20181033 Ver 1_(REV) Resp to IRT Comments_2-6-20_20200224

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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
area.
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.
8. 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, UT2B, UT2 upstream of the crossing, UT7B: 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 2B, and UT7B
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 EII 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

Vickie Miller
Project Manager