R-2457CC

t..
} F -v
V ?
Site 2 Section CC (Permit Drawing 5 of 24 dated 3/22/02) and Site 10 Section C
(Permit Drawing 29 of 34 dated 3/22/02 and 30 of 34 dated 3/22/02) and Plan Sheet 5
-Permit drawing indicates a PSH is located at Station 145+40. The plan sheet indicates
that this device has been shifted to Station 145+20.
The drainage was not adjusted on the permit drawing for the lengthened bridge and
there are drainage structures shown in the bridge. In the current plans, the
drainage structures were shifted back line so these structures would not conflict
with the bridge.
-Permit drawing indicates a level spreader that is 27m long at station 147+20. This device
is not depicted on the plan sheet
This level spreader was overlooked and unintentionally left off the drainage plans,
but on further investigation the slope of the natural ground where the level spreader
is to be located is approximately 10% and there is not adequate right-of-way to
achieve the specified length. Per DWQ requirements, level spreaders should be used
only on slopes of 8% or less.
-Plan sheets depict an additional cross pipe that originates from the end bent that outfalls
into a PFSH.
Due to the increased length of the Marks Creek bridge necessary to span the
buffers, a drainage system was required on the bridge. The pipes shown tie the
bridge system to a drainage system so they can be directed to the PFSH.
-Permit drawing indicates a 1350mm pipe that conveys a stream that outlets into a
channel with riprap lined banks. The outlet of this pipe is located outside of the wetland
boundary. The plan sheet indicates that the outlet of this pipe has been shifted and is now
located inside the wetland boundary. This would indicate an additional wetland impact.
There should be no additional impact since this is in the area included under
mechanized clearing. Also, this pipe conveys off-site cross drainage and not
stormwater runoff from the road.
-Plan sheet indicates that a headwall is located at the inlet of the 1350mm pipe. The
permit drawing depicts the structure without a headwall.
The headwall does not impact any additional area. The pipe was designed to be
buried 20%.
-Permit drawing depicts a PFSH at 146+40. This device is not depicted on the plan sheet.
Due to the super-elevation of the roadway, the drainage box was no longer required,
so the PFSH was removed.
Site 3 Section CC (Permit Drawings 6 of 24 dated 3/22/02 and 7 of 24 dated 4/8/02)
and Plan Sheet 5 and 6
-Permit drawing indicates a 1800mm cross pipe w/o a headwall at inlet. Plan sheet
indicates this pipe has a headwall at the inlet.
R-2457CC PERMITS 2
The headwall does not impact any additional area. The pipe was designed to be
buried 20%.
-Permit drawings indicates level spreader on the east side of the roadway that is straight.
The plan sheet indicates a level spreader in this location that is rounded.
Level spreaders are to be constructed along the contour of the existing land. The
rectangular level spreaders shown on the permit drawings are for illustrative
purposes only. In fact, the level spreaders shown on the permits are not depicted at
the correct length, so PDE's will be required to construct.
Site 4 and 5 Section CC (Permit Drawings 8 Of 24 dated 1/7/03 and 9 of 24 dated
1/7/03) and Plan Sheet 7
-Permit drawing indicates a lateral ditch flowing into a level spreader on the east side of
the roadway. The plan sheet indicates toe protection along the eastern fill slope and a
PFSH located approximately 30m away from the riparian buffer.
In the original drainage design provided by NCDOT, two low areas existed that
would not drain properly. Two cross pipes were added to drain the low areas and
collect off-site drainage. The ditch shown in the permit drawing would not work as
shown. By adding the pipes, a ditch was no longer needed and toe protection could
be used instead. The location of the level spreader shown on the permit is on a 20%
slope. Per DWQ requirements, level spreaders should be used only on slopes of 8%
or less. The runoff from the roadway drainage has been directed to a PFSH.
-Permit drawing indicates a 0.9m base ditch along the western side of the roadway that
flows to a level spreader. This lateral ditch has been redesigned on the plan sheet.
The ditch was not altered from original NCDOT design files where it was shown as
a lateral v-ditch. The ditch label on the permit drawing is shown incorrectly.
Site 6 Section CC (Permit Drawings 12 of 24 dated 3/22/02 and 13 of 24 dated
4/8/02) and Plan Sheet 8
-Plan sheet indicates 10m of riprap for bank stabilization at the outlet of the structure.
This riprap is not indicated on the permit drawing.
Riprap is as shown from NCDOT's original drainage file and is standard practice to
place riprap on banks at the outlet of culverts.
-Permit drawing depicts a lateral base ditch that originates at the railroad and terminates
at the creek on the west side of the roadway. The plan sheet indicates that this lateral
ditch has been decreased in length and reconfigured. Additionally, toe protection is
located along the western fill slope.
Upon redesign of the drainage, the 2GI at station 159+30 left was no longer
required. A portion of the ditch was removed in lieu of toe protection.
-Permit drawing depicts a lateral base ditch that terminates at the creek on the eastern
side of the roadway. The plan sheet depicts a reconfigured lateral ditch that terminates at
R-2457CC PERMITS 3
the edge of the riparian buffer. Toe protection is depicted along the fill slope within the
riparian buffer.
The way the permit drawing is shown renders the level spreader useless. On the
permit, a ditch is also shown being cut through the buffers. The drainage was
revised to route the runoff into the level spreader to provide diffuse flow into the
buffer. Toe protection was added in the buffer, which is less impact on the buffer
since no ditch will be installed.
Site 7 and 8 Section CC (Permit Drawings 14 of 24 dated 4/8/02 and 15 of 24 dated
4/8/02) and Plan Sheets 10A and 10D
-Plan sheet 10A indicates that the structure is a 900mm pipe. The permit drawing
indicates that the structure is a 1500mm pipe.
Upon reviewing the original design from NCDOT, the 1500mm pipe was found to be
excessive. The cross pipe was revised to a 900mm pipe.
-Permit drawing indicates a headwall at the inlet of the structure that captures a stream.
Plan sheet 10A indicates a junction box and additional drainage structures that flow into
this pipe.
The stream at the inlet of the pipe is shown on the permit as being filled by
construction of -L-. Upon reviewing the original design from NCDOT, a diversion
was detected. To correct the diversion, it was necessary to add a cross pipe under
-L-. Also, it was determined that there was not sufficient room between the fill
slopes to have an open channel, so an open throat catch basin was specified.
-Plan sheet 10A indicates toe protection along the eastern fill slope of the -L- line that is
within the riparian buffer. This toe protection is not depicted on the permit drawing.
Toe protection does not impact any additional area and is used to stabilize the
slopes.
-Permit drawing indicates that a PSH is located along the Y line at Station 16+00. This
PFSH has been eliminated from the plan sheet.
Upon reviewing the original design from NCDOT, the PFSH was moved to the
opposite side of -Ramp BDY1- as the location shown on the permit drawing is on the
side of a 2:1 slope.
-Permit drawing indicates that the two structures are separated and 2m of live stream is
located between the pipes. Plan sheet IOD indicates that the two structures are joined by
a junction box.
The drainage shown on the permit drawing will not function as fill is covering both
pipe ends. This has been revised to add an open throat catch basin where the fill
slopes converge.
-Plan sheet 10D indicates that the structure is a 900mm pipe. The permit drawing
indicates that the structure is a 1500mm pipe.
Upon reviewing the original design from NCDOT, the 1500mm pipe was found to be
excessive. The cross pipe was revised to a 900mm pipe.
R-2457CC PERMITS
4
-Permit drawing indicates that a PFSH is located along the Y line at Station 14+30. This
PFSH has been eliminated from the plan sheet.
Upon reviewing the original design from NCDOT, the drainage structure was no
longer needed. The runoff that was collected by this structure is treated in a PFSH
at approximately station 15+30 -Ramp CY1-.
-Plan sheet 10D indicates toe protection within the riparian buffer along both sides of the
stream. The permit drawing depicts toe protection with the buffer only south of the
stream.
Toe protection does not impact any additional area and is used to stabilize the
slopes.
Site 9 and Site 10 Section CC (Permit Drawing 16 of 24 dated 4/8/02 and 17 of 24
dated 4/8/02) and Plan Sheets 10D and 11C
The approved permit sheets 16 and 17 contradict each other and show two separate
layouts for drainage. Sheet 16 shows several pipes that outlet directly into the
stream.
-Plan sheet 10D indicates that riprap will be placed at the outlet of the structure where
bank excavation has been conducted. The permit drawing does not depict the riprap and
instead depicts a cross vane at the outlet.
The cross vane was inadvertently left off the drainage plans. It will be added to the
plans, but it appears a PDE will be required to construct. The riprap on the
channel banks should remain for stability.
-Plan sheet 10D indicates toe protection within the buffer along the southern fill slope of
this Y line. This toe protection is not depicted on the permit drawing.
Toe protection does not impact any additional area and is used to stabilize the
slopes.
-Plan sheet 10D depicts a PFSH along the southern fill slope directly outside of the
riparian buffer. The permit drawings depict a level spreader in this area. Additionally,
drainage structures have been eliminated in this area within the riparian buffer.
Due to the contour of the existing land, a PFSH is better suited for this area. No
drainage structures have been eliminated. The drainage structure moved so the
length of pipe was shortened. The PFSH was sized per NCDENR-DWQ guidelines.
-Plan sheet 10D depicts toe protection and a lateral base ditch along the northern slope of
this Y line in the buffer. The permit drawing does not depict either of these features in
the buffer.
Upon reviewing the original design from NCDOT, a low area existed right of station
16+75 -Ramp CY1- that was not previously addressed. The drainage revision
required a cross pipe to be added to drain this area. With the addition of this pipe,
a lateral ditch was required at the outlet. The drainage area that the ditch carries is
R-2457CC PERMITS 5
too large to implement a level spreader or PFSH. Almost all of the drainage is from
off site.
-Plan sheet 10D depicts a portion of stream near the outlet of the structure that is outside
of the fill limits will be filled. The permit drawing does not indicate that this section of
the stream channel will be filled.
This part of the stream channel is denoted as `Fill in Surface Waters' on the permit
drawings.
-Plan sheet I IC depicts toe protection within the riparian buffer along the northern and
southern fill slopes of this Y line. These features are not depicted on the permit drawing.
Toe protection does not impact any additional area and is used to stabilize the
slopes.
-The permit drawing depicts a level spreader to the immediate north of the inlet of this
structure. This device does not appear to be depicted on plan sheet 11C.
This level spreader was located at the outlet of a system that has been removed. The
concentrated flow no longer exists, thus the level spreader was no longer necessary.
-The permit drawing indicates that the structure is a 1350mm pipe. Plan sheet 11C
depicts the structure is a 1200mm pipe.
Upon reviewing the original design from NCDOT, the 1350mm pipe was found to be
excessive. The cross pipe was revised to a 1200mm pipe.
-The permit drawing depicts the inlet of the structure originating directly outside of the
fill slope and not connecting to a pipe underneath an adjacent road. Plan sheet 11C
depicts the inlet of the structure directly connected to the pipe underneath the adjacent
road.
The fill slope is shown incorrectly on the permit. The channel is actually completely
covered by the bridge approach fill requiring the cross pipes to be connected by a
junction box.
-The permit drawing depicts drainage structures that flow to a level spreader at Station
17+60 on the Y line. This device is not depicted on Plan sheet 11C.
Upon reviewing the original design from NCDOT, several drainage boxes were
found to be excessive and were removed. This drainage system was removed and
therefore the level spreader was no longer needed.
-Plan sheet 11C depicts a pipe extension and channel relocation at Station 22+60 left.
This activity does not appear to be depicted on any permit drawings. This should be
investigated to determine if there are any Section 404/401 or riparian buffer concerns
with this activity.
This is not a jurisdictional stream. It is an existing concrete ditch within the existing
interchange.
R-2457CC PERMITS 6
Site 11 and Site 12 Section CC (Permit drawing 18 of 22 dated 3/22/02) and Plan
Sheets 14 and 15
-Plan sheet 14 depicts the placement of Class B riprap within the wetland limits at Station
184+90 Rt. The permit drawing does not depict this riprap.
The riprap will be removed from within the wetland limits in the drainage file.
-Plan sheet 15 depicts a PFSH and a cross line pipe inside the wetland limits at Station
186+05 Rt. These features are not depicted on the permit drawing.
These features are depicted on the permit drawing revised 9/6/02.
Site 13 Section CC (Permit drawing 19 of 24 dated 3/22/02 and 20 of 24 dated 4/8/02)
and Plan Sheet 20
-The permit drawing depicts a lateral ditch that flows to a level spreader on the south side
of the roadway. The plan sheet depicts a reconfigured lateral ditch that conveys
additional drainage from the north side of the road.
No additional drainage has been added to the lateral ditch from NCDOT's original
design.
-The permit drawing depicts a drainage pipe with a PFSH located to the east of the cross
line. The plan sheet depicts the PFSH on the other side of the structure.
The revised layout better protects the buffers. In the revised layout, shoulder berm
gutter is extended beyond the stream crossing and collects the runoff from the road
that before was spilling directly into the stream and directs it to a preformed scour
hole.
-The plan sheet depicts a lateral ditch and toe protection on the north side of the roadway.
These features are not depicted on the permit drawing.
Toe protection does not impact any additional area and is used to stabilize the
slopes. The lateral ditch is necessary to drain the area and does not impact the
buffer area.
Site 14 Section CC (Permit Drawing 21 of 24 dated 2/7/01 and 22 of 24 dated 2/7/01)
and Plan Sheet 13
-The permit drawing depicts fill in surface water (but does not depict a relocated channel
for this fill). The plan sheet depicts the stream relocation, which will be conveyed by a
riprap lined channel (including riprap in the bottom of the channel).
The newest permit drawing is dated 9/6/02. This stream relocation is depicted in this
drawing although some of the surrounding drainage has been modified since that
time.
-The plan sheet depicts a lateral ditch along the northern fill slope of the roadway. This
lateral ditch is not depicted on the permit drawing.
The lateral ditch is shown on the latest permit drawing dated 9/6/02.
R-2457CC PERMITS 7
-The permit drawing depicts a drainage structure along the southern fill slope of the
roadway. The plan sheet depicts a lateral base ditch in along this fill slope. Additional
drainage structures are depicted in this area on the plan sheet.
A lateral base ditch was added. Subsequent to that, the design was further revised
to make use of existing storm drainage systems that were originally believed to not
be in place.
"Please note that there are significant discrepancies in reference to cross line pipes and
drainage structures on the permit drawings and plan sheets. These should be investigated
to determine any potential problems with riparian buffer regulations.
All cross pipes were designed to NCDOT standards and have been buried 20% (to a
maximum depth of one foot) per NCDENR-DWQ requirements.
Please notify us of your recommendation for each site as to whether a permit
modification is warranted or not.