Site Plan Revised 4-10-14 (6)Top of Dam Elevation
Trash Rack Bottom Elev.
CLElev Erosion (see detail) of Spillway
Cone Baffle I S
T. Floating
Skimmer Riser
3:1
'1 Y
Bottom Elev. -J J Anti -Seep Collar
of Pool Sediment
Storage Anti- Flotation L Cuttoff Trench:
Device (see detail) 2'deep
Tbottom
2:l side slopes
Rip -Rap Outlet
(see outlet detail)
Riser
Basin
Drainage
Areas (Ac)
Disturbed
Area (Ac)
Min, Surface
Area
Min. Sediment
Storage
Bottom Elev.
Of Pool
Min.
Dimensions
Top Elev.
of Pool
Top of ]riser
Elev.
Bottom El".
Of Spillway
Top of Berm i
Elev.
Riser Dia
011.)
Barrel Dia.
(in.)
1
29.0
29.0
34,060 sq -ft
19,000 cu -ft
181.0'
t30' x 262'
186.3'
185.0'
186.3'
188.0'
54
42
2
45.0
30.0
75,392 sq -ft
54,000 w -ft
135'
160' x 472'
142'
139'
142'
144.5'
54
42
#4 bra Layout Shown is suggested:
However, other layouts may be used
provided openings are 640:L square in area
TRASH RACK DETAIL
I
Concrete
Gram
3'mn�.,
Riser
Concrete
Basin I
Dimensions
#1
6"
5' x 5''-6x 3-0 "
#2
x 6-0"
x 3'
ANTI - FLOTATION DEVICE
Top of Dam
Elevation
Width
i bi Freeboard
1 Max. Depth of Flow
3 fo rS
r 25 -yr. tomn
Line with grass accordion-------- __ -____
to Seeding Schedule \_Comp redEottom El".
Subgrade of Spillway
SPILLWAY (cross section)
Riser
Basin
Mier
Slope
Max.
Slope
Bottom Elev.
of Spillway
Top of
Dam Elev.
Width
Max. Depth of Flow
for 25 -yr. Storm
Freeboard
#1
4.0%
4.0 %v
186.3'
188.0'
18'
0.54'
1.0'
fl2
2.7%a
5.3%
142.0'
144.5'
32'
1.21'
1.29'
Construction Specifications:
L Site preparations - Clear, grub, and strip topsoil from areas under the embankment to remove trees, vegetation, toots, and other objectionable material. Delay clearing the pool area until the dam is complete
and then remove brush, lives, and other objectionable materials to facilitate sediment clearing. Stockpile all remand or soil containing organic matter for use on the outer shell of the embankment to facilitate
vegetative establishment. Place temporary sediment control measures below the basin as needed
2. Cm- offtrench- Excavate a cut -off trench along the center line of the earth fill embankment. Cut the trench to stable soil material, but in m case [take it less than 2 feet deep. The cut-offmrnch must
extend into both abutments to at least the elevation of the riser =at Make the minimum bottom width wide enough to parmit operation of excavation and compaction equipment, but in no case less than 2
feet. Make side slopes of the trench no steeper than 1:1. Compm:tion requirements ate the same as those for the embankment Keep the trench dry during backfilling and compaction operations.
3. Embankment --Take fill material from the approved areas shown on the plans. It should he clean mineral soil, free of roots, woody vegetation, rocks, and other objectionable material. Scarify areas on
which fill is to be placed before placing fill. The fill material must contain sufficient moisture wit can be formed by hand into a ball without crumbling. If water can be squeezed out of the ball, his too wet
fer proper compaction. Place fill material in 6 m 8 inch continuous layers over the entire length of the fill area and compact it. Compaction may be obtained by routing the construction hauling equipment
over the fill so the the entire surface of each layer is traversed by at least one wheel or tread track of heavy equipment, or a compactor may be used. Construct the embankment to an elevation 10 percent
higher than the design height to allow for settling.
4. Conduit spillways -- Securely attach the riser to the barrel or barrel stub to [Hake a watertight structural connection. Secure all connections between barrel sections by approved watertight assemblies. Place
the barrel and riser on a firm, smooth foundation of impervious and. Do not use pervious material such as send, gravel, or crushed stow as backfill around the pipe or anti -seep collars. Place the fill material
mound the pipe spillway in 4 -inch layers, and compact it under and emend the pipe to a least the same density as the adjacent embankment. Care most be taken not to raise the pipe from firm contact with its
foundation when compacting under the pipe haunches.
Place a minimum depth of 2 feet of compacted bwkfill over the pipe spillway before crossing it with construction equipment Anchor the riser in place by concrete or other satisfactory means to prevent
flotation. In no case should the pipe conduit be installed by cutting a trench through the dam after the embankment is complete.
5. Emergency spillway - Install the emergency spillway in undisturbed soil The achievement ofpknned elevations, grade, design width, and entrance and exit channel slopes are critical to the swoessful
operation of the emergency spillway.
6. Inlets -- Discharge water into the basin in a manner to prevent erosion. Use diversions with outlet protection to divert sediment -laden water to the upper end of the pool men to improve basin trap efficiency.
7. Erosion control -- Construct the structure so that the disturbed area is minimized. Divert surface water away from bare meal. Complete the embankment before the aura is cleared. Stabilize the emergency
spillway embankment and all other disturbed areas above the neat of the principal spillway immediately after construction.
8. Install porous baffles.
9. Safety - -Scri meut basins may attract children and can be dangerous. Avoid steep side slopes, and fence and mark basins with warning signs if trespassing is likely. Follow all state and local requirements.
Maintenance:
Inspect sediment basins at least weekly and after each significant (% inch or greater) rainfall event and repair immediately. Remove sediment and restore the basin to its original dimensions when it
accumulates to one-half the design depth. Place removed sediment in an area with sediment controls.
Check the embankmmnt, spillways, and outlet for erosion damage, and inspect the embankment for piping and settlement. Make all necessary repairs immediately. Remove all trash and other debris from the
riser and pool arcs.
U
SEDIMENT BASIN DETAILS AND SPECIFICATIONS I
10
to
I
1.5'/100'
ANTI -SEEP
COLLAR
V-
SEDIMENT BASIN 'B' DETAIL
NO SCALE
Pipe Outlet
Starting
Ending
�
d50 Size /Class
-
Width
Width
0
_
Sed Basin #1
11 ft.
26 ft.
22 ft.
9 inch. = Class B
Sed Basin #2
11 ft
26 R.
22 ft.
9 inch. = Class B
Pipe At -ewh
61
48 ft.•
20 R
10 inch. =Class 1
Pipe A2
61L
24 ft
22 fL
13 inch. = Class 2
* TOTAL WIDTH FOR BOTH PIPES TOGETHER
RIP -RAP OUTLET DETAIL
NO SCALE
ORIG. GROUND
BOTTOM
1' SWALE
1.5 R min hc}md
ditch bank
Channel Width
Vanes
Plan View of Check Dam
1.5 ft Min
Class B Ripmp
12" ofNCDOT #5 m #57 -
Washed Stone
O - C'
„= 00000 2 a Fla
tmr)
00000`?OOG
O O O O q O` C 1 2Rmax.
00000000000000E at center
0 0 0 060 0 0
,100000t`f 00000000..
o�0_,O
Filter Fabric
Cross - Section View of Check Dam
Length is the distance such that points A and B
are of equal elevations
�-- 3.1
Not to Scale
Spacing for Check Dams
Construction Specifications:
1. Piece atone to the lines and dimensions shown in the plan on a filter fabric foundation.
2. Keep the center stone section at least 9 inches below manual ground level where the dam abuts the channel banks.
3. Extend stone a least 1.5 feet beyond the ditch bank to keep water from cutting around the ends of the check dam
4. Set spacing between damns to mature that the elevation at the top of the lower dam u the same as the low 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 other areas of the channel, such as culvert connotes below the check dams, are not subject to damage or blockage from
displaced atones.
Maintenance:
Inspeatcheck dams and chamels at least weekly and after each significant (12 inch or greater) rainfall event and repair immediately. Clean
out sediment, straw, 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 crane dam. Correct all damage
immediately.
Remove sediment accumulated behind the dams u needed to prevent damage to channel vegetation, allow the channel to drain through the
stow check dam, and prevent large flows from carrying sediment ova the dam. Add stones to dams es needed to mmutain design height and
cress section.
Temporary Rock Check Dam
Dike 4 mm
Hold -down ' r 3:
1 I5'
Zs�y
Stakes °^?.'?.+? -IGr j °%y3r,� tnin..
Inlet }
a
C�'t19 � -III
Pi
Southt
outlet T'
4'ran' }
level section
Construction Specifications
A common failure of slope drains is caused by water saturating the soil and seeping along the pipe.
This creates voids from consolidation and piping and causes washouts. Proper backfrlling around and
under the pipe "haunches" with stable soil material and hand compacting in 6 -inch lifts to achieve firm
contact between the pipe and the sell at all points will eliminate this type of faihue.
1. Place slope drains on undisturbed soil a well compacted fill at locations and elevations shown on
the plan..
2. Slightly slope the section of pipe under the dike toward its outlet.
3. Hand tamp the soil under and around the entrance section in lifts not to exceed 6 inches.
4. Ensure that fill over the drain at the rap of the slope has minimum dimensions of 1.5 feet depth, 4
feet top width, and 3:1 side slopes.
5. Ensure that all slope drain connections are watertight.
6. Ensure that all fill material is well- compacted. Securely fasten the exposed section of the drain with
grommets or stakes spaced m more than 10 feet apart.
7. Extend the drain beyond the toe of the slope, and adequately protect the outlet from erosion.
8. Make the settled, compacted dike ridge no less than 1 feet above the top of the pipe at every point.
9. Immediately stabilize all disturbed areas following construction.
Maintenance
Inspect the slope drain and supporting diversion after every rainfall, and promptly make necessary
repairs. When the protected area has been permanently stabilized, temporary measures may be
removed, materials disposed of properly, and all disturbed areas stabilized appropriately.
TEMPORARY SLOPE DRAIN
TOD Width
--Install Collar with corrugations Vertical
- -Collar to be of same gauge as the pipe with which it used
NOTES FOR COLLARS:
1. All materials to be in accordance with
construction and construction material.
specifications.
2. When specified on the plans, coating of
collars shall be in accordance with con -
strution and construction material
specifications.
3. Unassembled collars shall be marked by
painting or tagging to identify matching
paw
4. The lap between the two half sections and
between the pipe and connecting band shall
be caulked with asphalt at time of installation.
5. Each collar shall he furnished with two
1/2" diameter rods with standard tank lugs
for connecting collars to pipe.
2t $ mcturung x MM9 B S e 2t
0 0 0_ -r- _ o 0 o T
Band
Conthntuns
Weld
Elevation of unassembled Collar B
Details of Corrugated Metal Anti-Seep Collar
Mm
Weld Both
Sides
Corrugated Metal
Sheer Welded to
Center of Bond
Section B -B
Use rods and lugs to clamp
hands securely to pipe
min /
Band of
Helical Pipe
Metal collar to be
welded to center of
helical pipe band
Partial Elevation
NOTE:
IFor details of fabrication dimensions,
minimmn gages, slotted holes, and
a notes, see detail above.
ANTI -SEEP COLLAR (typical)
Sin and spacing of slotted
openings shall be the same Weld 1 -1/8" z 1 -1 /8" x 1/8" angles
as shown fm CM collar to collar or bend a 90" angle
1 -1/8" wide as shown in drawing
Rod end Le Sheet metal collar shall be
8 cut out to fit corrugations
of helical band, and welded
with a continuous weld.
Isometric View
NOTE:
Modifications of the details shown may be
used providing equal water tightness is main-
tained and detailed drawings are submitted
and approved by the Engineer prior to delivery.
Details of Helical Pipe Anti-Seep Collar
NOTE: Two other types of anti -seep collars
are:
1. Corrugated metal, similar to upper detail,
except shop welded to a short (oft)
section of the pipe and connected with
connecting bands to the pipe.
2. Concrete, six inches thick formed ammtd
the pipe with #3 rebar spaced 15"
horizontally and vertically.
NOTES:
1. Slopes will be tracked during construction to aid in the establishment of vegetative cover.
2. All exposed areas will be stabilized immediately following construction.
EXISTING OVERBURDEN
not to stale
'fax.
tax.
fax.
80 100
%' EDIMENT BASIN 1
OHEMM N(:Obf a5
oast w�srmo SroxE
Construction Specifications:
1. Clear the entrance and exit area of all vegetation, roots, and other objectionable material and properly grade it
2. Place the gravel to the specific glade and dimensions shown on the plans, and smooth it.
3. Provide drainage to carry water to a sediment trap or other suitable outlet.
4. Use geotextile fabrics because they improve stability of the foundation in locations subject to seepage or high
water table.
Maintenance
Maintain the gravel pad in a condition to prevent mud or sediment from leaving the construction site. This may
require periodic topdnessing with 2 -inch stone. After each rainfall, inspect any stmenne used to trap sediment and
clean it out as necessary. Immediately remove all objectionable materials spilled, washed, or tracked onto public
roadways.
NOTE:
1. NCDOT #5 stone is preferred. Pad to be 100 ft. L x 20 ft. W x 6 in. thick (min.).
2. Turning radius sufficient to accommodate large trucks.
3. Must be maintained in a condition which will prevent trading or direct Row uttered onto streets. Periodic
topdressing may be necessary
Construction Entrance
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NOTES FOR COLLARS:
1. All materials to be in accordance with
construction and construction material.
specifications.
2. When specified on the plans, coating of
collars shall be in accordance with con -
strution and construction material
specifications.
3. Unassembled collars shall be marked by
painting or tagging to identify matching
paw
4. The lap between the two half sections and
between the pipe and connecting band shall
be caulked with asphalt at time of installation.
5. Each collar shall he furnished with two
1/2" diameter rods with standard tank lugs
for connecting collars to pipe.
2t $ mcturung x MM9 B S e 2t
0 0 0_ -r- _ o 0 o T
Band
Conthntuns
Weld
Elevation of unassembled Collar B
Details of Corrugated Metal Anti-Seep Collar
Mm
Weld Both
Sides
Corrugated Metal
Sheer Welded to
Center of Bond
Section B -B
Use rods and lugs to clamp
hands securely to pipe
min /
Band of
Helical Pipe
Metal collar to be
welded to center of
helical pipe band
Partial Elevation
NOTE:
IFor details of fabrication dimensions,
minimmn gages, slotted holes, and
a notes, see detail above.
ANTI -SEEP COLLAR (typical)
Sin and spacing of slotted
openings shall be the same Weld 1 -1/8" z 1 -1 /8" x 1/8" angles
as shown fm CM collar to collar or bend a 90" angle
1 -1/8" wide as shown in drawing
Rod end Le Sheet metal collar shall be
8 cut out to fit corrugations
of helical band, and welded
with a continuous weld.
Isometric View
NOTE:
Modifications of the details shown may be
used providing equal water tightness is main-
tained and detailed drawings are submitted
and approved by the Engineer prior to delivery.
Details of Helical Pipe Anti-Seep Collar
NOTE: Two other types of anti -seep collars
are:
1. Corrugated metal, similar to upper detail,
except shop welded to a short (oft)
section of the pipe and connected with
connecting bands to the pipe.
2. Concrete, six inches thick formed ammtd
the pipe with #3 rebar spaced 15"
horizontally and vertically.
NOTES:
1. Slopes will be tracked during construction to aid in the establishment of vegetative cover.
2. All exposed areas will be stabilized immediately following construction.
EXISTING OVERBURDEN
not to stale
'fax.
tax.
fax.
80 100
%' EDIMENT BASIN 1
OHEMM N(:Obf a5
oast w�srmo SroxE
Construction Specifications:
1. Clear the entrance and exit area of all vegetation, roots, and other objectionable material and properly grade it
2. Place the gravel to the specific glade and dimensions shown on the plans, and smooth it.
3. Provide drainage to carry water to a sediment trap or other suitable outlet.
4. Use geotextile fabrics because they improve stability of the foundation in locations subject to seepage or high
water table.
Maintenance
Maintain the gravel pad in a condition to prevent mud or sediment from leaving the construction site. This may
require periodic topdnessing with 2 -inch stone. After each rainfall, inspect any stmenne used to trap sediment and
clean it out as necessary. Immediately remove all objectionable materials spilled, washed, or tracked onto public
roadways.
NOTE:
1. NCDOT #5 stone is preferred. Pad to be 100 ft. L x 20 ft. W x 6 in. thick (min.).
2. Turning radius sufficient to accommodate large trucks.
3. Must be maintained in a condition which will prevent trading or direct Row uttered onto streets. Periodic
topdressing may be necessary
Construction Entrance
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DESIGNED: LAB
DRAWN: LAB
CHECKED: LAB
DATE: DEC. 2013
REGION: SOUTH
LOCATION: GARDNER
HA_GARDNER, X -1
DWG FILE:
SCALE:
HORIZONTAL:
1' = 200'
VERTICAL:
SHEET NO.:
X =3