20030179 Ver 6_Public Comments_20071105 (2)

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P~nergy®
Carolinas
October 25, 2007
VIA OVERNIGHT MAIL
Mr. Steve Tedder
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c/o John Dorney
North Carolina Division of Water Quality
401/Wetlands Unit
2321 Crabtree Blvd
Raleigh, NC 27604
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Subject: Dillsboro Hydroelectric Project (FERC Project No. 2602)
401 Water Quality Certification
Public Hearing Comments
Dear Mr. Tedder:
HYDRO LICENSING
Duke Energy Carolinas, LLC
EC12Y/526 South Church Street
Charlotte, NC 28202-1802
Mailing Address:
EC12Y/P.O. Box 1006
Charlotte, NC 28201-1006
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NOV 5 2007
DENR -WATER QUALITY
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Duke Energy Carolinas, LLC ("Duke") is the Federal Energy Regulatory Commission ("FERC")
licensee for the Dillsboro Hydroelectric Project ("Project") located in Jackson County, North
Carolina. In 2004, Duke submitted a License Surrender Application to the FERC for the
removal of the Project in accordance with the Nantahala Cooperative Stakeholder Team
Settlement Agreement and the Tuckasegee Cooperative Stakeholder Team Settlement
Agreement ("Agreements"). The Agreements were signed by 30 parties, including among
others, the United States Fish and Wildlife Service ("USFWS"), the North Carolina Wildlife
Resources Commission ("NCWRC"), and the North Carolina Department of Environment and
Natural Resources ("NCDENR"). The North Carolina Division of Water Quality ("NCDWQ")
issued a 401 water quality certification in conjunction with the License Surrender Application in
May, 2005 and the FERC issued its License Surrender Order requiring removal of the Project in
July, 2007.
Condition 6 of the 401 water quality certification issued by NCDWQ on May 15, 2005, requires
the submittal of a demolition and monitoring plan to NCDWQ. Enclosed please find a copy of
Duke's Water Quality Monitoring Plan that has been prepared in consultation with the USFWS,
NCWRC, and the NCDENR.
The License Surrender Application filed by Duke with the FERC outlined the process to be used
during the removal of the Project facilities including the dam and powerhouse. This process
involved the phased removal of the Project dam followed by a series of flushing flows to move
the accumulated sediment, which primarily consists of sand, within the reservoir downstream.
Only limited amounts of sediment removal in the powerhouse area were proposed. This

proposed process was evaluated by the USFWS in its Biological Opinion dated August 11, 2006
("Biological Opinion"). On page 34 of the Biological Opinion, the USFWS stated that:
Project demolition has the potential to result in sedimentation in the Tuckasegee
River. To minimize the potential for sedimentation, Duke Power has developed
specific erosion-control measures, including a detailed construction sequence,
phased drawdown, turbidity monitoring, and bank stabilization for this Project
that are designed to protect environmentally sensitive areas. Sediment inputs
from demolition activities should be of relatively short duration.
During subsequent planning activities, agency representatives from the USFWS, NCDENR, and
the NCVVRC encouraged Duke to explore the potential for a sand mining operation to remove the
accumulated sand deposits within the reservoir. However, the parties involved understood that a
large-scale sand removal operation was an enhancement to the removal effort rather than a
critical component of the removal plan. Duke agreed to pursue the option and ultimately
identified a sand mining operator potentially interested in removing the accumulated sand, so
long as a market for it exists. While the preliminary testing of the sand indicates that it is
marketable, Duke will not know if the sand mining operation is commercially viable until the
operation is fully permitted and active.
In anticipation of dam removal activities, Duke submitted a number of water quality certification
requests for activities associated with removal of the Project facilities. Duke requested 401
water quality certification in association with the US Army Corps of Engineers ("USAGE") 404
Nationwide permits. Duke also requested a discharge permit associated with the proposed sand
mining operation. At the advice of NCDWQ staff during an on-site meeting, Duke requested
that the requirements of the discharge permit associated with the return of water from the
proposed sand mining operation be incorporated into the terms and conditions for the 401 water
quality certifications.
Duke attended the public hearing hosted by NCDWQ regarding Duke's water quality requests
held on September 25, 2007, at Western Carolina University and offers the following
information in response to the comments provided during the hearing.
Duke does not believe that those speakers opposed to NCDWQ issuing the necessary approvals
for Duke to move forward with the removal of the Project identified any evidence that would
support their opinions. Many speakers addressed topics other than water quality, including
historic resources, whitewater recreation, aesthetics, financial mitigation, and other issues not
relevant to the 401 application at issue. These other issues have already been formally addressed
in detail during the FERC relicensing and license surrender processes.
Contrary to the statements of several speakers, the Dillsboro Dam is not an effective sediment
trap. Based on studies conducted during the relicensing effort, there are approximately 100,000
cubic yards of accumulated sediment within the reservoir. This represents one to two years of
the mean annual sediment yield from the watershed. Most of this sediment load is transported

during a few high-flow events. As the reservoir has reached equilibrium with respect to
accumulated sediments, sediments now flowing into the reservoir pass through the Project
reservoir and continue their movement downstream.
Several speakers also stated their belief that Duke should not be allowed to utilize the original
concept of flushing flows, but should instead be required to conduct the sand mining operation
regardless of the marketability of the sand. Duke does not agree with this position and has seen
no data supporting such a position. In point of fact, all of the objections that Duke has seen and
heard to the proposed flushing flows have been based on conjecture instead of any actual data.
The only data we have seen indicate that the use of flushing flows is appropriate. As discussed
above, the sediment currently within the reservoir is equivalent to the mean annual sediment
yield of no more than two years. In fact, the two-year frequency flood flow could move ail the
sediments within the reservoir downstream within just two days. Further, the accumulated
sediments consist primarily of sand that will move downstream as opposed to being deposited.
As was stated in the Sediment Transport Study and supported in the USFWS Biological Opinion,
while there maybe some short-term downstream deposition of sand, this should be temporary in
nature. Duke does not believe that any evidence has been provided that quantifies any long-term
negative environmental impacts of allowing the sand to move downstream with flushing flows as
originally proposed. Duke therefore does not agree that the sediment must be removed prior to
dam removal. Duke believes that if the sand mining operation is not approved or if the sand is
not marketable, Duke should be allowed to remove the dam as originally planned with the use of
flushing flows to move the sediment downstream.
Duke would also like to point out that, as far as we have been able to ascertain, sediment removal
has not been a requirement for any previous dam removal in the state of North Carolina. As
recently as 2005, the Carbonton Dam was removed without any dredging. The same applies to
the Lowell Mill Dam removed in 2005, the Quaker Neck Dam removed in 1998, and the Cherry
Hospital Dam removed in 1998. Given this precedence and the absence of any data supporting
the need for sediment removal at Dillsboro, Duke questions why it should be required to conduct
a sediment removal effort. However, as NCDWQ has indicated that a Sediment Management
Plan is necessary, Duke is enclosing such a plan.
One speaker questioned the validity of the Sediment Contamination Assessment prepared by the
USFWS. Based on the data presented within the report, we believe that the speaker's concerns
regarding sediment contamination at Dillsboro are unfounded.
One speaker expressed concern that Duke would remove a rock ledge lying under the Dillsboro
Dam during the demolition process. Duke has no knowledge that such a ledge exists and the
speaker did not provide any evidence of its existence. Regardless, Duke is not planning to
remove any naturally occurring rock ledges if in fact any are located under the Dillsboro Dam.
Several speakers also stated their belief that Duke would generate less hydropower (which they
termed as "green power") if it removed the Dillsboro Project. Since hydropower is without
question an existing use of the Little Tennessee River Basin and the NCDWQ must consider

protection of existing uses when it issues 401 water quality certifications, Duke is compelled to
respond. The Agreements incorporated the removal of the Dillsboro Dam as significant stream
restoration, which would effectively offset other aquatic habitat improvements that could
otherwise have been obtained by providing additional continuous flows in bypassed river reaches
associated with other Duke hydro projects in the area (namely the East Fork Hydro Project
(FERC Project No. 2698), the West Fork Hydro Project (FERC Project No. 2686), and the
Nantahala Hydro Project (FERC Project No. 2692)). By removing the Dillsboro Project and
restoring the affected portion of the Little Tennessee River, lower continuous flow requirements
in bypassed river reaches were allowed at the other Duke hydro projects, which reduced the
amount of water that bypassed the larger, much more efficient hydro stations. The result of
Dillsboro Dam removal is definitely greater protection for hydropower as an existing use of the
waters of the Little Tennessee River Basin.
Please do not hesitate to contact Mr. John Wishon at 828.369.4604 or Ms. Jen Huff at
980.373.4392 should you have further questions regarding these issues.
Sincerely:
~~
Jeffrey G. Lineberger, PE
Manager, Hydro Licensing
Enclosures: Water Quality Monitoring Plan
Sediment Management Plan
cc w/o enclosure: Lolleen Sullins, NC Division of Water Quality
John Wishon
Jen Huff
Garry Rice
Scott Fletcher, DTA