SW6191005_Plan (SCM Detail)_20191218

1
FOR OFFICIAL USE ONLY
2
3
5
7 I 8
9 I 10
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11' TYPI
NOTE: 3:1 MAX SIDE SLOPES IF/WHERE
VEHICLES CROSS AND USE COURSE
AGGREGATE TO FORM THE DIVERSION BERM.
—DITCH LINER
COMPACTE (SEE PLAN)
SOIL
(SEE NOTE)
2•
S EMPx �sFFir,�9�- 18" MIN. FLOW FROM SITE
N � OIF 1MP�
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NOTE: ANY CLEANWATER DIVERSION DITCHES
SHALL BE STABILIZED WITH VEGETATION
IMMEDIATELY AFTER CONSTRUCTION AND THE
CHANNEL FLOW AREA SHALL REMAIN STABILIZED
THROUGH THE DURATION OF CONSTRUCTION TO
AVOID SEDIMENTATION OF UNDISTURBED AREAS.
MAINTENANCE
INSPECT TEMPORARY DIVERSIONS ONCE A WEEK AND
AFTER EVERY RAINFALL. IMMEDIATELY REMOVE
SEDIMENT FROM THE FLOW AREA AND REPAIR THE
DIVERSION RIDGE. CAREFULLY CHECK OUTLETS AND
MAKE TIMELY REPAIRS AS NEEDED. WHEN THE AREA
PROTECTED IS PEMANENTLY STABILIZED, REMOVE
THE RIDGE AND THE CHANNEL TO BLEND WITH THE
NATURAL GROUND LEVEL AND APPROPRIATELY
STABILIZE IT.
SEE PRETREATMENT
DETAIL
TO BUILDING ADDITION
OR PARKING LOT
2' MIN.
CONSTRUCTION SPECIFICATIONS
1. ENSURE THAT THE MINIMUM CONSTRUCTED CROSS SECTION
MEETS ALL DESIGN REQUIREMENTS.
2. ENSURE THAT THE TOP OF THE DIKE IS NOT LOWER AT ANY
POINT THAN THE DESIGN ELEVATION PLUS THE SPECIFIED SETTLEMENT
3. PROVIDE SUFFICIENT ROOM AROUND DIVERSIONS TO PERMIT MACHINE
REGRADING AND CLEANOUT
4. VEGETATE THE SOIL BERM IMMEDIATELY AFTER CONSTRUCTION,
UNLESS IT WILL REMAIN IN PLACE LESS THAN 30 WORKING DAYS.
5. SEED AND MULCH DIVERSION DITCH IMMEDIATELY AFTER CONSTRUCTION
UNLESS IT WILL REMAIN IN PLACE LESS THAN 30 WORKING DAYS.
DITCH
DEPTH
BOTTOM
SIDE
LINER
(V)
WIDTH (W)
SLOPES
TD#1-TD#4
1.5'
0'
3:1
S75
TEMPORARY DIVERSION DITCH
CG102 IC-505 NOT TO SCALE
4" MIN. CLEAN SAND UNLESS
THE NATIVE SOIL IS EQUIVALENT
(1-2% FINES OR LESS).
BASIN BOTTOM
(MAX)1 3
1' MIN. UNDISTURBED IN -SITU
2' MIN. SOIL (K= 0.52"/HR. MIN.)
NOTE: REFER TO GRADING PLAN FOR THE
GRADING INFORMATION.
SHWT = SEASONAL HIGH WATER TABLE
MAINTENANCE:
4' MIN.
(MAX)1
3
SHWT
2' MIN.
4" MIN.
GRAVEL
CLOTH
NOTE: PLACE AT LOCATIONS SHOWN ON CG104
FOR INFILTRATION BASINS 2 & 3.
PEA GRAVEL PRETREATMENT
THE DRAINAGE AREA SHALL BE CAREFULLY MANAGED TO REDUCE THE SEDIMENT LOAD TO
THE INFILTRATION BASIN.
IMMEDIATELY AFTER THE INFILTRATION BASIN IS ESTABLISHED, THE VEGETATION SHALL BE
WATERED TWICE WEEKLY IF NEEDED UNTIL THE PLANTS BECOME ESTABLISHED
(COMMONLY SIX WEEKS).
NO PORTION OF THE INFILTRATION BASIN IS TO BE FERTILIZED AFTER THE INITIAL
FERTILIZATION THAT IS REQUIRED TO ESTABLISH THE VEGETATION.
THE VEGETATION IN AND AROUND THE BASIN SHALL BE MAINTAINED AT A HEIGHT OF
APPROXIMATELY SIX INCHES.
AFTER THE INFILTRATION BASIN IS ESTABLISHED, IT SHALL BE INSPECTED ONCE A
QUARTER AND WITHIN 24 HOURS AFTER EVERY STORM EVENT GREATER THAN 1.0 INCHES
(OR 1.5 INCHES IF IN A COASTAL COUNTY). RECORDS OF INSPECTION AND MAINTENANCE
SHALL BE KEPT IN A KNOWN SET LOCATION AND SHALL BE AVAILABLE UPON REQUEST.
STORMWATER MANAGEMENT INFILTRATION BASIN
CS101 lC-505 NOT TO SCALE
CG 1031V
CG 104
CLASS B RIPF' "
12" OF NCDOT #5 OR #57
WASHED ST(
FILTER CLOT
4' TO 6'
CROSS-SECTION VIEW
MAINTENANCE:
1 ti' RAIN
INSPECT CHECK DAMS AND CHANNELS AT LEAST WEEKLY AND AFTER EACH SIGNIFICANT
(1/2 IN. OR GREATER) RAINFALL EVENTS AND REPAIR IMMEDIATELY. CLEAN OUT STRAW,
SEDIMENT, LIMBS, OR OTHER DEBRIS THAT COULD CLOG THE CHANNEL WHEN NEEDED.
ANTICIPATE SUBMERGENCE AND DEPOSITION ABOVE THE CHECK DAM AND EROSION
FROM HIGH FLOWS AROUND THE EDGES OF THE DAM. CORRECT ALL DAMAGE
IMMEDIATELY. IF SIGNIFICANT EROSION OCCURS BETWEEN DAMS, ADDITIONAL
MEASURES CAN BE TAKEN SUCH AS, INSTALLING A PROTECTIVE RIP RAP LINER IN THAT
PORTION OF THE CHANNEL.
REMOVE SEDIMENT ACCUMULATED BEHIND THE DAMS AS NEEDED TO PREVENT DAMAGE
TO CHANNEL VEGETATION, ALLOW THE CHANNEL TO DRAIN THROUGH THE STONE CHECK
DAM, AND PREVENT LARGE FLOWS FROM CARRYING SEDIMENT OVER THE DAM. ADD
STONES TO DAMS AS NEEDED TO MAINTAIN DESIGN HEIGHT AND CROSS SECTION.
TEMPORARY CHECK DAM
CG102IC-505 NOT TO SCALE
EXCAVATED AREA (AS REQUIRED)
CONSTRUCTION SPECIFICATIONS
1. CLEAR THE AREA OF ALL DEBRIS THAT MIGHT HINDER
EXCAVATION AND DISPOSAL OF SPOIL.
2. GRADE THE APPROACH TO THE INLET UNIFORMLY.
3. PROTECT WEEP HOLES BY NCDOT #5 OR # 57 WASHED STONE.
4. WHEN THE CONTRIBUTING DRAINAGE AREA HAS BEEN
PERMANENTLY STABILIZED, SEAL WEEP HOLES, FILL THE BASIN
WITH STABLE SOIL TO FINAL GRADING ELEVATIONS, COMPACT IT
PROPERLY, AND STABILIZE.
ACCUMULATED
SEDIMENT
CONSTRUCTION SPECIFICATIONS:
1. PLACE STONE TO THE LINES AND DIMENSIONS SHOWN
IN PLAN ON A FILTER FABRIC FOUNDATION.
2. KEEP THE CENTER STONE SECTION AT LEAST 9 INCHES
BELOW NATURAL GROUND LEVEL WHERE THE DAM
ABUTS THE CHANNEL BANKS.
3. EXTEND STONE AT LEAST 1.5 FEET BEYOND THE DITCH
BANK TO KEEP WATER FROM CUTTING AROUND THE
ENDS OF THE CHECK DAM.
4. SET SPACING BETWEEN DAMS TO ASSURE THAT THE
ELEVATION AT THE TOP OF THE LOWER DAM IS THE SAME
AS THE TOE ELEVATION OF THE UPPER DAM.
5. PROTECT THE CHANNEL AFTER THE LOWEST CHECK DAM
FROM HEAVY FLOW THAT COULD CAUSE EROSION.
6. MAKE SURE THAT THE CHANNEL REACH ABOVE THE
MOST UPSTREAM DAM IS STABLE.
7. ENSURE THAT THE OTHER AREAS OF THE CHANNEL,
SUCH AS CULVERT ENTRANCES BELOW THE CHECK
DAMS, ARE NOT SUBJECT TO DAMAGE OR BLOCKAGE
FROM DISPLACED STONES.
NCDOT #5 0� ��
OR # 57
WASHED STONE
NCDOT #5 OR # 57 WASHED
STONE SUPPORTED BY
HARDWARE CLOTH TO
ALLOW DRAINAGE AND
RESTRICT SEDIMENT
MOVEMENT
MAINTENANCE
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PLAN
INSPECT, CLEAN, AND PROPERLY MAINTAIN THE EXCAVATED BASIN AT
LEAST WEEKLY AND AFTER EACH SIGNIFICANT (1/2 INCH OR GREATER) RAINFALL
EVENT AND REPAIR IMMEDIATELY UNTIL THE CONTRIBUTING DRAINAGE
AREA HAS BEEN PERMANENTLY STABILIZED. TO PROVIDE
SATISFACTORY BASIN EFFICIENCY, REMOVE SEDIMENT WHEN THE
VOLUME OF THE BASIN HAS BEEN REDUCED BY ONE-HALF. SPREAD CAII'',,
ALL EXCAVATED MATERIAL EVENLY OVER THE SURROUNDING LAND ; R�<i,�'�;
AREA OR STOCKPILE AND STABILIZE IT APPROPRIATELY. .�oF off. 9
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EXCAVATED DROP INLET PROTECTION (TEMPORARY) DETAIL I I I I I i I `7\2�7612079
CG101 C-505 NOT TO SCALE ISSUED FOR
CONSTRUCTION
US Army Corps
of Engineers®
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SHEET ID
C-505