20170175 Ver 1_Modifications_20170613

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W"iVI 1 -GTON
NORTH CAROLINA
Ms. Karen Higgins, Supervisor
401 and Buffer Permitting Branch
NC Division of Water Resources
Department of Environmental Quality
1617 Mail Service Center
Raleigh, NC 27699-1617
DATE: lune 7, 2017
Public Services
Administration
209 Coleman Drive
PC Box 1810
Wilmington, NC 28402-1810
3 910 343-4777
910 341-0099 fax
wilmingtonnc.gov
Dial 711 TTY/Voice
RE: Requested clarifications to the 401 Water Quality Certification (#4114; DWR# 17-0175) for
Clear Run Stream and Floodplain Restoration, City of Wilmington
Dear Ms. Higgins;
Thank you for the 401 Water Quality Certification issued on April 24, 2017 to the City of
Wilmington for our proposed work to restore the stream and floodplain of Clear Run Branch in
Wilmington. After careful review of the Certification and its conditions, we request clarification
of the following conditions preferably as an amended Certification. We do not object to these
conditions but request the following clarifications in order to make certain that the City of
Wilmington understands clearly understands what the Division expects from the City for this
project.
Condition 2: Compensatory Mitigation
Original language: Visual monitoring of the restoration/ enhancement project shall be
conducted at a minimum of quarterly for the first year or two bankfull events (whichever is
longer), and then annually until the site is stable (particularly after storm events) and vegetation
is successful per the monitoring plan provided in the application. Any failures of structures,
stream banks, or vegetation may require future repairs or replacement, which requires
coordination with the Wilmington Regional Office to ensure the stability and water quality of
the stream and downstream waters. Annual reports of vegetation and stream stability
monitoring and adaptive management activities shall be submitted to the Division on or before
June 1St of each year [ 15A NCAC 02H. 0505(b)(2)j.
Suggested language: There does not appear to be an end date for the monitoring of the
reconstructed channel. We suggest that DWR specify a five year time limit which has been
typical for other stream mitigation projects in the Wilmington area such as Doctor's Branch
Stream Restoration Project. We concur with the rest of the condition but request this
clarification.

Original language: All work in or adjacent to stream waters shall be conducted so that
the flowing stream does not come in contact with the disturbed area. Approved best
management practices from the most current version of the NC Sediment and Erosion Control
Manual, or the NC DOT Construction and Maintenance Activities Manual, such as sandbags,
rock berms, cofferdams, and other diversion structures shall be used to minimize excavation in
flowing water. (15A NCAC 02H. 0506(b)(3) and (c)(3)j.
Suggested language: Please consider adding the following clarification. A pump -around
process shall be used whereby the flow in the channel is pumped around the section of the
stream being reconstructed. The pump around process will work sequentially up or down the
stream channel. The pump -around process on any particular segment can end when the
channel and adjacent floodplain have been cleared, graded, construction completed, and
stabilization measures installed.
Condition 9: Placement of Culverts and Other Structures in Waters and Wetlands [ 15A NCAC
02H 0506( b)( 2) and ( c)( 2))
Original language: Culverts required for this project shall be installed in such a manner
that the original stream profiles are not altered and to allow for aquatic life movement during
low flows. Existing stream dimensions (including the cross section dimensions, pattern and
longitudinal profile) must be maintained above and below locations of each culvert.
Placement of culverts and other structures in waters, streams must be below the elevation of
the streambed by one (1) foot for all culverts with a diameter greater than 48 inches, and 20
percent of the culvert diameter for culverts having a diameter less than 48 inches, to allow low
flow passage of water and aquatic life.
Suggested language: The above language depicts what is planned at the Mallard Drive
crossing with the additional clarification that there will be slight regrading of the otherwise
undisturbed channel above and below the road crossing in order to transition the channel into
and out of the culvert.
The channel above and below the College Acres Drive crossing is proposed to be placed in a
concrete storm sewer and there will no longer be an open channel above College Acres Drive.
Therefore, we believe Condition 9 does not apply to this area since it is not solely a road
crossing and no open channels will remain for aquatic life to colonize. In order to clarify this, we
suggest that the 401 Certification be rewritten as follows:
We suggest the addition of a clause to clarify that this condition only applies to the Mallard
Drive crossing. That condition should also note that there will be a slight regrading of the
otherwise undisturbed channel above and below the Mallard Drive road crossing in order to
transition the channel into and out of the culvert.

Thank you for consideration of our request. if you have additional questions, please contact
either myself at9lO.S4I.S88OorJason Doll orJohn Dorney atMoffatt & Nichol at9l9-782-
462G.
Cr: Jason Doll via email
John Dorney via email