20181318 Ver 1_relocation_plan_9/28/2018 2:12 PM

UT to Long Creek
NC 274
TIP W-5601R
Gaston County

The North Carolina Department of Transportation (NCDOT) plans to construct TIP W-
5601R, improvements to NC 274 south of SR 1405 to north of SR 1443 in Gaston
County. To avoid and minimize impacts to jurisdict ional resources, NCDOT proposes
relocation of the unnamed tributary to Long Creek (UT) using natural stream design
outside the roadway fill.

EXISTING CONDITIONS

TIP W-5601R is located in Gaston County northwest of Bessemer City on NC 274,
Tryon Courthouse Road. The project begins just south of the bridge over Long Creek
and ends north of the Bessemer City limits. Land use is a mix of agriculture and forests
with few residential houses.

The UT to Long Creek generally flows northwest parallel to the existing alignment of NC
274 to its confluence with Long Creek near the beginning of the project. The drainage
area comprises approximately 0.3 square miles. The headwater of the UT is mainly
forested but the channel has been relocated to the edge of a cattle pasture close to the
confluence of Long Creek. Near Station 15+00, the UT abuts the toe of slope of the
existing road. In this section, the channel is 1.5 feet wide with 3 to 5 feet banks. Prior
access by the cattle and lack of woody vegetation has caused erosion along the banks of
the channel and caused degradation of instream habitat and water quality. Near the
confluence with Long Creek, woody vegetation lines the right bank of the channel and
both banks of Long Creek. The existing channel that will be restored is incised with no
floodplain access. The channel contains a buffer vegetated with grasses on the left bank
and the right bank is composed of grasses with sparse trees and shrubs that provide
limited shade. The stream channel appears stable, however no habitat was observed in or
around the channel. A NCSAM Functional Assessment was conducted on the UT to the
section of Long Creek where stream mitigation has been proposed on October 16, 2017.
The UT to Long Creek was categorized as a Size 1 Piedmont Stream. UT to Long Creek
received a score of Low in the three primary stream function categories of Hydrology,
Water Quality and Stream Habitat with an overall score of Low.

PROPOSED CONDITIONS

Construction of the road project requires relocatio n of approximately 150 feet of the
existing channel from approximately Station 14+00 to Station 16+00. The channel will be
constructed with a 1.5 foot base width and 2 foot depth at top of bank. An 8 foot bench
will be graded on both sides of the relocated channel allowing overbank flooding to
access the streamside areas. Following construction the banks and bench will be covered
with coir fiber matting and woody buffer of approximately 30 feet on the left bank and
10-30 feet on the right bank providing improved stability and stream side habitat. Based
on site conditions, a rock cross vane may be constructed at the end of this section to
improve channel stability and habitat. Re-establishment of a stream side buffer will also
provide an increase in stream shading and opportunities for in stream habitat over time in
the form of sticks and leaf packs. A projected NCSAM functional assessment was
conducted based on the expected uplift the proposed mitigation would provide. The
projected NCSAM assessment following construction would receive a high score in
Water Quality function category and a medium score in the two stream function
categories of Hydrology, and Stream Habitat with an overall score of Medium. In an
effort to make a consistent NCSAM evaluation, Metric 12 on Aquatic Life on both the
Pre-Construction and Post-Construction was evaluated as though no water was present in
the stream. The actual post-construction conditions would likely support a typical benthic
community and may result in a High overall score.

Downstream of Station 13+00, the bench on the left bank will be tapered to tie into the
confluence with Long Creek. No work will be done on the right bank through this
section.

Excavated areas will be ripped and disked prior to planting of the site if necessary. The
restoration areas will be planted with a mix of appropriate species as shown on the
reforestation sheet.

SUCCESS CRITERIA AND MONITORING

Success of the site will be determined based on stability of the channel along with
survival of the buffer vegetation. NCDOT shall monitor the mitigation site by visual
observation and photo points along the channel and within the planted buffer. NCDOT
shall monitor the site for a minimum of three years or until the site is deemed successful.
Monitoring will be initiated upon completion of the site planting. NCDOT will document
monitoring activities on the site in an annual report distributed to the regulatory agencies.