HomeMy WebLinkAbout20201004 Ver 1_1-2020-09-22-Slusher - ACOE-DWR Response To Comment_20200923FUSCO
LAND PLANNING & DESIGN, PLLC
September 22, 2020
Kaylie Yankura
Environmental Specialist - Asheville Regional Office
Water Quality Regional Operations Section
NCDEQ - Division of Water Resources
2090 U.S. Hwy. 70
Swannanoa, N.C. 28711
Re: Request for Additional Information; Slusher - Sapphire Farm, DWR# 20201004
Ms. Yankura,
We appreciate the opportunity to address your request for additional information associated
with the Slusher - Sapphire Farm project. I have included your questions along with our
response below.
On August 4, 2020, the Division of Water Resources (Division) received your application
requesting a 401 Water Quality Certification from the Division for the subject project. The
Division has determined that your application is incomplete and cannot be processed. The
application is on hold until the following items are addressed:
1. Please enumerate all proposed wetland and stream impacts on the site plan and
clearly label all impacts (Wetland/Stream Impact 1, etc.). The impacts on the
site plan should correspond with those listed within the PCN. [15A NCAC 02H
.0502(a)]
- Updated plan attached clarifying impacts as requested.
2. Please verify the stream, wetland, and open water impacts listed within the PCN
impact tables. The impact totals provided in the cover letter narrative do not
match those listed within the PCN. [15A NCAC 02H .0502(c)]
- Updated PCN tables attached which matches plan sheets and narrative.
3. The project proposes 175 linear feet of streambank stabilization. The project
application also proposes the removal of 20 linear feet of culvert for stream
daylighting associated with dam improvements. Please provide a streambank
LANDSCAPE ARCHITECTURE - CONSERVATION PLANNING - LOW IMPACT DEVELOPMENT
P.O. Box 8013 - Asheville, NC 28804 - PH. 828-243-6604
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stabilization plan and typical drawings for these activities. [15A NCAC 02H
.0502 (c)] [15A NCAC 02H .0506(b)(2) and (3)]
- For the stream bank stabilization we will take a multi -pronged approach.
First, natural boulders will be installed in the vicinity of the proposed rock
vane and near the apex of the point bar where the pool area will be expanded.
The boulders will be dug into the bank and stepped back to ease the grade in
those areas. In areas where we are less concerned with scour, the bank will be
laid back to a gentle slope which will allow for easier access to the water.
Finally, the area will be renaturalized with native riparian vegetation,
including within any void areas between the boulders. Void areas below the
water level of the stream will provide additional habitat for aquatic
organisms as well.
- The pipe removal indicated in the narrative is within an area where we are
installing the new dam structures. In this area, The pipe will be removed and
the area will be flooded as part of the dam improvements. No stream bank
work will be required.
- We are going to remove an additional 20' foot pipe along the existing drive
to the cabin site once the cart road below the dam is complete. For this area,
we will plan to lay the banks back and revegetate with native riparian
vegetation. We do not plan to add boulders at this location currently. For
reference, this is the crossing we looked at with you and Andrea while onsite
September 8th along tributary S3.
4. Please provide further clarification on how the proposed rock vane structure
included within item "D" of the application cover letter is to be installed and
how permanent restrictions to streamflow and aquatic passage will be
avoided. [15A NCAC 02H .0502 (c)] [15A NCAC 02H .0506(b)(2) and (3)]
- See detail on sheet L6.03& L6.04. Our current plan is to divert the stream
while doing the work. Based on guidance from our structural engineer, we
plan to create a keyway in the bedrock to accept the stone structure, which
will be pinned into the bedrock. There will be gaps between the base
boulders similar to a traditional rock vane structure which will allow for
aquatic passage. Along the top of the structure, there will be stepper stones
pinned in which will provide gaps that will allow flows to run over the
structure and into a step/pool profile which will extend back down to
existing grade. The step/pool profile will be constructed with a series of 4"
drops using larger boulders and the gaps will be filled with graded river
cobble ranging in size from 2 to 6" size. Pools will vary in size, which will help
reduce velocities and provide intermediate protection for aquatic organisms.
- The structure itself will sit below the bankfull height of the stream by 12 to
18" which will allow for overtopping in a flood event. Also, the location of
LANDSCAPE ARCHITECTURE - CONSERVATION PLANNING - LOW IMPACT DEVELOPMENT
P.O. Box 8013 - Asheville, NC 28804 - PH. 828-243-6604
www.fuscola.com
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the structure sits in an area with a large point bar floodplain zone which will
help to reduce pressure on the structure in a flood event. Lastly, the existing
wetland, which was installed by the owner prior to conducting our
preliminary jurisdictional review, will act as a conveyance when the stream
swells, but may not reach a full flood situation.
Our propose solutions have been informed by the following publications and
consultation with local experts.
Yochum, Steven E. 2018. Guidance for Stream Restoration. U.S. Department
of Agriculture, Forest Service, National Stream & Aquatic Ecology Center,
Technical Note TN-102.4. Fort Collins, CO.
U.S. Fish & Wildlife Service, Northeast Region, June 2019
Fish and Aquatic Conservation, Fish Passage Engineering, Ecological Services,
Conservation Planning Assistance.
5. Please clarify if the proposed grade changes and inclusion of flashboard risers
within item "E" of the application cover letter are still requested. During a site
visit conducted on September 8, 2020, it was indicated that these components
are no longer required. If these activities are still proposed, please provide an
explanation for why grade changes and flashboard risers are required and a plan
for how this work will be completed. [15A NCAC 02H .0502(c)]
Based on the current condition of the wetland/bog complexes, we have
decided to forego the requested flashboard risers at this time.
6. The project proposes to perform restoration activities within 20.76 acres of
wetland/bog complexes onsite. Please clarify what the proposed restoration
activities are and provide information on how these activities are to be
performed. [15A NCAC 02H .0502 (c)] [15A NCAC 02H .0506(b)(2) and (3)]
At this time, we are planning to monitor the wetland/bog complexes and
manage as necessary to maintain open areas. Work in these areas will be
conducted using hand tools and other non -mechanized equipment. In
addition, we plan to work with the NC Wildlife Resources Commission to
identify long term maintenance and improvement activities.
Thank you,
/s/ MatthewJ. Fusco
MatthewJ. Fusco
Enclosures
LANDSCAPE ARCHITECTURE - CONSERVATION PLANNING - LOW IMPACT DEVELOPMENT
P.O. Box 8013 - Asheville, NC 28804 - PH. 828-243-6604
www.fuscola.com
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