20200034 Ver 1_Mitigation Evaluation_20220422

From: Davis, Erin B
To: Baker, Caroline D
Subject: FW: [External] Approval Letter/ NCDMS Pierce Terrace Mitigation Site/ SAW-2020-00046/ Gates County
Date: Friday, April 29, 2022 9:19:42 AM
Attachments: Approval Letter NCDMS Pierce Terrace SAW-2020-00046.pdf
Draft Mit Plan Comment Memo NCDMS Pierce Terrace SAW-2020-00046.odf
Laserfiche Upload: Email & Attachments
DW R#: 20200034 v.1
Doc Type: Mitigation Evaluation
From: Browning, Kimberly D CIV USARMY CESAW (USA) <[e-mail]>
Sent: Friday, April 22, 2022 10:41 AM
To: Crocker, Lindsay <[e-mail]>
Cc: Raymond Holtz ([e-mail]) <rholz@restoration systems. com>; Alex Baldwin
<[e-mail]>; Haywood, Casey M CIV USARMY CESAW (USA)
<[e-mail]>; Tugwell, Todd J CIV USARMY CESAW (US)
<[e-mail]>; Davis, Erin B <[e-mail]>; Bowers, Todd
<[e-mail]>; [e-mail]; Merritt, Katie <[e-mail]>;
Wilson, Travis W. <[e-mail]>; Dunn, Maria T. <[e-mail]>;
Barnes, Kyle W CIV USARMY CESAW (USA) <[e-mail]>; Crumbley, Tyler A CIV
USARMY CESAW (USA) <[e-mail]>; Recktenwald, Marc
<[e-mail]>
Subject: [External] Approval Letter/ NCDMS Pierce Terrace Mitigation Site/ SAW-2020-00046/ Gates
Cou my
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Hi Lindsay,
Attached is the Pierce Terrace 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.
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
April 22, 2022
Regulatory Division
Re: NCIRT Review and USACE Approval of the NCDMS Pierce Terrace Mitigation Site / Gates
Co.
USACE ID: SAW-2020-00046
NCDMS Project # 100139
NCDWR # 2020-00034
Lindsay Crocker
North Carolina Division of Mitigation Services
217 West Jones St.
Raleigh, NC 27603
Dear Mrs. Crocker:
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 Pierce Terrace Draft Mitigation Plan, which
closed on February 23, 2022. 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
USACE Mitigation 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 contact me at Kim berly.d.brown ing(a-)usace.army.mil or [phone].
Sincerely,
Kim Browning
Mitigation Project Manager
for Tyler Crumbley, Deputy Chief
USACE Regulatory Division
Enclosures
Electronic Copies Furnished:
NCIRT Distribution List
Marc Recktenwald—NCDMS
Alex Baldwin, Raymond Holz—RS

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
March 21, 2022
SUBJECT: NCDMS Pierce Terrace Mitigation Site - NCIRT Comments during 30-day Mitigation Plan
Review, Gates 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-2020-00046
NCDMS #: 100139
NCDWR#: 202000034
30-Day Comment Deadline: February 23, 2022
NCWRC Comments, Travis Wilson:
The plan does not use the 4th approximation of The Guide to Natural Communities of North
Carolina. River birch and Persimmon are not primary species found in Coastal plain non-riverine
wet hardwood forests. Persimmon may be found in low numbers in this type of system, as it
grows in a very wide range of habitats, but should be planted in dryer portions of the site with a
focus on edge planting or clumps. River birch is associated with more riverine systems; while
possible to have this species present, the percentage of planted stems should be significantly
reduced.
USEPA Comments, Todd Bowers.-
Note.- It is understood that site visits have been made by IRT members during the development
of site feasibility to provide mitigation credit. In that regard, I feel it necessary to denote that I
have not been on -site during this process and that my comments may reflect a lack of on -site
observation and evaluation.
1. General:
a. I appreciate the considerations for the synergistic effects the PT site will have on the
adjacent Hofler Mitigation Project (HMP). These considerations are not taken lightly given
the ongoing adaptive management required at the Hofler site. As such it appears that the
PT site will serve to greatly benefit the HMP as a sink for hydrology rather than a source
as the final design will move water off -site at a set pre -determined elevation that will not
exceed the outfall of the HMP. The inclusion of the Water Balance Calculation and the
conclusions was very welcome.

b. Inclusion of upland buffers around wetlands is an excellent approach and one that
strengthens the long-term success for the site.
c. Connectivity to the Merchant's Mill Pond state park natural area and the greater Lassiter
Swamp/Bennet's Creek corridor is an excellent element of the project, however the
corridor between the project and the natural areas is very limited and maintained by the
culvert under the farm/haul road. Was there any discussion to upgrade the culvert at the
northern ditch outlet to one better suited for aquatic organism passage? Was access to
other parcels the primary concern for the landowner? Was there any discussion of
incorporating the forested areas adjacent to the PT project to provide a direct connection
to the nearby natural areas?
2. Table 1/Page 11: Noted that a newer version of Table 1 that conforms to the template for
crediting was provided for inclusion in next/final revision.
3. Section 3.4/Page 17: The correct number of acres for wetland creation should be 5.670.
4. Section 6.4/Page 28: 1 appreciate the effort that went to working with Dominion Energy to
relocate the powerline adjacent to the road and out of the TP site.
5. Section 7.4/Page 30: Stems per acre of non-riverine swamp forest species (320) does not match
Table 11 (355).
6. Section 8/Page 33 and Table 14: 1 concur with the number and type of proposed vegetation
monitoring sites adjusted downward based on the size and homogeneity of the site.
7. Table 16/Page 36: Recommend adding "placement of large woody debris" into the habitat
objectives to match the narrative on Page 20 (Large woody debris will be placed throughout the
Site to provide a source of organic material for the soil and habitat for wildlife.) and Table 9.
8. Table 17/Page 37: Very robust adaptive management plan incorporating potential causes and
actions based on performance of the HMP.
DWR Comments, Erin Davis:
1. Page 1, Section 1.3 — Please confirm the monitoring year for HMP (page 7 references year 7).
2. Page 9, Section 3.4 — Please correct the wetland creation acreage to 5.67.
3. Page 16, Section 4 — What measures were taken to identify a regional vegetative reference
community site?
4. Page 18, Table 9 — For consistency with Table 16, please add "plant woody vegetation" under
the water quality and hydrology objectives.
5. Page 20, Section 7.1 — Drainpipes are mentioned, have any drain tiles been located onsite?
6. Page 21, Section 7.1 — The HMP will eventually transfer to DEQ Stewardship, has there been
any consideration to potentially working with the State to further reduce the berm elevation?
7. Page 21, Section 7.2 —
a. Are there any concerns that a 17-foot plug may be insufficient to block drainage? The
IRT typically recommends a minimum 50-foot ditch plug for coastal plain projects.
b. Has a lateral drainage effect analysis been performed to demonstrate the impact of the
existing ditches are currently having on the proposed wetland reestablishment credit
areas?
c. Please include the minimum distances from wetland credit areas to the nearest existing
ditch to remain open (e.g. Silver Springs Road ditches, ditch north of Wetland
Reestablishment Area 1, ditch east of Wetland Reestablishment Area 2). Has a lateral
drainage effect analysis been performed to demonstrate that ditches to remain open will
not affect the proposed credit areas? If not, DWR requests that this analysis be
completed.
d. Will the proposed upland pond have any hydrologic connection to the mitigation project?
e. If the seven culverts will be removed, what is meant by "minor modifications" to them?
Also, please briefly describe the current condition of the two driveway culverts proposed
to remain (e.g. stability, capacity). This paragraph discusses only 9 of the 12 culverts

shown on Figure 6, please update this section to address all identified culverts. Are any
existing culverts being replaced? If so, please include a typical detail in the construction
plan.
8. Page 21, Section 7.3 — Please include a description of the proposed aggregate material for
approval in the final mitigation plan. Is the 1-2 feet of soil to be removed from the ditches
proposed for reuse onsite?
9. Page 23, Table 11 — Please confirm that all proposed species are appropriate for the coastal
plain region (e.g. persimmon) and non-riverine community type (e.g. river birch).
10. Page 24, Section 8 — DWR recommends adding a sentence to this section stating that success
criteria and monitoring will be completed in accordance with the 2016 NCIRT Guidance.
11. Page 25, Section 8 —
a. As requested by the IRT during the site walk, please provide all available pre -construction
groundwater gauge data in the final mitigation plan for review.
b. DWR ok with the requested reduced total veg plots due to proposed habitat uniformity.
However, DWR may request additional plots/transects during monitoring if problem areas
present.
12. Page 26, Table 14 — Please update the growing season dates in the table to match the footnote.
13. Page 27, Table 15 — DWR would be ok with the understory/shrub species planted being exempt
from the vigor performance standard to encourage site diversity.
14. Page 28, Table 16 — For consistency with Table 9, please include the "add woody debris" under
the habitat objective.
15. Page 29, Table 17 — DWR appreciates the inclusion of this table. Many of our concerns are
captured in the potential causes bullets (e.g. site too wet/dry, pine colonization, outlet erosion,
and negative ditch effect from outside the easement) and we are glad that measures have been
considered in how to address these issues.
16. Page 30, Section 11.3 — Please confirm that a majority of the site includes an upland buffer
within the conservation easement. DWR appreciates that a buffer zone was included between
Wetland Area 1 and the CIE boundary to the west and north. However, we remain concerned
with the risks associated with no buffer surrounding Wetland Reestablishment Area 2.
17. Sheet C-03C — Please add bare root and live stake planting details.
18. Sheet C-03E — Due to observed vegetative establishment issues along relic haul roads, DWR
requests that an effort be made to locate them outside proposed credit areas to the greatest
extent feasible (and outside the project easement if at all possible).
19. Sheet C-03F — Please consider renaming sheet title from "Wetland Rehabilitations".
20. DWR appreciates efforts made to enhance the proposed project, including: relocating utilities,
coordinating with DOT on roadside drainage, increasing species diversity (including seed mix
pollinator benefits), adding woody debris habitat, conducting a thorough soil investigation and
AMP considerations. We also recognize this is a unique opportunity to improve the functional
uplift of an existing mitigation site through greater landscape connectivity.
USACE Comments, Casey Haywood:
1. Pg.7 Section 2- What monitoring year is the Hoffler Mitigation Plan Site in? This section states
the HMP Site is in its seventh year of monitoring, however Section 1.3 says it's in the eighth year
of monitoring. Please update.
2. Pg 21 Section 7.2-
a. Given that the ditch plug material is comprised primarily of silt and clay content, is the
proposed plug length of 17-30 feet enough? It is recommended that the minimum length
filled should be based on the permeability of the backfill material. Typically, the minimum
length of fill material for a plug using high clay content soils is 50-feet.
b. This section states there will be a total of six clay ditch plugs, however, I could only locate
five on Figure 6. Please update.

c. During the February 19, 2020 site visit RS discussed creating habitat depressions in the
Wetland Creation areas. If these are still being proposed, please include this in the
narrative and ensure these areas are identified on the redline record drawings. To ensure
these areas are seasonally dry, we recommend a max depth of 14".
d. The narrative in this section states that there will be minor modifications to seven of the
nine culverted driveways along the roadside ditches of Silver Springs Road. However,
Figure 6 shows these are being removed. Please clarify. Additionally, please discuss the
condition, and any proposed work of the four culverts that will remain.
3. Pg 21 Section 7.3-
a. Is there any concern that the log sill structures proposed in the ditch outfall locations will
rot?
b. Please add more discussion on the type and size of aggregate material that will be used.
4. Pg 23 Table 11- River birch is typically more prevalent in riverine systems and does not seem
appropriate for the community type identified. Please confirm. Recommend removing or
significantly reducing the number of river birch in the planting plan.
5. Figure 8- Please move 3 of the proposed wetland gauges closer to the exterior edges of the
HMP site.
6. Construction plans- Please include the planting details for bare roots and live stakes.
7. Response to DMS comment 15- Please confirm that the pre -construction gauges have been
installed. Additionally, please include this data along with an updated map in the final mitigation
plan.
USACE Comments, Kim Browning:
1. Please provide all available pre -construction groundwater gauge data in the final mitigation plan
for review. We would like to review this data prior to receiving the final mitigation plan.
2. The requested reduced total veg plots due to proposed habitat uniformity is acceptable;
however, for future reference please note that monitoring plots should make up 2% of the planted
portion of the site, not only the credited areas.
3. There is concern that the log sill structures in the ditch outfalls will rot over time. We have
observed this on several sites recently. You may want to consider using rock or something that
will not degrade with time and weathering.
4. Figure 8: Please move at least one vegetation plot to the west side of HMP in the non-riverine
swamp planting area.
5. Figure 8 and Tables 14-16: Two additional groundwater gauges should be added to capture the
NSF area. Currently, there is only one gauge in the NSF area, located where proposed road
drainage enters the site.
6. Page 21, Section 7.3: Please elaborate on the aggregate proposed to fill the ditches.
7. Figure 7: The legend shows 127.5 ac conservation easement, but the planting area totals 125.73
acres. Section 1.4 lists 125.7 acres. Please clarify.
8. Figure 7: Does the conservation easement bisect the north parcel? It appears that the easement
line just above HMP runs along the old ditch line.
9. Figure 7: Did you intend for the NWHF and NSF polygons to overlap? These planting zones do
not appear to overlap on Sheet C-03G. According to the description on page 22, the polygons
should overlap.
10. Design Sheets: Perhaps it's just my printed copy, but the planting plan (species, quantities,
wetland indicator) was missing from the design sheets.
11. Sheet C-09: Are the elevations for borrow area # 3 correct? (Top elev = 32.0, bottom elev =
23.0) Is this the area that is out of the easement and will be a pond? Was this area evaluated
during the PJD?

12. Page 20: The mitigation plan should contain more details on the braided ephemeral flow path.
Is "ephemeral" the correct word to use? It was unclear where this was proposed. Please add
this to the legend on Figure 6. I understand the need for this flow path to maintain positive
drainage from the DOT road; hopefully this will not have a draining effect on the adjacent
wetland.
13. Table 7 does not list river birch or sycamore. Please reduce the percentages of these species in
the planting plan.
14. Table 10- Even though there is no suitable habitat on -site, please make sure that documentation
for the Red -cockaded Woodpecker is included in the categorical exclusion documents to satisfy
Section 7(a)(2) of the ESA and the new RCW SLOPES.
15. Table 12: Are all these species appropriate for this site? It would be helpful to include the
wetland indicator status for these species.
16. During the IRT site visit, it was agreed that a soil specific performance standard would be
required. Please add a performance standard to Table 15 that addresses the site's ability to
maintain its appropriate saturation period and develop hydric soil conditions such as organic
matter, clay content, and soil structure.
17. Page 30: I appreciate the discussion on hydrologic trespass; however, many of the proposed
wetland reestablishment areas go to the easement boundary, so it's reasonable to expect wetter
conditions on adjacent parcels. Many of the elevation lines on adjacent parcels are actually lower
than the project elevations. Impacts to adjoining parcels that are not under control of the
sponsor/applicant raise concern of future ditching outside the easement.
Kim Browning
Mitigation Project Manager
Regulatory Division