20190495 Ver 1_Approval Letter SAW-2019-00487_20210105

Strickland, Bev
From:
Browning, Kimberly D CIV USARMY CESAW (USA)
<[e-mail]>
Sent:
Tuesday, January 5, 2021 1:58 PM
To:
Baumgartner, Tim; Bradley Breslow
Cc:
Tugwell, Todd J CIV USARMY CESAW (US); Kim Browning; Davis, Erin B; Merritt, Katie;
Wilson, Travis W.; [e-mail]; Bowers, Todd; Dunn, Maria T.;
Haywood, Casey M CIV (USA); Brittingham, Cathy; Twyla Cheatwood; Smith, Ronnie D
CIV USARMY CESAW (USA); McLendon, C S CIV USARMY CESAW (USA); Matt Butler;
Crocker, Lindsay
Subject:
[External] Approval Letter/ NCDMS Cowford Mitigation Site/ Onslow County/
SAW-2019-00487
Attachments:
Approval Letter_Cowford_SAW-2019-00487.pdf, Draft Mit Plan Comment
Memo-NCDMS Cowford_SAW-2019-00487.pdf
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Mr. Baumgartner,
Attached is the Draft Cowford Mitigation Plan approval letter and copies of all comments generated during the project
review. Please note that this letter approves the Draft Mitigation Plan provided that the Final Mitigation Plan
adequately addresses all comments on the attached memo. Please provide a copy of the Final Mitigation Plan when you
submit the Preconstruction Notice for the NWP 27. If no permit is required to construct the project, please submit a
copy of the Final Mitigation Plan to our office at least 30 days prior to beginning construction. Also, please ensure that a
copy of the Final Mitigation Plan is posted to the NCDMS project documents so that all members of the IRT have access
to the Final plan.
Please let me know if you have any questions about the process or the attached letter.
Very Respectfully,
Kim Browning
Mitigation Project Manager, Regulatory Division I U.S. Army Corps of Engineers

REPLY TO
ATTENTION OF:
Regulatory Division
DEPARTMENT OF THE ARMY
WILMINGTON DISTRICT, CORPS OF ENGINEERS
69 DARLINGTON AVENUE
WILMINGTON. NORTH CAROLINA 28403-1343
January 5, 2021
Re: NCIRT Review and USACE Approval of the NCDMS Cowford Mitigation Site / Onslow Co./
SAW-2019-00487/ NCDMS Project # 100095
Mr. Tim Baumgartner
North Carolina Division of Mitigation Services
1652 Mail Service Center
Raleigh, NC 27699-1652
Dear Mr. Baumgartner:
The purpose of this letter is to provide the North Carolina Division of Mitigation Services
(NCDMS) with all comments generated by the North Carolina Interagency Review Team
(NCIRT) during the 30-day comment period for the Cowford Draft Mitigation Plan, which closed
on December 9, 2020. These comments are attached for your review.
Based on our review of these comments, we have determined that no major concerns
have been identified with the Draft Mitigation Plan, which is considered approved with this
correspondence. However, several minor issues were identified, as described in the attached
comment memo, which must be addressed in the Final Mitigation Plan.
The Final Mitigation Plan is to be submitted with the Preconstruction Notification (PCN)
Application for Nationwide permit approval of the project along with a copy of this letter. Issues
identified above must be addressed in the Final Mitigation Plan. All changes made to the Final
Mitigation Plan should be summarized in an errata sheet included at the beginning of the
document. If it is determined that the project does not require a Department of the Army permit,
you must still provide a copy of the Final Mitigation Plan, along with a copy of this letter, to the
appropriate USACE field office at least 30 days in advance of beginning construction of the
project. Please note that this approval does not preclude the inclusion of permit conditions in
the permit authorization for the project, particularly if issues mentioned above are not
satisfactorily addressed. Additionally, this letter provides initial approval for the Mitigation Plan,
but this does not guarantee that the project will generate the requested amount of mitigation
credit. As you are aware, unforeseen issues may arise during construction or monitoring of the
project that may require maintenance or reconstruction that may lead to reduced credit.

Thank you for your prompt attention to this matter, and if you have any questions
regarding this letter, the mitigation plan review process, or the requirements of the Mitigation
Rule, please call me at 919-554-4884, ext 60.
Sincerely,
BROWNING.KIMBER
LY.DANIELLE.15276
83510
Digitally signed by
BROWN ING.KIMBERLY.DANIELLE.
1527683510
Date: 2021.01.05 13:46:39-05'00'
Kim Browning
Mitigation Project Manager
for Ronnie Smith, Deputy Chief
USACE Regulatory Division
Enclosures
Electronic Copies Furnished:
NCIRT Distribution List
Lindsay Crocker—NCDMS
Brad Breslow, Matt Butler—RES

DEPARTMENT OF THE ARMY
WILMINGTON DISTRICT, CORPS OF ENGINEERS
69 DARLINGTON AVENUE
WILMINGTON, NORTH CAROLINA 28403-1343
REPLY TO
ATTENTION OF:
CESAW-RG/Browning
MEMORANDUM FOR RECORD
December 21, 2020
SUBJECT: Cowford Mitigation Project - NCIRT Comments during 30-day Mitigation Plan Review
PURPOSE: The comments listed below were received during 30-day comment period in accordance
with Section 332.8(g) of the 2008 Mitigation Rule in response to the Notice of NCDMS Mitigation Plan
Review.
NCDMS Project Name: Cowford Mitigation Site, Onslow County, NC
USACE AID#: SAW-2019-00487
NCDMS #: 100095
30-Day Comment Deadline: December 9, 2020
USACE Comments, Kim Browning:
1. Figure 9, Buffer Width Zones: Without being able to review the actual data spreadsheet, it's
difficult to determine whether terminal ends were accounted for. In the table provided on Figure
9 it appears you used the old version of the buffer tool. The new version (attached) allows
terminal ends where the project exits the property to be exempt from counting against you. In
this situation, the terminal end that ends at Kinston Highway would be exempt from the buffer
rule. Additionally, the terminal end of KJ1-B that connects with the headwater valley would be
exempt from being counted against you, but the terminal end, as drawn, should not extend into
the headwater area. Lastly, the total stream length should not be entered into the spreadsheet
that includes the headwater length, as this is a detriment to you. Please re -run the buffer tool to
account for the crossing terminal end, clip the headwater from the actual buffer, and correct the
length entered in the spreadsheet. I'm happy to meet with you if you need additional explanation.
a. Please adjust Table 14 and any asset tables.
2. Figure 10: Please also include fixed image locations at the culvert at the terminal end of the
project under Kinston Highway, and at the crossing. Channel formation is a concern on this site
so please supplement gauge data with photo documentation.
3. Section 5 and Table 8 discuss the functional uplift potential and references the functional
pyramid, including the physiochemical and biological uplift. These are benefits that are
presumed and will not be measured by the monitoring. The footnote indicates that these will be
measured indirectly. Regarding Table 8, the "measurement method" for biology is listed at an
As -built survey, which is not a measure of biological uplift. Please modify these sections.
4. Wetland reestablishment —In addition to adding wood to the channel it would be beneficial to
add some coarse woody debris to the depressional areas and throughout the wetland for
habitat, and to help store sediment, increase water storage/infiltration, and absorb water
energy during overbank events.

5. It would have been beneficial to have additional buffers placed around the wetlands especially
since immediately adjacent land uses may affect the function and sustainability of the site.
Farming practices often result in equipment encroaching along the easement boundary. The
effects of ditching immediately adjoining wetland projects is also a major concern if the farm
fields become too inundated to farm.
6. The design sheets show field tile outlets in the project stream. We do not encourage any type of
outlets through buffers, even if it's non -perforated, and into project streams. There will eventually
need to be maintenance done of the tile which could disturb the buffer and channel. Please
confirm that these tiles will be redirected and outlet outside the conservation easement.
7. The swales entering the conservation easement appear to be about 2' deep, there is concern
that these may have a draining effect on the wetland.
8. Page 25: Please explain further how much of the wetland area is anticipated to be open
water/marsh pockets. If it's a significant area you may want to consider planting herbaceous
species and proposing a performance standard of a diversity of at least 4 species and over 75%
cover.
9. Table 13: Please add wetland indicator status to this table.
10. Section 8.1.2: The 30 consecutive days of flow must be demonstrated annually. 30 days
consecutive flow should be a minimum, not a goal.
11. Section 8.1.4: Longitudinal images SHOULD indicate the absence of developing bars within the
channel...
12. Section 8.2.1: There is conflicting information for hydroperiods in this section. Please correct.
Given that Muckalee soils are very wet, please use a hydroperiod of 16%. Please update Table
15 as well.
13. Page 19: Regarding the reference site being located in a different watershed, especially since
this project is located in the outer coastal plain, please confirm that the reference site and the
Cowford site have similar topography, soils, drainage area, and ecoregion. Reference sites
should have similar landscape position.
14. Section 8.3: Any volunteer species on the approved planting list must be established for at least
2 years to count towards success and will be subject to the average height standard.
15. Section 4.3: Additional projects risks and constraints to discuss include beaver, replacement of
the road culvert on Kinston Highway, adjacent ditching or drainage tile, etc.
16.Appendix D Credit Release Schedule: The IRT will review the Record Drawing/As-Built reports
according to the 2008 Mitigation Rule's streamlined review process prior to approving the initial
credit release. Please alter the statement regarding credits being released by DMS without prior
written approval of the DE.
17. Hay bales for toe protection seem a little risky if the system does not stay inundated. I understand
that RES has successfully used this design in other states on low gradient systems with heavy
live -staking; however, with this being an intermittent channel there is concern that it will not stay
inundated. I am open to the use of new/different techniques and ultimately it is up to RES to
demonstrate success and stability.
WRC Comments. Travis Wilson & Maria Dunn:
1. The culvert crossing to be installed should be designed so the low flow barrel size closely
matches the width of the baseflow channel in order for the structure to neither over widen nor
constrict the channel flow. The secondary pipe elevation should be set at the established
bankfull elevation. (This may already be the case, however it is not evident in the typical culvert
crossing detail.)
2. This is a relatively small watershed and hopefully can restore function as presented and
desired; sometimes these features in agriculture fields are difficult to get to perform as desired
and stay maintained.

3. It was difficult to locate specific detail on how much of the former CRP easement vegetation
will remain. Understanding there will be construction activity in the area, but trying to have a
few of those old, more established trees would have a benefit.
EPA Comments. Todd Bowers:
1. Section 5.1.3/Page 15: Recommend caution when using wood grade control or other
instream structures in an intermittent stream/HWV such as KJ1-A.
2. Section 7.2.1.2/Page 20: Denote that KJ1-B is undergoing P1 restoration and that the
existing channel will be filled and/or graded to provide wetland habitat.
3. Section 7.4.1/Page 25: Recommend revising this date to NLT April 15 in order to allow
for some buffer time to complete monitoring before November 1 and that the provider will
seek IRT concurrence or approval to plant outside of the dormant season. Also, I
recommend that the provider seek IRT approval to plant alternate species if any of the
primary species of the Proposed Plant List per Table 13 are not available at the time of
planting.
4. Table 13/Page 26: Recommend adding Wetland Indicator Status for bare root planting
tree species.
5. Table 14/Page 29: Approach Priority Level for KJ1-A should be HWV and not P1
Restoration.
6. Section 9.5/Page 34: Recommend adding an additional gauge in an adjacent upland area
to verify and document the wetland boundary.
7. Table 15/Page 36: Recommend adding the number of consecutive days needed to meet
the 9-12 percent of the growing season success criteria (approximately 29 days?). Two
different criteria for wetland water table performance standards are listed here (9-12%
and 12%).
8. Recommend including a random mobile plot to the wetland areas each monitoring year
in lieu of using all fixed plots.
9. Recommend that the Conservation Easement is extended around the wetlands to include
a 50-foot upland buffer to ensure drainage effects from the adjacent fields is minimized.
DWR Comments, Erin Davis:
DWR Comments for the Cowford Draft Mitigation Plan — December 21, 2020
1. Page 8, Section 3.2.4 — Please expand on the future land use discussion to include potential
adjacent area and watershed land use changes.
2. Page 13, Section 4.3 —
a. During the IRT site walk, the IRT recommended relocating the existing crossing to the
upstream end of the project. Please provide a justification for keeping the easement break
in the middle of the project. Also, why does the easement break need to be over 60 feet
wide?
b. Please confirm that the proposed project easement does not overlap the utility and
roadway easements, and that no known DOT work is planned for the downstream
road/culvert.
c. Not sure if it's a constraint or risks/uncertainties discussion, but have you evaluated the
risk of hydrologic trespass that could result in ditching outside the proposed project
easement?
3. Page 20, Section 7.2.1.1 —
a. Is any work proposed for the three ditches connect at the top of the project? Watershed
size and slope in this area were major concerns noted during the IRT site walk.
b. Please confirm if the wood structures will be installed in a pilot channel.

4. Page 20, Section 7.2.1.2 — Should filling the existing channel and grading the existing ditch to a
swale be included as restoration activities?
5. Page 20, Section 7.2.1.3 — During the IRT site walk, there was a discussion of a P1 approach
below the wetland. Even with the additional buffer width, a P2 approach is being proposed?
Considering this reach composes 47% of the project steam length, please discuss why a P1 is
not feasible and the limitations of potential functional uplift associated with a P2 approach.
6. Page 21, Section 7.2.1.6 — Is there a concern with long term channel stability in using log
structures for grade control on this intermittent stream?
7. Page 21. Section 7.2.1.7 — Has the amount of available onsite woody material for proposed
stream stabilization and habitat structures been evaluated? If necessary, will offsite woody
material be sourced to complete construction of all of the structures shown on the design sheets?
8. Page 24, Section 7.2.3 — What is the possible drainage effect from Swale A on the proposed
wetland restoration? Based on the design profile, Swale A appears to be approximately 2 feet
deep.
9. Page 26, Table 13 —
a. It would be helpful to have the wetland indicator status included. Also, DWR recommends
adding a few alternate/substitution species.
b. The narrative notes planting zones at multiple points. DWR supports this level of detail
and would like to see the table reflect the breakdown of species by planting zone. Given
that multiple habitat types are expected onsite, were the inclusion of more shrub or
midstory species considered, or additional live stake species for the headwater valley,
treatment swale and pool plantings?
10. Page 30, Section 8.1.2 (and Table 15) — Please clarify that surface flow is an annual performance
standard.
11. Page 30, Section 8.1.5 — Please rephrase the first sentence, the surface water flow performance
standard applies to headwater valley approaches.
12. Page 31, Section 8.2.1 — This section notes multiple hydroperiods, which is a bit confusing. Table
15 lists 12%. DWR supports a minimum 16% wetland hydroperiod performance standard
threshold.
13. Page 34, Section 9.3.1 — Due to flow concerns, DWR may request an additional gauge or
supplemental documentation (e.g. video, photos) during monitoring to demonstrate that the
performance standards are being met.
14. Page 34, Section 9.6 — If open water and marsh cover could potentially constituent more than
20 percent of the wetland credit area, DWR recommends including an alternate herbaceous
species diversity success criteria and monitoring plan.
15. Page 35, Section 9.7 — In the baseline report, please make sure to include redline drawings and
soil profiles at installed wetland well locations.
16. Page 36, Table 15 — Please confirm whether fencing is proposed.
17. Page 38, Section 11 — DWR recommends higher sign posts or PVC extensions be considered
along the easement boundaries that abut row crop if corn will continue to be in rotation.
18.Appendix F — Since a culverted crossing is proposed, it should be monitored for any issues
during the monitoring/maintenance period.
19. Sheet E2 — Please call out the drain tile lines.
20. Sheet W1 — DWR appreciates the attempt to provide a buffer along the proposed wetland
restoration area. What is the minimum buffer width shown? Figure 12 shows the 10YR
inundation area along the northern CE boundary. Was additional buffer in this area discussed
with the landowner?
21. Sheet D3 — Tile Drain Outlet — DWR does not support outlet structures within the CE. DWR
understands the site specific concerns of hydrologic trespass and is ok with the proposed outlet
design and up to 7 proposed locations, if the structures can be shifted outside the CE so that
the vegetated swales start at the CE boundary. This would eliminate the need for the landowner
to request access from Stewardship if structure repairs/maintenance are needed. And it would

avoid direct discharges within the CE. DWR requests that each swale be inspected during the
project's monitoring/maintenance period for signs of instability and noted in the annual reports.
22. Sheet D3 — Hay Bale Toe — Please provide more information about this technique (including
photos over time) and situations/places it has been successfully implemented. Also, please
provide adaptive management strategies for dealing with potential bank instability issues in
these proposed treatment areas for this site. What are the benefits of this treatment compared
to brush toe? Was onsite brush toe material availability a consideration for its use along the
entire KJ1-B reach?
BROWNINGNM Digitally signed by
BROWN INGXIMBERLY.D
BERLY.DANIELL ANIELLE.1527683510
E.1527683510 Date:2020.12.21
15:18:35-05'00'
Kim Browning
Mitigation Project Manager
Regulatory Division