20071505 Ver 4_Staff Comments_20160422

Burdette, Jennifer a
From: Price, Zan (George)
Sent: Friday, April 22, 2016 12:01 PM
To: Burdette, Jennifer a; Higgins, Karen
Cc: Fox, Tim
Subject: Asheville Regional Office Comments - DWR# 07-1505 V4
Jennifer,
See Asheville Regional Office (ARO) comments below addressing the additional information provided from ClearWater
Environmental, Inc (ClearWater) for the Seven Falls Bonded Phase (DWR # 07-1505V4) application. The additional
information was provided in a letter to Karen Higgins dated March 3, 2016.
- Culvert #9: ClearWater indicated that culvert #9 would need to be removed and replaced with a longer culvert with a
larger diameter. No details or cross-sections were provided to illustrate how the culvert will be installed to allow for
aquatic passage and how it will be constructed "in the dry".
- Culverts #10, #11, and #12: ClearWater states that an "engineered solution" will be used at these culvert outfalls to
ensure aquatic life passage and that a site specific design for each engineered solution would be prepared and submitted
after issuance of the permit. ARO recommends either including a condition to the approval that a site specific design shall
be submitted for approval prior to implementation or request additional site specific design information prior to permit
approval.
- Culverts #3, #4, and #12 stream restoration: ClearWater provided a conceptual plan for 75 linear of stream restoration
below culvert #12 and the areas below culverts #3 and #4. Additional information is needed to determine if the proposed
stream restoration plans are appropriate for these areas. Additional information should include proposed vegetation lists,
work in the dry details, instream structure locations and details, matting specifications, existing and proposed slopes, and
the existing and proposed stream channel pattern, profile, and dimensions. ARO recommends either including a condition
to the approval that a site specific restoration design shall be submitted for approval prior to implementation or request
additional site specific design information prior to permit approval.
- Lot #139: ARO recommends either including a condition to the approval that a site specific design shall be submitted
for approval prior to implementation or request additional site specific design information prior to permit approval.
- Sediment removal plan: ClearWater stated several times that the sediment would be placed at least 30 -feet from the
stream channel and stabilized. No details are provided on how they will stabilize the removed sediment.
- DWR visited the site with ClearWater and the Army Corps on January 14, 2016. We discussed the four in-line ponds
that are downstream from the "Sediment Removal 4" area. The first pond has captured a lot of sediment and has
naturalized to a wetland area while the remaining ponds are still open waters. We all agreed to leave the first
pond/wetland area alone and to reevaluate the remaining ponds for sediment impacts after the proposed upstream
sediment removal and site stabilization activities are completed. ClearWater does not mention this area in the additional
information provided.
- Monitoring Requirements: ARO recommends applicable monitoring requirements for culvert repairs and restoration
activities that are consistent with similar projects. Example language: "Visual monitoring of the restoration project shall be
conducted at a minimum of quarterly for the first year or two bankfull events (whichever is longer), and then annually until
the site is stable (particularly after storm events) and vegetation is successful. Any failures of structures, stream banks, or
vegetation may require future repairs or replacement, which requires coordination with the Asheville Regional Office to
ensure the stability and water quality of the stream and downstream waters. [15A NCAC 02H .0506(b)(2) and (b)(3)]"
Feel free to call Tim Fox or myself if you have any questions regarding our comments.
Thank you.
Zan Price, P.E.
Assistant Regional Supervisor —Asheville Regional Office
Water Quality Regional Operations Section
NCDEQ — Division of Water Resources
828 296 4500 office
828 231 9634 mobile
email: zan.priceQncdenr.gov

2090 U.S. Hwy. 70
Swannanoa, N.C. 28778
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