20141189 Ver 1_More Info Requested_20141113

Carpenter,Kristi
From:Shaver, Brad E SAW <[e-mail]>
Sent:Thursday, November 13, 2014 3:48 PM
To:O'Loughlin, David K
Cc:Glynn, Amanda T; Mathis, Stonewall D; Herndon, Mason; Lane, Stephen
Subject:Greenfield Lake RCBC (UNCLASSIFIED)
Attachments:Culvert Sill_Floodplain detail.pdf
Classification: UNCLASSIFIED
Caveats: NONE

Dave,

I had a chance to look through the package and have formulated a few things that either are
present and I can't figure out or that are missing from the package. Mason has reviewed and
added to this list as well.

- Whereas I could have been more clear in the preliminary response, the site when scoped back
in February of 2013 was deemed to be a section 10 water. That fact alone does not affect the
request for culvert and clean up but you will need to request a NW 12 for the utilities
relocation. I must make sure you meet the terms and conditions of NW 12, specifically
regional condition 4.1,
http://www.saw.usace.army.mil/Portals/59/docs/regulatory/regdocs/NWP2012/NWP12_3-23.pdf. You
will need to show where the new lines are going and their ultimate depth under the stream
bottom. Go ahead and change the first page of the PCN to indicate section 10 authority.

- You have listed that the culverts being replaced are 200 feet in length but you have a new
permanent impact of 86 feet. Is this the difference between the existing culvert length and
the new culvert length? Utilizing the available scaling I’m not sure how you get the 86 foot
impact reported. Please update section B.3.e to state existing and proposed length of culvert
replacement.

- There is no mention of the site 2 specifics in your description of overall project detail
section B.3.e. please include some discussion here of the work item. Again please include
existing length and proposed length.

- Please provide a description of the dewatering plan for both culverts in section B.3.e.

-Please provide a detail of the sill configuration and proposed floodplain bench. An example
from NCDOT Hydraulics Unit is attached. Please note that native material will be required
to be placed in the low flow barrels to match the streambed elevation. Native material will
also be required in the overflow barrel to match the elevation of the floodplain bench. Rip
rap, capped with native earth material, is permissible in the overflow barrel.

-Stormwater Management – Is there any potential to provide some level of treatment of
stormwater on the outlet end of the culvert with grass swales or other BMP. There appears to
be uplands adjacent to the outlet of the culvert that could be utilized for this
purpose. Secondly, if utilities or other conflicts prevent the construction of grass swales
or other BMPs in this area, how are you proposing to prevent the piped outlets from causing
scour and instability at their discharge points.

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- Finally you stated that there was no DCM AEC in the project area. Again during scoping
Stephen Lane with DCM claimed this system as a public trust water and therefore you will need
to check with that agency regarding necessary approvals to complete the proposed work.

Please consider this the official incomplete notification. The Corps' and DWR’s review clock
will begin once the application is complete. Please provide the above requested information
back to this office within two weeks of this correspondence. If not the Corps will withdraw
the application and you will need to resubmit at a later time.

Call if any questions,

Brad

Brad E Shaver

Project Manager

US Army Corps of Engineers

69 Darlington Ave
Wilmington, NC 28403

[phone]

Fax# [phone]
Website: http://www.saw.usace.army.mil/WETLANDS

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Classification: UNCLASSIFIED

Caveats: NONE

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