20160366 Ver 1_IRT Response Letter_20170323

W ILDLANDS
E N G I N E E R 1 N G
March 17, 2017
Andrea Hughes
United States Army Corps of Engineers
Wilmington District
11405 Falls of Neuse Road
Wake Forest, NC 27587
RE: IRT Review Comments for Mitigation Plan
Martin Dairy Mitigation Site (DMS #97087)
Neuse 03020201, Orange County, NC
Dear Ms. Hughes,
We have reviewed the comments on the Mitigation Plan for the above referenced project dated March
14, 2017 and have revised the Mitigation Plan and plan set based on these comments. The Final
Mitigation Plan is submitted with this letter including the revisions described herein. Below are
responses to each IRT member's comments. For your convenience, the comments are reprinted with
our response in italics.
Comments from Mac Hauat and Vireinia Baker. NCDWR (February 15. 201
1. The Martin Dairy Mitigation Plan appears to be a straightforward project with a work plan and
approach that aligns with the project goals.
Thank you.
2. On Page 22, performance standards for MY7 (210 planted stems per acre) should be listed in
section 9.2 as they are in Table 14.
The first paragraph has been corrected to show a final vegetation survival rate of 210 stems per
acre.
3. For Clarity, DWR recommends stating that full monitoring reports will be submitted in years
1,2,3,5, and 7 in Section 10.0 Monitoring Plan. This section refers to the DMS Annual Monitoring
Template (April 2015) which has the DMS stream and Wetland Monitoring Guidelines —
February 2014 listed as a "companion" document. The February 2014 DMS Guidelines has
complete monitoring reports only required for years 1,3,5, and 7.
This section has been updated to state full monitoring report will be submitted in years 1,2,3,5,
and 7. Also, separate reports for monitoring associated with buffer credits will be submitted to
NCDWR in years 1,2,3,4, and 5.
W Wildlands Engineering, Inc. (P) 919.851.9986 • 312 West Millbrook Road, Suite 225 • Raleigh, NC 27609

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Todd Bowers. USEPA (February 17, 201
1. Recommend the sponsor gather some sort of biological data to establish baseline water quality
conditions of the site even if it is assumed to be not -functioning. A change in macroinvertebrate
community populations can indicate an uplift in water quality after several years of monitoring
and while this does not have to be tied directly to a performance standard, it would allow the
sponsor to possibly reclassify the physiochemical and/or biological functions from NR to another
category to demonstrate uplift. Without this information, it is a dubious position to conclude
that the stream (Martin Dairy) is "Functioning" when only 3 of the 5 categories are rated and
only two are showing actual uplift in function.
This project is intended to address three of the five categories within the pyramid as they have
the highest degree of obtainable and measurable success. It is of the opinion of Wildlands that a
statistically significant difference in physicochemical and biological data and indicators would
not be achievable duing the monitoring period. Additionally, lack of baseline water quality data
in this watershed does not allow for a statistically sound comparison of pre- and post restoration
conditions. However, the Division of Mitigation Services has chosen to do an independent
evaluation of the water quality on site with their own sampling protocol and we hope that will
yield valuable information. That sampling protocol is outside of the scope of this mitigation plan.
2. Page 22: Section 9.2 Vegetation: Please include the performance standard for MY7 (usually 210
stems/acre). This will conform to Table 15 on Page 24.
The first paragraph has been corrected to show a final vegetation survival rate of 210 stems per
acre.
3. Please have the sponsor provide a contingency plant to deal with beavers (Castor canandensis)
and associated damage they may cause to the project.
Table 1 in Appendix 7: Maintenance Plan, has been updated to include the removal of beaver
dams and potential trapping of beavers, if appropriate, during the monitoring period.
4. Page 27: Table 18b. Is the sponsor suggesting credit for buffer within 50 feet of the stream
bank? This would seem to suggest that credit is being given for the 20 feet within the required
stream riparian buffer zone.
An error in this table (now 17b) has been corrected. Buffer Area A is TOB —100'. There is credit
given to the 20 feet within the required buffer zone. This follows standards set by current buffer
rules (15A NCAC 02B .0295(n)(2)(B), € and (n)(4)) that became effective November 1, 2015.
5. Recommend adding either Corylus americana or Carpinus caroliniana to the riparian buffer
planting plan to add understory/sub-canopy diversity.
W Wildlands Engineering, Inc. (P) 919.851.9986 • 312 West Millbrook Road, Suite 225 • Raleigh, NC 27609

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The existing project site to be planted is an open pasture. The viability of understory species
planted in full sun is low and has not been successful in past projects. We anticipate understory
species to volunteer from neighboring existing riparian buffers.
6. Overall the plan appears to be low -risk, fairly straightforward, appropriate and adequate to
perform a successful restoration of the streams and riparian buffer on -site.
Thank you.
Andrea Hughes, USACE (February 20, 2017)
1. Page 13, Design Channel Morphological Parameters: The plan states that ranges of pattern
parameters were developed within the reference reach ranges with some exceptions (MWR, Rc)
based on best professional judgement and knowledge from previous projects. The proposed
design MWR is 2.4 and the design Rc is 1.8. For a C/E4 stream design we typically expect a MWR
of no less than 3.5 and Rc no less than 2.0. Please explain the specific reasoning for deviating
from the reference standards. Also, please provide the flood prone width.
The purpose of this section is to explain our deviations from references above the minimums we
found in the data and this has been clarified in the report. Appendix 4 includes the full range of
our reference data for this project. The MWR of our two reference reaches had minimums of 1.0
and 2.3, however we have found that for CIE channels, it should be kept above a minimum of 2.4
to naturally dissipate energy through meander bends during high flow events to limit impacts of
shear stress on streambanks. The rationale for Rc ratios is similar. Our reference data had Rc
ratios as low as 1.1 but past project experience led us to use a minimum of 1.8, well above some
of the existing references. The lower limits for MWR and Rc are based on values used for many
years on many successful designs.
In the final designs, we were able to achieve MWRs at the higher end of the appropriate ranges,
3.2 and above on Martin Dairy, and 2.7 and above on UT1 (due to a more confined valley). The
Rc ratios in the final designs utilized the entire range of appropriate values..
Floodprone width data is located in Appendix 4 in the comprehensive geomorphology tables.
2. The technical document indicates the utility poles will be relocated outside of the easement.
The current plan does not mention moving the utility poles. Also, the mitigation plans indicates
a short distance of restoration below the culvert on Reach 1 before the easement break. Given
the short distance bordered by a road crossing and utility easement, we have concerns with
potential impacts and long term sustainability for this small reach. We advise beginning the
project below the utility crossing.
The relocation of utility lines was proposed during the technical proposal phase of the project.
After meetings with the utility company it was determined not to be feasible. As explained in
Section 8.8, the maintenance easement for the utility line is very low risk. There is direct access
to all utility poles on site via a gravel drive on the property. The stream has been designed in this
W Wildlands Engineering, Inc. (P) 919.851.9986 • 312 West Millbrook Road, Suite 225 • Raleigh, NC 27609

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section with a riffle that could sustain the impact from an emergency vehicle if access were
required. Therefore, the only difference in the function of this section will be lower -growing
vegetation with potential for periodic maintenance. Considering this information, we would
prefer to proceed with the project limits as shown in the current plans. No credit is being
requested within the easement limits.
3. Page 21, Section 9.0: Please remove the last sentence in the first paragraph regarding early
termination.
This sentence has been removed.
4. Page 22, Section 9.2: Please note that the final success criateria (at year 7) is 210 stems per acre
and the monitoring period is 7 years. Also, please remove the third paragraph regarding early
termination.
The first paragraph has been corrected to show a final vegetation survival rate of 210 stems per
acre. The third paragraph has been removed.
Page 25, Section 11.0: Under long term management, you must specify the long-term manager.
If the long term manager will be the NCDEQ stewardship program then please remove (or 3rd
party if approved). Of NCDEQ will not serve as the long term manager, please provide the name
and contact information for the 3rd party. If NCDEQ will be the longterm manger, you should
remove or revise the third sentence to state that NCDEQ will assume responsibility for funding
of longterm management activities.
NCDEQ will be the long-term manager for this project. The statements above have been removed
from the text to reflect that.
6. Design Sheet 2.0, Planting Plan: Please remove Tag Alder from the planting plan (Alnus
serrulata).
Tag Alder has been removed from the planting plan.
If you have any questions, please contact me at [e-mail] or [phone] x 106.
Sincerely,
f
Angela Allen, P.E., Project Manager
W Wildlands Engineering, Inc. (P) 919.851.9986 • 312 West Millbrook Road, Suite 225 • Raleigh, NC 27609