20191333 Ver 1_More Info Received_20191120

Strickland, Bev
From:
Kristi Suggs <[e-mail]>
Sent:
Wednesday, November 20, 2019 3:57 PM
To:
Johnson, Alan
Cc:
Aaron Earley; Ian Eckardt
Subject:
[External] RE: Torrence creek
External email. Do not click links or open attachments unless you verify. Send all suspicious email as an attachment to
[e-mail]
Alan,
Here are our replies to your comments/concerns from the Site walk on November 6, 2019. Sorry for the
delay. Please let me know if you need anything further.
1.) He wasn't aware of the large project and was curious if the county/Wildlands/etc. every had any preliminary
meetings/discussions with any regulatory agencies (DWR/USACE/etc.) at the concept stage?
Wildlands Response: (AE] We did not have preliminary discussions with agencies. Should this be part of the
process from now on?
2.) Is the current restoration approach proposed on Park North and South Tribs necessary? He wondered if a lighter
hand approach like keeping the channel on-line and doing more benching rather than taking it off-line in the
tight meanders and thereby reducing the need for all the in -stream structures. He was of the option that the
channel was at a stable bed elevation below the headcut and perhaps just benching and then letting the channel
stabilize itself was possible?
Wildlands Response: (AE] Benching at that low of an elevation would result in much more tree loss and
earthwork than raising the channel. We also had to consider impacts to the mountain bike trails.
3.) What is the difference in the baseflow and stormflow discharges for the Park Tribs? Again trying to understand
the amount of grade control and work proposed.
Wildlands response: (AE] There are three primary reasons why the Park Tribs were design like they were:
a. The valley slope and type between upstream and downstream tie-in locations
pointed us towards a step pool B-channel design. We aimed for a somewhat
consistent slope between tie-in points, which necessitated raising the channel
bed.
b. The proposed alignments is somewhat straighter than existing due to the B-
channel type and valley width. We've also seen where tight meander bends in
higher slope channels tend to eroded/fail.
c. We had to consider site use and landowner objectives. Stakeholders want to
minimize impacts to nearby trails and minimize tree loss. Keeping the channel
bed elevation at the existing elevation would require significantly wider grading
due to deeper cuts. This would have impacted trails and increased tree loss.
4.) Lastly, he had a comment that he would like to see us working around 8" and greater diameter trees where
feasible.
Wildlands response: [AE] We are contracted to be out there during construction and will work with the
contractor to save as many trees as possible.
Thanks!
Kristi

From: Johnson, Alan <[e-mail]>
Sent: Friday, November 15, 2019 11:46 AM
To: Kristi Suggs <[e-mail]>
Subject: Torrence creek
Just waiting on those couple of comments from the site meeting
Thanks
Alan
DWR
DkAsi-pn of WAtnr IkC:Jiqurces
Alan D Johnson — Senior Environmental Specialist
NC Dept. of Environment & Natural Resources (NCDENR)
Division of Water Resources - Water Quality Regional Operations
610 East Center Ave., Suite 301, Mooresville, NC 28115
Phone: [phone] Fax: [phone]
E-mail correspondence to and from this address may be subject to the North Carolina Public Records Law and may be
disclosed to third parties unless the content is exempt by statute or other regulation.