20200712 Ver 1_Mitigation Plan Review_20220628

From: Davis. Erin B
To: Baker, Caroline D
Subject: Fw: [External] Notice of Intent to Approve/ NCDMS Cool Run Mitigation Site/ SAW-2020-01428/ Brunswick County
Date: Tuesday, June 28, 2022 8:29:59 AM
Attachments: Draft Mit Plan Comment Memo NCDMS Cool Run SAW-2020-01428.odf
Cool Run Fia.9 markuo.odf
Laserfiche Upload: Email & Attachments
DWR#: 20200712 v.1
Doc Type: Mitigation Plan Review
From: Browning, Kimberly D CIV USARMY CESAW (USA) <[e-mail]>
Sent: Monday, June 27, 2022 3:27 PM
To: Tugwell, Todd J CIV USARMY CESAW (US) <[e-mail]>; Haywood, Casey M CIV (USA) <IMCEAEX-
_o=Exch a ngeLa bs_ou=Exch a n ge+20Ad m i n istrative+20G rou p+20+28 FYD I BO H F23 SP D LT+29_cn=Reci p ients_cn=225d 3fe2693d 4f009c3cd baa 99d e8fef-
[e-mail]>; Davis, Erin B<[e-mail]>; Bowers, Todd <[e-mail]>; Merritt,
Katie <[e-mail]>; [e-mail] <[e-mail]>; Wilson, Travis W. <[e-mail]>;
Dunn, Maria T. <[e-mail]>; Brittingham, Cathy <[e-mail]>; fritz.rohde <[e-mail]>
Cc: Crocker, Lindsay <[e-mail]>; Dow, Jeremiah J <[e-mail]>; Crumbley, Tyler A CIV USARMY CESAW (USA)
<[e-mail]>; Fennel, Tommy E CIV USARMY CESAW (USA)<Tommy. E.Fen nel @usace.a rmy.m il>;
[e-mail] <[e-mail]>
Subject: [External] Notice of Intent to Approve/ NCDMS Cool Run Mitigation Site/ SAW-2020-01428/ Brunswick County
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Good afternoon IRT,
We have completed our review of the Draft Mitigation Plan for the NCDMS Cool Run Mitigation Site (SAW-2020-01428). Please see the attached
memo, which includes all NCIRT comments that were received during the review process along with additional comments provided by Wilmington
District staff following our review. Also attached is a groundwater gauge markup from DWR.
We have evaluated the comments generated during the review period, and determined that the concerns raised are generally minor and can be
addressed in the final mitigation plan. Accordingly, it is our intent to approve this Draft Mitigation Plan (contingent upon the attached comments
being addressed in the Final Mitigation Plan) unless a member ofthe NCIRT initiates the Dispute Resolution Process, as described in the Final
Mitigation Rule (33 CFR Section 332.8(e)). Please note that initiation of this process requires that a senior official of the agency objecting to the
approval of the mitigation plan (instrument amendment) notify the District Engineer by letter within 15 days of this email (by COB on July 12,
2022). Please notify me if you intend to initiate the Dispute Resolution Process.
Provided that we do not receive any objections, we will provide an approval letter to NCDMS at the conclusion of the 15-day Dispute Resolution
window. This approval will also transmit all comments generated during the review process to NCDMS, which must be addressed in the Final
Mitigation Plan to be submitted with the Preconstruction Notification Application for NW P 27. All NCIRT members will receive a copy of the
approval letter and all comments for your records.
Thank you for your participation. Please contact me if you have questions or wish to discuss
Be well,
Kim
Kim (Browning) Isenhour
Mitigation Project Manager, Regulatory Division I U.S. Army Corps of Engineers 1 919.946.5107

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
June 27, 2022
SUBJECT: NCDMS Cool Run Mitigation Project - NCIRT Comments during 30-day Mitigation Plan
Review, Brunswick County, NC
PURPOSE: The comments listed below were received during the 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.
USACE AID#: SAW-2020-01428
NCDMS #: 100142
NCDWR#: 2020-0712
30-Day Comment Deadline: April 27, 2022
DWR Comments, Erin Davis:
1. Page 7, Section 2 — This section notes that "Cool Run is located within an area subject to some
of the highest rates of population growth in the country". This is helpful information to have, and
to that end, please include a discussion of projected future watershed and adjacent area land
use. DWR encourages the consultation with local/county planning agencies and NCDOT, as well
as review of available planning documents (e.g., comprehensive land use plan, community
master plan) as due diligence in assessing potential future watershed and adjacent land use
changes that may affect the long-term success of the project (e.g., risks of utility/roadway
encroachments and influx of sediment/nutrient inputs).
2. Page 23, Table 10C — Would a goal of the project be to protect the resources in perpetuity? If
including performance criteria, please include the vigor standard, that bankfull events shall be in
separate years, and 30 consecutive days' flow for the intermittent reach. Also, please address
the "to be determined" column for the final mitigation plan.
3. Page 26, Section 7.6 — Please clarify the discussion of the landowner in this section. Is the risk
of hydrologic trespass not expected because the landowner is ok with increased hydrology
beyond the easement on their land? How does the trespass risk change if the property owner
changes?
4. Page 27, In -stream Structures —
5. Log cross -vanes are the only grade control structure proposed for intermittent reach UT-1. DWR
has observed log structures on intermittent reaches breaking down before the end of the
monitoring period. Are there any concerns about the long-term stability of UT-1?
6. Log vanes and cross -vanes are the only habitat structures proposed for this project. Will these
structures provide sufficient instream habitat enhancement uplift? While currently there are no
instream habitat performance standards, DWR does looks for evidence of instream habitat
diversity and uplift during monitoring visits.

7. Page 28, Table 12 — For UT-1, should the installation of the marsh treatment area be listed?
8. Pages 28-29, Sections 8.3 & 8.4 — Please confirm whether any grading is proposed within
wetland credit areas beyond ditch filling and stream channel/bench excavation. If so, please
include a brief description and proposed wetland grading plan (color -coded to highlight areas to
be graded greater than 12 inches).
9. Page 29, Section 8.7 — Thank you for including this section. Please briefly describe any proposed
decompaction and/or surface roughness measures. How will haul roads in proposed wetland
credit areas be addressed? Is there any timber bedding onsite? If so, are there any concerns
with wetland uplift and seeded/planted vegetation establishment?
10. Page 30, Section 8.8 — Please use the most updated version available of Schafale.
11. Page 30, Section 8.8.2 — Please list existing nuisance species observed onsite. Also, a controlled
burn was mentioned in the IRT site walk meeting minutes. Is this activity still proposed?
12. Page 31, Table 13 — DWR is ok with select species in Zone 1 being proposed at greater than 20
percentage composition. However, please keep Zone 2 species capped at 20 percent, and if
need be please add/request substitutions.
13. Page 31-32, Table 13A — Please add species wetland indicator status. Are there any concerns
with the high percentage of Juncus effusus seeding affecting woody stem survival and growth?
14. Page 32, Section 9.0 — Is vegetation monitoring considered wetland or stream monitoring? Who
will be responsible for inspecting the easement boundary? With multiple monitoring firms, please
take care to QA/QC annual monitoring reports to ensure all required aspects are covered and
presented in a consistent and unified manner.
15. Page 33, Table 15 —
16. Restored intermittent reaches must demonstrate a minimum 30 days' consecutive flow annually.
Please add a flow gauge within the upper one-third of intermittent reach UT-1.
17. Based on my calculations (2% of 22.71 planted acres with 0.0247 acre plots), there should be
18 veg plots proposed. Veg plots are not limited to credit areas. Please add one more fixed plot
and two random plots.
18. Please make a table note of the two Mill Creek reference groundwater gauges proposed for
monitoring. Also, DWR requests two additional groundwater gauges and a shifted location of
GWG #6 (see figure mark-up). And please confirm that the haul roads shown on Sheet E03E
will not impact installed gauges (e.g. #8, #9, #13).
19. Page 34, Section 9.1 — Please reference the 2016 NCIRT mitigation guidance document.
20. Page 35, Section 9.2 — Please note that some of the listed actions will require IRT review as
adaptive management and may need USACE/DWR permit authorizations.
21. Page 36, Beaver — Is there any concern that waiting until fall/winter to trap beaver may result in
further loss of vegetation and additional stream problem areas?
22. Page 36, Section 9.2.2 —
23. IRT consultation and approval will be necessary if any future earthwork is proposed. Depending
on the depth of proposed ephemeral pools, the credit ratio may change to reflect wetland
creation.
24. Please discuss potential risks associated with wetland credit extending along the conservation
easement boundary (e.g. encroachment, ditch creation immediately adjacent).
25. Page 37, Section 9.2.3 — We recommend an additional sentence addressing any identified cause
for observed veg issue(s) (e.g. beaver trapping, soil amendments, additional signage for
encroachments). Also, is there is a risk of any wetland credit area(s) becoming too wet to support
tree establishment? If so, please discuss the contingency of a wetland mosaic target with non-
standard monitoring and performance criteria for non -forested wetland types.
26. Page 38, Table 17 — Please confirm Table 17 and Table 10C are consistent.
27. Page 39, Section 10 — DWR was glad to see a discussion on non -desirable species
management. Recolonization by Ioblolly pine and sweet gum affecting planted stem
density/vigor and wetland hydrology is a major concern for this site.
28. Figure 6B — Please show the second marsh treatment area called out on Sheet C11.

29. Sheet C01A —Please confirm whether riprap riffles and fencing are proposed for this project. If
so, please add typical details and show on plans.
30. Sheet CO2A — Please include a typical detail(s) for live stake and bareroot plant installation.
31. Sheet CO2C, Floodplain Interceptor — Please briefly describe the function of proposed floodplain
interceptors. Will these features be seeded and planted? The minimum length along the stream
channel is listed at 3 feet; what is the maximum width into the bankfull bench/floodplain area?
32. Sheet C05 — Figure 6A calls out a culvert crossing upgrade. If this activity is being completed as
part of this project, please include a typical detail and callout in the design plans.
33. Sheet C06 — Please confirm all existing channels/ditches will be filled to meet surrounding grade.
Are proposed contour lines anticipated to follow the same sinuous pattern of the limits of grading
lines?
34. Sheet C09 — If there is ditch filling east of Station 21 +75, please add a callout.
35. Sheets C13-C16 — Please confirm these sheets are just showing the CIE line and existing
contours.
36. E02A — Is pond dewatering proposed for this project? Also, please update sheet information to
match the native seed mixes and dates included in Table 13A. Fescue is NOT approved for
application within the conservation easement.
37. E03E — Is vegetation removal proposed beyond the LOD lines on the east side of the project?
These areas are shown on Sheet P01 as Planting Zone 2. DWR would be concerned if mature
Ioblolly pines were left within the conservation easement, likely to become seed trees.
38. General Design Comment — Lack of large woody debris was noted in Table 12, DWR
encourages adding LWD to stream and wetland project features for habitat enhancement.
39. DWR appreciates efforts made to enhance the proposed project by first and foremost having no
easement breaks (woohoo!), as well as including water quality BMPs, areas of wetland buffer
and species diversity over multiple planting zones.
USACE Comments, Kim Browning:
1. Figures 6A and 12: Please ensure that the work being done outside the conservation easement
boundaries, upstream and downstream of the project where you propose to tie into existing
channels/ditches and upgrade an existing culvert, are included in the PCN impacts.
2. Figure 613: A marsh treatment area is proposed in the area where there is currently a ditch. If
this area is currently a jurisdictional ditch, (i.e., meets the definition of an RPW) it is not
appropriate to place a BMP in a jurisdictional feature. Please confirm that this ditch is not
jurisdictional.
3. Figures 4A and 12: It appears that there is an existing wetland proposed for rehabilitation that
is located in the existing channel, on the north-west side of Cool Run Upstream. Will this wetland
have impacts due to stream relocation?
4. Please label the stream reaches on Figures 613, 9 and 12. Additionally, please label each wetland
area for easier reference (i.e., use the wetland labels from the PJD).
5. Figure 9:
a. The random veg plots should capture different wetland enhancement and restoration
areas each year.
b. 2-3 additional veg plots should be added to make up 2% of the planted area.
c. An additional wetland gauge should be placed at the northwest edge of the wetland
reestablishment area near the bottom of the project.
d. Please show locations of fixed photo points.
e. A flow gauge should be located in the upper 1/3 of UT-1.
6. Table 4: The Regulatory Considerations section of this table should be located in Section 7 to
support the categorical exclusion discussion.

7. CE Documents and Section 7.0: Correspondence with Travis Wilson, WRC, mentions a
potential future NCDOT highway project in the area. Are there anticipated future encroachments
for this project?
8. Section 3.5.1: It would be helpful to include a table to summarize the gauge data. This will be
particularly important in monitoring reports to compare baseline data with current data, to
demonstrate hydrologic uplift.
9. Section 4.0: Please describe the vegetation for the reference stream?
10. Sections 4.2 & 8.8: Please use the updated version of the Guide to the Natural Communities of
North Carolina, Fourth Approximation, dated March 2012.
11. Table 10C:
a. Planted stems must have an average height of 7 feet in MY5 and 10 feet in MY7.
b. Please indicate where existing drain tile is located and will be removed on existing
conditions map.
12. Section 7.1:
a. Please include the RCW SLOPES determination key results. If a survey has not been
conducted yet, please include the results in the final mitigation plan.
b. Was a plan survey conducted for the Cooley's Meadowrue and Rough -leaved Loostrife
during the appropriate time. Please elaborate in the text. Please note that plant surveys
typically have an expiration date of 18 months — 2 years and must be conducted during
the appropriate survey window. Please refer to the USFWS NC Imperiled Plant Survey
Windows publication.
13. Section 7.6: What is the potential for hydrologic trespass onto adjacent fields? Stream
restoration work may have an impact on the hydrology of the adjacent land, resulting in increased
flooding and/or reestablishment of wetlands on those parcels. Given that the soils and
topography on the site do not immediately change at the edge of the conservation easement, it
seems logical that wetland reestablishment right next to the property line will impact both sides
of the boundary. There is also no way of ensuring that the adjacent landowners will not construct
new ditches immediately adjacent to your project that would result in drainage of wetlands
restored on your site. With no guarantee that the adjacent parcel will not be transferred to a
different landowner in the future, this potential site constraint should be discussed in the text.
14. Figures 6A & 9: Please be prepared to provide photo documentation and vegetative transects
in the Priority 2 bench areas and the location of the old road during monitoring.
15. Section 8.8.1: The text states that planting will be performed between December 1 and March
15 to allow plants to stabilize during the dormant period. This seems contradictory to the
proposed extended growing season in Section 9.1.1, which will presumably begin in early
February.
16. Table 13: It would be preferable to reduce the percent of Sycamore. You may want to update
some of the species after consulting the 4t" Approximation since this community type has been
updated since the 3rd Approximation.
17.Table 16, Surface Flow: The text states that continuous surface flow must be documented
annually for at least 30 days. This only applies to intermittent streams. The 30-day metric was
established to show success in the Coastal Plain Headwater guidance and was not intended to
demonstrate success for intermittent flow. Intermittent streams only dry seasonally and
therefore should have flow or the presence of water for periods much longer than 30 days. It is
recommended that cameras are also used to monitor flow for both consecutive days and
cumulative days.
18. Section 9.1.1: Once you have established a growing season based on the vegetative indicators
and soil temperatures, please stick with those dates throughout the life of the project for
consistency. Ideally, this should have been established during pre -monitoring data collection.
19. Section 9.2.2: It would be beneficial to add some coarse woody debris to the depressional
areas in the buffers and throughout the adjacent wetlands for habitat, and to help store
sediment, increase water storage/infiltration, and absorb water energy during overbank events.

Additionally, please confirm that ephemeral pools will not exceed 14 inches and will dry
seasonally.
20. Since this project is adjacent to active agricultural lands, signage will be important in the
beginning of the project to establish visual boundaries for the landowner. We recommend the
use of horse -tape or some other visual barrier for the first few years of monitoring.
21. Section 9.2.3: This section should discuss contingencies/adaptive management strategies for
controlling natural vegetative regeneration, particularly since there is a seed source of red
maple, loblolly pine and sweet gum.
Kim (Browning) Isenhour
Mitigation Project Manager
Regulatory Division

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