Draft Mit Plan Comment Memo_RES CatawbaESA UMB-BeaverTail_SAW-2022-00657

DEPARTMENT OF THE ARMY
WILMINGTON DISTRICT, CORPS OF ENGINEERS
69 DARLINGTON AVENUE
WILMINGTON, NORTH CAROLINA 28403-1343

REPLY TO
ATTENTION OF:

February 6, 2024

CESAW-RG/Kichefski

MEMORANDUM FOR RECORD

SUBJECT: RES Catawba Expanded Service Area UMB- Beaver Tail Mitigation Site -
NCIRT Comments during 30-day Mitigation Plan Review, Catawba County, NC

PURPOSE: The comments listed below were received from the NCIRT during the 30-
day comment period in accordance with Section 332.8(d)(7) of the 2008 Mitigation Rule.

USACE AID#: SAW-2022-00657 30-Day Comment Deadline: November 1, 2023
DWR #: 2022-0451 V2

Maria Polizzi, NCDWR:
1. Was an internal ford crossing considered for landowner access rather than an
easement break? If so, why was this option not feasible? Internal crossings are
preferable as they allow for maintenance to be performed.
2. In Section 3.7 the plan describes soils as “demonstrating a high potential for
successful wetland creation” and “soil characteristics suitable for wetland
creation”. Are there characteristics besides texture that were observed and
considered suitable? What characteristics are you looking for and subsequently
which ones were identified?
3. DWR finds Table 9 to be a helpful summary.
4. In Section 5.1, “impervious cover and stormwater runoff” is listed as a stressor
identified in the watershed that will be addressed by the project. Is any
impervious surface being removed as a part of this project? If this will be
addressed to a greater extent than improved buffers, please describe how.
5. DWR encourages the inclusion of particle size distribution data (pebble count), if
available, when discussing sediment transport.
6. DWR appreciates the inclusion of Section 6.1.4 highlighting changes from the
prospectus and a response to previous IRT comments.
7. Is there any concern about tree mortality in areas of supplemental planting due to
shading effects, competition, etc. Some previous projects have had trouble
establishing understory plantings especially when they are bare root. Could
containerized be considered for these areas?
8. What planting strategies will be used to ensure species diversity? DWR has
observed veg. plots on monitoring reports that sometimes have minimal species
diversity, not due to mortality, but due to the location and spacing at which
individual trees were planted.
9. Section 6.2.3: Is organic material an amendment that will be considered for
application? Old ag fields often have very minimal, if any, organic matter (O
and/or A horizon) remaining. Mulch or compost could be a valuable amendment
as it provides many useful functions for both soil and vegetative health, including
moisture retention, nutrient retention, decreased bulk density/compaction risk,
microbe habitat and food source, pH buffering, etc.
10. DWR requests at least 2 vegetation plots (one fixed and one random plot) be
located within supplemental planting areas. An alternative performance standard
should be proposed for these locations.
11. Please ensure that there is a wetland gauge placed at the very top and bottom of
the wetland creation area so that the extent of hydrologic presence can be
documented. A wetland gauge is not required in the preservation area, so that
gauge could be relocated to the areas requested above. A brief description of
any visual observations during monitoring for the preservation area should be
included in the monitoring reports.
12. DWR disagrees that WE is a headwater wetland. Headwater wetlands are
typically found at the very top of a topographic crenulation on first-order or
smaller streams. Often the stream will form below the base of the headwater
wetland. Based on the geographic and landscape position of WE, a different
floodplain wetland type would be more fitting. Although it will most likely not
change anything substantially, it may be worth running the WAM calculator
again, as wetland type does have a significant effect on how results are
calculated.
13. Thank you for including the detailed hydric soils report. It may be worth adding all
the soil borings to the map, rather than just the borings associated with a profile
description. Having the profile description borings shown in a different color or
symbol is advisable so that they can be identified, but I would like to see a more
detailed map of which soil borings were hydric vs. which weren’t. Based on the
text there were 58 borings dug during the investigation, which is an ideal number,
I just want to be able to see the results (“in” vs. “out”) on the map.
14. DWR requests a hydroperiod of 12% since soils are described as similar to
Wehadkee and/or anticipated to have characteristics similar to Wehadkee. 12%
is the low end of the hydroperiod range for Wehadkee soils and still within the
ideal range for Chewacla soils.
15. How concentrated is the ag runoff from livestock pens in the location of the
proposed swale and BMP? The swale and treatment pool BMP may make sense
if runoff is currently concentrated, but if runoff is diffuse / dispersed, it may not be
ideal to concentrate it. This is a very small treatment pool with no baffles, and
therefore the amount of nutrient and sediment reduction may be limited. DWR
wonders if continued diffuse flow through the improved riparian buffer would be a
better treatment (even if the buffer is smaller in this location). Alternatively,
multiple small treatment areas may be preferable. It is also important to consider
the longevity of this device, as its function will decrease when filled with sediment
over time. Additional thoughts and discussion on this BMP would be helpful.
16. Thank you for co-locating the utility easement with the road crossing.

Olivia Munzer/David McHenry, NCWRC:
1. Page 7, Table 6: It is indicated there is no habitat present for tricolored bat.
According to the pictures, it looks like potential habitat occurs at the site.
2. Page 28, Section 6.2.1: some of the scientific names are not italicized and there
is inconsistency with capitalization of common names.
3. The NCWRC would like to see a seed mixes and tree/shrub planting plans
specific to the various habitat types (wetland vs. riparian) and with the
appropriate indicator status. For example, species such as swamp milkweed is a
wetland/freshwater marsh species that is an obligate and should not be planted
in riparian or more upland habitats. We also recommend at least 2, but preferably
more, flowering herbaceous species per habitat type.
4. The WRC requests that any woven wire fence that is used also be gapped at the
bottom about 6 inches to facilitate passage by some wildlife. I believe that
recommendation is referenced in 6.6.1 of the guidelines as well.
5. I do like the sill detail with the short “splash pad”, which I’ve seen in the field a
couple times. It seems to be a good measure in many cases to help ensure AOP,
particularly portions of channel on fill.
6. In contrast, I don’t have much experience with them, but “treatment pools” seem
like a problem for bedload aggradation (aka sediment basin). I saw where a
designer had built some on a decent sized stream and the pools were functioning
more as mini in-line frog ponds. And, they were indeed filling up. Now I only see
one shown on these plans, and that looks like a drainage that is entering the
mitigation area, so no potential deal here.
Steve Kichefski, USACE:
1. As stated in the IRT prospectus comments, the Service Area for this bank
should align with the current approved Service Area Map.
2. No red-lined UMBI template for this project was found or reviewed. Please
submit for review with the comment response. Has a real estate package been
submitted? If not, when do you anticipate submittal?
3. Section 3.4.1 Regulatory Considerations:
a. A new 60 LF ford crossing is proposed as external to the project CE. If
seeking an ag exemption for this crossing, make sure it is properly
submitted with the 404 application/impact list/impact map. Feel free to
coordinate over what is temporary vs permanent prior to PCN submittal
and update Section 3.4.6.
b. Previous IRT comments stated a preference for an internal ford crossing
for landowner access rather than an easement break? Why was this
option not feasible? Internal crossings are preferable as they allow for
maintenance to be performed.
c. Is any additional buffer included outside the DOT ROW in case of future
DOT improvements? Please add current DOT culvert dimension and
conditions in this section (is pipe in good shape/perched/etc.).

4. Section 3.4.3 Threatened and Endangered Species: Make sure to update
Tricolored Bat information prior to the PCN submittal (including language in this
Section, Table 6/7 and App B).
5. Section 3.7: The incision of LD1 could support the rationale of lower groundwater
hydrology in the area of WE and proposed wetland creation, however there is no
indication of relic hydric soils in a large portion of the creation area based on the
Hydric Soils report. Please provide thoughts as to why and what other landscape
modifications are currently draining the soils/water table in the creation area.
6. The USACE also appreciates the inclusion of Section 6.1.4 highlighting changes
from the prospectus and a response to previous IRT comments.
7. USACE agrees that at least 2 vegetation plots (one fixed and one random plot)
be located within supplemental planting areas and that an alternative
performance standard could be proposed for these locations.
8. Please ensure that there is a wetland gauge placed at the very top (northern
extent) of the wetland creation area so that the extent of hydrologic presence can
be documented. USACE would prefer the wetland gauge to be retained in the
preservation area so that changes to the hydrology due to nearby wetland
creation construction and ditch work can be assessed.
9. Section 7.2 and Table 17: The USACE agrees with NCDWR comment #14
regarding a 12% hydroperiod, which seems supported by the hydric soils report.
We understand that the initial year of monitoring may find a lower hydroperiod
while the water table adjusts to the newly constructed conditions.
10. USACE also is concerned about the concentration and the volume of discharge
from the livestock pens in the location of the proposed swale and treatment pool?
Provide more detail regarding the output to be captured by this swale/treatment
pool so we can be more confident it is appropriately sized, whether it could be
dispersed in a more diffuse way thru the buffer to better filter and/or avoid scour
from concentrated flow, thoughts regarding the adequate size/design of the
treatment pool verifying it is appropriately sized and will be self-maintained over
time. Is this swale and treatment pond just designed for treatment of the livestock
pen effluent or will it also be preventing any hydraulic trespass on the adjacent
field? Make sure there is a photo point at the treatment pool and pool outlet into
the stream.
11. Section 12 Table 20: Please update the Wetland Credit Release Schedule with
the appropriate District template.
12. Section 13 Long-Term Management Plan: The last paragraph states that a five
percent return is assumed for the endowment calculation, however the submittal
by Unique Places to Save shows a 3.5% capitalization rate. USACE considers
5% too high but is comfortable with the 3.5% rate. Please verify what rate was
used and correct.
Figures/Appendices
13. Figure 9: Please add a table of soil type to this figure for soils within the project
area.
14. Figure 14a/b: Please add 1 groundwater gauge near the northern portion of the
wetland creation (Wetland WA).
15. Sheet D3: Provide more detail of the “Impervious Select Material” noted in the
Channel Plug detail so we can ensure it is appropriate for use on the site.
16. Sheet D7: Are the Stone Protection and Cascade shown utilized anywhere else
on this project other than Sta 16+50 to17+00 on Sheet S3 (where the elevation
drops as the channel approaches Lutz Dairy Farm Road)?
17. No fencing plan was found. Will livestock be present on any property adjacent to
the CE? If so, include a fencing plan and verify whose responsibility fencing will
be in perpetuity. Keep in mind there needs to be adequate access for regulatory,
IRT, and stewardship staff to inspect the site. If no fencing is needed to exclude
livestock, then verify all old fencing will be removed from the CE.

Sincerely,

Steve Kichefski
Project Manager - Mitigation Branch
USACE Regulatory Division

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