DWQ Letterhead

Environmental
Quality
MEMORANDUM
To: Mr. Toiuiuy Register, P.E.
Froin:
Subject
ROY COOPER
Gorc<runr•
MICHAEL S. REGAN
Secrer�n�,�
S. JAY ZIMMERMAN
I����«,o��
Septeinber 30, 2017
Garcy Ward, Division of Water Resources, Washuigton Regional Office
Start of Study
NCDOT STIP R-5739
Wideniug of NC 46 from NC 48 to Virainia State Line, Northampton County, North Carolina
The Divisiou of Water Resources has reviewed the infonnation provicleci iti the� start of shldy letter for the above
mentioned project anci offeis the following comme�nts:
L Any impacts to waters or weflands covered under a USACE Nationwide or Regional General permit would
require a corresponding Water Qiiality General Certification from the Division of Water Resotirces.
2. Banies Creek falls within t1�e project area and is class C: NSW waters of t1�e State. The NCDWR is very
concerned with sediment and erosion impacts that could result from tliis project The NCDWR
recommends that highly protective sediment and erosiou coutrol BMPs be iuiplemented to reduce the risk
of nutrient runoff to these features. Additionally, to meet the requirements of NCDOT's NPDES peniut
NCS00002�0, the NCDWR requests that road design plans provide treatment of the storm water nmoff
through best management practices as detailed ui the most recent version of the Nor�h Carolina
Deparmrent o f Trai�spor�atioT� Stormwa�ei� Best Mrn�agenaen! Practices Toolbox manual.
3. Review of the project area reveals the presence of numerous u�uamed tribtltaries draining to the Roanoke
River/Roanoke Rapids Lake which is classified as Water Supply Critical Area. Given the potential for
iinpacts to these resources duri�g the project implementation, the NCDWR requests that NCDOT strictly
adhere to North Carolina regulations entitled Design Star�dnrds in Sensitive T�areTsheds (15A NCAC 04B
.0124) throu�hout design and construction of the project. This would apply for any area that drains to
streains havi�g WS CA (Water Supply Critical Area) classifications.
4. The NCDWR is very concerned with sediment and erosion impacts that could result from fliis project The
NCDOT shall address these concerns by describing the potential iinpacts that ivay occur to the aquatic
enviromnents and any initigatiug factors that would reduce flie nnpacts.
5. All work in or adjacent to stream waters shall be conducted in a dry work area. Approved BMP ineasures
from the most current version of tlie NCDOT Constiliction and Maintenance Activities �anual such as
sandbaas, rock bei7ns, cofferdains and othes dive�rsion struchues shall be used to preveilt e�xcavation in
flowing water.
6. Unless otherwise authorized, placement of culverts and other stnichlres in waters and streains shall be
place�d i�elow the elevation of the streambe�d by one foot far all culve�rts with a diameter greater thai148
inches, and 20 percent of the culvert diameter for culve�rts having a diameter less than 48 inches, to allow
low flow passage of water and aquatic life�. De�siQn and placement of culverts aild other struchires
including temporaiy e�rosioil control measures shall not be� conducte�d in a inam7er that inay result iu dis-
equilii�rium of wedands or streambeds ar banks, adjacent to or upstream and downstream of the above
stnzchues. The� applicant is required to provide e�vidence that the equilibrium is beina maintained if
requested in writing by the NCDWR. If this condition is unable to be met due to bedrock or other limiting
''""l�J�thoid�t� �n�a��re��;
State of North Caroliva I EvviroLuueutal Quality
1617 Mail Szrvice Center I Raleigh, Noith Carolin� 27699-1617

features encountered during construction, please contact the NCDWR for guidance on how to proceed and
to determine whether or not a permit modification will be required.
7. If multiple pipes or barrels are required, they sl�all be designed to mimic natural stream cross section as
closely as possible including pipes or barrels at flood plain elevation, floodplain benches, and/or sills may
be required where appropriate. Widening the stream cl�annel should be avoided. Stream cl�annel widening
at the inlet or outlet end of structures typically decreases water velocity causing sediment deposition that
requires increased maintenance and disrupts aquatic life passage.
8. In accordance with the Environmental Management Commission's Rules (15A NCAC 2H.0506[h]),
mitigation will be required for impacts of greater tl�an 1501inear feet to any perennial stream. In the event
tl�at mitigation is required, the mitigation plan shall be designed to replace appropriate lost functions and
values. The North Carolina Division of Mitigation Services may be available for assistance with stream
mitigation.
Thank you for requesting our input at this time. The NCDOT is reminded tl�at issuance of a 401 Water Quality
Certif'ication requires tl�at appropriate measures be instituted to ensure that water quality standards are met and
designated uses are not degraded or lost. If you l�ave any questions or require additional information, please
contact Garcy Ward at [phone] or garcy.ward�cdenr.gov.