20180874 Ver 1_T&E Supplemental info for PCN Form_20180622

Supplemental Information
PCN Form — US 21 and Gilead Road Intersection Improvements — STIP U-5114
C. Project Information and Prior Project History
4. Project Description
4g. Describe the overall project in detail, including indirect impacts and the type of
equipment to be used:
The NCDOT, in cooperation with the Town of Huntersville, proposes to improve the intersection
of US 21 (Statesville Road) and SR 2136 (Gilead Road) in Huntersville, NC. This project would
include the construction of a dual lane, and signalized U-turns on US 21 both north and south of
Gilead Road. A service road would be constructed, using parts of existing Columbia Drive,
between Boulder Park Drive and Commerce Centre Drive, and Dallas Street would be realigned
to help mitigate for changes in access proposed on US 21 and Gilead Road. The project length is
approximately 0.9 mile on US 21 and 0.4 mile along Gilead Road.
A portion of the stream and associated wetland that are located south of Dallas Street, between US
21 and Hillcrest Drive will be impacted for the realignment of Dallas Street, and are the only
proposed impacts to waters of the U.S. (see Figure 4B in the attached Jurisdictional
Determination). The wetland will be impacted by the temporary hand clearing of vegetation (<0.01
acre), minor excavation (<0.01 acre) required to direct the stream flow into the headwall and pipe
culvert extension, and the riprap/fill (0.01 acre) required for the bank stabilization/flood bench that
will be constructed at the pipe culvert extension headwall to direct the stream flow into the pipe
culvert extension.
The proposed 48" diameter pipe culvert extension will impact approximately 189 linear feet (0.02
acre) of the stream. The pipe culvert extension will connect with the existing 36" diameter pipe
culvert located under US 21 (Statesville Road). The proposed 48" diameter pipe culvert extension
has a series of junctions with horizontal bends and vertical grade changes prior to discharging into
the 36" pipe culvert. In order to connect with the existing perched 36" diameter pipe culvert located
under US 21 and to avoid blockages within the 48" diameter pipe culvert extension, the 48"
diameter pipe culvert extension cannot be buried. The 48" diameter pipe culvert extension is larger
and steeper than the existing 36" diameter pipe culvert extension. This was designed to increase
the capacity of the pipe system to reduce flood potential to upstream residential structures. This
design has been created in cooperation with the NCDOT and has been approved by the NCDOT
for this project.
D. Proposed Impacts Inventory
3j. Comments
Recent guidance has been presented by the NCDWR in an e-mail from Alan Johnson on April 25,
2018. The DWR "questions asked" list is as follows:
1) How is the stream channel going to be brought back up to the original elevation entering
and discharging from the culvert? Provide the information, the schematics. Are there
sills? Is there grade controls to prevent future head cutting? Is there some backfilling
immediately up and down stream of the culverts?
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2) How is the base flow going to be maintained through an overwide culvert (designed to
handle large storm event)? Are there baffles? If not explain how aquatic passage is to be
maintained. Is the culvert to be backfilled? What type of soil/gravel/rock medium is
proposed?
3) Is the "mickey mouse" concept used to handle storm surge and base flow (goes back to
above comments)
4) Provide cross section and longitudinal profile of the culvert, proposed sills, proposed
baffles, constructed benches, etc... In construction details, remove the extraneous
information that is not of concern or pertinent to the review.
5) Riprap dissipaters proposed? How is it constructed to ensure that baseflow flows over
the riprap, rather than through the riprap.
6) Information legible???? 2 pt font isn't legible!
Responses:
1) The stream channel to be piped will be an extension of an existing 36" downstream pipe
that extends under US 21 and will maintain the elevation of the existing pipe. No changes
to the existing downstream pipe outlet are proposed. A flood bench will be placed at the
inlet to the pipe extension.
2) The upstream end of the existing 36" pipe culvert is at the invert of the existing stream and
is not buried. The outlet end of the 36" pipe west of US 21 had silt accumulated. The
proposed 48" pipe culvert extension has a series of junctions with horizontal bends and
vertical grade changes. Burying pipe systems that have multiple bends and grade changes
tend to cause blockages. The proposed 48" RCP extension acts as a funnel since it is
steeper than the existing pipe, increasing the capacity of the system and thereby mitigating
the risk in flood potential to upstream residential structures. Any decrease in capacity will
negate the intended result. There are no sills, baffles, or grade controls necessary. There
is no backfilling up or downstream of the pipe system.
3) No "mickey mouse" concept will be used, only one main culvert is needed to carry larger
storm events in this case.
4) The attached permit impact plans depict the cross section and longitudinal profile of the
pipe culvert including the proposed constructed flood bench.
5) Riprap is proposed only on the banks on the upstream side for the flood bench. There is
no riprap proposed at the end of this pipe as to not disturb the wetlands.
6) All of the information on the permit plans is legible on the printed plans and the .pdf file
of the permit plans can be enlarged for easy on-screen viewing.
E. Impact Justification and Mitigation
1. Avoidance and Minimization
la. Specifically describe measures taken to avoid or minimize the proposed impacts in
designing the project.
The realignment of Dallas Street is the only part of the intersection improvements project that will
require impacts to the jurisdictional waters within the project study area (Stream C, the U.T. to
Torrence Creek, and Wetland B; See Figure 4, 4A and 4B located in the attached Jurisdictional
Determination). As per the NCDOT "Policy on Street and Driveway Access to North Carolina
Highways" the relocation of driveways on US 21 and the realignment of Dallas Street is required
to meet distance safety standards due to the location of the proposed U-turn bulb. All of the other
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jurisdictional waters of the U.S. that are present within the project study area have been avoided
through design.
lb. Specifically describe measures taken to avoid or minimize the proposed impacts through
construction techniques.
NCDOT Best Management Practices for Construction and Maintenance Activities will be installed
and maintained during construction activities to allow for the least adverse effect on the project
study area streams and wetlands, and the associated water quality. The proposed sediment and
erosion control will include silt fencing and oi•ange construction fencing placed around the
construction areas that will prevent impacts to downslope streams and wetlands. A puinp around
operation for the piping of the stream will be put in place priar to conducting work to ensure that
all work is performed in dry conditions. Temporary impacts associated with the dewatering
operations will occur within the pernzanent impact area of the stream.
G. SupplementalInformation
5. Endangered Species and Critical Habitat
STV conducted a protected species habitat assessment on June 4 and June 9, 2014, and on
September 21, 2017. As of June ], 2017 tl�e United States Fish and Wildlife (USFWS) lists six
federally protected species, under the Endangered Species Act (ESA) for Meciclenburg County
(Table 1). For each species, a discussion of the presence or absence of habitat is included below
along with the Biological Conclusion rendered based on survey results in the study area.
Table 1. ESA federally protected species listed for Mecklenburg County.
Scientific Name Common Name Federal Habitat Biological
Status Present Conclusion
Bombus affinis Rusty-patched bumblebee E No NE*
Echinacea laevigata Smooth coneflower E Yes NE
Heliarithus schweiyaitzii Schweiilitz's sunflower E Yes NE
Lasmigona decorata Carolina heelsplitter E No NE
Myotis septentrionalis Northern long-eared bat T Yes MA-NLAA
Rhus michauxii Michaux's suinac E Yes NE
E - Endangered
T - Threatened
MA-NLAA - May Affect — Not Likely to Adversely Affect
NE - No Effect
*- Historic record (the species was last observed in the county more than 50 years ago)
Rusty-patched bumble bee
USFWS Optimal Survey Window: Early June — mid-August
Habitat Description: Rusty-patched bumble bees once occupied grasslands and tallgrass prairies
of the Upper Midwest and Northeast, but most grasslands and prairies have been lost,
degraded, or fragmented by conversion to other uses. Bumble bees need areas that provide
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nectar and pollen from flowers, nesting sites (underground and abandoned rodent cavities
or clumps of grasses), and overwintering sites for hibernating queens (undisturbed soil).
Biological conclusion: No Effect
Potential habitat does not exist within the project study area. There are historical records
of rusty-patched bumble bee being located in Mecklenburg County, but no records of rusty-
patched bumble bee in the Cornelius, NC USGS topographic quadrangle. The NCNHP
website was reviewed (March 15, 2018) to determine the locations of the nearest
populations of rusty-patched bumble bee. The NCNHP determined that no populations of
rusty-patched bumble bee were present within one mile of the project study area, and no
effect to rusty-patched bumble bee is anticipated.
Smooth Coneflower
USFWS Optimal Survey Window: late May-October
Habitat Description: Smooth coneflower, a perennial herb, is typically found in meadows, open
woodlands, the ecotonal regions between meadows and woodlands, cedar barrens, dry
limestone bluffs, clear cuts, and roadside and utility rights-of-way. In North Carolina, the
species normally grows in magnesium- and calcium-rich soils associated with gabbro and
diabase parent material, and typically occurs in Iredell, Misenheimer, and Picture soil
series. The plant grows best where there is abundant sunlight, little competition in the
herbaceous layer, and periodic disturbances (e.g., regular fire regime, well-timed mowing,
careful clearing) that prevents encroachment of shade-producing woody shrubs and trees.
On sites where woody succession is held in check, it is characterized by a number of species
with prairie affinities.
Biological Conclusion: No Effect
Suitable habitat for smooth coneflower is present in the project study area (PSA) within
the roadside rights-of-way. Surveys were conducted by STV biologists throughout areas of
suitable habitat on June 4 and June 9, 2014, and on September 21, 2017. No individuals of
smooth coneflower were observed and the field surveys were conducted during the
flowering season. A review of North Carolina Natural Heritage Program (NCNHP) records
on March 15, 2018, indicates no known occurrences within one mile of the PSA.
Schweinitz's sunflower
USFWS Optimal Survey Window: late August-October
Habitat Description: Schweinitz's sunflower, endemic to the Piedmont of North and South
Carolina. The few sites where this rhizomatous perennial herb occurs in relatively natural
vegetation are found in Xeric Hardpan Forests. The species is also found along roadside
rights-of-way, maintained power lines and other utility rights-of-way, edges of thickets and
old pastures, clearings and edges of upland oak-pine-hickory woods and Piedmont longleaf
pine forests, and other sunny or semi-sunny habitats where disturbances (e.g., mowing,
clearing, grazing, blow downs, storms, frequent fire) help create open or partially open
areas for sunlight. The plant is intolerant of full shade and excessive competition from other
vegetation. Schweinitz's sunflower occurs in a variety of soil series, including Badin,
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Cecil, Cid, Enon, Gaston, Georgeville, Iredell, Mecklenburg, Misenheimer, Secrest,
Tatum, Uwharrie, and Zion, among others. This perennial plant is generally found growing
on shallow sandy soils with high gravel content; shallow, poor, clayey hardpans; or shallow
rocky soils, especially those derived from mafic rocks.
Biological Conclusion: No Effect
Suitable habitat for Schweinitz's sunflower is present in the PSA along roadside shoulders.
Surveys were conducted by STV biologists throughout areas of suitable habitat on June 4
and June 9, 2014, and on September 21, 2017. No individuals of Schweinitz's sunflower
were observed and the September field survey was conducted during the flowering season.
A review of NCNHP records, updated March 15, 2018 indicates no known occurrences
within one mile of the PSA.
Carolina heelsplitter
USFWS Recommended Survey Window: year round
Habitat Description: The Carolina heelsplitter was historically known from several locations
within the Catawba and Pee Dee River systems in North Carolina and the Pee Dee and
Savannah River systems, and possibly the Saluda River system in South Carolina. In North
Carolina, the species is now known only from a handful of streams in the Pee Dee and
Catawba River systems. The species exists in very low abundances, usually within six feet
of shorelines, throughout its known range. The general habitat requirements for the
Carolina heelsplitter are shaded areas in large rivers to small streams, often burrowed into
clay banks between the root systems of trees, or in runs along steep banks with moderate
current. The more recent habitat where the Carolina heelsplitter has been found is in
sections of streams containing bedrock with perpendicular crevices filled with sand and
gravel, and with wide riparian buffers.
Biological Conclusion: No Effect
A mussel survey for the Carolina heelsplitter was conducted by NCDOT biologists on July
30, 2014. Suitable habitat for the Carolina heelsplitter is not present in the PSA and no
mussels were observed. A review of NCNHP records, updated March 15, 2018 indicates
no known occurrences within one mile of the PSA.
Northern long-eared bat
USFWS Recommended Survey Window: June 1— August 15
Habitat Description: In North Carolina, the Northern long-eared bat (NLEB) occurs in the
mountains, with scattered records in the Piedmont and coastal plain. In western North
Carolina, NLEB spend winter hibernating in caves and mines. During the summer, NLEB
roost singly or in colonies underneath bark, in cavities, or in crevices of both live and dead
trees (typically >3 inches dbh). Males and non-reproductive females may also roost in
cooler places, like caves and mines. This bat also been found, rarely, roosting in structures
like barns and sheds, under eaves of buildings, behind window shutters, in bridges, and in
bat houses. Foraging occurs on forested hillsides and ridges, and occasionally over forest
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clearings, over water, and along tree-lined corridors. Mature forests may be an important
habitat type for foraging.
Biological Conclusion: May Affect, Not Likely to Adversely Affect
Potential habitat exists within the wooded areas of the project study area. There are records
of NLEB being located in Mecklenburg County, but no records of NLEB being located in
the Cornelius, NC USGS topographic quadrangle. The NCNHP website was reviewed on
March 15, 2018 to determine the locations of the nearest populations of NLEB. The
NCNHP determined that no populations of NLEB were present within one mile of the
project study area. The USFWS record of occurrence for the NLEB is greater than 40 miles
from the PSA, so it is anticipated that the project may affect, not likely to adversely affect
NLEB. As per the recommendation of the USFWS, a tree cutting moratorium between May
15 and August 15 will be implemented as feasible to further reduce the probability of "take"
for this species.
Michaux's sumac
USFWS Optimal Survey Window: May-October
Habitat Description: Michaux's sumac, endemic to the inner Coastal Plain and lower Piedmont,
grows in sandy or rocky, open, upland woods on acidic or circumneutral, well-drained
sands or sandy loam soils with low cation exchange capacities. The species is also found
on sandy or submesic loamy swales and depressions in the fall line Sandhills region as well
as in openings along the rim of Carolina bays; maintained railroad, roadside, power line,
and utility rights-of-way; areas where forest canopies have been opened up by blowdowns
and/or storm damage; small wildlife food plots; abandoned building sites; under sparse to
moderately dense pine or pine/hardwood canopies; and in and along edges of other
artificially maintained clearings undergoing natural succession. In the central Piedmont, it
occurs on clayey soils derived from mafic rocks. The plant is shade intolerant and,
therefore, grows best where disturbance (e.g., mowing, clearing, grazing, periodic fire)
maintains its open habitat.
Biological Conclusion: No Effect
Suitable habitat for Michaux's sumac is present in the PSA along roadside shoulders.
Surveys were conducted by STV biologists throughout areas of suitable habitat on June 4
and June 9, 2014, and on September 21, 2017. No individuals of Michaux's sumac were
observed and the field reviews were conducted during the survey window. A review of
NCNHP records updated March 15, 2018 indicates no known occurrences within one mile
of the PSA.
US 21 and Gilead Road Intersection Improvements — STIP U-5114