HomeMy WebLinkAbout20181154 Ver 1_Mitigation Plan Review_20200605Strickland, Bev
From: Browning, Kimberly D CIV USARMY CESAW (USA)
<Kimberly.D.Browning@usace.army.mil>
Sent: Friday, June 5, 2020 1:06 PM
To: Crocker, Lindsay; Dow, Jeremiah J; Cara Conder; Kayne Vanstell
Cc: Tugwell, Todd J CIV USARMY CESAW (US); Haupt, Mac; Davis, Erin B; Wilson, Travis W.;
kathryn_matthews@fws.gov; Bowers, Todd; Merritt, Katie; McLendon, C S CIV USARMY
CESAW (USA); Crumbley, Tyler A CIV USARMY CESAW (USA); Jones, M Scott (Scott)
CIV USARMY CESAW (USA); Haywood, Casey M CIV USARMY CESAW (USA)
Subject: [External] Notice of Intent to Approve/ NCDMS Banner Branch Mitigation Site/
SAW-2018-01760/ Stokes Co.
Attachments: Draft Mit Plan Comment Memo -Banner Branch SAW-2018-01760.pdf
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Good afternoon,
We have completed our review of the Draft Mitigation Plan for the NCDMS Banner Branch Mitigation Project (SAW-
2018-01760). Please see the attached memo, which includes all NCIRT comments that were submitted site during the
review process along with additional comments provided by Wilmington District staff following our review.
We have evaluated the comments generated during the review period, and determined that the concerns raised are
generally minor and can be addressed in the final mitigation plan. Accordingly, it is our intent to approve this Draft
Mitigation Plan (contingent upon the attached comments being addressed in the Final Mitigation Plan) unless a member
of the NCIRT initiates the Dispute Resolution Process, as described in the Final Mitigation Rule (33 CFR Section
332.8(e)). Please note that initiation of this process requires that a senior official of the agency objecting to the approval
of the mitigation plan (instrument amendment) notify the District Engineer by letter within 15 days of this email (by COB
on June 20, 2020). Please notify me if you intend to initiate the Dispute Resolution Process.
Provided that we do not receive any objections, we will provide an approval letter to NCDMS at the conclusion of the 15-
day Dispute Resolution window. This approval will also transmit all comments generated during the review process to
NCDMS, which must be addressed in the Final Mitigation Plan to be submitted with the Preconstruction Notification
Application for NWP 27. All NCIRT members will receive a copy of the approval letter and all comments for your records.
Thank you for your participation.
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
DEPARTMENT OF THE ARMY
WILMINGTON DISTRICT, CORPS OF ENGINEERS
69 DARLINGTON AVENUE
WILMINGTON, NORTH CAROLINA 28403-1343
REPLY TO
ATTENTION OF:
CESAW-RG/Browning
MEMORANDUM FOR RECORD
June 5, 2020
SUBJECT: Banner Branch Mitigation Site - NCIRT Comments during 30-day Mitigation Plan Review
PURPOSE: The comments listed below were received during 30-day comment period in accordance
with Section 332.8(g) of the 2008 Mitigation Rule in response to the Notice of NCDMS Mitigation Plan
Review.
NCDMS Project Name: Banner Branch Mitigation Site, Stokes County, NC
USACE AID#: SAW-2018-01760
NCDMS #: 100080
30-Day Comment Deadline: May 13, 2020
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.
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 UT1 B and UT3.
3. Page 31, Section 3.4.5 — When were WLS' field investigations completed? Please include
wetland determination data forms 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.
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?
6. Page 39, Table 14 —
a. The UT1 B existing to mitigation footage increases from 391 LF to 488 LF, with a Ell
approach please explain this stream length increase.
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.
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.
8. Page 49, Section 6.2.2 — Please include the location of reference wetland (coordinates/map).
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.
10. Page 57, Section 6.5 — Please indicate the total planted area.
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.
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.
13. Page 62, Section 6.8.1 — DWR recommends depressional areas, which are not called out as
vernal pools, not exceed 6-8 inches.
14. Page 63 — Please include a discussion/section on evaluated Project Risks and Uncertainties.
15. Page 68 — DWR requests flow gauges be installed in the upper one-third of subject intermittent
reach.
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.
17. Figures — Please either show property boundaries on one of the included figures or an additional
figure.
18. Figure 9 — It is very difficult to see the restoration and preservation stream color lines over the
aerial at this scale.
19. Figure 10 —
a. Please include flow gauges on the intermittent Restoration reach of UT1 C and
Enhancement I reach of UT2A. Also, please shift the location of the flow gauge on UT2
upstream at least 150 feet.
b. In order to demonstrate enhancement please include veg plots within wetlands W5 and
W5A; and to demonstrate reestablishment please include veg plots within wetlands W9
and W8A.
c. Please include additional cross -sections on UT2 and 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.
21. Sheet 3 — DWR recommends that benches be at least two times bankfull width for C type stream
restoration.
22. Sheets 14, 23 & 33 — Please callout stream crossings/easement breaks on 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.
24. Sheet 13 — Please confirm the profile callouts for existing ground and design thalweg are
indicating the correct features.
25. 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.
26.Sheet 22 — The tributary connecting with UT1-R3 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 BB-R1, please include a brief description of the channel condition.
27. Sheet 26 — DWR echoes DMS' question regarding UT3 and BB-R2 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 BB-R2 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.
28.Appendix 12 - Since reach names have changed, please include the concept figure that
corresponds to the IRT site visit meeting minutes.
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.
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
3. UT 1 R3 Station 34.32 permanent crossing is set at 7% that is extremely steep, aquatic passage
will not occur, and downstream scour is almost certain.
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.
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.
3. Section 3.5: Please add a section regarding potential future adjacent development or logging.
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.
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.
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.
7. The IRT site visit notes indicate that UT1-R1 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.
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 BBR3, which
scored Medium, is proposed for restoration. Perhaps cattle exclusion on the Ell 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.
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.
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.
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.
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.
13. Please show the location of the reference wetland on 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.
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.
Digitally signed by
BROWN ING.KIMBERLY. BROWNING.KIMBERLY.DANIELLE.15
DANIELLE.1 52768351 0 27683510
Date: 2020.06.05 12:47:35-04'00'
Kim Browning
Mitigation Project Manager
Regulatory Division