20181154 Ver 1_MP_FINAL_IRT Response Letter_20200902

WATER & LAND SOLUTIONS
7721 SIX FORKS ROAD, SUITE 130, RALEIGH, NC 27615
(919� 614 - 5111 1 waterlondsolotlons.com
July 24, 2020
US Army Corps of Engineers
Regulatory Division, Wilmington District
Attn: Kim Browning
3331 Heritage Trade Drive, Suite 105
Wake Forest, NC 27587
RE: WLS Responses to NCIRT 30-day Review Comments Regarding Task 3 Submittal, Final
Mitigation Plan Approval for the Banner Branch Mitigation Project, USACE AID# SAW-2018-
01760, NCDEQ DMS Full -Delivery Project ID #100080, Contract #7610 and 7701, Roanoke
River Basin, Cataloging Unit 03010103, Stokes County, NC
Dear Ms. Browning:
Water & Land Solutions, LLC (WLS) is pleased to provide our written responses to the North Carolina
Interagency Review Team (NCIRT) review comments dated June 5th, 2020 regarding the Final Draft
Mitigation Plan for the Banner Branch Mitigation Project. We are providing our written responses to
the NCIRT's review comments below, which includes editing and updating the Final Draft Mitigation
Plan and associated deliverables accordingly. Each of the NCIRT review comments is copied below in
bold text, followed by the appropriate response from WLS in regular text:
DWR Comments, Mac Haupt & Erin Davis:
1. DWR appreciates that WLS is conducting pre- and post -restoration benthic and water
quality sampling for this project. Response: WLS appreciates this comment as we believe that the
WQ sampling will help us determine the associated functional lift that may be achieved considering
site constraints and existing conditions.
2. Page 8, Table 1 - As noted in below comments, DWR has questions about the proposed
approach for UT1-R1, credit ratio for UT4-R1, and the credit lengths for UT113 and UT3.
Response: Table 1 has been updated to reflect the credit changes to UT1B per DWR Response #6a,
UT4-R1 for the 1.25:1 for the 233 LF adjacent to the pond (DWR Response #9), and revising UT-R1
upper from Restoration to Enhancement I per DWR Response #23. WLS has addressed UT3 per DWR
response #27 and there are no changes in Table 1 for UT3.
3. Page 31, Section 3.4.5 - When were WLS' field investigations completed? Please include
wetland determination data forms in Appendix 9. Response: The field investigations were
completed by WLS and George Lankford during March 2018 and September 2019. Section 3.4.5 has
been updated and the data forms have been included in Appendix 9.
4. Page 31, Section 3.5 - DWR considers easement breaks as site constraints since
fragmentation impacts the site's potential functional uplift. Please include a discussion on the
coordination completed to minimize the quantity and width of proposed stream crossings.
Also, please explain why an additional crossing is proposed on UT4-R1 that was not part of
the original concept plan. Response: WLS has added additional language to Section 3.5.7 that
discusses the location and number of stream crossings across the project area. We have coordinated

with all four landowners to locate the crossings as shown on the plans. The adjoining landowners
requested an additional crossing along UT4-R1 after the concept plan stage to accommodate current
farm operations and future access if the property was ever sold or subdivided. We understand that
stream crossings and easement breaks (i.e. fragmentation) are not favorable and impacts the sites
functional uplift potential. However, they are often a landowner requirement for property access and
many restoration sites could not be implemented without proper planning and incorporating these
crossings. The functional impacts are considered minimal and only account for 1.5% of the total
stream length to be permanently protected in the easement as a result of the project.
5. Page 31, Section 3.5.4 - Since proposed wetland restoration credit areas abuts the
conservation easement, have you evaluated the risk of hydrologic trespass that may result in
the landowner ditching outside the easement? Response: WLS has evaluated the risks of
hydrologic trespass from potential changes in adjacent land use. We have discussed the proposed
design approach with the landowners and explained how the post -restoration conditions will
increase groundwater tables and saturation levels within the valley bottom. Fortunately, all the
creditable wetland areas within the easement boundary abut pasture areas and not agricultural
fields, therefore crop loss will not be a concern. We have taken necessary measures to ensure that
project features/elements are not adversely affected by external perturbations. Should situations
arise that warrant corrective action, WLS will deal with those issues swiftly and judiciously and in
coordination with the IRT.
6. Page 39, Table 14 -
a. The UT1B existing to mitigation footage increases from 391 LF to 488 LF, with an EII
approach please explain this stream length increase. Response: The increase in stream
length along UT113 is the result of extending the reach to connect to UT1-R2. The existing
channel terminates in an existing wetland and has lost channel definition. The enhancement
approach is to create a natural stable connection to UT1-R2 through a constructed channel
with in -stream structures to provide grade control and bedform diversity. WLS has revised
Table 14 to split this reach into upper and lower sections. Upper UT113 will match the existing
stream length of 391 LF with a proposed Enhancement II approach. Lower UT113 (97 LF) is
the extension of this reach needed to connect with UT1-R2, and we propose an EI approach
at 1.5:1 credit ratio.
b. Please confirm that the section of UT4-R1 within Wetland W3 will be Priority 1. Page
45 appears to indicate that P2 is proposed for this lower reach, which may affect
wetland hydrologic uplift. Response: The portion of UT4-R1 within Wetland W3 is being
proposed as Priority Level 1 restoration. Language has been added to this section to better
describe the proposed design approach in lower UT4-R1 above the ponded area.
7. Page 47 - This section notes that proposed BMPs will be located outside of the conservation
easement, however, Section 6.7 states that BMPs will be located inside easement. If no long-
term maintenance is required, then DWR prefers BMPs be located inside the easement.
Response: The BMPs are located inside the conservation easement. WLS has revised Section 6.1.2
and Section 6.7 to state that all BMPs will be within the conservation easement and require no
maintenance.
8. Page 49, Section 6.2.2 - Please include the location of reference wetland (coordinates/map).
Response: The reference wetland 'W8' location has been added with coordinates as an insert to
Figure 11.

9. Page 55, Section 6.4 - DWR expects that the narrow right side buffer adjacent to the
agriculture/recreational pond will limit the potential functional uplift of the restored stream
section. To reflect the reduced functional uplift DWR supports a credit ratio of 1.25:1 for the
233LF section of UT4-R1 with buffers of less than 30 feet. Response: WLS has updated Section
6.1.2, page 46 to reflect the reduced credit ratio for the 233 LF. Tables 1 and 14 have been updated
accordingly. Table 14 has a note about the reduced credit ratio for this 233 LF of UT4-R1.
10. Page 57, Section 6.5 - Please indicate the total planted area. Response: WLS has included the
total planted area in Section 6.5.1, page 59, of the mitigation plan. 24.3 acres are restoration planting
and 5.10 acres are supplemental planting for a total of 29.4 acres.
11. Page 58, Table 21 - DWR appreciates the species and stratum diversity; however, we
recommend a slight adjustment to the percentages so at least 50% of stems are canopy
species. Response: Table 21 has been adjusted to increase the canopy species to approximately 76%
of the total stems planted.
12. Page 60,6.5.2 - Please indicate if fescue will be treated prior to or during site construction.
DWR recommends early treatment based on observations of fescue impeding planted
vegetation establishment and vigor. Response: WLS understands DWR's concern with fescue
impeding planted areas. We do not believe that herbicide treatment of fescue is appropriate for this
site due to the adverse environmental impacts. The site preparation includes clearing and grubbing
which will help reduce fescue pressure. Grading activities will also remove much of the fescue
seed/root source. The combination of these two techniques will help control fescue regeneration. If
fescue becomes pervasive within the conservation easement, WLS will address the issue through a
remedial action plan. Language has been added to Section 6.5.2 to address this concern.
13. Page 62, Section 6.8.1 - DWR recommends depressional areas, which are not called out as
vernal pools, not exceed 6-8 inches. Response: There are no depressional areas other than those
created by common floodplain grading activities as part of this project. The depressional areas will
not exceed 8 inches and this language has been added to Section 6.8.1.
14. Page 63 - Please include a discussion/section on evaluated Project Risks and
Uncertainties. Response: Section 6.8.4 Future Project Risks and Uncertainties has been added to the
mitigation plan.
15. Page 68 - DWR requests flow gauges be installed in the upper one-third of subject
intermittent reach. Response: Section 8.2.3 has been revised to state that flow gauges will be
installed in the upper one-third of subject intermittent reaches. On Figure 10 (Monitoring Features),
flow gauges have been added to reaches UT1C and UT2A per Comment #19.
16. Page 69 - Please confirm that 16 veg plots represent 2% of the proposed planted area.
Since a large area of supplemental planting is proposed, DWR requests an additional 2-3 plots
to track survival rates not necessarily tied to success criteria. Response: Section 8.4 has been
updated to 20 vegetation plots, which is 2% of the estimated riparian planting area (24.3 ac). The
planting plan in the design plans has also been revised to reflect Proposed Riparian Planting and
Riparian Supplemental Planting Zones. The estimated supplemental planting area is 5.1 acres and
dispersed throughout the project areas. These areas will be included in the visual assessment each
monitoring year. Based on the final planting locations documented in the as -built report, WLS may
add two 50m x 2m transects in the supplemental planting areas to track survival rates that will not
be tied to success criteria. These two possible transects have been added to Figure 10 on reaches
UT113 and UT4-R2.

17. Figures - Please either show property boundaries on one of the included figures or an
additional figure. Response: The property boundaries have been added to Figure 6 - Current
Conditions.
18. Figure 9 - It is very difficult to see the restoration and preservation stream color lines over
the aerial at this scale. Response: Figure 9 has been revised to clearly depict the stream mitigation
types/colors.
19. Figure 10 -
a. Please include flow gauges on the intermittent Restoration reach of UT1C and
Enhancement I reach of UT2A. Also, please shift the location of the flow gauge on UT2
upstream at least 150 feet. Response: Flow gauges have been added to UT1C and UT2A.
While reach UT1C is intermittent in the upper part of the reach, the project only captures the
lower third of this reach. The entire jurisdictional reach is 527 LF, but only 227 LF are in the
easement area; the first 69 feet are preservation and the last section is 151 ft of restoration.
The location of the flow gauge on UT2 has been moved upstream a bit, but it is already well
within the upper third of the reach. UT2 continues past the easement break and is currently
1,315 LF.
b. In order to demonstrate enhancement please include veg plots within wetlands W5
and WSA; and to demonstrate reestablishment please include veg plots within
wetlands W9 and W8A. Response: Vegetation plots have been added to these four wetland
areas.
c. Please include additional cross -sections on UT2 and UT3. Response: There was one
riffle cross-section shown on UT2 below the crossing, but an additional cross-section has
been added. Also, cross -sections have been added to UT3.
20. Sheet 2 - Please add legend icons for vernal pool and the hatching shown on plan view
indicating to grade, seed, mat and live stake areas. Response: Legend icons for vernal pool and
the hatching shown on plan view indicating to grade, seed, mat and live stake areas have been added
to sheet 2 of the construction plans.
21. Sheet 3 - DWR recommends that benches be at least two times bankfull width for C type
stream restoration. Response: Floodplain benches have been minimally designed equal to or
greater than an entrenchment ratio of 2.2.
22. Sheets 14, 23 & 33 - Please callout stream crossings/easement breaks on the profile views.
Response: Stream crossings/easement breaks have been noted in the profile views.
23. Sheet 18 - Based on the proposed work, UT1-R1 appears to align more as an Enhancement
I approach compared to Restoration, where the full length of stream will have dimension,
pattern and profile improvements. Additionally, only partial buffer planting is proposed.
Further justification is needed for DWR to support this reach for restoration credit. Response:
WLS has revised the approach along UT1-R1 to Enhancement Level I with a 1.5:1 credit ratio. The
original concept approach was to relocate and re-establish the incised channel away from the right
toe of slope. We have updated Table 1, Table 14, and Section 6.1.2, pg 47 accordingly.
24. Sheet 13 - Please confirm the profile callouts for existing ground and design thalweg are
indicating the correct features. Response: WLS has revised sheet 13 profile callouts and confirmed
other sheets have correct profile callouts as well.

2 5. Sheet 15 - The CE crosses the southwest corner of the existing pond. Please show how this
area will be graded within and immediately adjacent to the CE line. Response: WLS has revised
the pond grading so that the entire CE break is a flat crossing and does not include the pond or any
part of the pond water surface.
26. Sheet 22 - The tributary connecting with UT1-113 at Station 43+00 is not mentioned
anywhere in the plan. Since a section of this trib. it is located within the project site and may
be potential sediment source for 1313-111, please include a brief description of the channel
condition. Response: The tributary shown on sheet 22 is Banner Branch which flows from the east
and connects with UT1-R3 near Station 43+00. We have added language to the existing reach
condition summary in Section 3.4.1, pg 24 that briefly describes the upstream channel condition.
27. Sheet 26 - DWR echoes DMS' question regarding UT3 and 1313-112 parallel alignment
through an existing wetland. At one point the two channels are less than 25 feet apart. Please
provide justification why it's not feasible to tie in UT3 further upstream on 1313-112 near Station
68+00. Additionally, please note that channel maintenance measures such as sediment or veg
removal should not be completed after MY3 in order to properly evaluate how the system is
trending. Response: As described in the DMS response comment, WLS designed the reach
alignments and confluence for UT3 and BB-R2 not to unnecessarily increase stream length/credit,
but to accommodate current stream/valley morphology, gradients and natural floodplain
connections so that they are not perpendicular to flow. In theory it is feasible to leave the existing
ditch in its current location to maintain base flow. However, in practice it is our design intent to
convey future base flow and overbank floods competently and without adverse effects to channel
hydraulics and floodplain conditions, and to allow for increased habitat and bedform diversity within
the appropriately sized bankfull channel. Furthermore, maintaining perennial stream flows within
the single thread channel will decrease concentrated flow energy, excess scour potential and stream
degradation while improving wetland hydrology across the wide valley bottom (>150'). As shown on
Plan Sheets 25 and Figure 7a historical aerial, the proposed alignment actually ties into the main stem
BB-R2/R3 at station 69+85 prior to the remnant channel feature near station 71+30. The channel
slope is —1.14% (drops 6.7 ft across 589 LF) with adequate riffle slopes and pool -to -pool spacing to
maintain stream bed/bank characteristics and channel form within the wetland area and valley
width. We do not anticipate channel maintenance measures to remove sediment or excess channel
vegetation after MY3.
28. Appendix 12 - Since reach names have changed, please include the concept figure that
corresponds to the IRT site visit meeting minutes. Response: the concept figure that corresponds
to the meeting minutes has been included in Appendix 12.
NCWRC Comments, Travis Wilson:
1. The generic permanent stream crossing detail does not illustrate or mention the possible
need for culverts set above bankfull elevation. It would be beneficial to including a cross
section detail specific to each culverted stream crossing. That will allow a better assessment
of the culvert sizing and configuration within the crossing. Response: The typical culvert crossing
detail is not reach specific mainly to limit the number of details within the project plans, so as to
minimize duplication and limit the number of plan sheets. Site specific culvert information is shown
in the plan/profile sheets of the construction documents. WLS has revised the permanent stream
crossing detail to include a bankfull culvert where and when it is called out in the construction
documents.
2. Note: duel lines of smaller diameter pipe in the channel are not preferred. Pipes typically
have to be placed 12"-18" apart causing the channel flow to split and potentially over widen
at the inlet and outlet. Response: WLS understands the concern about dual pipes, but have had good

success with this design approach without deleterious effects to the stream. However, we have
revised the current crossing to include a single channel culvert and two floodplain culverts.
3. UT1-113 Station 34+32 permanent crossing is set at 7% that is extremely steep, aquatic
passage will not occur, and downstream scour is almost certain. Response: WLS has revised the
culvert slope to be less steep. However, due to the change in grade between reaches we could only
reduce the pipe slope to 5.79%.
USACE Comments, Kim Browning:
1. When submitting the PCN, please combine all impacts by reach. For example, if there are
three 60' culverts on reach 1, list it as 180' of permanent impact rather than listing it as three
separate impacts. But permanent and temporary impacts still need to be separated. Also,
please estimate the number or acres of trees to be cleared to address the NLEB 4(d) rule.
Response: WLS will combine all impacts by reach (permanent and temporary separated) for the PCN
and will estimate the acres of trees to be cleared per the NLEB 4(d) rule.
2. Section 6.4: 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. I was pleased to see the inclusion of wood in the stream design for habitat. Response:
WLS appreciates this comment and will direct the contractor to add coarse woody debris to the
depressional areas in the buffers and wetlands for habitat which is also described in the technical
specifications. This has been added to Section 6.4 also.
3. Section 3.5: Please add a section regarding potential future adjacent development or
logging. Response: Section 3.5.6 Potential Future Land -Use has been added, as well as Section 6.8.4
Future Project Risks and Uncertainties per DWR Comment #14.
4. Though Stokes County is considered a mountain county, all analysis and data are based on
piedmont ecoregion categorization. I recognize that the conservation easement has probably
already been finalized, but It seems more appropriate for 50' buffers on this site. Response:
WLS understands and agrees with this comment, but Stokes County is currently listed as a mountain
county with 30-ft buffers, so WLS followed the current guidance. You are correct that the easements
have already been finalized. We will consider this for any future projects in Stokes County.
5. Considering the very small watershed drainage areas for UT1A and UT2A, there is concern
for loss of flow. It would be beneficial to supplement with photo -points to document flow.
Response: WLS will install flow gauges on these reaches instead of photo -points since DWR already
requested a flow gauge for UT2A in Comment #19a.
6. In the future, please maintain the same reach names throughout the project, including the
JD. It's difficult to refer to our field notes when reaches are renamed. Additionally, it's difficult
to see the channel lines with the colors selected on Figures 9 and 10. Please use the same
colors throughout the life of the project to designate the different mitigation approaches.
Response: WLS understands the importance of this request and has made every effort to adhere to
this on recent projects. Figures 9 and 10 have been revised to better depict the channel lines without
changing colors for the mitigation types.
7. The IRT site visit notes indicate that UT1-111 above UT1C should be enhancement II, rather
than restoration. Section 3.4.1 indicates that this reach is mostly stable with a mature woody
buffer. Please explain why restoration is proposed here, especially since the listed functional

uplift is only 8% and it scored a Medium NCSAM rating. Response: As noted above in DWR
response comment #23, WLS has revised the approach along UT1-R1 to Enhancement Level I with a
1.5:1 credit ratio. The meeting minutes state that this area should be Enhancement Level II, then a
section of preservation, and that restoration could begin near the old house where the stream is
incised. The original concept approach was to relocate and re-establish the incised channel away
from the right toe of slope. We will be conducting Enhancement Level I activities such as excavating
floodplain bench and installing in -stream structures to increase bedform diversity and aquatic
habitat. Table 1, Table 14, and Section 6.1.2, pg 47 have been updated accordingly.
8. NCSAM: UT3 was not mentioned in the text on page 30. An interesting observation is that
many of the reaches proposed for enhancement II score a Low SAM rating while reach 1313-113,
which scored Medium, is proposed for restoration. Perhaps cattle exclusion on the EII reaches
will provide the most uplift, but it would be interesting to compare the scores of NCSAM and
SQT to see the results of the functional assessments. Response: WLS appreciates the comment
and likes the suggested comparative observation. Although there are similarities between the NC
SAM and the SQT assessment methods and functional summaries, our understanding is that NC SAM
is intended as a more of a rapid functional assessment and the SQT requires more data collection
and analysis in order to determine the restoration potential and associated lift that can be achieved
for the project, especially considering site constraints and existing conditions. For example, BB-R3 is
scored medium primarily because of existing buffer vegetation and limited cattle access at the lower
portion of the reach; similarly, UT1-R2 is the longest stretch of Enhancement II and scored medium
with a wooded buffer and cattle access.
9. Table 14: The wetland comments section does not distinguish the difference between the
different levels of work being performed on wetland rehabilitation versus re-establishment.
For example, the work performed is the same for W1 and W1A, but they're receiving different
credit ratios. Response: Soil manipulation has been added to the re-establishment wetlands. The
work being performed on both proposed wetland areas is very similar, however the credit ratios, are
different because the wetland rehabilitation areas are jurisdictional wetlands (poorly functioning),
while the re-establishment areas contain favorable hydric soils for wetland re-establishment. Both
wetland types will receive similar levels of work.
10. Table 21: Considering the inclusion of riparian wetlands proposed for this site, it would
be beneficial to add additional FACW species to the overstory and understory list. Response:
WLS agrees with this comment and Table 21 has been adjusted to include additional FACW species.
11. Ephemeral/vernal pools should be 8-14" depressions that dry up yearly so that predatory
species cannot colonize, and should not be so numerous that trees do not grow in large areas
of the buffer. Response: WLS agrees with this comment and the vernal pools/floodplain depressions
will not exceed 8-14" deep as suggested. We have revised our channel plug detail to reflect this intent.
Annotations within the design plan sheets will further emphasize the size and depth of the floodplain
depressional feature to prevent overly deep pools resulting in stagnant water conditions that prevent
tree growth. WLS has corresponded with WRC on past projects to better define the definition, spatial
distribution and function of vernal pool ecology as it relates to floodplain depressions in the riparian
zone. These are generally intended as floodplain features such as meander scars and tree throws are
commonly found in natural riparian systems. These features are appropriately added to provide
additional habitat and serve as water storage and sediment sinks throughout the riparian corridor.
12. Please show the location of the rain gauge and fixed photo points on Figure 10. If cross -
sections are to be used for photo points, please indicate in the text. Additionally, it would be
helpful to have photo points at crossings to show the condition of the culverts. Response: The
rain gauge has been added to Figure 10. There are no fixed photo points proposed for stream
monitoring as WLS opted to install flow gauges instead on those reaches. Cross -sections and

vegetation plots will be used as photo points. This language was already in Section 8.2.2, but has also
been added to Section 8.1 Visual Monitoring. WLS has added crossing photo points for culverts to
Figure 10.
13. Please show the location of the reference wetland on Figure 11. Response: Please see DWR
response comment #8. The reference wetland 'W8' location has been added with coordinates as an
insert to Figure 11.
14. I'm glad to see the inclusion of water quality and benthic monitoring. Are these reaches
proposed for additional credit? If so, please add this to Table 1. Also, please add the
monitoring locations to Figure 10. Response: WLS appreciate this comment, however, these
reaches are not proposed for additional credit. WLS is conducting this monitoring independent of
credit determination to improve our project implementation and document potential functional
uplift. This additional monitoring is not tied to success criteria and the two locations have been added
to Figure 10.
USEPA Comments, Todd Bowers:
I have completed my review for the Banner Branch wetland and stream mitigation site. I have
no site -specific comments to submit at this time. Response: Noted and thanks.
Please contact me if you have any additional questions or comments.
Sincerely,
Water & Land Solutions, LLC
Kayne M. Van Stell
Vice President, Ecosystem Design Services
Water and Land Solutions, LLC
7721 Six Forks Road, Suite 130
Raleigh, NC 27615
Office Phone: [phone]
Mobile Phone: [phone]
Email: kayne0waterlandsolutions.com