SW1191201_Plan (SCM Detail)_20200518

AQUATTIC BENCH ELEV: 1202.00
OUTSIDE EDGE OF AQUATIC BENCH IS
6-IN ABOVE PERMANENT POOL ELEV
FOREBAY•
6' WIDE AQUATIC BENCH TOP OF WEIR -
AROUND ENTIRE POND ELEV: 1201.50
(SEE SHEETS C4.1 & C6.1) AQUATIC BENCH ELEV: 1201.00
INSIDE EDGE OF AQUATIC BENCH IS 6-FT LENGTH
31 T SUBMERGED 6-IN BELOW PERMANENT POOL ELEV FOREBAY WEIR
ELEV : 1200.00
1-PCKtMf1pLENT OL ELEV__fWX0 �7
�1 FOREBAY ENTRANCE ELEV: 1197 1 2 AEXIT
_ EXIT ELEV:1198
42" RCP IN -LET- PIPE RIPRAP PAD FOREBAY
----------- EMBANKME
TOP OF PERM. SED. STOR.
FOREBAY ENTRANCE TOP OF PERM. SED.
ELEV: 1197.00 FOREBA
BOT. OF PERM. SED. STOR. ELEV: 1197.00
FOREBAY ENTRANCE 6" IMPERVIOUS FILL
ELEV: 1196.00 LAYER UNDER ALL -
BOT. OF PERM. SED. STOR. WATER SURFACES
FOREBAY EXIT
.. ELEV:1196.50
SEQUENCE OF CONVERSION FROM SEDIMENT BASIN TO STORMWATER
CONTROL MEASURE
1. INSTALL POND BARREL, OUTLET STRUCTURE, EMBANKMENT AND
ALL OTHER POND COMPONENTS.
2. CALL FOR SITE INSPECTION PRIOR TO BACKFILLING POND BARREL.
3, INSTALL TEMPORARY SKIMMER TO OUTLET STRUCTURE.
4. EXCAVATE POND TO TEMPORARY SKIMMER BASIN DIMENSIONS,
SEE EROSION CONTROL PLAN.
5. INSTALL BAFFLES AND OTHER TEMPORARY SKIMMER BASIN
COMPONENTS, SEE TEMPORARY SKIMMER BASIN DETAIL.
6. REFER TO TEMPORARY SEDIMENT SKIMMER BASIN DETAIL FOR
ELEVATION OF SKIMMER CONNECTION.
7. SEE CONSTRUCTION SEQUENCE ON EROSION CONTROL PLAN FOR
INFORMATION,
8. ONCE SITE IS APPROVED, REMOVE TEMPORARY SKIMMER,
BAFFLES AND OTHER TEMPORARY COMPONENTS
9, FILL HOLE IN OUTLET STRUCTURE FROM SKIMMER WITH
NON -SHRINK GROUT. PROVIDE PERMANENT WATERTIGHT SEAL.
10. EXCAVATE SEDIMENT AND GRADE TO FINAL CONTOURS, SEE
GRADING PLAN.
11. CONSTRUCT WET POND STORMWATER CONTROL MEASURE AS
SHOWN ON THE DRAWINGS.
AS -BUILT SURVEY REQUIREMENTS
NOTE: CONTRACTOR SHALL PROVIDE AS -BUILT TOPOGRAPHIC
SURVEY PERFORMED BY A PROFESSIONAL LAND SURVEYOR CERTIFYING
WET DETENTION POND AREA DIMENSIONS AND ELEVATIONS OF THE
FOLLOWING:
1. TOPOGRAPHIC SURVEY OF THE WET POND AND EMBANKMENT
2. OUTLET STRUCTURE TOPS AND INVERTS
3. OUTLET STRUCTURE DIMENSIONS
4. ORIFICE DIAMETERS
5. BARREL PIPE SIZES AND INVERTS
6. EMERGENCY SPILLWAY ELEVATION AND DIMENSIONS.
OUTLET STRUCTURE NOTES
1. CAST -IN -PLACE CONCRETE RISER IS REQUIRED WITHOUT
EXCEPTION.
2. CLASS "A" (3,000 PSI) CONCRETE TO BE USED.
6. ALL MORTOR JOINTS ARE 1/2" f 1/8".
7. GROUT SHALL BE NON -SHRINK (ASTM-C1107)
S. ALL STRUCTURES OVER 3'-6" IN DEPTH TO BE PROVIDED WITH
STEPS 1'-2" ON CENTERS. STEPS SHALL BE IN ACCORDANCE WITH
STANDARD 840.66.
9. LOCATE MANHOLE OVER STEPS.
6-IN DUCTILE IRON DRAIN PIPE
WITH GATE VALVE AND HAND
WHEEL
d°
°
CONCRETE Y
PIPE ANCHOR
PVC PRIMARY SPILLWAY
]I-
ORIFICE DIAMETER: 3.5-IN
E=:)
LL
-
jF -
- - -
-;-/- - -
TEMPORARY SKIMMER TO BE \ /
REMOVED (SEQUENCE OF �/
FILL SKIMMER
CONVERSION FROM SEDIMENT
HOLE WITH
BASIN TO STORMWATER
NON -SHRINK
CONTROL MEASURE)
GROUT FOR
WATERTIGHT
SEAL
X
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°
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4.
°
°
8-IN
L
CAST IN PLACE RISER IS
REQUIRED WITHOUT
EXCEPTION I
OUTLET
BARREL
142-LF 24-IN RCP
8-IN
4-FT °
°
° ° a
°
CONTRACTOR SHALL PROVIDE
STEP IN ACCORDANCE WITH
NCDOT STD. 840.66. STEPS
SHALL BE PLACED AT 16" O.C.
OUTLET STRUCTURE
PLAN VIEW
3
1�
24-IN THICK CLASS B
RIPRAP OVER FILTER
FABRIC
TOP OF EMBANKMENT ELEV: 1208.00
100-YR STORM ELEV
1206.60
10-YR STORM ELEV
1205.10
2-YR STORM ELEV
1204.02
1-YR STORM ELEV
1203.68
PROVIDE 6' X 6' DEPRESSED AREA
2-FT BELOW PRINCIPAL SPILLWAY
WITHIN AQUATIC BENCH FOR
ADEQUATE DRAINAGE
PERMANENT POOL ELEV: 1201.50
MAIN POOL INV=1197.20
TOP OF PERM. SED. STOR. ELEV: 1197.00 -
BOT. OF PERM. SED. STOR. ELEV: 1196.00
SEASONAL HIGH WATER TABLE BELOW ELEV: 1192.00
TOP ELEV: 1205.5
6-FT WIDE ACCESS
PAD TO OUTLET
STRUCTURE 6-IN
BELOW WEIR
10-FT WEIR WIDTH
3
11
SPILLWAY CREST ELEV: 1206.50
'Il= o 0 0 0
'
1 1 I -I 1 I -I 1 I -I 1 I-1 I I -III -I 11-III-III-III-III-T
EMERGENCY SPILLWAY SECTION
10-FT
3
1F_
24-IN THICK CLASS B
RIPRAP OVER FILTER
FABRIC
1��1~ EMERGENCY SPILLWAY CREST ELEV: 1206.50 1
PRINCIPAL
SPILLWAY =-
INV=1203.30 L /COMPACTED6-INCOMPACTED \
OUTLET STRUCTURE '• ••• � SELECT FILL 7 ., � SELECT FILL / �
N / N \
INV=1201.50 I N
- - - - - - - - - - - - - - @ - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
BARREL OUTLET BARREL: 142-LF 24" RCP 17.2% SLOPE ASTM C-76 CLASS III GASKETED JOINT PIPE MANUFACTUR
SEED & MULCH EMBANKMENT SEE SEEDING SCHEDULE
(INSTALL SLOPE PROTECTION MATTING ON ALL SLOPES
STEEPER THAN 6: 1)
WV EXISTING DROP INLET
=III,��III�
CORE DRILL AND PROVIDE
WATERTIGHT CONNECTION TO
EXISTING DROP INLET
SCHEDULE A PRE -INSTALLATION
CONFERENCE PRIOR TO
CONSTRUCTION OF THE
STORMWATER CONTROL MEASURE
ED WITHOUT LIFT HOLES. GASKETED I INV=1171.00
INV=1197.00 JOINT PIPE SHALL BE WRAPPED WITH A DOUBLE LAYER OF NON -WOVEN FILTER FABRIC ON THE OUTSIDE OF THE PIPE AT EACH JOINT.
`----------------------------------------------
d d
INV=1197.10
• . • � 6-�TH/CK���tu�_
• , • • N CONCRETE PIPE N N / I / 4 • ° 4 • °
COLLAR TO CONC. ANTI -SEEP COLLAR (6" WIDE)
6" DUCTILE IRON 's ,
DRAIN PIPE SPRINGLINE 3 TOTAL UNDER EMBANKMENT WITH \ \ i� , .
POND AND EMBANKMENT SECTION
IV
ONE COLLAR UNDER CENTER OF \ \ - / N • ° ' ° °
DAM / \, CONCRETE \
24" PIPE
°
RCP A41COLLAR
---�I \ z
a
e• °• N
,° • • •• ••
A °
\ 24„ 24„ /
\ MIN MIN /
\ ANTI -SEEP COLLAR
\ \ ENLARGEMENT /
WET DETENTION BASIN MAINTENANCE SCHEDULE
DAM EMBANKMENT CONSTRUCTION STANDARDS
1. CONTROLLED FILL, AS SPECIFIED BY THE GEOTECHNICAL ENGINEER, IN THE DAM EMBANKMENT SHALL BE PLACED IN 6-INCH LOOSE LAYERS (3-INCH LOOSE LAYERS WITHIN 3-FEET OF
DESCRIPTION
METHOD
FREQUENCY
SEASON
EITHER SIDE OF THE PRINCIPAL SPILLWAY PIPE TO A DEPTH OF 2-FEET OVER THE PIPE) AND SHALL BE COMPACTED TO A DENSITY OF NO LESS THAN 95% OF THE STANDARD PROCTOR
MAXIMUM DENSITY AT A MOISTURE CONTENT OF + OR - TWO PERCENTAGE POINTS OF THE OPTIMUM MOISTURE CONTENT IN ACCORDANCE WITH ASTM D698.
EMBANKMENT
2. ALL VISIBLE ORGANIC DEBRIS SUCH AS ROOTS AND LIMBS SHALL BE REMOVED FROM THE FILL MATERIAL PRIOR TO COMPACTION TO THE REQUIRED DENSITY. SOILS WITH ORGANIC MATTER
INSPECT AND REPAIR
VISUAL
ONCE PER YEAR
ALL
CONTENT EXCEEDING 5% BY WEIGHT SHALL NOT BE USED. STONES GREATER THAN 3-INCH (IN ANY DIRECTION) SHALL BE REMOVED FROM THE FILL PRIOR TO COMPACTION.
EROSION / ANIMAL NESTINGS
3. FILL MATERIAL PLACED AT DENSITIES LOWER THAN SPECIFIED MINIMUM DENSITIES OR AT MOISTURE CONTENTS OUTSIDE THE SPECIFIED RANGES OR OTHERWISE NOT CONFORMING TO
INSPECT AND RESEED
VISUAL
WHENEVER NEEDED
ALL
SPECIFIED REQUIREMENTS SHALL BE REMOVED AND REPLACED WITH ACCEPTABLE MATERIALS.
- - - - - -
GRASS COVERAGE
4. ANY FILL LAYER THAT IS SMOOTH DRUM ROLLED TO REDUCE MOISTURE PENETRATION DURING A STORM EVENT SHALL BE PROPERLY SCARIFIED PRIOR TO THE PLACEMENT OF THE NEXT SOIL
LIFT.
OUTLET STRUCTURE
5. SURFACE WATER AND STREAM FLOW SHALL BE CONTINUOUSLY CONTROLLED THROUGHOUT CONSTRUCTION AND THE PLACEMENT OF CONTROLLED FILL.
\ \
DEBRIS / OBSTRUCTIONS
BY HAND
WHENEVER NEEDED
ALL
6. FOUNDATION AREAS MAY REQUIRE UNDERCUTTING OF COMPRESSIBLE AND/OR UNSUITABLE SOILS IN ADDITION TO THAT INDICATED ON THE PLANS. ALL SUCH UNDERCUTTING SHALL BE
END CAP WITH
/ DRILL OPENING \
PERFORMED AT THE DISCRETION OF THE GEOTECHNICAL ENGINEER AND SHALL BE MONITORED AND DOCUMENTED. IN NO CASE SHALL THERE BE AN ATTEMPT TO STABILIZE ANY PORTIONS
/ DIAMETER: 3.5-IN \
OF THE FOUNDATION SOILS WITH CRUSHED STONE.
/ \
OPERATE POND DRAIN VALVE
BY HAND
ONCE PER YEAR
ALL
7. TREATMENT OF SEEPAGE AREAS, SUBGRADE PREPARATION, FOUNDATION DEWATERING AND ROCK FOUNDATION PREPARATION (I.E., TREATMENT WITH SLUSH GROUTING, DENTAL CONCRETE,
/
\
ETC.) MAY BE REQUIRED AT THE DISCRETION OF THE GEOTECHNICAL ENGINEER. ALL SUCH ACTIVITIES SHALL BE CLOSELY MONITORED AND DOCUMENTED BY THE GEOTECHNICAL ENGINEER.
/
° d
\
EROSION AT OUTLET DISCHARGE
VISUAL
ONCE PER YEAR
ALL
8. FILL ADJACENT TO THE RISER AND PRINCIPAL SPILLWAY PIPE SHALL BE PLACED SO THAT LIFTS ARE AT THE SAME LEVEL ON BOTH SIDES OF THE STRUCTURES.
/
°
\
9. EARTHWORK COMPACTION WITHIN 3-FEET OF ANY STRUCTURES SHALL BE ACCOMPLISHED BY MEANS OF HAND TAMPERS, MANUALLY DIRECTED POWER TAMPERS OR PLATE COMPACTORS OR
°
ANCHOR \
MINIATURE SELF-PROPELLED ROLLERS.
°
DRAWDOWN
\
FOREBAY / MAIN POOL
10. COMPACTION BY MEANS OF DROP WEIGHTS FROM A CRANE OR HOIST SHALL NOT BE PERMITTED.
�
d
PIPE TO WALL
°
° °
11. HEAVY EQUIPMENT SHALL NOT BE ALLOWED TO PASS OVER CAST -IN -PLACE STRUCTURES (INCLUDING THE CRADLE) UNTIL ADEQUATE CURING TIME HAS ELAPSED.
SEDIMENT / DEBRIS
BY HAND
ONCE PER YEAR
ALL
/ 10 IN
12. TO RE-ESTABLISH VEGETATION AFTER CONSTRUCTION, A 2- TO 3-INCH LAYER OF TOPSOIL SHALL BE PLACED ON THE DISTURBED EMBANKMENT SURFACE AND THE AREA SEEDED AND
MULCHED OR HYDROSEEDED.
REMOVE TRASH
BY HAND
WHENEVER NEEDED
ALL
4"PVC
° "°
CONTRACTOR SHALL BE RESPONSIBLE FOR MAINTENANCE UNTIL PROJECT CLOSE OUT
TESTING, OBSERVATION, AND CERTIFICATION
I
°
1
AT WHICH TIME OWNER WILL ASSUME MAINTENANCE RESPONSIBILITY.
1. TESTS OF THE DEGREE (%) OF COMPACTION OF THE PLACED FILL IN THE DAM SHALL BE PERFORMED AS A PART OF THE PERMITTEE'S NORMAL QUALITY CONTROL PROGRAM FOR THE
d ° d
PRIMARY
CONSTRUCTION OF THE DAM. TESTS SHALL BE CONDUCTED CONCURRENT WITH THE INSTALLATION OF THE COMPACTED FILL AND THE CONTRACTOR SHALL COORDINATE THE CONSTRUCTION
I 4"PVC TEE
°
SPILLWAY
OF THE DAM SO THAT THE TESTING CAN BE COMPLETED. SHOULD THE RESULTS OF THE TESTS INDICATE THAT THE SPECIFIED DEGREE OF COMPACTION HAS NOT BEEN OBTAINED; THE
INV=1201.50
PORTIONS OF THE DAM REPRESENTED BY SUCH TESTS SHALL BE REWORKED OR REBUILT. ALL PORTIONS OF THE DAM SHALL ACHIEVE THE SPECIFIED MINIMUM DEGREE OF COMPACTION.
PERM. POOL ELEV: 1201.50
I
2. CONSTRUCTION OF CLASS A, B AND C DAM EMBANKMENTS SHALL BE DONE UNDER THE OBSERVATION OF A QUALIFIED GEOTECHNICAL ENGINEER, WHO IS REGISTERED AS A PROFESSIONAL
I
ENGINEER IN THE STATE OF NORTH CAROLINA. THE GEOTECHNICAL ENGINEER MUST HAVE EXPERIENCE IN THE DESIGN AND CONSTRUCTION MONITORING OF DAMS OF THE SIZE AND SCOPE
° °
COVERED BY THESE STANDARDS AND GUIDELINES.
d
3. ON CLASS A, B, AND C DAMS (WITH THE EXCEPTION OF DETENTION ONLY CLASS C DAMS THAT COLLECT DRAINAGE FROM AN AREA OF 25-ACRES OR LESS), THE GEOTECHNICAL ENGINEER,
°
4"PVC
WATERTIGHT
NON -SHRINK
I
AS DEFINED ABOVE, SHALL OBSERVE ALL ASPECTS OF THE CONSTRUCTION OF THE DAM (I.E., PREPARATION OF THE FOUNDATION, INSTALLATION OF THE CUT-OFF TRENCH, INSTALLATION OF
GROUT
I
THE PRINCIPAL SPILLWAY PIPE, INSTALLATION OF THE INTERNAL DRAINAGE, INSTALLATION OF COMPACTED FILL, ETC.). THE FREQUENCY OF OBSERVATION AND TESTING MUST BE
8-IN
°d
SUFFICIENT FOR THE GEOTECHNICAL ENGINEER (OR THE DESIGN ENGINEER ON CLASS D DAMS AND CLASS C, DETENTION ONLY, DAMS) TO STATE, IN HIS/HER PROFESSIONAL OPINION,
THAT THE SPECIFIC ITEMS OBSERVED AND TESTED WERE INSTALLED IN ACCORDANCE WITH THE APPROVED CONSTRUCTION DRAWINGS AND SPECIFICATIONS.
ANCHOR
/
DRAWDOWN
/
\
°°
PIPE TO WALL
/
\
•
/
HEAVY DUTY
VALVE STEM
\ /
WHEEL
\ END CAP WITH /
DRILL OPENING
\ /
DIAMETER: 3.5-IN
CONCRETE SLAB
3" DIA. CONCRETE CORE
5-IN THICK
MANHOLE RING AND COVER
CONCRETE SLAB
\ PRIMARY SPILLWAY /
#4 BARS 8" O.C. E.W.
\ /
24"
6-FT WIDE ACCESS
#4 BARS
ENLARGEMENT
PAD TO OUTLET
8"O.C. E.W. 3"R
�\
TOP SLAB ELEV: 1205.50
STRUCTURE 6-IN TOP SLAB ELEV: 1205.50
- \
o'
BELOW WEIR
o•
- - - \
#4 REBAR 6" O.C. E.W.
\
TRASH RACK
TRASH RACK
TRASH RACK (ALL
\
•0 '
IS ON ALL
FOUR SIDES
3"
•0 '
IS ON ALL
FOUR SIDES
FOUR SIDES OF
\
WEIR ELEV: 1203.30
e
1 RIM ELEV: 1203.30
e
OUTLET STRUCTURE)
_ I
\
��II�I�I�
ANCHOR TRASH RACK
\
8-IN
8-IN
6-IN
-
8-IN
(ALL CONTACT POINTS)
8-IN
\
\ PRIMARY � - -
�.
VALVE STEM GUIDE. ATTACH
'
,
\ SPILLWAY /
TO RISER WITH THREADED
MID POINT OF
/
\
ROD FILLED WITH GROUT
AQUATIC BENCH
PRIMARY
/
• °, ,
INV=1201.50
. °,
SPILLWAY
INV=1201.50
•
°
PERMANENT POOL ELEV: 1201.50
7
1
I
HEAVY DUTY
VALVE STEM
`' I I���
•
�� I I� I I� I I�
,e
II•IIII
TEMPORARY SKIMMER TO
\ \
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°•
°•
BE REMOVED ( SEE
CONSTRUCTION
\ \
�
U SHAPED STEEL
3
1
�
3
1 F
SEQUENCE)
\ \
+•
BRACKET ATTACHED TO
_
_ _ _ _ _
FILL SKIMMER HOLE WITH
\ \
BASE WITH THREADED
NON -SHRINK GROUT.
\ \
ROD FILLED WITH GROUT
PROVIDE PERMANENT
• '
\
ELEV: 1199.00
WATERTIGHT SEAL.
8-IN
OUTLET
EXTEND PIPE
OUTSIDE
_ _ _
-1�=1�1-'
I J I I- '
'•
• ,
INV=1197.00
BARREL
142-LF 24-IN RCP
II I
'
EMBANKMENT
/
I I- "
INV=1197.10
DEWATERING
•
INV=1197.20
TOP PERMANENT SEDIMENT STORAGE ELEV: 1197.00
1
11
°°
6" DUCTILE IRON DEWATERING PIPE
PIPE INV=1197.10
°
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6-FT X 6-FT X 2.5-FT DEEP
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CONCRETE FILL •
r` ° •.
• ° •
° CONCRETE FILL •
° t
• ° •
DEPRESSION UNDER PRINCIPAL
BOTTOM PERMANENT SEDIMENT STORAGE ELEV: 1196.00
/ \ /
, ,
' TO EXCEED • • N
TO EXCEED °
• ° N �.
SPILLWAY FOR ADEQUATE
/
• BUOYANT FORCE
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• • q BUOYANT FORCE • °
a
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DRAINAGE. TIE BACK TO AQUATIC
/
CONCRETE
°
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BENCH AT 3:1 SLOPE.
/
PIPE ANCHOR
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FLANGED, NRS, RESILIENT WEDGE GATE
/ \
VALVE WITH EXTENSION STEM, HAND WHEEL
/ \ AND STEM GUIDES AS MANUFACTURED BY
/
\ CLOW OR APPROVED EQUAL.
/
..
24 IN
OUTLET STRUCTURE
OUTLET STRUCTURE
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SECTION X-X
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Revisions
No.
Date
2
2020 FEB 12
3
2020 APR 07
FINAL
2020 MAY 18
Project Number: 1711-13
Date: 2020 JAN 20
Drawn by: FS
SITE DETAILS
Sheet Number:
0