20091169 Ver 1_Mitigation Bank Proposal Review_20091110

NCDENR
North Carolina Department of Environment and Natural Resources
Division of Water Quality
Beverly Eaves Perdue Coleen H. Sullins
Governor Director
November 10, 2009
Mr. Andrew Williams
U.S. Army Corps of Engineers
Raleigh Regulatory Field Office
3331 Heritage Trade Drive, Suite 105
Wake Forest, NC 27587
Re: Little Troublesome Creek Stream Mitigation Bank
October 2009 Draft Prospectus J.
Rockingham County
DWQ #09-1169
Dear Mr. Williams:
Dee Freeman
Secretary
The Division of Water Quality (DWQ). 401 Oversight and Express Review Permitting Unit has
reviewed the Draft Prospectus for the above-referenced site.
DWQ visited the site on March 12, 2009. Both Irwin Creek and Little Troublesome Creek are
quite unstable, and are incised with actively eroding banks. However, the site is completely
forested with relatively mature trees (with the exception of the utility easements). It is DWQ's
experience that many stream restoration projects typically involve completely clearing a wide
(e.g. 100-foot) swath through the woods in order to construct the new channel and grade the
floodplains. Once the new channel is constructed, bare-root seedlings are typically planted. A
loss of nutrient removal function occurs, at least until the site achieves sufficient vegetative
growth to remove nutrients. We also note that especially in Piedmont sites, bare-root seedlings
have some difficulty surviving and thriving in the disturbed clay soils which are now fully
exposed to the sun.
We have approved a number of projects in which small pieces of equipment were used, and the
restoration was conducted while retaining many of the riparian zone trees, especially the larger
specimens of desirable species. This method of restoration is certainly more expensive and the
work takes longer, but the result is a higher-quality restoration in which riparian zone functions
(nutrient removal, shading, organic matter input) recover more quickly. During the site visit, we
did discuss the concept of locating the new channel in areas with less trees, and several potential
1650 Mail Service Center, Raleigh, North Carolina 27699-1650 ,
Location: 2321 Crabtree Blvd., Suite 250, Raleigh, North Carolina 27604-2260 One
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Mr. Williams
Little Troublesome Creek Stream Mitigation Bank
Draft Prospectus
Page 2 of 2
corridors were observed through which a new channel could be constructed with fairly minimal
large tree removal.
DWQ recommends that full consideration of the methodology described above be used to
develop the restoration plan, and some clear, measureable means of assessing uplift in aquatic
fimction should be presented, in order for us to support full-blown restoration of streams within
mature wooded corridors.
Based on the information provided in the Draft Prospectus, the site may be a good candidate for
a mitigation site, as long as the concerns listed above are addressed. However, DWQ reserves
the right to provide additional comments based on review of more detailed design plans.
Please feel free to contact Eric Kulz at [phone] if you have any questions regarding this
project or our comments.
Sincerely,
e?G
Cyndi B. Karoly, Program Manager
401 Oversight and Express Review Program
cc: File Copy (Eric Kulz)
Sue Homewood - DWQ WSRO
1650 Mail Service Center, Raleigh, North Carolina 27699-1650
Location: 2321 Crabtree Blvd,, Suite 250, Raleigh, North Carolina 27604-2260 One
Phone: [phone] FAX: [phone] Customer Service: 1-877-623-6748 NOrthCarofina
Internet: rtunity \ a usln l Natu"a?iff
An Equal Opportunity 1 Affirmative tive Action Employer oyer