Mit Plan Comment Memo_WEI Tar-Pam 01 UMB-Great Meadow_SAW-2021-01714

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

CESAW-RG/Tugwell April 9, 2024

MEMORANDUM FOR RECORD

SUBJECT: Action ID. SAW-221-01714, Wildlands Tar-Palmlico 01 Umbrella Mitigation
Bank – Great Meadow Mitigation Site: Comments from 30-day NCIRT Mitigation Plan
Review, Nash County, NC

1. 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. The
30-day comment deadline is January 7, 2024.

2. Maria Polizzi, NCDWR (NCDWR # 20211423 v1):

a. Are two crossings needed on Shard Branch? It seems like access could still be
provided with one. Additionally, the northern crossing will impact wetlands which
could be avoided if the crossing was eliminated or moved south where there are
no wetlands. (This wetland, BB, scores with a SAM score of Medium)

b. Is the crossing needed on Fox Branch? No crossing is currently shown on the
existing conditions map, so further discussion about the need for this crossing
would be helpful. This crossing is also not mentioned in Section 3.5 (Site
Constraints). In general, please provide more detail about the necessity of
crossings in the report.

c. DWR appreciates the diversity of structure types proposed in this project.

d. Please include at least 2 wetland gauges on Fisher Branch and Shard Branch to
monitor the effect of stream restoration on wetland hydrology.

e. More photos of Gideon Swamp would be appreciated, there is only one included.
Photos of other reaches are very helpful.

f. I do not have as much background on this project as some other IRT members,
but I want to make sure that I understand everything correctly, so my apologies for
any repeated questions/discussion. I see that in the 9/23/22 correspondence from
Samantha Daily a 2.5:1 credit ratio for Gideon Swamp was agreed upon. Was this
wider buffer area proposed for buffer credit and nutrient offsets at that time? If not,
I want to make sure we are not double dipping. Additionally, the removal of a
crossing is described as an additional enhancement measure, but I don’t see a
crossing on the existing conditions map, and based on other sections of the plan
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it sounds like this was a proposed crossing, not an actual crossing to be removed.
Am I understanding that correctly? Depending on the answers to the above
questions, it may be worth having an updated discussion about the credit ratio for
this area. DWR is in support of a higher-than-normal credit ratio due to the
existence of the T&E species in the reach and does not wish to disrupt previously
agreed upon ratios, so clarity on this topic would be most helpful.

g. Section 3.3.3 states that the LSS report is included in Appendix 1. I couldn’t find it
in the hard copy, or the digital version submitted to Laserfiche. I see a soils map
(Figure 7), which I am assuming is based on the NRCS Soil Survey data, but not
a full soils report or even a map with the soil boring locations. Please provide this
report and associated map in the final plan.

h. DWR appreciates that invasive management will begin prior to construction and
sees benefit to starting early on this.

i. There are multiple symbols for existing trees. Do each of these symbols represent
a different type of tree? If so, can they be labeled?

j. Would it be possible to increase the easement size slightly to include entire
wetland units? If cattle have access to a wetland that extends from the stream to
the pasture, this can become a source of water quality impairment. Excess
nutrients, fecal coliform, turbidity, and other pollutants will have a direct input to the
system, minimizing the uplift that can be achieved by the project.

k. Multiple maps (including Figures 8, 9, 12 & 13) show Shard Branch Reach 1 as
“Restoration 2.5:1”, while Table 11 lists the credit ratio as 1:1. Please ensure that
all figures and/or tables are up-to-date.

l. The design plans show several woody structures (log vanes, woody riffles, etc.)
along Shard Branch Reach 1, which is intermittent. Is there concern about these
structures decomposing over time? If not, why not? If so, are there alternatives
that can be utilized?

m. Can the lower (southern) crossing on Shard Branch be straightened? Typically, it
is preferable for crossings to be as close to 90 degrees as possible. This minimizes
the length of stream impact, the width of buffer impact, and is also more stable. Is
it possible to straighten the farm road slightly allowing for an improved crossing?

n. Is any supplemental planting planned for this project in areas that are already
forested or partially forested?

o. DWR feels that the enhancement II ratio for Fox Branch Reach 2 should be lower.
Typically, a 2.5:1 ratio involves spot bank shaping/repairs, some in-stream
structures, full easement planting, and potentially the addition of BMPs. Since no
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stream work is proposed and minimal planting, this leaves cattle exclusion as the
primary uplift, which would more closely align with a 4-5:1 ratio.

p. DWR appreciates the 3’ fencing offset from the CE.

q. Design Sheet 5.6-5.7: The proposed fencing through the internal crossing appears
to overlap with the crossing itself for the crossing Fox Branch and lower Shard
Creek. It is somewhat difficult to tell as the crossings are not specifically shown on
these figures, but based on station numbers and comparison to other figures it
appears that there may be overlap. Please clarify the plan for the fencing in these
areas.

r. Is there a reason why boulder toes were selected? These are a pretty hefty feature
to use on an intermittent reach of an almost coastal plain project. I understand the
need to avoid a structure that may rot, but since this is for bank stabilization rather
than grade control, it seems like there may be a better alternative than armored
banks. I am open to discussion on this, as I am not an engineer, but additional
justification would be helpful if an alternative is not viable.

s. Section 6.7.2 Land Management: I would be interested in what soil amendments
are selected and what soil testing is performed. I understand that this information
is not available at this point but would appreciate if it could be included in the as-
built report or monitoring reports, if additional soil amendments are added at a later
point. Soil is a critical component of plant viability and since this occurs later in the
process, we do not often see these details. But it would be useful to understand
the standard practices and any variability in approaches across landscape types,
etc. I would also recommend incorporating organic matter however possible
(onsite mulching could potentially be a good source). Additionally, consider ripping
the pasture area in addition to roadbeds and construction-impact areas.

t. Are the sinuosity values, provided in Table 82 and the appendix tables, correct?
For example, Shard Branch Reach 1 in the appendix shows that minimum
sinuosity is 7.5 and the max is 0.47. Besides being listed backwards, these values
are quite extreme and therefore make it difficult to assess what a realistic average
for the reach would be. Note that other reaches have similar numbers, so this is
not limited to Shard Branch. If these values are correct, please provide more
context on what these numbers mean and/or how they were calculated.

3. Kathy Matthews, USFWS:

a. I recommend that a schematic of the proposed double row of silt fence be added
to the construction plans, to make those requirements clear to the contractor(s).
For example, the plans should indicate the maximum distance between each row
of silt fence (we recommend a maximum of 5 feet), and a minimum offset for the
silt fence outlets (we recommend a minimum of 20 feet between outlets where
possible). The construction plans and/or other contract specification documents
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should include a requirement to follow all of the enhanced sedimentation and
erosion control measures that we provided in our February 9, 2023 letter to Tasha
King. In recent months, we have realized that these conditions often do not get
passed on to the construction contractor, and compliance has been an issue.
Ensuring that the contract specifications and construction plans explicitly include
them as requirements will assist with compliance.

b. I also recommend that the Corps include implementation of these measures as a
condition of the permit:*
• Conduct work in Fisher Branch, Shard Branch, and Fox Branch in the dry,
as much as possible.
• Avoid aerial drift of herbicides or pesticides by utilizing only target
application, such as spot spraying, hack-and-squirt, basal bark injections,
cut stump, or foliar spray on individual plants.
• Utilize a double row of silt fence, to ensure that erosion is captured
effectively.
• Silt fence and other erosion control devises should not include outlets that
discharge closer than 50 feet to the top of Swift Creek.
• Silt fence outlets for each row of silt fence should be offset to provide
additional retention of water and sediment in the outer row.
• Conduct twice-weekly inspections of all erosion and sedimentation controls.
In addition to twice-weekly inspections, inspect also within 24-hours of rain
events (including a 1-inch total rain event or an event where rainfall rates
are 0.3 inch/hour or greater). Inspect all of the erosion and sedimentation
controls to ensure the integrity of the devices.
• Maintain all controls as necessary to ensure proper installation and function.
Repair and replace sections of controls as needed to minimize the potential
for failure.
• Revegetate with native species as soon as possible.
• Any spills of motor oil, hydraulic fluid, coolant, or similar fluids into the
riparian wetlands or floodplain must be reported to the Corps and Service
immediately.
• Educate the construction crew about the presence of sensitive species by
providing information or installing signs on the silt fence.

c. With the commitment to include the stringent erosion control measures from our
February 9, 2023 letter in the permit conditions and contract specifications, the
Service can concur with a species determination of Not Likely to Adversely Affect
for the Neuse River waterdog, Carolina madtom, yellow lance, Atlantic pigtoe, and
Tar River spinymussel.

* Please Note that we intend to include the above conditions in the Nationwide Permit
Verification for this project. Please contact us if you foresee any issues with being able
to comply with these conditions prior to submittal of the Final Plan/permit application.

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4. Erin Davis, USACE:

a. Please QAQC any errors noted in the Table of Contents.

b. Page 10, Section 3.5 –

a. Similar to the background given on Gideon Swamp in Section 4.2.1, it would
be helpful if you would provide a narrative that discusses the removal of the
Boy Scouts property from the proposed project since this change occurred
after the final prospectus was public noticed and the initial evaluation letter
was issued. In response to this modification request the IRT had identified
concerns that needed to be addressed in order to support the project
moving forward, please include this email correspondence from June 2022
in Appendix 4.

b. With the removal of the Boy Scouts property from the project, please
provide justification for having two crossings on Shard Branch.

i. In the final prospectus the easement boundary extended from the
property line at the top of Shard Branch down to Swift Creek, and
downstream easement break was oriented to provide access from
the Boy Scouts property to the Fisher property east of Shard Branch.
In the draft mitigation plan, this crossing has been repositioned to be
solely on the Fisher property and widened from a proposed 60-ft to
88-ft easement break. The IRT asked for this crossing to be made
internal to the easement, but the necessity for this second crossing
still needs to be explained.

ii. During the 2021 IRT site walk we discussed the possibility of
relocating the Shard Branch upstream crossing to the top of the
easement boundary. Why wasn’t it feasible to relocate this crossing?

c. It would be helpful to note in this section the utility right-of-way break in the
conservation easement area west of Gideon Swamp.

d. Page 16, Section 6.2 – Was distance from the project site a factor when selecting
reference sites? Given that the site is located at the edge of the Eastern Piedmont
physiographic province in the Eastern Slate Belt, please explain how Boyd Branch
is a suitable reference reach.

e. Page 20, Section 6 – What is the current use of Pond A? Is the pond remaining an
open water feature within the easement? If so, is there any intent for continued use
of the pond? Please confirm whether any allowable maintenance activities are
being proposed.

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f. Page 22, Section 6.7.1 – Was the coastal plain vegetative community selected
based on a local reference site? All of the stream reference sites are located in the
piedmont and mountain ecoregions.

g. Page 23, Section 6.7.2 – Inclusion of this section is appreciated. Based on the IRT
site walk the privet coverage is significant, is any supplemental planting proposed
in understory areas where the privet will be removed? Please consider lessons
learned from dealing with marsh dewflower on other Wildlands’ projects.

h. Page 14, Section 6.8 – While Section 4.3 notes that flood modeling is not expected
to be required for floodplain compliance, have you considered modeling to
evaluate the risk of hydrologic trespass if/when beavers dam project reaches after
site closeout? How susceptible could the open fields along easement boundaries
be to flooding if beaver dams raise water levels above what is calculated for
proposed Priority 1 restoration?

i. Pages 24-24, Section 7.0, Table 11

a. Based on the current conditions and level of functional uplift proposed for
Fox Branch Reach 2, we support a 4:1 enhancement ratio.

b. Based on the current conditions and the level of functional uplift proposed
for Fisher Branch Reach 2, we support a 4:1 enhancement ratio.

j. Page 27, Section 10, Table 16 – The total annual funding of $967.37 does not
match the sum of the annual monitoring costs listed in the table, please confirm.

k. Figures – Please include a figure showing all mitigation credit types on one map,
including all proposed stream and buffer/nutrient offset assets.

l. Figure 12 –

a. Several of the fixed veg plots do not appear to be located within designated
planting areas based on Sheets 4.2 – 4.9 (two on Fisher Branch, one on
Shard Branch Reach 2, and two on Fox Branch Reach 2), please confirm
and update as necessary. Please add a fixed veg plot to Fisher Branch
Reach 3.

b. The Appendix 10 BPDP Plan Figure 9 shows additional veg plots not shown
on Figure 12, please include these monitoring stations on Figure 12 and
provide associated data collection in the stream project annual monitoring
reports.

c. Please add fix photo points at all crossing locations.

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m. Sheets 1.1.1 & 1.1.2 – Is there any concentrated flow entering the easement
through the two wetland areas that also have top of bank features surveyed? If so,
is long-term stability a concern (head cutting, sediment source)? How will flow be
directed into the project stream (grading, tie-in)? Similar questions for the
drainages shown on Sheets 1.1.5 & 1.1.6 on Fisher Branch.

n. Sheet 1.2.5 – What is the use/purpose of the concrete pad? Is there any
concentrated runoff from the pad into the project? Is there an adequate setback
from the easement for maintenance or removal of the structure without disturbing
the project site?

o. Sheet 4.0 – Is it possible to replace the proposed 10% black willow canopy stems
with another native wetland subcanopy or shrub species?

p. Sheets 5.3, 5.6, 5.11 & 5.12 – In response to the removal of the Boy Scouts
property from the project, the IRT commented that Shard Branch and Fisher
Branch should be fenced to their confluences with Swift Creek to reduce risk of
further degradation of stream sections that would no longer be protected within the
project easement. Please show existing fence lines referred to in the plant callouts
to demonstrate that this concern has been addressed.

q. Appendix 7 is missing. Please make sure to use the updated bank instrument
template posted on RIBITS. When you submit the draft Instrument for review,
please be sure to send a pdf copy and a redline version that shows all the changes
made to the template.

r. While we did not reiterate all concerns noted by the IRT, we support their
comments included above.

Todd Tugwell
Chief, Mitigation Branch

Electronic Copies Furnished:

NCIRT Distribution List