19970412 Ver 1_Staff Comments_20010306

o?O? W A r1R%
O "C
Michael F. Easley
Governor
William G. Ross, Jr., Secretary
Department of Environment and Natural Resources
Kerr T. Stevens, Director
Division of Water Quality
6 March, 2001
Mr. Charles Readling Dept. of EHN
Hubbard Health Care, LLC
206 Southgate Drive MAR 13 2001
PO Box 2210
Boone, North Carolina 28607
Salem;

Dear Mr. Readling,
This Office has reviewed the subject stream mitigation proposal. Please be reminded that mitigation credits will not be
given for the downstream section of this project (455 linear feet, off-site) since you are unable to obtain adequate buffers
and a conservation easement. Also, based on the information provided, and field observations the existing channel will
become unstable since the "restoration" was not designed properly. In addition we understand that this reach must be
restored by the landowner. Please describe how you plan to handle this shortfall in stream length. Also you need to
specify how many linear feet of on-site restoration you are hoping to get and how much mitigation will remain. The
proposed stream restoration design seems very similar to the conditions that currently exist in place. We have noted in
three previous correspondences (10 July 2000, 2 August 2000 and 16 November 2000) that this approach is
unacceptable, since it will result in an unstable channel. Again this most recent plan contains numerous vague
descriptions and/or confusing facts that make the review of this document difficult. Please keep in mind that even if the
approach did appear to be valid, insufficient and apparently inaccurate information was provided. Some of reasoning for
our decision is listed below.
? The location of the project and reference reaches illustrated in Appendix A is difficult to determine. Please
locate these stream reaches on a much smaller scale map. Also note that the reference reach needs to be of
similar stream order (reference 16 November letter) and must be stable. The reach used for reference
conditions appeared to be much larger than the subject stream. How long of a reference reach was used for
design and does it meet DWQ requirements for design? Due to this difference in stream size, dimensionless
ratios should be used for design.
? The entrenchment ratio noted in the Morphological Measurements Table suggests that the design is an A4
(not a B4a) and as such would be unstable.
? Data contained in the Morphological Measurements Table are confusing. For example the valley slope is
much less in this reiteration that in previous documents. Changes were also noted for drainage area, bankfull
mean velocity and depth, and others. Are these new calculations from the same reach? Please explain
these differences.
? The consultant's shear stress analyses resulted in 3.74 Ibs/ft3. This still appears to be excessive (reference 2
August 2000 letter). We believe that this stress will result in degradation of the channel. He suggests that the
channel will have the competence to move a D84 of 600mm (over 2 feet), and that a D100 of 2048mm (over 6
feet) would not move so that the channel would not degrade. Other than a small outcrop of bedrock, we do
not recall having observed any boulders of this size in the existing channel. These results suggest that his
proposed grade control is insufficient to maintain stability.
? We still have concerns about the size and permanent protection of the buffers (reference 10 July and 2
August 2000 letters).
? The planting plan as noted on P1 also appears to be vague.
? We recommend noting in the monitoring plan that all annual reports are sent to DWQ for review and
comment.
? Please address concerns regarding the culvert, specifically how will this structure be designed to allow for
passage of fish?
?A
NCDENR
North Carolina Division of Water Quality; Wetlands/401 Unit
1650 Mail Service Center; Raleigh, NC 27699-1650
2321 Crabtree Blvd., Raleigh, NC 27604-2260
Telephone: [phone]; Fax: [phone]
http://h2o.enr.state.nc.us/ncwetlands
Michael F. Easley
0?O? W A T ?9QG
\ Governor
r William G. Ross, Jr., Secretary
Department of Environment and Natural Resources
Kerr T. Stevens, Director
Division of Water Quality
In summary we feel that the design as submitted is not appropriate for a 134a channel. Instead the consultant needs to
redesign this project for an Al or 2; 131 or 2 channel type since those designs would result in a more stable channel for
this stream. In addition, the consultant needs to be aware of, and to incorporate, all comments regarding this project as
noted in the correspondences dated 10 July 2000, 2 August 2000 and 16 November 2000. Please call me at 919/733-
9646 if you have any questions.
Sincerely,
rhnDorney
Cc: Dave Penrose and Todd St. John, DWO Wetlands Unit
Jennifer Frye, Winston-Salem Regional Office
Sara Massey, Hubbard Health Care, LLC
Jeff Jurek, Wetlands Restoration Program
Mickey Henson, Appalachian Environmental Services
File Copy
NCDENR
North Carolina Division of Water Quality; Wetlands/401 Unit
1650 Mail Service Center; Raleigh, NC 27699-1650
2321 Crabtree Blvd., Raleigh, NC 27604-2260
Telephone: [phone]; Fax: [phone]
http://h2o.enr.state.nc.us/ncwetlands