20181033 Ver 1_USACE eApproval Ltr SAW-2018-01165_20200213

Strickland, Bev
From:
Browning, Kimberly D CIV USARMY CESAW (USA)
<[e-mail]>
Sent:
Thursday, February 13, 2020 10:53 AM
To:
Baumgartner, Tim
Cc:
Tugwell, Todd J CIV USARMY CESAW (US); Kim Browning; Haupt, Mac; Davis, Erin B;
Wilson, Travis W.; Merritt, Katie; Byron Hamstead; Bowers, Todd; Jones, M Scott (Scott)
CIV USARMY CESAW (USA); Brown, David W CIV USARMY CESAW (US); Crumbley,
Tyler A CIV USARMY CESAW (USA); McLendon, C S CIV USARMY CESAW (USA); Leslie,
Andrea J; Wiesner, Paul; Furr, Benjamin; Miller, Vickie M. (Raleigh); Ryan Smith; Xu, Lin
Subject:
[External] eApproval Letter/ NCDMS Owen Farms Stream and Wetland / Transylvania
County / SAW-2018-01165
Attachments:
100064_Owen Farms -Response to IRT Comments.pdf, 100064_Owen Farms _2020_01_
08_IRT Meeting Minutes.pdf, Figure 17- Project Asset Map Revised.pdf; eApproval
Letter -Owen Farms_2018-01165.pdf
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Mr. Baumgartner,
Attached is the Owen Farms Stream and Wetland Site Draft 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 Pre -Construction 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.
Respectfully,
Kim Browning
Mitigation Project Manager, Regulatory Division I U.S. Army Corps of Engineers
3331 Heritage Trade Dr, Ste. 105 1 Wake Forest, NC 27587 1 919.554.4884 x60
BUILDING STRONG (r)

UT 2A
LEGEND
UT 213
UT 8 a
_ Wa
UT 3
W2
WISA
7
W6
W4
UT 4A UT 6A
UT 6
Cross Sections Stream Preservation Permanent Vegetation Plot
Powerline Easement Stream Enhancement I Random Vegetation Plot
A Groundwater Gauge Stream Enhancement II (2.3:1) Wetland Group 1 (RR, Enh, 2:1)
• Flow Gauge Stream Enhancement II (2.5:1) 0 Wetland Group 2 (RR, Re-est.,1:1)
Proposed Easement Stream Enhancement II (3.5:1) Wetland Group 3 (RR, Rehab, 1.5:1)
Property Boundary Stream Enhancement II (4:1)
Non -Creditable Stream — Stream Restoration
FN
0 Feet 400
UT 7A
UT 713
PROJECT ASSET MAP
OWEN FARMS MITIGATION SITE
FIGURE 17
PATH: ZAOWEN_FARMS\T.0_GIS\T.1_MAP OOCSI7.1.5_MIT PLAN FIGURESIFIGURE 17- PROJECT ASSET MAP REVISED.- - USER: BF0041 - OATE:2XI2020 OW EN FARMS MITIGATION PLAN

REPLY TO
ATTENTION OF:
Regulatory Division
DEPARTMENT OF THE ARMY
WILMINGTON DISTRICT, CORPS OF ENGINEERS
69 DARLINGTON AVENUE
WILMINGTON, NORTH CAROLINA 28403-1343
February 13, 2020
Re: NCIRT Review and USACE Approval of the NCDMS Owen Farms Mitigation Site /
Transylvania Co./ SAW-2018-01165/ NCDMS Project # 100064
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 Owen Farms Draft Mitigation Plan, which
closed on August 25, 2019. A follow-up meeting was held with the provider and the IRT January
8, 2020 to discuss concerns with the draft mitigation plan. These comments, and the revised
asset map, 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,
Digitally signed by
BROWN INGXIMBERLY. BROWN INGXlMBERLY.DANIELLE.
DAN I E LLE.1527683510 1527683510
Date: 2020.02.13 10:38:28-05'00'
Kim Browning
Mitigation Project Manager
for Tyler Crumbley
Enclosures
Electronic Copies Furnished:
NCIRT Distribution List
Paul Wiesner— NCDMS
Benjamin Furr, Ryan Smith—LMG
Vickie Miller—HDR

Meeting Minutes
Project: Owen Farms Stream and Wetland Mitigation Site (DMS # 100064)
Subject: IRT Meeting to Discuss Comments on Mitigation Plan
Date: Wednesday, January 08, 2020
Location: USACE Office, Wake Forest, NC
Attendees: Ryan Smith (LMG)
Paul Wiesner (via phone, DMS)
Mac Haupt (DWR)
Kim Browning (USACE)
Todd Tugwell (USACE)
Ben Furr (LMG)
Vickie Miller (HDR)
Erin Davis (DWR)
Andrea Leslie (via phone, WRC)
The IRT meeting to discuss comments on the Owen Farms Stream and Wetland Mitigation Plan was held
at 10:00am on Wednesday, January 8, 2020 at the USACE Office in Wake Forest. The following
represents highlights of discussions that occurred during the meeting:
1. Mac Haupt began by reviewing DWR comments, specifically regarding DWR concerns about
bench width on West Fork French Broad River (WFFBR). DWR stated that they are concerned
bench width is too narrow and may result in stream bank erosion, particularly through the reach
depicted on plan sheets 5 and 6. HDR understands concerns voiced by DWR and assured all in
attendance that proposed conditions models and previous experience have been reviewed to
determine bank stress on proposed conditions.
2. Mac also discussed concerns about UT 3 originating in a headwater wetland and whether it will
maintain single channel flow throughout the monitoring period. LMG explained that the
enhancement work on UT 3 is simply being done to stabilize UT 3 as it converges with WFFBR
and that there should be enough slope through the enhanced reach of UT 3 to maintain single
channel flow. LMG stated that additional discussion will be added in the mitigation plan to
explain why enhancement 1 is necessary on UT 3.
3. USACE questioned why some of the ratios and proposed mitigation approaches were changed
between the proposal phase and the mitigation plan phase. LMG explained that additional data
was collected during the design phase that led to revisions in mitigation approach in certain
areas.

4. Mac questioned the floodplain interceptors and associated typical in the design sheets.
Specifically, DWR wants to make sure that mitigation credit is not being granted to reaches with
large portions of rip -rap along the stream banks. LMG explained that floodplain interceptors are
typically small (i.e. — 5 feet wide) and intended to stabilize the bank in areas where concentrated
overland flow enters the stream channel. LMG also stated that the intent is to use native
material from on -site to construct the floodplain interceptors where material is readily available.
LMG will add a statement on the typical, detailing use of native material.
5. Todd Tugwell asked a question about why an impervious channel plug was shown overlapping
the wetland enhancement area on plan sheet 5, near the confluence of UT 5 and WFFBR. LMG
noted that it appears to be a mistake and that it will be corrected on the plan sheets and credit
tables to ensure that wetland enhancement credit is not being generated where channel plugs
and/or floodplain interceptors are being installed. Wetlands that are currently shown as
enhancement where UT 5 will be filled will be changed to wetland restoration since that area is
not an existing wetland but will revert to wetlands once construction has been completed. DWR
also mentioned that the area near the confluence of UT 5 and WFFBR may be a weak point in
the left bank of WFFBR given the close proximity of W3 to the stream bank. LMG explained that
soil lifts with toe wood and impervious channel plugs would be installed along the left bank at
this location to promote bank stability.
6. DWR requested that one of the groundwater gauges proposed for the W3 Re-establishment
area be moved slightly west into the W3 Rehabilitation area to improve coverage of
groundwater gauges throughout W3. LMG agreed and will update the Mitigation Plan
accordingly.
7. USACE and DWR also have questions concerning the limits of construction lines shown on plan
sheet 11 and why they extended into wetland re-establishment/re-habilitation areas. LMG
explained that restoration of UT 5 at this location was a Priority I restoration and that there
would not be a bench cut to the limits of construction as there is on WFFBR. The limits of
construction lines on UT 5 will be revised to more accurately depict where grading will occur.
8. Andrea Leslie explained that WRC wanted language added to the Mitigation Plan stating that
some amount of herbaceous dominated coverage within wetlands on -site was acceptable and
appropriate based on reference bog complexes in the area. LMG agreed to add language to the
performance standards section and adaptive management sections of the Mitigation Plan to
discuss the potential for herbaceous dominated areas within wetlands on -site. WRC also
requested that additional shrubby species be included with the planting plan for W3 to improve
diversity (swamp rose was mentioned as an example). LMG stated that additional shrubby
species could be added to the planting plan but questioned how that would affect performance
standards (i.e. would areas planted with mostly shrubby species still be held to the same vigor
standards as tree species). USACE stated that the Swamp Forest/Bog complex communities are
naturally dominated by shrubby and herbaceous species and would not be held to the same
vigor standards as communities dominated by tree species. Everyone agreed that there are few,
if any good reference Swamp Forest/Bog complex communities in the vicinity of the project and
WRC suggested using Schafale and Weakley as a reference for potential vegetation that could be
added to the planting plan to improve diversity. WRC also asked if herbaceous species would be
planted in the wetlands. LMG explained that the existing wetlands already exhibit a variety of
herbaceous wetland species but that any disturbed and/or restored wetland areas would be

planted with a native riparian seed mix. LMG will add the native seed mix to the planting plan
within the Mitigation Plan.
9. Credit Ratio Discussion:
a. LMG explained that tributary reaches were lumped together from a crediting standpoint
to avoid having too many small reaches with different credit ratios (as was discussed
during the initial IRT site walk). DWR and USACE agreed with this approach but
disagreed with some of the credit ratios allocated to certain tributaries.
b. Following discussion about the varying degrees of cattle impact across the site, buffer
widths, and opportunity for functional uplift at each tributary, the following credit ratios
were agreed upon for each tributary (ratios that were changed from what was proposed
in the Mitigation Plan are highlighted):
i. UT 1 (4:1)
ii. UT 2 (3.5:1)
iii. UT 2A (2.5:1)
iv. UT 2B (2.5:1)
v. UT 3 (1.5:1)
vi. UT 4 (2.5:1)
vii. UT 4A (2.3:1)
viii. UT 4B (4:1)
ix. UT 5 (1:1)
x. UT 6 (10:1)
xi. UT 6A (10:1)
xii. UT 7 (R = 1:1, E2 = 3.5)
xiii. UT 7A (10:1)
xiv. UT 7B (2.5:1)
xv. UT 8 (1:1)
c. LMG will update the Mitigation Plan to reflect the credit ratios listed above. Kim
Browning requested a more detailed discussion on how HDR determined ratios for each
stream reach. LMG agreed to add language to the Mitigation Plan to provide more
explanation on how some stream reaches are lumped together to determine credit ratio
(for example UT 4). LMG will also add discussion in the Mitigation Plan to explain that
the beaver dams on UT 2 appear to be relic (i.e. not active beaver dams).
10. Utility Lines:
a. LMG explained that there is an existing utility easement overlapping the conservation
easement.
b. USACE explained that an exception for utility maintenance will need to be included in
the stewardship transfer document and requested that language also be added to the
Mitigation Plan discussing this issue.
c. LMG clarified that no stream or wetland credits were being generated within the utility
easement.
d. USACE suggested using a different stream centerline color for portions of streams within
utility easements that are not generating credits. LMG will modify Project Asset Map
(Figure 17) accordingly.

e. IRT stated that the utility easement label should be changed from "proposed" to
"existing". LMG will update the plan sheets accordingly.
f. IRT requested that shrubby species be planted in the wetland rehabilitation area within
the utility easement. LMG will update the Planting Plan to include the area within the
utility easement.
11. USACE questioned the extent of grading that would occur within wetland restoration areas.
LMG explained that restoration of W3 would require grading to a depth of less than 11 inches
and that grading within W5 restoration areas would consist of removing distinct spoil piles
adjacent to UT 7. USACE suggested adding language to the Mitigation Plan describing that
distinct spoil piles will be removed as part of W5 restoration.
12. DMS asked what the IRT needed to move forward with approval of the Mitigation Plan. The IRT
requested that HDR submit the following items for review and final approval of the Mitigation
Plan:
a. Revised Response to IRT Comments
b. Revised Project Asset Map (Figure 17)
c. Final Meeting Minutes from 01-08-2020 meeting

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January 31, 2020
Dear Ms. Browning,
We have reviewed and addressed IRT comments on the draft Mitigation Plan as follows:
NCWRC, Andrea Leslie:
1. We appreciate the provider's consideration of NCWRC's recommendations made in the field and via email
earlier in 2019. One of these recommendations is to rescue any stranded aquatic animals (including fish,
salamanders, and crayfish) in sections of channel that will be abandoned. It is important that this rescue
operation be performed as soon as the flows are diverted from the old channel, and animals should be
netted, placed into a bucket, and transported downstream of the impact area.
Response: This recommendation will be noted in the construction documents and communicated to the
contractor. HDR will have a representative on -site during the rescue operation.
2. If hellbenders are seen on site, place into a bucket and transport downstream of the project area. Please
notify Lori Williams ([e-mail]) and Andrea Leslie ([e-mail]) if
hellbenders are seen and/or moved.
Response: HDR will show the contractor pictures of hellbenders and instruct them to transport
hellbenders downstream of the project area if encountered during construction. Contractor will be
instructed to notify HDR immediately if hellbenders are encountered.
3. The 130 ft section of the West Fork French Broad River that will be under a powerline will have pattern,
profile, and dimension restored, but the plan notes that this will not be planted. We ask that at a
minimum, the banks be planted with livestakes so that a narrow shrubby buffer can be established. This
should help ensure longer term stability of this section of channel.
Response: The planting plan was revised to show that live stakes will be planted along the stream banks
through the utility easement. Language was also added to Section 5.1.1 and 5.1.2 to state that stream
banks under the powerline easement will be planted with live stakes.
4. We ask that the streamside woody species list be expanded to include tree and shrub species seen on site
and just upstream/downstream of the project —this would include rhododendron, dog hobble, and other
species. Do not include black walnut, however.
Response: Several of the species included in the planting plan currently occur on or near the site.
Rhododendron is not included because it does not grow well in full sunlight. Rhododendron prefers partial
to full shade underneath mature canopy. Given the abundance of rhododendron along the tributaries on -
site, it is expected to colonize the floodplain of West Fork French Broad River (WFFBR) as the planted
species mature. Doghobble is not included due to its propensity to form dense thickets and choke out
other planted species before they have time to mature.
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5. Please inform Andrea Leslie at least 2 weeks before project construction begins.
Response: HDR will notify Andrea Leslie at least 2 weeks before project construction begins.
DWR Comments, Mac Haupt and Erin Davis:
1. HDR's response to the DMS comment letter included a response to Appendix J which was concerning
Buffer calculations. DWR would like to see the spreadsheet table showing the footage above the minimum
and the footage below the required. In addition, DWR would like to know what is the percentage of the
buffers on site that are less than the minimum.
Response: HDR will provide the buffer calculation spreadsheet to DMS for distribution to the IRT. The
spreadsheet includes a summary tab that shows linear feet of stream below the minimum required buffer
(354 LF) and linear feet of stream above the required buffer (8,421 LF).
2. One of the issues regarding this site will be the appropriate ratios for several of the enhancement reaches.
Especially since Table 3 shows three of these reaches with Overall NCSAM ratings of High (UT1, UT2a, and
UT6). While UT6 is preservation, the other reaches are proposed enhancement reaches and some
discussion of appropriate ratios will follow in other DWR comments later in this document.
Response: Stream reach conditions and impairments were discussed in depth during the initial IRT site
visit as documented in the meeting minutes dated August 1, 2018 provided in Appendix H. HDR developed
the proposed credit ratios based on existing site conditions, proposed enhancement measures, and
feedback from the IRT during the initial site visit. Although UT 1 and UT 2A have similar NCSAM ratings the
buffers and level of impact cattle are having on the streams is significantly different. Item 8 in the meeting
minutes notes the severe impact cattle were having on UT 2A (cattle are accessing large portions of UT 2A
for shade and water), in which members of the IRT were in agreement with during the site visit. In
comparison, cattle are accessing UT 1 in select locations along the reach but severity of impact is less than
it is on UT 2A. Cattle appear to only access UT 6 near its confluence with WFFBR and therefore impacts are
minor and preservation is appropriate. Following further discussion with the IRT on 01-08-2020, HDR will
revise the credit ratios for UT 1 and UT 4B to 4:1. In addition, UT 2 will be revised to 3.5:1. Credit ratios for
other stream reaches will remain as proposed in the Mitigation Plan submitted on 12-12-2019.
3. DWR does not recall UT3 from the site visit but given the fact this reach originates from a wetland
spring/seep, the provider should be warned that constructing single thread channels in and from these
areas have shown a propensity for evolving into wetlands versus showing channel -like features.
Response: Noted. UT3 is currently headcutting/eroding as it converges with WFFBR, enhancement
measures are necessary to stabilize UT3 at its confluence with WFFBR. The slope of UT 3 through this
enhancement reach should be steep enough to maintain single channel flow.
4. Section 5.6- DWR and the IRT take notice when significant grading is planned for wetland re-establishment
or rehabilitation. While the plan states that spoil is to be removed at varying depths (3 to 11 inches), any
grading of 12 inches or more will result in the wetland approach being classified as creation.
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Response: Noted. The proposed grading is to remove spoil that was excavated from UT 5 and UT 7 and
placed in the wetland areas adjacent to each stream. Removing this material will only be re-establishing
natural contours in the floodplain of each tributary, not artificially lowering elevations to create wetlands.
Additional language will be added to the Mitigation Plan to explain that spoil adjacent to UT 7 is in the
form of distinct spoil piles, whereas spoil adjacent to UT 5 has been spread out.
5. Section 5.8- DWR suggests that the provider add verbiage that states some of the wetland restoration
areas which may exhibit a Bog complex may have more herbaceous vegetation that may persist through
the monitoring period. However, DWR would like to emphasize that these areas should be kept to a
minimum.
Response: The following verbiage was added to Section 5.8, "Bog Complex communities may have more
herbaceous vegetation that may persist through the monitoring period, when compared to other Swamp
Forest communities." The site will be planted to minimize areas dominated by herbaceous vegetation.
Planted species within the Bog Complex will be dominated by shrubs and therefore may not meet the vigor
standards as set forth in IRT monitoring guidance. A note will be added to the Performance Standards
Table indicating that Box Complex communities may have a lower vigor and stem count when compared
with other communities at the Site.
6. Table 13- DWR and the IRT are recommending that all Ash species be removed from planting plans
because of the Emerald Ash Borer.
Response: Based on comments from DWR and USACE, green ash will be removed from the planting plans.
7. Section 6.1- The 30-day flow requirement is for intermittent streams only. Perennial streams are expected
to have near continuous flow.
Response: Noted, the 30-day flow requirement was included in the performance standards simply to
provide evidence that the streams proposed for mitigation credits were "at least" intermittent during the
monitoring period and thus jurisdictional streams.
8. Section 6.3- The wetland performance criterion should be 12% based on the soil borings from the Licensed
Soil Scientist. While the site may be mapped as Rosman (which is not a hydric soil series), the borings
showed a hydric soil with the associated taxonomic subgroup (Fluvaquentic Humaquept) which
corresponds to the Ela soil series in the October 2016 Mitigation Update. Please update Table 14 to reflect
this required change.
Response: Table 14 was updated to show the wetland performance criterion of 12% as requested.
Verbiage was also added to Section 6.3 to reflect this update.
9. Table 15- DWR will be recommending the addition of 3 groundwater wetland gauges and we will specify
the location when the Design sheets are reviewed. This table will need to reflect the change in number of
gauges.
Response: A total of 6 groundwater gauges (3 currently proposed plus 3 additional gauges requested by
DWR) seems excessive for monitoring wetland hydrology on 1.32 acres of restored wetland (only 0.35 ac of
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the 1.32 ac is proposed as re-establishment). HDR will coordinate with DWR regarding placement of the 3
originally proposed groundwater gauges. HDR will also add an additional groundwater gauge in W5 as
requested in DWR comment 16.
10. DWR is very concerned about the 15 foot minimum benches proposed for many sections of the West Fork
of the French Broad. DWR noted but does not agree with the response letter to DMS regarding this
matter. DWR strongly recommends for a stream of this drainage area that the floodplain benches be at
least 2 times bankfull width. Particularly of interest are the bench widths on the meander bends where
much of the flow energy vectors are directed.
Response: The bankfull benches have been maximized where feasible and measures have been proposed
to protect the channel (i.e. toe wood with soil lifts along outside meander bends). Additionally, the two
dimensional HECRAS model did not result in erosive velocities in the proposed channel nor on the
proposed floodplain.
11. Design sheet 2D- DWR is concerned with the Floodplain Interceptor typical. Basically this looks like a rip
rapped stream bank. DWR will need to know where these are planned for, or where the designer thinks
they may occur. Typically, we do not allow stream credit where banks are total rip rap.
Response: The floodplain interceptor is a stabilized conveyance of a single point discharge where overland
sheetflow is connected to the proposed channel. It is intended to protect the channel bank from erosion
in locations that become apparent during construction and are therefore not located on the plans.
Floodplain interceptors are only used when necessary. Floodplain interceptors will incorporate native
channel material where available (a note regarding use of native channel material for interceptors will be
added to the typical).
12. Design sheet 5: DWR is concerned about several issues on this sheet:
a. The bench widths are not adequate for the meander bend at station 20+00. Even though there is
channel fill on the inside of the bend with presumably a wider bench, the energy vectors from the
flow are still directed primarily at the outer bend, especially the lower third of the meander bend.
Response: The bench width along the outside meander bend has been modified around station
20+00 to accurately reflect the proposed grading plan and now proposes a wider floodplain in this
a rea.
b. In addition to the above, the UT5 confluence is located at the lower end of the meander bend and
appears to be stepped down to the riffle. DWR believes this portion of UT5 is at a high risk for
stability.
Response: UT5 is proposed to be stepped down to connect to WFFBR via in -stream rock structure
that will aid in stream stability.
c. UT4 also has its confluence in virtually the same area. Does the Designer believe there is enough
of a riffle to dissipate the energy from the two confluences in addition to West Fork of the French
Broad as well?
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Response: The model, which was completed to evaluate the proposed design, does not indicate
velocities that are problematic.
d. To further exacerbate the above, a wetland is adjacent to the streambank on stream left just
below the confluence of the two aforementioned tributaries. The wetland drainage toward the
streambank will put lateral hydrologic pressure on the streambank and likely result in increased
risk for streambank stability.
Response: Impervious channel material and toe wood with soil lifts are proposed along the
outside channel meander in an effort to stabilize potentially vulnerable areas.
e. We looked for but could not find the profile representation of the lower end of UT5 where it has
its confluence with the main stem. Was this included in the design sheets?
Response: The profile for UT5 can be found at the bottom of Sheets 10 and 11.
13. Design sheet 6- the bench widths are not adequate in the areas near station 28+25 to the next cross vane.
Response: The bench widths in this location transition to meet the existing top of bank for the
enhancement reach where no channel modification is proposed with the exception of bank stabilization
where indicated/necessary.
14. Design sheet 11- DWR recommends an additional wetland gauge be placed on stream right (20 feet
beyond the bench cut, dotted line?) at station 16+00.
Response: HDR will locate one of the proposed wetland gauges at this location but additional wetland
gauges will not be added to W3 (i.e. a total of 2 wetland gauges will be located within W3 Rehabilitation
area, and 1 wetland gauge will be located within W3 Re-establishment area).
15. DWR recommends another gauge in W3 below the powerline.
Response: See response to DWR comment 14. One of the two groundwater gauges proposed for the W3
rehabilitation area will be located below the powerline as requested by DWR (Figure 17 has been updated
accordingly).
16. Design sheet 12- DWR recommends an additional wetland gauge be placed on stream right at
approximately station 10+75.
Response: Figure 17 and Table 15 have been updated to reflect adding an additional wetland gauge as
requested.
17. Stream reach ratios: DWR has the following recommendations regarding the appropriate ratios on the
following stream reaches:
a. UT1- DWR believes this tributary should be at least a 4:1 ratio if not higher. As you may recall,
this is the tributary where we had a lot of discussion regarding the initially proposed 2.5:1 ratio.
Our recommendation is based on the existing vegetation (mostly vegetated overstory), lack of a
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minimum required buffer, and minimal impact from cattle, and an Overall High rating from the
NCSAM assessment.
Response: See response to DWR comment number 2. In addition, although cattle have not
caused severe stream bank erosion/instability along UT 1, cattle routinely access UT 1 for shade
and water resulting in direct fecal inputs. Excluding cattle from the stream and planting a wider
riparian buffer will improve water quality in UT 1 and corresponds to the level of intervention
discussed during the initial IRT site visit. Based on discussions with the IRT on 01-08-2020, HDR
will revise the credit ratio for UT 1 to 4:1.
b. UT2A- this reach was ranked as an Overall High by your NCSAM assessment. Given that the reach
is wooded with perhaps moderate cattle impact, DWR recommends a ratio of 3:1.
Response: See response to DWR comment number 2. In addition, the existing wooded buffer
along UT 2A is narrow (-10-15') and has been degraded by frequent cattle access. Following
enhancement activities UT 2A will exhibit a minimum buffer width of 30 feet with portions of the
buffer exceeding 50 feet in width. HDR proposes to maintain a 2.5:1 credit ratio for UT 2A.
USACE Comments, Kim Browning:
1. The USACE ID for the cover page is SAW-2018-01165.
Response: USACE ID number has been added to the cover page.
2. Please change the colors of the stream preservation and Enhancement II (2:1) on figure 17. It's very
difficult to discern the difference between the two shades of green.
Response: Figure 17 has been updated to address the color issue.
3. It's noted that there are several crossings, both culverts and fords. Please include who will be responsible
for the culvert maintenance in the monitoring section, and how cattle will be excluded from these
crossings.
Response: Maintenance of crossings and fencing is addressed in Section 9.0. The property owner will be
responsible for culvert maintenance. Gates will be installed at each crossing to promote cattle exclusion
when the crossings are not in use.
4. There are several reaches of stream restoration proposed that will impact existing wetlands. Please
describe how you will ensure that no functional loss/loss of waters occurs. Please include wetland gauge
data in the monitoring reports annually.
Response: See Item 3 from the meeting minutes dated August 1, 2018 provided in Appendix H. Existing
wetland impacts resulting from stream restoration will be offset by wetland area gained in the footprint of
the abandoned channel. In addition, raising the stream inverts will restore and enhance the hydrology of
adjacent wetlands. Impacts to existing wetlands will be identified in the permit application and the overall
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net gain in wetland as a result of the mitigation project will be discussed in the permit as well. Wetland
gauge data will be reported in the annual monitoring reports.
5. 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.
Response: Woody material removed during restoration activities will be used on -site for stream bank
stabilization and habitat creation within the floodplain/wetlands.
6. Please depict photo points/digital image stations on Figures 11. If the fixed cross-section locations are to
be used, please describe that in the text.
Response: Fixed cross section locations and vegetation plot locations will be used as photo points.
Verbiage was added to Section 7.0 to explain.
7. Please discuss how fescue will be treated in conjunction with buffer establishment.
Response: HDR does not plan to actively treat the site to eliminate fescue. As planted stems mature and
the canopy develops, any remaining fescue within the buffer should be shaded out. The site will be
treated to control fescue during the monitoring phase if the presence of fescue is jeopardizing the
establishment of native woody vegetation.
UT4A: The majority of this reach (about 400 LF) will only have fencing and possible supplemental planting,
while the bottom 71 LF of this reach will require channel work to tie into UT4. 3.5:1 is more appropriate for
the 400' reach, and 1.5:1 is acceptable for the 71' at the confluence.
Response: As discussed in the meeting minutes attached in Appendix H (see item 10), UT4A is routinely
accessed by cattle. The buffer is significantly degraded from reference condition and the floodplain on
both sides of UT4A shows signs of heavy cattle traffic. HDR agrees that the 400' reach should not receive a
1.5:1 ratio; however, based on existing conditions and proposed enhancement measures, HDR proposes
that the 400' reach receive a 2.5:1 ratio similar to other reaches that have a minimal buffer and are heavily
impacted by cattle. In addition, based on discussions and recommendations from the IRT during the initial
site visit, HDR recommends using a weighted ratio (2.3:1) for the entire reach instead of splitting it out into
two reaches (see item 9 in meeting minutes, Appendix H).
9. UT2A, UT26, UT2 upstream of the crossing, UT76: These areas are more appropriate for 3.5:1 or 4:1 due to
some existing buffer which will require only supplemental planting and cattle exclusion.
Response: See response to DWR comment number 2 and number 17. Based on discussions with the IRT
on 01-08-2020, HDR will revise the credit ratio for UT 2 to 3.5:1. Credit ratios for UT 2A, UT 26, and UT76
will remain as proposed in the Mitigation Plan.
10. Section 5.6.1: Please specify the amount of spoil that will be removed from W5 to ensure that this area is
appropriate for wetland re-establishment rather than wetland creation. Typically any removal over 12"
garners a 3:1 ratio.
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Response: See response to DWR comment number 4. Spoil adjacent to UT 7 is in the form of distinct spoil
piles. Spoil piles will be removed to match natural elevations in the floodplain adjacent to the spoil areas.
11. Please explain what you plan to stabilize the banks/floodplain with in restoration areas that fall under the
powerline easement.
Response: See response to NCWRC comment number 3. In addition, the floodplain underneath the
powerline easement will also be planted. The planting plan will be revised accordingly.
12. Please include an estimate of trees to be cleared in the PCN in relation to NLEB habitat.
Response: An estimate of trees to be cleared will be included in the PCN as requested.
13. Credit Release: NCDMS has recently requested that all previously mentioned As -Built reports will now be
referred to as Record Drawing. Please verify this with DMS and correct as advised.
Response: HDR will coordinate with DMS concerning reference of As -Built vs. Record Drawings and update
project documents accordingly.
14. UT1: Please specify how much of this reach doesn't meet the minimum buffer width, and specify of overall
buffers on site that do not meet the minimum width exceed 5% of the total easement.
Response: See response to DWR comment number 1. The entirety of UT 1 meets the minimum buffer
requirement (i.e. 30 feet) and the overall buffers that do not meet the minimum width are approximately
4% of the total.
15. Section 6.1, Stream Dimension: The 20% variance over as -built conditions is only applicable to individual
bank pin measurements in the guidance. Bankfull cross -sectional area must not increase by more than 15%
over the duration of the monitoring period.
Response: 20 percent was changed to 15 percent in Section 6.1, Stream Dimension.
a. Please remove the statement "Therefore, more leeway on pool section geometry is expected."
Response: This statement has been removed.
16. Crossings shown on UT1 and UT2A seem like they could potentially be moved to the top of the reach and
outside the easement. Please justify current placement. These two reaches also scored high on NCSAM,
please justify the Ell ratio proposed aside from cattle exclusion.
Response: See response to DWR comment number 2 and number 17. The crossings could not be moved
to the top of the reach for UT 1 and UT 2A because the existing topography is too steep in those areas.
17. Section 6.1, Hydraulics: 30-days consecutive flow is only applicable to intermittent streams.
Response: See response to DWR comment number 7.
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18. Section 6.2: Please remove the statement "Or a species included in the Classification of the Natural
Communities of North Carolina descriptions for proposed vegetative communities at the site." NCIRT 2016
guidance should be used.
Response: This statement has been removed from Section 6.2.
a. Any corrective measures or remediation proposal should be proposed to the IRT through an
Adaptive Management Plan for IRT review and approval.
Response: Language was added to Section 6.2 to reference Section 8.0 and state that IRT
approval is required prior to implementing any corrective measures.
19. UT2 and UT2A: There is currently a beaver dam affecting the hydrology of Wetland 1. What is the
anticipated effect of beaver on the stream channels and buffer of these reaches?
Response: Based on current observations, the downstream portions of UT 2 and UT 2A are affected by
backwater from the beaver dams but the system is stable overall and provides high quality habitat.
Vegetation in these areas is suited to a saturated/inundated hydrologic regime and vegetation mortality is
not anticipated in the near future as a result of the beaver dams. HDR does not foresee the beaver dams
having a negative effect on UT 2 or UT 2A or the project as a whole. Language will be added to the
Mitigation Plan explaining that beaver dams on UT 2 and UT 2A appear to be relic (i.e. not active dams).
20. Veg Plots should be located in all wetland areas proposed for re-establishment (1:1).
Response: Vegetation Plots 12 and 18 will be relocated to occur inside of wetland re-establishment areas.
21. It is recommended to cap the proposed percentage of green ash (Fraxinus pennsylvanica) to be planted at
5% since emerald ash borer (Agrilus planipennis) has the potential to impact long-term tree density and
canopy cover.
Response: See response to NCDWR comment number 6.
22. Table 14: Performance standard for flood attenuation should be four bankfull events in separate years.
Response: Table 14 was revised accordingly.
a. Please include a vigor standard for riparian habitat.
Response: A vigor standard (i.e. height measurement) of 6 feet at Year 5 and 8 feet at year 7 was
added to Table 14 and Section 6.2. A note will also be added to the Performance Standards Table
indicating that Bog Complex communities may exhibit lower vigor and stem density compared to
other communities at the Site.
23. Table 15: Please include culvert/crossing maintenance.
Response: Visual inspection of culverts and crossings was added to Table 15.
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24. General comment regarding fencing: Please depict all existing and planned fencing on the plan sheets.
Additionally, it is recommended that gate access is provided to the easement for annual monitoring and
Long Term Management.
Response: Existing and proposed fencing was added to the plan sheets. Means of access to the easement
will be provided via kissing gates.
Sincerely,
HDR Engineering
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Vickie Miller
Project Manager
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