STORMWATER POND DUE TO
ENCOUNTERING SIGNIFICANT BEDROCK ON THE NORTHERN BANK OF THE POND. TO LIMIT THE
AMOUNT OF BLASTING ON -SITE, AND ASSOCIATED POTENTIAL DAMAGE TO NEARBY
RESIDENCES, THE NORTHERN POND EMBANKMENT WILL FOLLOW THE EXCAVATED BEDROCK.
THE TOP EMBANKMENT ELEVATION OF THE POND HAS BEEN RAISED BY 0.3-FEET,
ENCROACHING INTO THE MAINTENANCE ACCESS ROAD SLIGHTLY. THIS ALTERATION ALLOWS
FOR THE VOLUME OF THE POND TO STAY RELATIVELY CONSISTENT WITH THE APPROVED
PLAN.
ADDITIONALLY, THE EMERGENCY SPILLWAY WILL BE WIDENED FROM 10-FEET TO 15-FEET
TO PROVIDE THE REQUIRED 1-FOOT FREEBOARD FOR THE 100-YEAR STORM ELEVATION.
AS WITH THE APPROVED PLAN, A 3-INCH "ENERGY BALANCE" ORIFICE WAIVER REQUEST
ACCOMPANIES THIS AMENDMENT. THE ROUTED FLOWS ARE LISTED IN THIS AMENDMENT,
WAIVER REQUEST, HYDROGRAPHS, AND STAGE STORAGE REPORTS, WHICH ACCOMPANY THIS
SUBMITTAL.
B. DUE TO THE PRESENCE OF BEDROCK, THE STORM PIPE BETWEEN STRUCTURE 1 AND
STRUCTURE 0 HAS BEEN REPLACED WITH GROUTED RIPRAP CHANNEL. THE STORM PIPE
FROM STRUCTURE 2 HAS BEEN REVISED TO 0.5% SLOPE WHICH WILL DAYLIGHT TO THE
NORTH OF THE POND. THE CHANNEL WILL EXTEND FROM THE NEW OUTFALL LOCATION INTO
THE FOREBAY. THE 6" UNDERDRAIN PIPE BEHIND LOT 19 - 28 WILL DAYLIGHT DIRECTLY
INTO THE OPEN CHANNEL.
CONTRACTOR'S RECORD DRAWING CERTIFICATION STATEMENT:
(SEE SHEET 3 FOR RECORD DRAWING REQUIREMENTS)
THIS HAND MARKED SET OF DRAWINGS HAS BEEN 'REDLINED" TO PROVIDE AN ACCURATE DETAILED RECORD OF ANY
SUBSTANTIVE CHANGES TO THE APPROVED DESIGN DRAWINGS. ANY ITEMS NOT 'REDLINED" ON THIS PLAN SET OR
SUBSEQUENT PAGES SHOULD BE CONSIDERED TO BE "CONSTRUCTED IN ACCORDANCE WITH THE DESIGN AS SHOWN"
NAME, TITLE
FOR:
/: 1
TRACTOR)
APPROVALS
DATE
DEPARTMENT OF COMMUNITY DEVELOPMENT
ENGINEERING
INSPECTIONS
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DATE:
06-11-2020
SCALE:
1" = 1000'
FILE:
WPO-2020-00034
RGA#:
8438
SHEET: 1 OF 18
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SEDIMENT BASIN-1
SEDIMENT BASIN S CHEMA TI C
FAFA.11 51=07WAS61
10' WIDE EMBANKMENT ® 425 CREST OF EMERGENCY
/ SPILLWAY ® 424
DESIGN HIGH WATER
.,(25-YR. STORM ELEV.)
SIIkgm
67 C.Y./ AC.
DRY STORAGE_
TOP WET STORAGE: 417.7 -
67 C.Y./ AC. -
WET " STORAGE
SEDIMENT CLEANOUT POINT
(" WET " STORAGE REDUCED
TO 34 C.Y./ ACRE)
RISER CREST: 422
DEWATERING DEVICE
48" RISER
� POND BOTTOM: 414
DESIGN ELEVATIONS WITH
EMERGENCY SPILLWAY
(2) ANTI -SEEPAGE
COLLARS 4.5'x4.5'
106LF-18" HP
PIPE 54.71%
1.1: 414
LID: 409
I I
SOURCE: VA. DSWC PLATE. 3.14-2
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ANTI- VORTEX DEVICE DESIGN
PRESSURE RELIEF
HOLES 1/2" DIA.
A O C
PLAN VIEW
D TACKWELD I
ALL AROU
#6 X 12"
SPACER E
(TYPICAL)
71
RT BAR SIZE
BAR MIN.)
KISLKI I
SECTION A -A
TOP STIFFENER (IF REQUIRED)
IS XX ANGLE WELDED
TO TOP AND ORIENTED PER-
O n PENDICULAR TO CORRUGATIONS
ISOMETRIC
TOP IS -GAGE CORRUGATED
METAL OR 1/8" STEEL PLATE.
PRESSURE RELIEF HOLES MAY
BE OMMITTED, IF ENDS OF
CORRUGATIONS ARE LEFT FULLY
OPEN WHEN THE TOP IS
ATTACHED.
CYLINDER IS GAGE CORRUGATED
METAL PIPE OR FABRICATED FROM
1/8"
STEEL PLATE.
NOTES:
1. THE CYLINDER MUST BE
FIRMLY FASTENED TO THE
TOP OF THE RISER.
2. SUPPORT BARS ARE WELDED
TO THE TOP OF THE RISER
OR ATTACHED BY STRAPS
BOLTED TO TOP OF RISER.
RECOMMENDED DEWATERING
FOR SEDIMENT
PROVIDE ADEQUATE
STRAPPING
TACK WELD
POLYETHYLENE CAP
PERFORATED POLYETHYLENE
DRAINAGE TUBING, DIAMETER
VARIES (SEE CALCULATIONS IN
APPENDIX 3.14-A)
DEPTH
VARIES AS
REQUIRED
FOR" DRY
STORAGE
WET
FERNCO-STYLE " COUPLING STORAGE
DEWATERING ORIFICE,
SCHEDULE 40 STEEL STUB 1-FOOT MI !MUM,
DIAMETER VARIES (SEE CALCULATIONS IN
CORRUGATED METAL RISER APPENDIX 3.14-A)
NOTE: WITH CONCRETE RISER, USE PVC SCHEDULE 40 STUB
FOR DEWATERING ORIFICE
SOURCE: VA. DSWC
DRAINAGE TUBING SHALL COMPLY WITH ASTM F667
AND AASHTO M294
PLATE. 3.14-15
1992 3.14
DETAILS OF CORRUGATED METAL
ANTI -SEEP COLLAR
E6TNL cawx wmI
C°MUWMMIB Y9lIN:xL W WA 10 � C£ QYME GCE AS TIE
FPE 'M111 WXICX R IS USEp
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,n• x r SLOi1FD XCIES f9R ,r MIN.
°/Y pwETER BGErz.
+ T�
MD
TEER-RZ
.wm "'°•cc SECTION B-B aF BwD
ELEVATION OF UNASSEMBLED COLLAR 3. UNASSEMBLED COLLARS SHALL BE MARKED BY
NOTES FOR COLLARS: PAINTING OR TAGGING TO IDENTIFY MATCHING
PAIRS.
1. ALL MATERIALS TO BE IN ACCORDANCE WITH 4. THE LAP BETWEEN THE TWO HALF SECTIONS
CONSTRUCTION AND CONSTRUCTION MATERIAL AND BETWEEN THE PIPE AND CONNECTING BAND
SPECIFICATIONS. SHALL BE CAULKED WITH ASPHALT MASTIC AT
2. WHEN SPECIFIED ON THE PLANS, COATING OF TIME OF INSTALLATION.
COLLARS SHALL BE IN ACCORDANCE WITH 5. EACH COLLAR SHALL BE FURNISHED WITH TWO
CONSTRUCTION AND CONSTRUCTION MATERIAL 1/2" DIAMETER RODS WITH STANDARD TANK
SPECIFICATIONS. LUGS FOR CONNECTING COLLARS TO PIPE.
DETAIL OF HELICAL PIPE
ANTI -SEEP COLLAR
SIZE AND SPACING OF SLOTTED �w'I Y/a'xOE
/�°•s/N oR> TOtown aR BEND x so'
OPENINGS SHALL BE THE SAME NOTE FOR BANDS AND COLLARS:
AS SHOWN FOR CM COLLAR. I' '/B' MODIFICATIONS OF THE DETAILS
USE RODS AND LUGS TO CLAMP SHOWN MAY BE USED PROVIDING
BANDS SECURELY TO PIPE. I/8. EQUAL WATERTIGHTNESS IS
MAINTAINED AND DETAILED
><< DRAWINGS IE - E SUBMITTED
APPROVED BYTHEENGINEER N PRIOR
*ZMED=
TO DELIVERY.
ISOMETRIC VIEW
ME
WI SH BE CUf TO RT
S6 Np1V1 HWo..Wo
n Cd NUOU° NIID.
NOTE: FOR DETAILS OF FABRICATION DIMENSIONS, MINIMUM GAGES,
SLOTTED HOLES, AND NOTES, SEE DETAIL ABOVE.
uErxE Wwn ro BE NOTE: TWO OTHER TYPES OF ANTI -SEEP COLLARS ARE:
NflCm 10 CENIFn E
'a'� nPE solo 1. CORRUGATED METAL, SIMILAR TO UPPER, EXCEPT SHOP
WELDED TO A SHORT (4FT.) SECTION OF THE PIPE AND
CONNECTED WITH CONNECTING BANDS TO THE PIPE.
PARTIAL ELEVATION 2. CONCRETE, SIX INCHES THICK FORMED AROUND THE PIPE
REF � R,.D "� WITH #3 REBAR SPACED 15" HORIZONTALLY AND VERTICALLY.
SOURCE: USDA-SCS
ANTI -SEEP COLLAR
SATURATED ZONE
CONNECTIONS BETWEEN
THE ANTI -SEEP AND
THE BARREL MUST BE
WATERTIGHT
VA.
PLATE. 3.14-13
PLATE. 3.
RISER PIPE BASE CONDITIONS
SOURCE: VA. DSWC
TYPICAL CONCRETE BASE
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SEDIMENT BASIN/DRY POND CONSTRUCTION
NOTES
1. GEOTECHNICAL CONSULTANT TO SPECIFY DAM EMBANKMENT MATERIAL, SEEPAGE
CONTROL DEVICES, CUT-OFF TRENCH DESIGN, CULVERT BEDDING REQUIREMENTS,
AND OTHER APPROPRIATE GEOTECHNICAL DESIGN REQUIREMENTS.
2. IMPERVIOUS CORE SHALL EXTEND TO THE 10-YR WATER SURFACE ELEVATION
UNLESS OTHERWISE NOTED.
3. FOUNDATION AND ABUTMENT AREA EXTENDING 10' BEYOND DAM FOOTPRINT SHALL
BE CLEARED, GRUBBED AND STRIPPED OF ALL VEGETATION TOPSOIL AND/OR
ORGANIC SOIL AND OTHER UNSUITABLE MATERIALS.
4. AFTER CLEARING, GRUBBING, STRIPPING, AND REMOVING ANY OTHER UNSUITABLE
MATERIALS, THE SUBGRADE SHALL BE PROOF -ROLLED WITH COMPACTION EQUIPMEL
UNDER THE OBSERVATION OF A QUALIFIED ENGINEER. THE COMPACTION EQUIPMEN
SHALL CONSIST OF THE HEAVIEST POSSIBLE EQUIPMENT THAT WILL NOT CAUSE
DISTURBANCE OF SUITABLE SUBGRADE SOILS. EXCESSIVELY SOFT OR UNSUITABLE
MATERIALS SHALL BE REMOVED AND REPLACED WITH COMPACTED FILL. WHERE ROCK
IS EXPOSED AFTER STRIPPING OR UNDERCUTTING, ALL LOOSE ROCK MATERIAL
SHALL BE REMOVED PRIOR TO PLACING COMPACTED FILL. ROCK SUBGRADES SHALL
BE INSPECTED AND APPROVED BY INSPECTOR OR ENGINEER PRIOR TO PLACEMENT
OF FILL.
5. COMPACTED FILL SHALL NOT BE PLACED PRIOR TO PERFORMING THE REQUIRED
FOUNDATION AND ABUTMENT PREPARATION, OR ON ANY FROZEN SURFACE.
COMPACTED FILL SHALL EXTEND TO THE FILL LIMIT LINES AND GRADES INDICATED
ON THE APPROVED CONSTRUCTION PLAN. COMPACTED FILL MATERIAL SHALL BE OF
THE TYPE CLASSIFICATION SYMBOL SPECIFIED BY THE GEOTECHNICAL CONSULTANT,
OR OF A BETTER QUALITY MATERIAL AS DEFINED BY THE UNIFIED SOIL
CLASSIFICATION SYSTEM (USCS). RESTRICTIONS ON LIQUID LIMIT AND PLASTICITY
INDEX OF MATERIAL MAY BE INCLUDED WHERE APPLICABLE. COMPACTED FILL SHALL
CONSIST OF MATERIAL FREE OF ORGANIC MATTER, RUBBISH, FROZEN SOIL, SNOW,
ICE, AND PARTICLES WITH SIZES LARGER THAN 3" OR ANY OTHER DELETERIOUS
MATERIAL.
6. COMPACTED FILL SHALL BE PLACED IN HORIZONTAL LAYER of 10"-12" IN LOOSE
THICKNESS. ACTUAL LIFT THICKNESS SHALL BE SPECIFIED BY THE GEOTECHNICAL
CONSULTANT. THE MOISTURE CONTENT SHALL BE CONTROLLED SUCH THAT
COMPACTION IS ACHIEVED WITHOUT YEILDING OF THE SURFACE. EACH LAYER SHALL
BE UNIFORMLY COMPACTED WITH SUITABLE COMPACTION EQUIPMENT TO AT LEAST
95% OF STANDARD PROCTOR MAXIMUM DENSITY IN ACCORDANCE WITH ASTM D-698,
AASHTO T-99, OR VDOT SPECIFICATIONS. ANY LAYER OF FINE GRAINED FILL WHICH
BECOMES SMOOTH SHALL BE SACRIFICED TO A DEPTH OF 2" TO ALLOW ADEQUATE
BONDING BETWEEN LAYERS.
7. COMPACTED FILL WITH A MOISTURE CONTENT WHICH WILL NOT PERMIT COMPACTION
TO THE SPECIFIES DENSITY STANDARD SHALL BE SACRIFICED, DRIED, OR WETTED AS
NECESSARY TO PERMIT PROPER COMPACTION.
OP OUTLET PROTECTION SPECIFICATIONS
if) CL I R��RAP
4" MIN. DEPTH ° FtB" PIPE
�W/UNDERLYING F.F
APRON LENGTH = 10' OP#1
3DO = 4.5'
LA = 10'
W = DO + LA = 14.5
SEDIMENT BASIN #1:
SEDIMENT BASIN #1 IS DESIGNED FOR 6.76 ACRES OF DRAINAGE.
THE DRAINAGE AREA TAKES INTO ACCOUNT THE REMOVAL OF
SEDIMENT TRAPS THROUGH DIFFERENT PHASES OF THE EROSION
AND SEDIMENT CONTROL PLAN.
TOP DAM = 425.30
BOTTOM = 414.00
BOTTOM WIDTH = 36'
DRAINAGE AREA TO SB #1: 6.76 ACRES
DRY/WET STORAGE REQUIRED: 453 c.y.
TOTAL STORAGE REQURIED: 906 C.y.
PROVIDED STORAGE @ 425.3: 3,235 c.y.
CLEAN OUT ELEVATION: 416.80
SLOPES: 3:1 UNLESS OBSCURED BY BEDROCK FOUND IN FIELD*
PRINCIPLE SPILLWAY: 48" RCP RISER
DIAMETER TRASH RACK/ANTI-VORTEX DEVICE DESIGN: 72 INCHES
zt
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TEMPORARY SEDIMENT BASIN V o
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PROJECT Belvedere Phase 5 PROJ NO. 8438
BASIN # SEDIMENT BASIN SB-1 DATE 5I312021 ° m
U U a N
' LOCATION BY RV O O ° d V) >
INPUT (4 Q 2 a 1SOo
Go ' DRAINAGE AREA 6.76 ac O w z N V)
TOTAL STORAGE REQUIRED 905.84 cy 1y p U s w
p Wo
BASIN VOLUME DESIGN W U a
' WET STORAGElp
.a 3
1. MINIMUM REQUIRED VOLUME FOR WET STORAGE 452.92 y! d
2 AVAILABLE BASIN VOLUME ZO 24
AVERAGE END AREA- BASIN VOLUME ESTIMATES v1 o
w � N
ELEVATION AREA E _ J hL VOLUME TOTAL w0 Z c m
it cY Cy a N
' 414 1,41230 N z
3,804.23 140.90 Q w > o
416 2,391.92 140.90 v V) •w-' a
8,197.21 303.60 �y V d
' 418 5,805.29 444.50 0. a w
600.00 22.22
Top of wet storage 418.1 6,194.76 466.72 o
' 6,020.74 222.99 Y
1 419 7,184.67� 1 689.71 M U
26,718.07 989.56
422 10,627.38 1,679.27
` 41,999.72 1,555.55
425.3 14,827.00 3,234.81
REQUI RED WET S TORAGE VOLUME 45292 cy
PROVIDED AT APPROX. ELEVATION 418.10
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O
' 4. AVAILABLE VOLUME BEFORE CLEANOUT REQUIRED 223.08 cy a
K
5. ELEVATION CORRESPONDING TO CLEANOUT LEVEL 416.80 0
' S. DISTANCE FROM DEWATERING ORIFICE TO C/O LEVEL 1.00
INVERT DEWATERING ORIFICE R'QD 417.80 Min. Elevation Req'
INVERTDEWATERING ORIFICE USED 418.10 at Wet stmge elevation
' APPROX. VOLUME AT INVERT USED 466.72 cy
DISTANCE FROM INVERT TO C/O LEVEL 1.30 ft ¢o
DISTANCE ACCEPTABLE
WET STORAGE VOLUME ACCEPTABLE to
' DRYSTORAGE O z
7. MNIMUM REQUIRED VOLUME 452.92 cy v�
5
' 8. TOTAL AVAILABLE VOLUME AT CREST OF RISER F F F
CREST OF RISER 422.00 Top of dry storage z z z z z w 8)APPROX. AVAILABLE TOTAL VOLUME 1679.27 cy o 2 2 2 2 it:
AD DRY STORAGE VOLUME a 2 2 2 2 0
1 9. DIAMETER OF DEWATERING ORIFICE o U U o z o
/ K 0 U U 0 Z 0
'U^ r r r r 2
Q (From Dewatering Sheet) 1.52 cfs o z z z z ¢� z
d (From Dewatering Sheet) 6.43 in O o 0 02
USE d 8 in (Never less than 3 inches) U U U U> z
1D. DIAMETER OF FLEXIBLE TUBING 10 in (minimum 2 inches larger}
a
STANDARD SIZE
� 0000.,�
N N N N N N
w o 0 0 0 0 0
N
PRELIMINARY DESIGN "o
0 N
11. PRELIMINARY DESIGN ELEVATIONS:
CREST OF RISER 422.00 ft oD o 0
' TOP OF DAM 425.30 It z ti N m a n n
DESIGN HIGH WATER 423.30 ft *design of high water assumes a peakflowrate
UPSTREAM TOE OF DAM 414.00 It
' BASIN SHAPE DESIGNED BY: UVN/JLF
12. LENGTH OF FLOW I EFFECTIVE WIDTH: DRAWN BY: I UVN/JLF
SURFACE AREA OF NORMAL POOL 6195 sf (wet storaae) CHECKED BY: JILT
LENGTH OF FLOW PATH 78 It
' EFFECTIVE WIDTH 79 It
LIWe 0.98 BAFFLES REQUIRED 8 PROVIDED ��P1,TH Op DI
RUNOFF
' (RATIONAL METHOD CALCULATION)
USE MAXIMUM C VALUE DURING CONSTRUCTION AND MINIMUM Tc VALUE UL_ 17 y q
13. FLOW FROM 2-YEAR STORM (from Hydro software)
C: 0.60 Jimmy L. Taggart
1 / A L'°' No.Tc: 7.7 I: 3.4 in/hr
4
Q= 15.9 cfs(from Hydraflowsoftware) �o�E053O %2021oti�w�
14. FLOW FROM 25-YEAR STORM Y&ZONAL E�
' C: 0.60
1 To: 7.7 I: 6.8 iWhr
J Q= 21.2cfs(from Hydraflowsoftware)
' PRINCIPAL SPILLWAY DESIGN
1 16. REQUIRED SPILLWAY CAPACITY. ¢_
EMERGENCY SPILLWAY? (YIN) Y Z
REQUIRED SPILLWAY CAPACITY: 15.9 CFS 0
' 16. AS 5UMED AVAILABLE HEAD: 04
ELEV. OF CREST OF E.S. IF USED: 424.00
AS5UMEDAVAILABLE HEAD= 2.00 ft W V]
' 17. RI SER DIMENSIONS: ""41
RISER DIAMETER 48.00 in (From Plate 3.14-8 orCalcs) LO 04
Q H
ACTUAL MAX. ELEV.: 422.55 ft (From Calcs if appropriate) LL
LL w W
' ACTUAL HEAD: 1.45 ft (From Plate 3.14-8 or Calcs) U) CO Q
' 18. BARREL LENGTH: J d a3
BARREL LENGTH: 106.00 ft w Z
BARREL INVERT OUT: 409.00 ft O U O z
HEAD H ON BARREL: 15.00 ft (From Plate 3.14-7) C) t j
19. BARREL DIAMETER W W QOZ A
BARREL DIAMETER: 18 in (From Plate 3.14Aor3.14B_ ) U
' EMERGENCY SPILLWAY DESIGN N x
1 21. REQUIRED SPILLWAY CAPACITY: W w QD
Qe= Q(25)-Qp= 5.2 CFS Q U Z
22. DIMENSIONS: W Q p e
Q ' PQ BOTTOM WIDTH (bj: 15.00 ft [From Table 3.1 4-C] >
SLOPE OF EXIT CHANNEL (s): 3.90 fUft [From Table 3.1 4-C] J x F5 E-1
MN. LENGTH EXIT CHANNEL (x): 33.00 ft [From Table 3.1 4-C] U) m < W
' ANTI -SEEP COLLAR DESIGN :2�
23. DIMENSIONS: W Q
DEPTH WATER § CREST OF P.S. (Y): 1.00 ft TW
' SLOPE UPSTREAM FACE DAM (Z): 3.00 :1
' SLOPE P.S. BARREL (Sb): 4,72 % Q
LENGTH BARREL IN SAT. ZONE (Ls): 62.00 ft (From Plate 3.14-11) 2
Number of collars req: 2.00 (From Plate 3.14-12) O
Dimensions 4.50 ft (From Plate 3.14-12) :4
FINAL DESIGN ELEVATIONS _j
' 25. ELEVATIONS:
TOP OF DAM _425.30 ft DATE: 06-11-2020
DESIGN HIGH WATER 422.55 ft SCALE: 1'20'
EMERGENCY SPILLWAY CREST: 424,00 ft FILE: WPO-2020-00034
PRINCIPAL SPILLWAY CREST: 427-00 ft RGA#: 8438
1 DEWATERING ORIFICE INVERT: 418.10 ft
7 � CLEANOUT ELEVATION: 415.80 ft
SHEET: 1 OF 18
3
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CLASS I RIP -RAP
PLUNGE POOL
OUTLET PROTECTION
APRON
OP
LENGHTH PER
OUTLET
PPnTFCTTnN nFCTFN
2:1 MAX.
P : 1 MAX. /
1-3 INCH COURSE AGGREGATE
OR OTHER LINING AS
DESIGNED FOR STABILITY
PLAN VIEW
TOP OF
LEVEL SPREADER
-SHALL BE FLAT
T
LENGTH OF LEVEL SPREADER LIP
TO BE BASED ON DESIGN FLOW
AND ALLOWABLE VELOCITY
OR
EXISTING OUTLET PROTECTION
APRON, WHICHEVER IS GREATER
IB"
TREATED
TM
TIMBERS
ALLOWABLE DESIGN:
13 LF OF ELS PER i cfs
CALCULATED DESIGN:
ELS LENGTH =
(131 x (2.135 cfs) = 27.8'
INTO EXISTING GRADE 18" CLASS I #4 REBAR TO SECURE
RIP -RAP TIMBERS
SECTION VIEW
NOTE REGARDING POST DEVELOPMENT
FLOW LEAVING STRUCTURE 42:
Q1 1.578 cfs
Q2 = 2.135 cfs
Q10 = 3.844 cfs
OUTLET PROTECTION (min) = 3.75' (3Do) x 8.5' (La) x 9.75' (W)
LED
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Channel Report
Hydrafiow 6yress E#ension fa /wtotleskw AutoCAO• CiW 30®byALLatlesk, Inc.
Tuesday. Apr 132021
Riprap channel
Trapezoidal
Highlighted
Bottom Width (ft)
= 2.00
Depth (ft)
= 0.26
Side Slopes (z:1)
= 2.00, 2.00
Q (cfs)
= 13.61
Total Depth (ft)
= 1.00
Area (sg1t)
= 0.66
Invert Elev (ft)
= 418.00
Velocity (ftfs)
= 2077.
Slope (%)
= 27.00
Wetted Perim (ft)
= 3A 6
N-Value
= 0.013
Grit Depth, Yc (ft)
= 0.85
Top Width (ft)
= 3.04
Calculations
EGL (ft)
= 6.97
Compute by:
Known Q
Known Q (cfs)
= 13.61
Elev (ft)
420.00
419.50
419.00
418.50
418.00
417.50
Section
0 7 2 3 4 5 s. 78
Reach (ft)
Depth (ft)
2.00
1.50
1.00
0.50
0.00
-050
oP OUTLET PROTECTION SPECIFICATIONS
INTO FOREBAY
L-CL 1-RIPRAP n
M�r24" MIN. DEPTH
W/UNDERLYING F
APRON LENGTH = 32
F OPEN CHANNEL
T
REGARDING WATER OUANITY ANALYSIS FOR POINT OF DISCHARGE #1:
COMPLIANCE OF 9VAC25-870. B.1.B (CHANNEL PROTECTION
IN ACCORDANCE WITH CHANNEL PROTECTION SECTION B.3.A) OF 9VAC25-870-66 OF VIRGINIA LAW; THE
MAXIMUM PEAK FLOW RATE FROM THE ONE-YEAR 24-HOUR STORM FOLLOWING THE LAND- DISTURBING
ACTIVITY APPEARS TO BE IN ACCORDANCE WITH THE ENERGY BALANCE METHODOLOGY:
QDEVELOPED < I.F.*(QPRE-DEVELOPED* RVPRE- DEVELOPED) /RVDEVELOPED
1YR QDEVELOPED S I.F.* (1YR QPRE-DEVELOPED * RVPRE-DEVELOPED)/RVDEVELOPED
0.064 S 0.80* (0.611 * 0.38) /1.27
0.144 (1.5" ORIFICE) S 0.144 A�
0.512 (3" ORIFICE)
COMPLIANCE OF 9VAC25-870-66.0 (FLOOD PROTECTION.
IN REFERENCE TO FLOOD PROTECTION SECTION C.1), THE SITE'S POINT OF DISCHARGE RELEASES CAPTURED
STORMWATER INTO A CONVEYANCE SYSTEM THAT, FOLLOWING LAND DISTURBING ACTIVITY, CONFINES THE
POST -DEVELOPMENT PEAK FLOW RATE FROM THE 10-YEAR 24-HOUR STORM EVENT WITHIN THE STOP' !`A/ATFP
CONVEYANCE SYSTEM. Q10POST-DEVELOPED S QtaPRE-DEVELOPED
Q10POST-DEVELOPMENT
(1.5" EB ORIFICE)
= 4.207 cfs
S Q10PRE-DEVELOPMENT
= 4.373 cfs
Q10POST-DEVELOPMENT
(3" EB ORIFICE) =
3.882 cfs S
Q10PRE-DEVELOPMENT =
4.373 cfs
NOTE REGARDING SHEET FLOW FOR THE REAR OF THE RESIDENTIAL LOTS:
ALL SFD UNITS TO HAVE SPLASH BLOCKS AT FOUNDATION DRAIN & ROOF DOWNSPOUTS TO ENSURE SHEET FLOW.
THE YARD AREAS WILL BE GRADED/SEEDED/LANDSCAPED AS NECESSARY TO FULLY STABILIZE THE SITE TO
PREVENT CONCENTRATED FLOW LEAVING THE REAR OF ANY RESIDENTIAL LOT WITHIN THE BELVEDERE PHASE 5
DEVELOPMENT.
TOWNHOUSE LOTS 1 - 14: ROOF DRAINS AND FOOTER/FOUNDATION DRAINS TO CONNECT TO HEADER PIPE AS
SHOWN.
TOWNHOUSE LOTS 19 - 28:ROOF DRAINS AND FOOTER/FOUNDATION DRAINS DAYLIGHT INTO GROUTED RIPRAP
CHANNEL AS SHOWN ON SHEET 10.
ALL SLOPES GREATER THAN 3:1 MUST BE STABILIZED WITH LOW MAINTENANCE VEGETATIVE GROUND COVER OTHER
THAN GRASS AS SOON AS FEASIBLY POSSIBLE.
9VAC25-870-66.B.3: CHANNEL PROTECTION
ENERGY BALANCE CALCULATIONS - 1 YEAR
DA AT POINT OF ANALYSIS
DA AT POINT OF ANALYSIS
PRE -DEVELOPMENT CONDITIONS
POST -DEVELOPMENT CONDITIONS
SITE AREA = 2.59 ACRES
SITE AREA = 7.35 ACRES
CURVE NUMBER (CN) = 61
CURVE NUMBER (CN) = 80
TIME OF CONCENTRATION = 21.8 MIN
TIME OF CONCENTRATION = 7.7 MIN
SCS METHOD
SCS METHOD
1 -YR Q(PEAK) = 0.611 CFS
1 -YR Q(PEAK) = 14.75 CFS
TIME TO PEAK = 12.17 HRS
TIME TO PEAK = 12.00 HRS
VOLUME = 3,566 CU.FT
VOLUME = 33,751 CU.FT
9VAC25-870-66C: FLOOD PROTECTION
10 YEAR FOR FLOOD PROTECTION
DA AT POINT OF ANALYSIS
DA AT POINT OF ANALYSIS
PRE -DEVELOPMENT CONDITIONS
POST -DEVELOPMENT CONDITIONS
SCS METHOD
SCS METHOD
SITE AREA = 2.59 ACRES
SITE AREA = 7.35 ACRES
CURVE NUMBER (CN) = 61
CURVE NUMBER (CN) = 80
TIME OF CONCENTRATION = 21.8 MIN
TIME OF CONCENTRATION = 7.7 MIN
10-YR Q(PEAK) = 4.373 CFS
10-YR Q(PEAK) = 38.81 CFS
TIME TO PEAK = 12.13 HRS
TIME TO PEAK = 11.97 HRS
VOLUME = 16,187 CU.FT
VOLUME = 89,409 CU.FT
T
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U� J7 ! 9
Jimmy L. Taggart
Lic. No.
4
Ado,,, 05%023/2021 �
ES'Q/ONAL Eta
Q
z
C5 W
W
a a
(},' :•.
O
0 w U
Z T
a 2 w 0 z
z Ir F o
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Z
WQ 0 Q U
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> m m.
to 04
H
O
DESIGNED BY:
UVN/JLF
DRAWN BY:
UVN/JLF
CHECKED BY:
JLTQD
DATE:
06-11-2020
SCALE:
1':60"
FILE:
WPO-2020-00034
RGA#:
8438
SHEET:
16 OF18
74
3.0" ENERGY BALANCE
ORIFICE TO BE PLUGGE
DURING CONSTRUCTION
UNPLUG WHEN
CONVERTING TO POND
12'
TRASH RACK
LI
Stage -Storage Report
Elev(Ft)
Storoge(CF)
Total Storoge(CF)
Areo(SF)
414.000
0.000
0.000
1,412
416.000
2,133
3,776
2,391
417.000
3,491
7,266
4,590
418.000
5,198
12,464
5,805
419.000
6,495
18,958
7,184
420.000
7,754
26,712
8,323
422.000
18,950
45,662
10,627
424.000
24,178
69,840
13,551
425.000
14,047
83,887
14,543
425.300
4,405
88,292
14,827
POND #1 STORAGE HAS BEEN SIZED TO
MEET WATER QUANTITY REQUIREMENTS FOR
THE FULL BUILD -OUT OF THE BELVEDERE
PHASE 5 (A AND B) DEVELOPMENT
ORIFICE SIZING NOTE AND WAIVER REQUEST:
TO SATISFY THE ENERGY BALANCE EQUATION, SEE SHEET 16, THE
1-YEAR FLOW LEAVING THE POND CAN NOT EXCEED 0.144 CFS. TO
SATISFY THE REQUIREMENT, AN 1.5" ORIFICE IS REQUIRED AT
ELEVATION 414.1. DUE TO THE RISK OF CLOGGING AND MAINTENANCE
ASSOCIATED WITH SMALL ORIFICES; AND DISCUSSIONS WITH COUNTY
ENGINEERING DEPARTMENT, THIS DESIGN FIRM RECOMMENDS THAT A
MINIMUM ORIFICE OF 3" SHOULD BE USED. IF A 3" ORIFICE IS USED, THE
1-YEAR FLOW LEAVING THE SITE WILL INCREASE TO, 0.512 CFS.
12"
0000
0000
0000
0000
FRONT SECTION
TRASH RACK 1" HOLES
30% OPENING AREA
0
000
0
O
SIDE SECTION
I
CONVERT OF SB-1 TO DRY POND #1
ORIFICE TRASH RACK DETAIL
°
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0 To 0
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HIGH DENSITY POLYETHYLENE METAL
NOTES:
I, ALL METAL IMACH RAGHS 36"IN DIAMETER AND LARGER OR WILL A TOTAL 3- ANTI VORTEX PLATE 13 TO BE USED WHEN SPECIFIED ON THE PLANS.
WEIGHT OF 75 L35 OR GREATER EHN.L HAVE A HINGED. LOCKABLE ACCESS COST OF FURNISHING AND PLACING THE ANTI VORTEX PLATE 15 TO
DOOR WITH A MINIINM 'e'X G. EDEAR OP,NNG. BE 19CLUDED IN THE BID PRICE FOR THE STRUCTURE.
2. ALL HIG1 DENSITY POLYE-HYLENE TIIA56 PACKS 45 IN DIAMETER AND LARGER
SHAG_ HAVE A HINGED, LOCKABLE ACCESS GOOD WITH A MINIMUM 2'A 2 CLEM
OPENING
SPECIFICATION STORMWATER MANAGEMENT DETAILS TRASH RACK wool
EFERENCE
FOR SWIM DRAINAGE STRUCTURES READ AND BRIDGE STANDARDS
302 PEVISON DATE SHEET 4 EF 5
VIRGINIA DEPARTMENT OF TRANSPORTATION 67/16 16 E,
DRY POND #1 DETAIL
(NOT TO SCALE) NOTE: TOP OF DAM TO BE COMPACTED TP 98%
COMPACTION, NO SETTLING WILL OCCUR.
Pond
Embankment
100YR WSE 424.29
Trash Rack for SWM
Drainage Structures
see sheet for details
Top of Dam Elev = 425.3
Geotechnical Engineer
to determine
necessity of
impervious Core**
concrete tsase
*Trash rack to be installed on orifice
as shown on details sheet.
**Impervious core and cutoff
trench shown for informational
purposes only. Final design to be
provided by geotechnical engineer.
-Embed 6"
in Concrete
3.0" Energy Balance
Orifice @ 414.1
Cutoff Trench**FAI
oP OUTLET PROTECTION SPECIFICATIONS
OTo�/ L T RIPRAP
OP� 1 4 24 MIN. DEPTH `n -'I PIPE 410 = 3.88 cfs
W/UNDE/R(LYING /F.F �
APRON LENGTH = 10'
3D0 = 4.5'
LA = 10'
W = DO + LA = 14.5
STORMWATER POND CONSTRUCTION SEQUENCE:
THE FOLLOWING IS ATYPICAL CONSTRUCTION SEQUENCE TO PROPERLY INSTALL A DRY ED POND. THE STEPS MAY BE MODIFIED TO
REFLECT DIFFERENT DRY ED POND DESIGNS, SITE CONDITIONS, AND THE SIZE, COMPLEXITY AND CONFIGURATION OF THE PROPOSED
FACILITY.
1. USE OF ED POND AS AN E&S CONTROL. AN ED POND MAY SERVE AS A SEDIMENT BASIN DURING PROJECT CONSTRUCTION. IF TF E
IS DONE, THE VOLUME SHOULD BE BASED ON THE MORE STRINGENT SIZING RULE (EROSION AND SEDIMENT CONTROL REQUIREMEN-
VS. WATER QUALITY TREATMENT REQUIREMENT). INSTALLATION OF THE PERMANENT RISER SHOULD BE INITIATED DURING THE
CONSTRUCTION PHASE, AND DESIGN ELEVATIONS SHOULD BE SET WITH FINAL CLEANOUT OF THE SEDIMENT BASIN AND CONVERSION
TO THE POST -CONSTRUCTION ED POND IN MIND. THE BOTTOM ELEVATION OF THE ED POND SHOULD BE LOWER THAN THE BOTTOM
ELEVATION OF THE TEMPORARY SEDIMENT BASIN. THE CONSTRUCTION NOTES SHOULD CLEARLY INDICATE THAT THE FACILITY WILL BE
DEWATERED, DREDGED AND RE -GRADED TO DESIGN DIMENSIONS AFTER THE ORIGINAL SITE CONSTRUCTION IS COMPLETE.
APPROPRIATE PROCEDURES SHOULD BE IMPLEMENTED TO PREVENT DISCHARGE OF TURBID WATERS WHEN THE BASIN IS BEING
CONVERTED INTO AN ED POND.
2. STABILIZE THE DRAINAGE AREA. FINAL GRADING AND CONSTRUCTION OF ED POND COMPONENTS SHOULD ONLY BE CONSTRUCTED
AFTER THE CONTRIBUTING DRAINAGE AREA TO THE POND IS STABILIZED.
3. ASSEMBLE CONSTRUCTION MATERIALS ON -SITE, MAKE SURE THEY MEET DESIGN SPECIFICATIONS, AND PREPARE ANY STAGING AREAS.
4. CLEAR AND STRIP THE PROJECT AREA TO THE DESIRED SUB -GRADE.
5. INSTALL E&S CONTROLS PRIOR TO CONSTRUCTION, INCLUDING TEMPORARY DE -WATERING DEVICES AND STORMWATER DIVERSION
PRACTICES. ALL AREAS SURROUNDING THE POND THAT ARE GRADED OR DENUDED DURING CONSTRUCTION MUST BE PLANTED WITH
TURF GRASS, NATIVE PLANTINGS, OR OTHER APPROVED METHODS OF SOIL STABILIZATION.
6. EXCAVATE THE CORE TRENCH AND INSTALL THE SPILLWAY PIPE.
7. INSTALL THE RISER OR OUTFLOW STRUCTURE AND ENSURE THE TOP INVERT OF THE OVERFLOW WEIR IS CONSTRUCTED LEVEL AT
THE DESIGN ELEVATION.
8. CONSTRUCT THE EMBANKMENT AND ANY INTERNAL BERMS IN 8 TO 12-INCH LIFTS, OR AS DIRECTED BY GEOTECHNICAL
RECOMMENDATIONS, AND COMPACT AS REQUIRED WITH APPROPRIATE EQUIPMENT.
9. EXCAVATE/GRADE UNTIL THE APPROPRIATE ELEVATION AND DESIRED CONTOURS ARE ACHIEVED FOR THE BOTTOM AND SIDE SLOPES
OF THE ED POND.
10. CONSTRUCT THE EMERGENCY SPILLWAY IN CUT OR STRUCTURALLY STABILIZED SOILS.
11. INSTALL OUTLET PROTECTION, INCLUDING EMERGENCY AND PRIMARY OUTLET APRON PROTECTION.
12. STABILIZE EXPOSED SOILS WITH TEMPORARY SEED MIXTURES APPROPRIATE FOR THE POND BUFFER. ALL AREAS ABOVE THE NORMAL
POOL ELEVATION SHOULD BE PERMANENTLY STABILIZED BY HYDROSEEDING OR SEEDING OVER STRAW.
13. PLANT THE POND BUFFER AREA, FOLLOWING THE PONDSCAPING PLAN. DINFARION
DAM CONSTRUCTION NOTES:
1. GEOTECHNICAL CONSULTANT TO SPECIFY DAM EMBANKMENT MATERIAL, SEEPAGE CONTROL DEVICES, CUT-OFF TRENCH DESIGN, CULVERT
BEDDING REQUIREMENTS, AND OTHER APPROPRIATE GEOTECHNICAL DESIGN REQUIREMENTS.
2. IMPERVIOUS CORE SHALL EXTEND TO THE 10-YR WATER SURFACE ELEVATION UNLESS OTHERWISE NOTED.
3. FOUNDATION AND ABUTMENT AREA EXTENDING 10' BEYOND DAM FOOTPRINT SHALL BE CLEARED, GRUBBED AND STRIPPED OF ALL
VEGETATION TOPSOIL AND/OR ORGANIC SOIL AND OTHER UNSUITABLE MATERIALS.
4. AFTER CLEARING, GRUBBING, STRIPPING, AND REMOVING ANY OTHER UNSUITABLE MATERIALS, THE SUBGRADE SHALL BE PROOF -ROLLED
WITH COMPACTION EQUIPMENT UNDER THE OBSERVATION OF A QUALIFIED ENGINEER. THE COMPACTION EQUIPMENT SHALL CONSIST OF
THE HEAVIEST POSSIBLE EQUIPMENT THAT WILL NOT CAUSE DISTURBANCE OF SUITABLE SUBGRADE SOILS. EXCESSIVELY SOFT OR
UNSUITABLE MATERIALS SHALL BE REMOVED AND REPLACED WITH COMPACTED FILL. WHERE ROCK IS EXPOSED AFTER STRIPPING OR
UNDERCUTTING, ALL LOOSE ROCK MATERIAL SHALL BE REMOVED PRIOR TO PLACING COMPACTED FILL. ROCK SUBGRADES SHALL BE
INSPECTED AND APPROVED BY INSPECTOR OR ENGINEER PRIOR TO PLACEMENT OF FILL.
5. COMPACTED FILL SHALL NOT BE PLACED PRIOR TO PERFORMING THE REQUIRED FOUNDATION AND ABUTMENT PREPARATION, OR ON ANY
FROZEN SURFACE. COMPACTED FILL SHALL EXTEND TO THE FILL LIMIT LINES AND GRADES INDICATED ON THE APPROVED CONSTRUCTION
PLAN. COMPACTED FILL MATERIAL SHALL BE OF THE TYPE CLASSIFICATION SYMBOL SPECIFIED BY THE GEOTECHNICAL CONSULTANT, OR OF
A BETTER QUALITY MATERIAL AS DEFINED BY THE UNIFIED SOIL CLASSIFICATION SYSTEM (USCS). RESTRICTIONS ON LIQUID LIMIT AND
PLASTICITY INDEX OF MATERIAL MAY BE INCLUDED WHERE APPLICABLE. COMPACTED FILL SHALL CONSIST OF MATERIAL FREE OF ORGANIC
MATTER, RUBBISH, FROZEN SOIL, SNOW, ICE, AND PARTICLES WITH SIZES LARGER THAN 3" OR ANY OTHER DELETERIOUS MATERIAL.
6. COMPACTED FILL SHALL BE PLACED IN HORIZONTAL LAYER OF 8"-12" IN LOOSE THICKNESS. ACTUAL LIFT THICKNESS SHALL BE
SPECIFIED BY THE GEOTECHNICAL CONSULTANT. THE MOISTURE CONTENT SHALL BE CONTROLLED SUCH THAT COMPACTION IS ACHIEVED
WITHOUT YEILDING OF THE SURFACE. EACH LAYER SHALL BE UNIFORMLY COMPACTED WITH SUITABLE COMPACTION EQUIPMENT TO AT
LEAST 95% OF STANDARD PROCTOR MAXIMUM DENSITY IN ACCORDANCE WITH ASTM D-698, AASHTO T-99, OR VDOT SPECIFICATIONS. ANY
LAYER OF FINE GRAINED FILL WHICH BECOMES SMOOTH SHALL BE SACRIFICED TO A DEPTH OF 2" TO ALLOW ADEQUATE BONDING
BETWEEN LAYERS.
7. COMPACTED FILL WITH A MOISTURE CONTENT WHICH WILL NOT PERMIT COMPACTION TO THE SPECIFIES DENSITY STANDARD SHALL BE
SACRIFICED, DRIED, OR WETTED AS NECESSARY TO PERMIT PROPER COMPACTION.
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DESIGNED BY:
UVN/JLF
DRAWN BY:
UVN/JLF
CHECKED BY:
JILT
DATE:
06-11-2020
SCALE:
NA
FILE:
wPo-2020-00034
RGA#:
8438
SHEET:
17 OF 18