20200002 Ver 1_Revised Draft Mit Plan Comment Memo_20230516

DEPARTMENT OF THE ARMY
WILMINGTON DISTRICT, CORPS OF ENGINEERS
69 DARLINGTON AVENUE
WILMINGTON, NORTH CAROLINA 28403-1343
CESAW-RGM/Kichefski May 16, 2023
MEMORANDUM FOR RECORD
SUBJECT: Eco Terra Three Creeks Farm Mitigation Bank Revised Draft Mitigation Plan
Review, Davidson County, NC
PURPOSE: The comments listed below were received from the NCIRT during the 30-
day comment period in accordance with Section 332.8(d)(7) of the 2008 Mitigation Rule.
USACE AID#: SAW-2019-02341 30-Day Comment Deadline: March 16, 2023
Todd Bowers, USEPA:
I have performed a brief cursory review of the Eco Terra Three Creeks Farm Mitigation
Bank draft mitigation plan dated January 2023. Responses from the sponsor pertaining
to my comments of the previous draft mitigation plan (dated December 2021) in the
letter dated January 23, 2023 have all been addressed to my satisfaction and I do not
have any substantial comments on the new revision. If either of you have any issue
areas with the document or the site plan that you would like me to look in depth on,
please do not hesitate to let me know.
Mac Haupt, NCDWR:
Folks had a lot of good comments, some of the comments below are the one's I believe
were not addressed adequately:
1. A couple of folks commented on the changing watershed. I believe there was
verbiage in the mit plan which stated that they did not believe significant
changes would occur in the near future. However, on page 4 it is stated, "The
project area has seen a 20-23% population growth since 1995... and expects
a 9.2% increase from 2020 to 2030".Given the project's location very close to
the Triad, DWR believes there will be sufficient changes to the project's
watershed.

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2. In Section 8.5.2 it was stated that a Sediment Transport Capacity assessment
was not performed because of the stability of the watershed. DWR believes
that because this is an alluvial channel with a sand bed stream and the
likelihood of a changing watershed that a sediment capacity analysis should
have been performed.
3. DWR concurs with COE's statement (Kim's comment #2) concerning the
parallel streams.
4. The site proposes significant areas of wetland re-establishment, rehabilitation
and enhancement; therefore, the plan should include significant hydric soil
investigations to support the wetland proposals. The soil report does not
provide enough information to adequately support the proposals given. The
report states that there 75 soil borings but only 5 borings were included with
profiles. Each boring should either have a profile or give the wetland indicator
status, or depth to hydric indicator. DWR recommends the provider obtain at
least 10 detailed soil profiles with wetland indicator status (e.g., F3) on each
wetland polygon (1-5).
Erin Davis. USACE:
1. The proposed 3-foot-deep floodplain depressions are deeper than the IRT
recommends for riparian habitat. Please show the extent of each constructed
floodplain depression on the project as -built and provide max. depth survey
points for each depression area.
2. If the headwater channel design is implemented during construction along
UT2 and/or UT3, please callout extents of this approach on the project as -
built and include a monitoring cross section and photo point within the
approach area.
3. It is appreciated that efforts were made to change two external easement
breaks to internal stream crossings. Please make sure to still callout internal
crossings and show the associated non-credit maintenance width on project
figures and design sheets.
4. Detail Sheets — There are two wetland conveyance details, WC 1 is 20'W and
WC 2 is 2'W, and both appear to be referenced for the same location on
different plan sheets, please correct. Also, please include a standard base
ditch detail as referenced in on Sheet PSH-05 as DD1 or update terminology.
Please make sure callouts on Sheets PSH-05 and PSH-11 are consistent.
Additionally, please confirm that the proposed wetland conveyance/ditch

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networks within the easement will be self-sustaining and will not require active
long-term management.
5. Regarding the response to DWR question 33, wrapping stream and ditch
plugs with impervious fabric is not a typical practice on seen on mitigation
projects in North Carolina. The IRT has had concerns with burying impervious
fabric within a floodplain and/or wetland credit area. Please propose an
alternative method/plug design (e.g., clay plug core).
6. Appendix I — Under the Initial Allocation of Released Credits section please
add: f. Documentation of the establishment of the long-term
endowment/escrow account.
Steve Kichefski, USACE:
1. Concerns still exist regarding previous USACE comments #2 and #12 regarding
parallel channel design and crediting. USACE recommends a call with the IRT to
discuss the proposed approach in further detail.
2. Concerns still exist regarding previous USACE comments #8, #23 & #25
regarding wetland conveyances/vernal pools. USACE recommends a call with
the IRT to discuss the proposed approach in further detail.
Steve Kichefski
Mitigation Project Manager
Regulatory Division