HomeMy WebLinkAbout20140333 Ver 1_IRT Field Meeting-Holman_20140411IRT Field Meeting Notes — Holman Mill
April 11, 2014
Meeting Attendees
Todd Tugwell/USACE
Tyler Crumbley/USACE
David Bailey/USACE
Andy Williams/USACE
Keleigh Yelverton/USACE
Eric Kulz/NCDWR
Ginny Barker/NCDWR
Travis Wilson/NCWRC
Kristie Corson/NCEEP
Jeff Schaffer/ NCEEP
John Hutton/Wildlands
Jeff Keaton/Wildlands
Angela Allen/ Wildlands
John Hutton of Wildlands Engineering, Inc. (Wildlands) led the group on a tour of the proposed
mitigation site. The purpose of the tour was to present the site to a group of IRT members and to get
input into the management/mitigation options implemented at the site. During the tour, the group
openly discussed the condition of the stream channels on the site and the design options and crediting
scenarios they felt would be most appropriate to restore and enhance the channels.
UT1
The tour began with Reach UTI. John explained that Enhancement II (E2) was proposed for this reach
with short sections of restoration where appropriate (to be determined after a full survey and existing
conditions assessment). Fencing out of cattle is proposed as part of E2 activities. The upstream end of
this reach is a culvert under Holman Mill Road and the downstream end is the confluence with Pine Hill
Branch. The following suggestions were made by members of the group:
• John mentioned that bedrock on site holds grade along the reach and that native rock will be
used on site for structures. Todd recommended that if there was not enough bedrock found in
the survey that grade control should be added.
• Travis mentioned the merits of doing restoration to establish floodplain connection from the
upstream culvert approximately 200' downstream to the nick point. Todd concurred that this
was a good approach and was a large enough reach to be called out separately for crediting as
restoration.
• It was discussed whether UT 1 downstream of the nick point should get a single credit ratio
between E2 and restoration because of the combination of these two practices. It was agreed
upon by Jeff S., Todd, and John that if habitat was added, the stream bed was raised so that the
stream could access to the floodplain, and the sections needing bank grading were repaired that
the combined treatments would be beyond E2 activities and it would be preferable for
Wildlands to request Enhancement 1 (E1) rather than a lower ratio or combination of E2 and
restoration ratios.
• Travis mentioned that the pond would limit the sediment load to UT1. John said that material
harvested from other channels and elsewhere on-site would be used to "seed" the UTI
streambed.
• Todd mentioned making sure the 90° bend approximately mid -way down UT1 is addressed in
the plans by adjusting the pattern.
• Tyler and David noted several potential jurisdictional wetland areas and questioned whether a
Jurisdictional Determination was being performed. John said that a JD would be performed and
assured all impacts would be accounted for.
• There was a discussion on re -using the fescue that currently lines the banks as sod mat during
construction in those areas. Todd and Travis agreed that limited use of existing fescue sod for
bank treatments was an acceptable practice but cautioned that extensive use of fescue is
discouraged.
Pine Hill Branch
The tour moved from UT1 and walked north along Pine Hill Branch. John explained that preservation
with a ratio of 5:1 would be requested for this reach. John noted that most of the floodplain would be
included in the riparian buffer, which is to extend 75-100 ft on either side of the stream. The following
discussion and suggestions were brought forth by members of the group:
• It was asked if the conservation easement would extend to the adjacent property on the eastern
bank of Pine Hill Branch. John noted that the property line is not along the stream centerline,
but rather is located off the right top of bank some currently unknown distance; however there
is an option on the adjacent property should a portion of that land need to be included.
• Travis asked if there would be any landowner crossings. John responded that there would be no
crossings for the entire project.
• Tyler noted that bedrock seams were spaced throughout the reach and there were very few
areas of erosion.
• Eric noted that the reach appeared stable and there were areas of sand deposition on the
floodplain indicating connection to the floodplain.
• The quality of the reach was discussed further and Todd suggested that E2 should be requested
for the reach maintaining the ratio of 5:1 because the stream wasn't high enough quality for
preservation and E2 activities were being performed in some locations.
• Jeff Shaffer wanted to ensure that the wetland area near the confluence with UT2 is included in
the riparian buffer and conservation easement in the final plans.
UT2A
The group then walked along UT2A. John explained that restoration was proposed for this reach with a
short section of Priority II restoration to tie into UT2. He also pointed out the remnant channel feature
and noted that it would be utilized in the restoration pattern and that cattle would be fenced out of the
area. Todd agreed with this approach and noted that this section had gravel and cobble substrate with
better bed formation than some other reaches. It was agreed that this material would be salvaged and
re -used on the restored channel.
UT2
The group then walked along UT2 and John explained that restoration would be requested for this reach
from the confluence with Pine Hill Branch until the bedrock nick point observed by the group. He also
stated that E2 was requested upstream with cattle fencing and buffer planting throughout. The
following recommendations and discussion were made by the group:
• The group noted that a small portion of the channel (from the nick point to just upstream of the
confluence with UT2A) was incised and likely had been ditched on the edge of valley but was of
higher quality. and the group questioned whether E2 would be more appropriate for that
portion of channel than restoration. John noted that in order to achieve a Priority I restoration
for the degraded downstream section, it may be necessary to raise grade through the higher
quality section through a restoration or E1 approach. Wildlands will assess both possible design
scenarios following site survey and will proceed with enhancement in the higher quality section
if it allows for a Priority 1 approach downstream. .
• E2 was agreed upon as the approach above the nick point.
UT2B
The group finished the site tour by walking along UT2B. John explained that it was an intermittent
channel and no work would be done on it except for fencing out cattle and planting a riparian buffer.
Todd and other members of the group agreed on the approach.
Overall, Todd noted that it is a strong project with low risk and high water quality improvement
potential. Eric noted the good uplift potential for the site.