20001432 Ver 1_More Info Letter_20090115

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STATE OF NORTH CAROLINA
DEPARTMENT OF TRANSPORTATION
BEVERLY EAVES PERDUE
GOVERNOR
January 15, 2009
NC Division of Water Quality
610 East Center Avenue, Suite 301.
Mooresville, NC 28115
Attn: Ms. Polly Lespinasse
NCDOT Coordinator, Division 8
Dear Madame:
EUGENE A. CONTI, JR.
SECRETARY
Subject: Response Letter for Section 401 Water Quality Certification for the US 4211NC 87
(Sanford Bypass) from east of NC 42 to NC 87 near SR 1138 in Lee County, Division 8.
Federal Aid Project No. STPNHF- 421(2), State Project Noy 8.T540402, WBS Element No.
34431.1.6, TIP No. R- 24170.
Sections 404 and 401 Permit Modification Applications dated November 4, 2008
Below are responses to questions sent by the North Carolina Division of Water Quality on January 8,
2009 via email concerning permit modification drawings for the R -2417C project. The NCDOT
responses are shown in red.
1. Could you please provide the details sheets for the project? I was C,�? .
trying to evaluate locations where culverts tic in with existing streams when they are ditchline or other
structures, etc. (example: detail sheet 2 -J, Basin #2 at Permit Site 16).
NCDOT Response: Detail sheets (2 4 and 2 -1<) were inadvertently left out of the permit package
(roadway plans). They were sent to NCDWQ and USAGE via email on Jatjuary 8, 2009
2. Permit Drawing Sheet 18 of 31 - I am trying to figure out what is happening at the outlet of Permit
Site 6. The matchline (Sheet 6) isn't included in my drawings. Does this stream go in and out of
culverts?
NCDOT Response: A matchlinc exists on Sheet 6, however Sheet: 6 (Permit Thawing Sheet 16 of 31) is
1 inch = 200 feet scale while Permit Drawing Sheet 18 of 31 is 1 itich = 100 feet scale. The pipe exits at
stream on Permit Drawing Sheet 16 of 31 20 feet North (left) of the niatchliric. The stream (U'T`5) and its
tributaries will be piped from bottom of Permit Drawing Sheet 18 of 31 to Permit Drawing Street 16 of
31.
3. Permit Drawing Sheet 20 of 31 - The culvert alignment at the outlet of Permit Site 8 doesn't look like
a great. Is there a plan to prevent streambank destablia-ation?
MAILING ADDRESS: LOCATION:
NC DEPARTMENT OF TRANSPORTATION TELEPHONE: 919 - 715 -1334 2728 CAPITAL BLVD.
PROJECT DEVELOPMENT AND ENVIRONMENTAL ANALYSIS FAX: [phone] SUITE 240
1598 MAIL SERVICE CENTER �/I/,Eg$fT1 =: VVW4V.lU'CDtJi.4F2G RALEIGH NO 27604
RALEIGH NO 27699 -1598

NCDOT Response: A Class II riprap pad (14 feet in length) is proposed at end of pipe to impede erosion
and bank destabilization of banks (banks are very shallow).
4. Permit Drawing Sheet 22 of 31 - Can you tell me what is going on with Permit Site 1 I? It looks like
there is some impact at the southern end and then it remains daylighted, then back into a culvert and I'm
not sure what happens to it after that? I'm also not sure of the flow direction.
NCDOT Response: You are correct in your assumption. Originally the stream was to be piped
completely, but it was determined to be daylighted wherever practicable for impact minimization. The
stream flows south into box culvert and then flows east into UT7.
5. Permit Drawing Sheet 24 of 31 - I don't understand what is happening to this stream. Is it being
moved to the tail ditch with riprap at the end? If so, it ties in to the stream at almost a right angle and we
typically don't prefer riprap in the stream. Will the streambank on the opposite side of the ditch
destabilize?
NCDOT Response: The stream is piped into the tail ditch. Riprap in the receiving channel is for channel
stabilization and cannot be avoided due to steep gradient and angle of tail ditch entrance. The riprap in
channel has been calculated as permanent impact.
6. Permit Drawing Sheet 26 of 31 - Are the proposed overflow channel and culverts completely out of the
stream?
NCDOT Response: The proposed overflow channel and culverts are completely out of the stream.
Will the overflow channel tie into the smaller of the two channels (Site 4) after flowing through the
wetland?
NCDOT Response: The flow is reversed; the inlet side of overflow channel receives flow from
tributaries through the wetland. Please refer to PDF files for this location sent to you electronically.
Why are the temporary stream impacts to Site 4 required?
NCDOT Response: The temporary impacted areas in Right-of-Way for construction of YRPI3 ramp and
culvert coil structi oil .
Is a riprap berm or other berm proposed where the overflow channel ties into Site 4? If so, will this be
- h fill and has it been accounted for.? }I/� Get
NCDOT Response: The referred overflow channel location is at inlet side and not outlet side, therefore
berm not necessary.
Looks like only mechanized clearing is proposed. Two (2) 6x6 culverts are proposed at Site 5. Will this
overwiden the channel? Are sills or floodplain benches proposed to maintain the normal stream width?
NCDOT Response: The two 6x6 culverts are existing culverts that will be extended only.
7. Permit Drawing Sheet 28 of 31 - The outlet depicts Class I riprap.
Will this be embedded in the stream? It can't impede low flow or aquatic passage and should be
accounted for in impacts if in the streambed.
1A

NCDOT Response: The Class I riprap will be embedded in stream according to NCDOT standard
practice. However, this should not impede low flow or aquatic passage and has been calculated as
permanent impact.
8. Permit Drawing Sheet 30 of 31 - How do you propose to maintain the normal channel width? Sills or
floodplain benches?
NCDOT Response: Sills are provided in box culverts to maintain low channel flow throughout project.
The thicker dark line shown on west barrel inlet (north end) is sill location.
9. Permit Drawing Sheet 16 of 31 - Permit Site 2 (- YRPC -): Looks like a couple of different ditches and
flared end sections are discharging to the stream. Can you provide some details on how they tie into the
stream?
NCDOT Response: please refer to Detail # 25 on page 24.1 of roadway plans (sent to you electronically)
for the lateral base ditches (not flared end one).
One appears to be discharging at an upstream angle (the one that looks like it is a flared end section).
NCDOT Response: The flared end section represents an energy dissipator. Details for this are located on
sheet 2 -K of roadway plans (sent to you electronically).
Mow will normal channel width be maintained on this stream (double box culvert installation)?
NCDOT Response: Sills will be used for the double box culvert installation to maintain low channel
flow.
,The NCDOT believes that the questions raised by NCDWQ have been adequately addressed. Please let
me know if you need other information.
Sincerely,
Greg Price
Cc: Richard Spencer, USACE Wilmington Field Office
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