20181271 Ver 1_IRT comment response_20201126

Wildlands Engineering, Inc.  phone [phone]  fax [phone]  1430 S. Mint Street, # 104  Charlotte, NC 28203

October 5, 2020

Ms. Kim Browning
Mitigation Project Manager
United States Army Corps of Engineers
69 Darlington Avenue
Wilmington, NC 28403-1343

Subject: Mitigation Plan Report and Construction Plans
Honey Mill Mitigation Site, Surry County
Yadkin River Basin HUC 03040101
DMS Project ID #100083
USACE #SAW-2018-01789

Dear Ms. Browning:
Thank you for your September 15, 2020 comment letter for the Honey Mill Mitigation Site draft
mitigation report and plans. We have made the necessary revisions to the draft documents and we are
submitting revised versions of the documents along with this letter. Below we provide your comments
followed by our responses in bold italics.

WRC Comments, Andrea Leslie
1) As noted previously in an early review letter provided directly to the applicant, wild trout
reproduction should not be impacted by this project, and a trout moratorium is not needed.
a) Noted – thank you.
2) Sambucus nigra is a European species of elderberry, but sometimes the native elderberry is included
in this group. Ensure that they are using the native elderberry (Sambucus canadensis).
a) This error has been fixed. The native elderberry (Sambucus cavadensis) now replaces the
European elderberry in the planting table.
3) Sweetbay magnolia is primarily a coastal plain species. Although it might be found in rare seepage
wetlands in this part of the state, it would not occur as a native species on typical stream banks.
a) Sweetbay magnolia (Magnolia virginiana) has been removed from the planting list.
4) Lindera melissifolia is a federally listed species of boggy coastal plain sites. Do they mean Lindera
benzoin, which would be a fine understory planting?
a) This error has been fixed. Spicebush (Lindera benzoin) is now listed in the planting table.
5) River birch is not often found on small streams – it’s typically associated with large rivers. Unless it is
found on site already, we recommend eliminating it and replacing it with something else.
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a) River birch (Betula nigra) has been removed from the planting list. Wildlands has made this
change due to the site being on the edge of its native range in NC rather than it’s association
with larger streams. Matthews (2011) supports that river birch is frequently associated with
small stream and narrow floodplains in addition to palustrine areas.
6) Acer negundo is also typically associated with larger streams, as well.
a) While boxelder (Acer negundo) is commonly associated with larger streams and natural levee
forests, it is also found in floodplains and palustrine areas of smaller streams (LeGrand et al.,
2020; Matthews, 2011; Schafale & Weakley, 1990). Wildlands argues that boxelder is an
appropriate planted species for this site at the proposed planting rate since it is documented
to inhabit floodplains of smaller streams as documented by LeGrand et al. (2020) and
Matthews (2011). Furthermore, boxelder grows quickly in open areas and serves as a valuable
‘nurse tree’ providing more favorable growing conditions for slower grower tree species (i.e.
oaks) that establish better in partially shaded environments.
7) Eliminate silver maple from the planting list –it is very limited in North Carolina, and it wouldn’t be
found on small streams.
a) Silver maple (Acer saccharinum) has been removed from the planting list.
8) Cut down on the % of sycamore planted (20% of stems).
a) Sycamore (Platanus occidentalis) has been reduced to 15% of stems in the riparian planting
zone.
9) It appears that ‘riparian planting’ areas will not include understory species. The ‘shaded
supplemental planting’ list has a nice diversity of subcanopy and shrub layers – we recommend
bringing some of these species into the ‘riparian planting’ areas. Could they include other species
already found on site in the riparian planting list?
a) American strawberry bush (Euonymus americanus), red mulberry (Morus rubra) and witch
hazel (Hamamelis virginiana) have been added to the riparian planting zone list. Additionally,
paw paw (Asimina triloba) and sourwood (Oxydendrum arboreum) will also occupy the
subcanopy layer in this planting zone.

WRC Comments, Travis Wilson
10) The draft plan does not include a detail of the stream crossings. It states the crossings are all
existing utility, ford, or culvert crossing but then mentions the culverts will be buried. Therefore, I
am assuming the crossing locations are existing but the structures will be reset to the restored
profile. If that is the case a detail showing the ford crossing and the culvert crossing should be
included.
a) A culvert crossing detail and a ford crossing detail are now provided. Please see detail
1/6.10 and 2/6.10 in the plans.

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EPA Comments, Todd Bowers
11) I wish to convey that I while I understand that Surry County is considered “mountain” for the
purposes of generating mitigation credit, this site does not seem to meet the qualification of a
“mountain stream” but rather a “piedmont stream”. I have several reasons for this consideration.
a) The site elevation ranges within the current proposed conservation easement between
approximately 980- and 1,050-feet above sea level. According the NC Wildlife Resources
Commission, “the piedmont physiographic ecoregion elevations range from about 1,500 feet in
the foothills to about 200 feet at the fall line.” This site would be located in the piedmont from
that perspective.
b) According to the sponsor and the draft mitigation plan, “the Site is located in the Tugaloo
terrane of the Piedmont physiographic province (NCGS, 2018). The Piedmont Province is
characterized by rolling, well rounded hills and long low ridges, with elevations ranging from
300 to 1500 feet above sea level.”
c) Cool water streams, while more common in the mountains of North Carolina, do exist widely in
the NC piedmont.
d) Many of the reference sites used to guide restoration of the site streams are located in the
piedmont ecoregion. According to the sponsor, “due to the variety of slopes and project stream
types present on the Site, the distribution of reference reaches is wide, throughout North
Carolina’s foothills and western Piedmont.”
e) The NC SAM zone used to evaluate the streams within the project boundaries is listed as
“Piedmont”.
f) According to Section 7.3.5 (Page 15-16), Wildlands developed a regional flood frequency
analysis tool that tailored the USGS 2009 publication “Magnitude and Frequency of Rural
Floods in the Southeastern United States, through 2006” to the Piedmont of North Carolina and
used several gages located in the Piedmont to develop flood frequency intervals for the project
streams.
i) Wildlands acknowledges your above considerations.
12) Since the site appears to have more piedmont than mountain characteristics, I highly recommend
that the sponsor reconsider the minimum buffer widths and conservation easement boundaries of
this project. The draft mitigation plan lists several instances where discreet constructed BMPs are
needed to offset drainage and polluted runoff from the surrounding landscape. The land
surrounding the site will continue to be used for livestock grazing following the establishment of
the conservation easement and completed fencing. The primary stressor on water quality for the
project streams will continue to be runoff from livestock excrement and the best BMP to counter
this stress is wider vegetated stream buffers. The sponsor even states on page 23 that additional
floodplain vegetation would lower the risk to the site from agricultural runoff. Therefore, I
recommend that the site incorporate 50-foot minimum riparian buffer widths. This will have the
added effect of protecting the stream floodplains and the pockets of wetlands contained within.
a) While Wildlands agrees that wider buffers always offer greater protection, we have provided
the required buffer widths as outlined in the governing rules and regulations (Wilmington
District 2003 Stream Mitigation Guidelines and the October 24, 2016 Stream and Wetland
Compensatory Mitigation Update). Our option agreements were set for 30-foot buffers
based on this guidance during the proposal stage of the project. The easements for the site
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are recorded with the 30-foot buffers presented in the plans.
13) I recommend that the vegetation height requirement for satisfactory performance of vegetative
vigor be increased from 8 to 10 feet at the conclusion of the 7- year monitoring period. The
elevation of the project is not sufficiently high enough to warrant the use of the lower standard
used for mountain streams.
a) Wildlands has set the vegetation height standards per requirements set forth in Section V.B.2
in the NC IRT October 24, 2016 Stream and Wetland Compensatory Mitigation Update – no
change has been made.
14) With the recommended wider buffers, I also recommend a corresponding increase in the number
of vegetation plots to monitor the vigor of planted trees.
a) The number of vegetation plots presented corresponds to the required buffer width recorded
and presented in the plan – no change has been made.
15) The planting plan for the site appears adequate and appropriate for both canopy and subcanopy
species. Recommend listing the species that will be considered for the final height requirement
performance standard as some will not likely meet the 10-foot requirement at the end of the
proposed monitoring period; namely those considered for shaded supplemental planting. I also
recommend that any significant deviations from the planting plan are approved by the IRT before
purchase and planting.
a) Species that will not be considered for the final height requirement are indicated in the tables
by an asterisk. They include red mulberry (Morus rubra), sourwood (Oxydendrum arborea),
paw paw (Asimina triloba), witch hazel (Hamamelis virginiana), American strawberry bush
(Euonymus americanus), ironwood (Carpinus caroliniana), sweetshrub (Calycanthus floridus),
spicebush (Lindera benzoin), flowering dogwood (Cornus florida), and American holly (Ilex
opaca).

USACE Comments, Kim Browning
16) Figure 9: the veg plot on Venable Creek R2 should be relocated to the confluence of R3 and
UT2, to include the existing wetland.
a) The vegetation plot was relocated to the wetland at the confluence of Venable Creek
Reach 3 and UT2.
17) Design sheets general note: Please ensure that when measuring the centerline of the channel for
crediting purposes that only one channel is measured at a confluence. An example is on Sheet 2.36
where it appears that both channels are measured. Additionally, please ensure that the centerline
is used for crediting determination, not the thalweg. This is unclear on sheets 2.1 and 2.5.
a) Station callouts and crediting were adjusted at the tributary confluences, and centerline
adjustments were made on Venable Creek Reach 1, 2, and 4.
18) Field notes indicate that the confluence of UT2 and UT2A is a wetland complex and would be best
suited as a wetland. This plan proposes single-thread restoration in this area. Please note the
concern of the IRT for this area to demonstrate wetland like characteristics and be willing to
document a single-thread channel throughout the monitoring period.

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b) Visual documentation of a single-thread channel on UT2 Reach 2 through the wetland
complex throughout the monitoring period has been added to the monitoring criteria. See
Section 8.1.2 of the revised mitigation plan.
19) Page 6 discusses UT2B; I’m unclear where this is on the Figures. (Perhaps it’s the small
unlabeled line outside the easement?)
a) UT2B was added to the figures. UT2B is located just upstream of the Venable Creek
Reach 3 and Reach 4 break.
20) Section 7.2.4: It would be interesting to note the approximate number of mature trees that are
left on-site in areas where restoration will occur and note the survival rate of these existing trees
through the monitoring period. On the Agony Acres site, we noticed that a large number of
mature trees that were left in the buffer were actually damaged during construction and began
to die between MY4 and MY5. This is just an observation and the data would be interesting to
see, not just on this site.
a) Wildlands has added two monitoring photo points to visually assess representative mature
tree save areas. The location of these photo points will be established post-construction.
Please reference Table 16, note 8, in the mitigation plan.
21) Section 7.1: It would be beneficial to discuss the potential for utility line maintenance, and the
road culverts to be replaced/widened on Siloam Rd (UT1) and Little Mountain Church Rd
(Venable Creek R1). It appears that the conservation easement is at least 50 ft from the road
right-of-way, which is appreciated.
a) This discussion is now included in Section 7.10, Project Risks and Uncertainties.
22) Section 7.9: There is some concern regarding the fact that the landowner is responsible for
installing the livestock watering facilities in relation to the fact that at least one of the crossings is
a ford crossing. Please confirm that these crossings will not be used for livestock access for
drinking if the landowner fails to install the watering tanks.
a) The ford crossing is in an internal easement break and will be fenced, gated, and only used
for coordinated crossing events. The conservation easement language requires the
landowner to restrict livestock access in the conservation easement. Table 14 outlines that
livestock will only access the ford during coordinated crossing events.

DWR Comments, Erin Davis
23) Page 4, Section 3.2 – DWR appreciates that Surry County planning documents were reviewed for
this plan.
a) Noted – thank you.
24) Page 6, Section 3.4 – Is the location of UT2B mapped on any of the plan figures? If not, can the
approximate location please be called out on Figure 2 (within and/or outside of the easement).
a) UT2B was added to the figures. UT2B is located just upstream of the Venable Creek Reach 3
and Reach 4 break.
25) Page 9, Section 4.1 – There are five BMPs shown on Figure 9, but only four points of inputs are
mentioned in the text. Please clarify.

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b) This section now references five potential agricultural input areas. Please refer to Section 7.7
for discussion on the BMPs.
26) Page 10, Section 4.5 – There are two areas of Wetland C that aren’t captured within the
conservation easement. Was protection of these resource areas discussed during site planning?
a) Wetland C is heavily accessed by cattle currently. The portion of the wetland not within the
conservation easement is an area required by the landowner to access the culvert crossing on
UT2. The local topography prohibited another approach to this crossing. Wildlands has
accounted for the impact to this wetland in the PCN.
27) Page 11, Section 5.3 – DWR requests a groundwater gauge be installed in existing Wetland K where
hydrology may be impacted by proposed stream relocation in order to demonstrate no significant
functional loss of the resource.
a) The existing onsite wetlands are not proposed for mitigation credit; therefore, no
groundwater gauges are proposed.
28) Page 13, Section 7.1 – This section notes that wetland hydrology was assessed with groundwater
gages. I suspect this is a carryover, but if gage data is available please include it in the final
mitigation plan.
a) Wetland hydrology was not assessed with gauges since wetlands are not proposed for
mitigation credit. The erroneous reference has been removed from Section 7.1.
29) Page 21, Section 7.6 – DWR appreciates that an effort was made to capture the tributary origins
within the conservation easement. Please confirm whether the UT2 stream origin is included
(Sheet 2.12), and if it’s not please explain why not (e.g. UT2A ends at property line).
a) UT2’s intermittent origin is within the conservation easement.
30) Page 22, Section 7.8 – Please include at least one target community for the proposed planting plan.
DWR would like to see a mix of early successional native species and appropriate climax species
based on the designated target community.
a) This information is now included in Section 7.8.
31) Page 26, Table 15 – There are differences in the goals and objectives compared to Table 6. Please
review.
a) Goals and objectives from Tables 6 and 15 now match.
32) Page 29, Section 10 – DWR recommends an annual inspection of the site.
a) This language comes from the most recent DMS mitigation plan template (June 2017). DMS
let us know this language was reviewed by the IRT and DEQ Stewardship prior to the issuance
of the mitigation plan template and guidance. DMS has requested that the approved
language remain in the mitigation plan as provided. Per DEQ Stewardship, DMS mitigation
sites accepted by the DEQ Stewardship program will be inspected every one to three
(maximum) years. Language in Table 18 has been updated to reflect the one to three year
inspection frequency.
33) Page 30, Section 11 – Please confirm whether Wildlands or DMS would notify the NCIRT of site
issues.
a) The section now states that Wildlands and DMS will coordinate with the IRT if remedial
actions are necessary.
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34) Page 30, Section 12 – The memo referenced for the credit ratios includes a summary table in which
management objectives for UT2R1, UT2A, UT3R1, UT4, UT5, and UT6R1 specifies “spot repair
erosion and incision”. However, only design sheets for UT4 show any stream work. Please explain
why spot erosion and incision areas identified during the proposal stage were not addressed in the
design stage.
a) The proposal approaches were field walked with the IRT, who noted less impacts than
observed by Wildlands field scientists during proposal development. The IRT reduced
crediting ratios on these streams to reflect the reduced approaches. Please refer to the IRT
meeting minutes and mapping in Appendix 6.
35) Figure 9 – DWR requests the veg plot along Venable Creek Reach 2 be shifted downstream to near
the next set of cross sections along Reach 3.
a) The vegetation plot was shifted to incorporate the wetland at the confluence of Venable
Creek Reach 3 and UT2.
36) Appendix 3 – Was NCWAM completed for the existing wetlands onsite? If so, please include the
corresponding forms. Also, two of the NCSAM rating sheets did not include an overall rating score,
please QAQC.
a) NCWAM forms were not completed since the existing wetlands are not proposed for
mitigation credit. NCSAM forms for Venable Creek 3, UT3 Reach 2, and UT4 have been
updated.
37) Sheet 0.3 – Please include roadway right-of-way boundary lines.
a) The parcel boundary lines indicate the 60’ right-of-way on Siloam Road and the 50’ right-of-
way on Venable Farm Road. No additional lines were added.
38) Sheet 2.1 – Are there any existing utility poles located within the internal crossing?
a) There are no utility poles within the internal crossing.
39) Sheet 2.2 – Will the existing farm road be relocated just outside of the easement? Are impacts to
Wetland B expected/accounted for?
a) The existing farm road will be relocated outside of the easement. All wetland impacts are
accounted for in the PCN.
40) Sheet 2.2 – The BMP detail (Sheet 6.9) includes an outlet channel, please show the approximate
location of this outlet channel on the plan view sheets (Sheets 2.2, 2.7 and 2.34).
a) This information has been added.
41) Sheet 2.12 – The Enhancement II Treatment Note #4 is confusing to see on sheets that do not show
any grading (Sheets 2.12-2.15, 2.18-2.22, 2.24-2.26 and 2.32). If spot grading is proposed, please
show on the sheets.
a) The Enhancement II treatment notes were revised for each plan sheet and areas receiving
spot grading are indicated on the plans.
42) Sheet 2.12 & 2.32 – Figure 2 indicates headcuts in the upper sections of UT2 and UT5. No stream
work is proposed for these reaches. Is further instability of these headcuts a concern? Monitoring
photo points may be helpful at these locations.

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b) The proposal approaches were field walked with the IRT, who noted less impacts than
observed by Wildlands field scientists during proposal development. The IRT reduced
crediting ratios on these streams to reflect the reduced approaches. Please refer to the IRT
meeting minutes and mapping in Appendix 6. Photo points will be added to monitor the
areas of concern on UT2 and UT5.
43) Sheet 2.16 – Please include a typical detail for the proposed culvert crossing.
a) This detail is now included. Please see detail 2/6.10.
44) Sheet 2.3 – DWR recommends that bench width be at least 1.5 times bankfull width. Particularly of
concern are the bench widths on the outer meander bends where much of the flow energy vectors
are directed.
a) Brush toe will be installed along the outer meander bend to add stability to the streambanks
and help prevent meander migration.
45) Sheet 2.4 – UT2 and UT3 are designed to tie in to Venable Creek at meander bends rather than riffle
straights. Are there any long-term stability concerns for these meander areas?
a) The elevation at the downstream extent of both streams match the downstream head of
riffle elevation on Venable Creek, and these bends are protected with brush toe, which will
prevent meander migration. Wildlands does not have long term stability concerns for these
ties.
46) Sheet 2.8 – A ford crossing detail was not provided. With the existing bedrock I understand that the
streambed doesn’t require reinforcement, but are the side slopes/access path areas stable? Is any
grading proposed? Will any riprap be placed along the banks?
a) This detail is now included. Please see detail 1/6.10.
47) Sheet 3.1 –
a) DWR questions whether sweetbay magnolia is an appropriate species for site based on the
species geographic range
i) Sweetbay magnolia (Magnolia virginiana) has been removed from the planting list.
b) It would be helpful for our review to have the wetland indicator status included in the tables.
i) The wetland indicator status has been added for each species.
c) DWR understands that quantity substitutions may be necessary based on the nursery’s species
available. However, we request that no species (excluding live stakes) account for more than
20 percentage of a specified planting zone in order to promote diversity within the designated
community type.
i) All riparian planting zone species are below 20 percent of total planted stems.
48) Sheet 6.9 – Will herbaceous plugs be installed in the shallow water planting zone of the
bioretention cells? I think fox sedge is the only OBL species in proposed seed mix.
a) Herbaceous plugs and wetland bare roots will be planted within the shallow water zone in
the BMP.

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50) Are channel plugs proposed? If so, please indicate approximate locations and include a typical
detail.
a) Channel plugs are not proposed within the plans. Channel plugs may be installed during
construction, if needed, at the discretion of the engineer.
51) Please include an overall fencing plan indicating existing and proposed fencing and approximate
locations of anticipated gates.
a) A fencing plan is now included with the plans. See sheets 7.1-7.6.

Please contact me at 704-332-7754 extension 109 if you have any questions.
Thank you,

Aaron Earley, PE, CFM
Senior Water Resources Engineer