20091242 Ver 1_More Info Received_20091214

Ph Duke
Energy®
December 10, 2009
Ms. Shari Bryant
North Carolina Wildlife Resources Commission
Habitat Conservation Program
1721 Mail Service Center
Raleigh NC 27699-1721
Subject: Response to NCWRC Request for Additional Information
Belews Creek Steam Station (BOSS) - Stokes County
Permanent Pumping System Pre-Construction Notification
Corps Action ID: SAW-2009-0181
DUKE ENERGY CORPORATION
526 South Church Street
Charlotte, NC 28202
Mailing Address:
P 0 Box 1006
Charlotte, NC 28201-1006
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DENR - WATER QUAUTY
WETLANDS AND S T 3RMWATER BRANCH
As a follow-up to your letter dated December 1, 2009, enclosed is additional information
requested to complete your review of the proposed plans for construction and operation of the
permanent pumping facility needed to maintain adequate water levels in Belews Lake to ensure
uninterrupted power production by Belews Creek Steam Station. Should you have additional
questions or wish to meet to coordinate agency reviews, please call me at [phone].
Sincerely,
Ronald E. Lewis
Water Management
Enclosures
cc w/ enclosures: Ms. Cindy Karoly, NCDENR Division of Water Quality,
1650 Mail Service Center, Raleigh NC 27699-1650
Mr. Andy Williams, US Army Corps of Engineers
Raleigh Regulatory Field Office, 331 Heritage Trade Drive,
Wake Forest, NC 27587
Mr. Gill Vinzani, NCDENR Division of Water Quality
1617 Mail Service Center, Raleigh, NC 27699-1617
www.duke-energy.com
NCWRC Additional Information
I.A. Alternative Intake Locations (Comments p. 2, para. 1, bullet 1)
Belews Lake is located near the most southern reach of the Dan River. The Dan River
flows from western Virginia southeast into North Carolina and then turns northeast near
Belews Lake and travels northeast back into Virginia. Please reference the attached
USGS map. Only 6.5 river miles of the Dan River is sufficiently close to Belews Lake
for consideration in locating a raw water intake and transfer pumping station. This
stretch of river was evaluated for the location of an intake.
Locations on the north bank of the Dan River were not considered for an intake because
of the necessity of crossing the river with a force main to transfer water to Belews Lake.
The selected location on the south side of the river is located at the confluence of Belews
Creek and the Dan River. Duke Energy owns the land upstream from this location to the
Pine Hall Bridge where the new USGS gage station is located (about 1.5 river miles). A
golf course occupies the land adjacent to the next mile of river upstream from the bridge.
From the golf course, the upstream reach is partly crowded by steep hillsides. The few
small areas that are relatively flat are occupied by train tracks, forests, and/or farmland.
Additionally, the river upstream of the Pine Hall Bridge does not offer more favorable
hydraulic conditions for an intake than the downstream portion, which is bordered by
land already owned by Duke Energy.
The land downstream of the confluence of Belews Creek and the Dan River is owned by
Duke Energy for approximately 1/4 river miles. However, this land is characterized by
steep slopes and is heavily forested. Beyond this, the land adjacent to the river is
crowded by steep hillsides or is occupied by forests or farmland.
Therefore, the land already owned by Duke Energy and bounded by the river, State Route
1138, Pine Hall Road, Belews Creek is the most suitable location for anew intake. This
location offers a very direct routing of the forcemains to Belews Lake across land that has
already been disturbed by agricultural activities or recent logging. Further, the presence
of the confluence of Belews Creek offers a location where one of the proposed velocity
caps (Velocity Cap #2) can be located out of the main Dan River channel and at the same
time allow for Velocity Cap #1, which is to be located in the Dan River channel, to be
downsized to further minimize impact. Both of the proposed velocity caps proposed for
this location are to be located out of the deeper main channel that is oriented along the
opposite bank from these intakes. This will serve to prevent obstruction to recreational
users while occupying areas of lower habitat value.
1.13. Canal and impoundment and/or J-hook (Comments p. 2, para. 1, bullet 2)
A canal and intake pond in this area would not be feasible for the reasons stated in the
Project Summary Memorandum (PSM) Section 4.3.3. Additionally, the Dan River
frequently floods overtopping its banks (elevation -578 feet msl). These flood events
deposit significant silt and soil in the floodplain which reaches south to the elevated
roadway of State Route 1138. This silt and soil deposition creates prime agricultural
land, but it would result in severe maintenance requirements to remove the sediment load
from a canal and intake pond. Silt and soil would naturally drop out and fill in a deep,
quiescent canal and pond.
A J-hook vane structure is not well suited to the river conditions available in the
aforementioned stretch of the Dan River. According to a paper by Dr. David L. Rosgen
of Wildland Hydrology, the J-hook vane requires a footer that is embedded in the
streambed and therefore, they are used in bed material ranging from cobble and gravel to
sand bed streams. As mentioned in the PSM, the Dan River's streambed in this section of
river consists primarily of weathered bedrock with good integrity. Disturbance to the
river channel in constructing a J-hook would be extensive as compared to the proposed
velocity caps. The J-hook would also have to be constructed to produce a large hydraulic
jump through the hook in order to provide the hydraulic grade differential necessary to
keep flow velocities adequate in a diversion canal that would prevent extensive soil
deposition from occurring during normal operations. This large hydraulic jump would
also have the potential to serve as an obstacle to recreational users as well as resulting in
destabilization of the opposite river bank that consist of highly erodible soils that overlay
the river bottom bedrock.
Geotechnical boring indicate that bedrock rises in a direction perpendicular from the
stream bed and is 8-10 feet above the river channel bottom as little as 50 feet from the
edge of the river. This rock creates a significant challenge for any type of construction
outside the river channel. This is particularly the case when considering the construction
of a diversion canal/channel and pond whose bottom would then have to be constructed
below the bottom of the existing river channel and as much as 15-20 feet into this rock.
The cost of this type of construction in combination with the construction of a J-hook will
greatly exceed the cost of the proposed intake arrangement.
I.C. Fish Protection, Handling, and Survivability (Comments p. 2, para. 1, bullet 3)
Fish screens are currently being evaluated for this intake pump station. Duke has
committed to selection of a screen with fish recovery and proven survivability
capabilities. In final selection of a screen, Duke is establishing performance criteria that
is equivalent or exceeds that offered by the already proven Ristroph bucket type fish
recovery system.
Velocity cap intakes in combination with a Ristroph traveling water screen provide an
integrated approach utilizing two highly efficient systems for excluding fish and aquatic
life from the pump bays both of which are EPA 316(b) approved. A velocity cap intake
is highly efficient at preventing capture of fish. According to Section 316(b) TDD
Chapter 5, "Efficiencies of velocity caps on West Coast offshore intakes have exceeded
90 percent."
The following two case studies concerning the Ristroph type traveling water screens are
excerpted from EPA's Section 316(b) TDD Chapter 5:
Impingement data collected during the 1970s from Dominion Power's Surry
Station indicated a 93.8 percent survival rate of all fish impinged. The facility has
modified Ristroph screens with low pressure wash and fish return systems (EPRI
1999).
At the Arthur Kill Station, 2 of 8 screens are modified Ristroph type; the
remaining six screens are conventional type. The modified screens have fish
collection troughs, low pressure spray washes, fish flap seals, and separate fish
collection sluices. 24-hour survival for the unmodified screens averages 15
percent, while the two modified screens have 79 and 92 percent average survival
rates (EPRI 1999).
The Traveling Water Screen Fish Protection System is designed to remove fish and
fingerlings which are unable to escape from in front of the screen, safely transport and
return them to the source water downstream of the intake.
OPERATION
Fish and debris removal functions of the traveling water screen will be separate with
dedicated spray headers and troughing for each. The spray will first wash fish from the
descending chain {rear} side of the screen, then the debris is removed from the
descending chain {rear} side of the screen.
The fish shall be lifted to the operating floor level in a watertight fish tray on the bottom
member of each screen tray. The fish will be washed off the tray by a low pressure
intermittent spray which shall gently flush the fish from the tray into a trough and sluiced
to the source water.
Fish Trays
The trays are watertight and maintain a minimum water depth while transporting the fish.
The contour of the pan shall facilitate complete flushing of its contents with a low
pressure spray. A fish bucket is an integral part of the lower tray member of each tray and
spans the entire width of the tray.
Fish Spray Piping
The fish spray headers shall be located above the fish trough on the descending chain
(rear) side of the screen. The fish spray will flush the fish from the trays and buckets
with a low pressure spray and not the debris deposited on the cloth. Operating pressure
for the fish spray header will be 15 PSI maximum.
Fish Protection Screen Baskets
Baskets shall be non-metallic construction. The basket shall be designed to maximize the
screening area available and the bottom rail fish buckets shall be designed to enhance fish
recovery and provide a protected area for the impinged fish. The fish bucket shall have
sufficient capacity to provide a suitable environment while fish are retained in the bucket
and the opening shall be sized to encourage fish to enter and to minimize damage when
emptying. The exact configuration of the bucket shall be either of a "proven design" or
determined by model/flume testing or computer analysis to ensure a hydraulically stable,
"stalled" fluid zone which attracts the fish, prevents damage to the fish while in the
bucket and prevents the fish from escaping the bucket.
The screen mesh shall be especially designed and manufactured to minimize harm and
abrasion to the impinged fish. The screen mesh shall be canted to facilitate entry of fish
into the fish bucket and the discharge of fish with minimal harm.
The fish return trough will be about 300 feet long. These return troughs are very
common and are frequently much longer than the one proposed.
1.D. Velocity Cap Position and Visibility (Comments p. 2, para. 1, bullet 4)
The velocity caps will be designed to be submerged even under historically low-flow
conditions and positioned out of the main channel. The weathered bedrock streambed
naturally diverts flow in the main channel towards the opposite bank as Sheet 1 in
Appendix A-7 of the PSM shows. Recreational users traveling this reach of water are not
expected to venture to or be directed by the natural channel flows toward the vicinity of
either velocity cap. Additionally due to the geometry and static nature of the velocity
caps, in addition to the relatively low velocities that will be present around the velocity
caps during periods when the river is being recreated, we do not believe the velocity caps
will pose a significant danger or obstruction. The preference at this time is not to have
signage or buoys indicating the presence of the velocity cap intakes.
2.A. Months of Operation (Comments p. 2, para. 2, bullet 1)
The permanent pumping operation would not pump during the April-May fish spawning
period. Pumping could occur during other months on an as needed basis when, and only
when, sufficient river flows allow for pumping.
2.13. River Flow and Pumping (Comments p. 2, para. 2, bullet 2)
That is correct. In keeping with the temporary pumping permit conditions, a minimum
flow-by of 110 cfs shall be maintained at all time during pumping operations as measured
by the new USGS gage at Pine Hall. Readings from the gage station are transmitted
every 15 minutes and the pump controls will be dependent on the gage station data. You
may view data from this gage on the USGS website.
River Flow (cfs) # Pumps On Water Pumped (cfs) Flow-By (cfs)
<110 0 0 <110
135 1 25 110
160 2 50 110
195 3 75 110
>210 4 100 >110
2.C. Summer Operation (Comments p. 2, para. 2, bullet 3)
Pumping during the summer months will be only on an as-needed basis. Figure 2.2-1 in
the PSM shows the lake level in Belews Lake for the past nine years. In some years, the
lake level dropped enough by August to October to initiate pumping. Pumping during
the summer mouths would not reduce rhQ river flow below the 110 cfs criteria. Figure
22-1 also shows events in the summer and fall months when the lake level rises as a
result of rain and runoff. Dan River flows during these rain events would allow the pump
station to operate at full capacity without affecting minimum flow-by.
3.A. Lake Level Trigger (Comments p. 3, para. 1, bullet 1)
A lake level of 722.5 feet would trigger the onset of pumping operations. Duke will
consider weather forecasts, time of year, and other conditions in making their
determination of whether or not to begin pumping. Duke Energy's goal is to achieve a
full pond condition during the higher winter and early spring river flow periods before the
spring spawning months of April and May.
3.13. Raising the Lake Level (Comments p. 3, para. 1, bullet 2)
Full pond in Belews Lake is 724.5 feet. The lake will overtop its gates at 725.0 feet. The
'/z foot of freeboard allows for containment of wave action within the lake. Raising the
lake level is not feasible due to environmental, civic, and cost considerations.
® North Carolina Wildlife Resources Commission
Gordon Myers, Executive Director
MEMORANDUM
TO: Andrew Williams, Raleigh Regulatory Field Office
U.S. Army Corps of Engineers
FROM: Shari L. Bryant, Piedmont Region Coordinator
Habitat Conservation Program
DATE: 1 December 2009
SUBJECT: Pre-Construction Notification for Belews Creek Permanent Pumping Station, Duke Power
Company, Rockingham County, North Carolina. Corps Action ID: SAW-2009-01801
Biologists with the North Carolina Wildlife Resources Commission (NCWRC) have reviewed the
subject document and we are familiar with the habitat values of the area. Our comments are provided in
accordance with provisions of the Clean Water Act of 1977 (as amended), Fish and Wildlife Coordination
Act (48 Stat. 401, as amended; 16 U.S.C. 661-667d), and North Carolina General Statutes (G.S. 113-131 et
seq.).
The applicant proposes to construct a permanent intake and pump station on Dan River. The
proposed project will result in permanent impacts to 0.045 acres of wetland, 25 linear feet of perennial
stream channel, and 0.082 acres of open water; and temporary impacts to 905 linear feet of perennial stream
channel, and 0.261 acres of open water. Since 2002, the applicant has received authorization to operate a
temporary intake structure to pump water from Dan River to Belews Lake. In the past 8 years, temporary
pumping was used on three occasions when Belews Lake was more than three feet below full pond. The
permanent intake and pump station would be used on an "as needed" basis to ensure adequate water levels in
Belews Lake to operate Belews Creek Steam Station.
Belews Creek is a tributary to Dan River in the Roanoke River basin. There are records for the
federal species of concern and state endangered green floater (Lasmigona subvirdis); the state threatened
bigeye jumprock (Scartomyzon ariommus); the state special concern riverweed darter (Etheostoma
podostemone) and North Carolina spiny crayfish (Orconectes [Procericambarus] carolinensis); and the state
significantly rare Roanoke hogsucker (Hypentelium roanokense) in Dan River. The site is located within the
Dan River Aquatic Habitat, a Significant Natural Heritage Area.
The applicant evaluated several alternatives including a wedgewire T-screen with air burst, side
channel diversion flume, canal and intake pond, and velocity cap. The preferred alternative is installation of
two, 50 cfs velocity caps. These would be located in the main channel, elevated one foot off of the channel
bottom, with an approach velocity below 0.5 feet/second at the outer perimeter of the cap. The pump station
would have 2 mm fine screening, a 0.5 feet/second approach velocity, and an integrated fish recovery
Mailing Address: Division of Inland Fisheries • 1721 Mail Service Center • Raleigh, NC 27699-1721
Telephone: [phone] • Fax: [phone]
Page 2
I December 2009
Belews Creek Pumping Station
Corps Action ID: SAW-2009-01801
system. Fish would be lifted to the top of the pump station and discharged back to Dan River through a
submerged fish chute.
We recognize a canal and intake pond may not be feasible at the proposed location discussed for the
velocity caps; however, it is unclear whether other sites nearby were evaluated for a canal and intake pond.
We believe a canal and intake pond may be a better alternative to the velocity caps, but there is insufficient
information included in the permit application to make that determination. Therefore, we have the following
questions and/or requests for additional information regarding the alternative analysis:
• Were other locations along Dan River evaluated for construction of a canal and intake pond?
o If so, please include a description of these locations and reason(s) this alternative (i.e., canal
and intake pond) would or would not be feasible at these locations.
o If not, then we request that other locations along the Dan River are evaluated to determine if
this alternative might be feasible.
• The applicant indicates the canal and impoundment will be prone to damage from floodwaters, and
sediment removal from canal and impoundment would be more labor and equipment intensive. It is
our understanding that if properly designed these should not be significant issues. If the applicant
has not already done so, we suggest consulting with a professional that has significant experience in
the construction of J-hooks. If the applicant has consulted with an expert in this field, we would
appreciate that information being included with the evaluation of this altemative.
The velocity caps would not have in-channel fine screening. The pump station would have a fish
recovery system that includes 2 mm traveling water screens; fish would be lifted to the top of the
pump station, and discharged back to Dan River. Due to the presence of several state-listed fish
species and possibly fish host species for the federal and state endangered James spinymussel
(Pleurobema collina), please provide the following information regarding the fish recovery system.
o How will fish be raised to the top of the pump station?
o How long is the submerged fish chute between the pump station and river?
o Has this system been used before by either Duke Energy or others? If so, are there data on
how many fish get entrained in the pump station? If fish are entrained, are there data on
what species or life stages are entrained, and the survival rates of released fish?
• The applicant indicates the velocity caps would be positioned out of the main channel; please
provide information on how these will be marked to notify recreational users of their location?
It appears when temporary pumping was initiated the time frame was December to March. Section
6.1 (p. 18) indicates water would not be withdrawn during low flow periods in the summer. Appendix A-4
(p. 5) indicates the pump station would allow pumping whenever there is sufficient flow in the river. Based
on information provided in the document, it appears that sufficient flow would be that flow that exceeds 110
cfs. Also, Section 4.2 indicates the structure would be designed to pump at different pumping rates (i.e., 25-
100 cfs). We have the following questions and/or requests for additional information regarding the
permanent pump station.
o During which months would the proposed permanent pump station be operated? We would
have concerns about impingement/entrainment of fish, but particularly fish eggs and/or
larvae, for any proposal to pump during spring spawning months.
o If the pumps cannot pump below 25 cfs, then we assume pumping would not be initiated
unless the Dan River flow is a minimum of 135 cfs. Is this correct?
Page 3
1 December 2009
Belews Creek Pumping Station
Corps Action ID: SAW-2009-01801
o It is unclear whether pumping would occur in the summer months, but if so, then we may
have concerns about the pumping operation maintaining consistently low flows (e.g., 110
cfs) in the river for extended periods of time during the summer months.
Section 2.3 (p.3) indicates the temporary pumping operations were initiated when lake level drops
more than three feet below full pond (724.5 feet). In Section 2.3.2 (p. 4) it indicates when lake level is
projected to be below 720 feet in early spring to initiate temporary pumping. Temporary pumping operations
were conducted between December and March. We have the following questions and/or requests for
additional information regarding the trigger when water will be pumped from Dan River to Belews Lake.
• With the permanent pumping station, is there a lake level (e.g., 721.5 feet) that would trigger the
need to pump water from Dan River to Belews Lake? We would prefer that pumping occur when
there are significant flows (e.g., from extreme weather event) in Dan River regardless of a specific
lake level.
• Is it possible to store water above 724.5 feet? Again, we would prefer pumping occur when there are
significant flows in the Dan River, and if it is possible to store water above 724.5 feet this might be
beneficial to aquatic resources in the river, by limiting pumping during periods when the flow is just
above the minimum (i.e., 110 cfs).
Thank you for the opportunity to review and comment on this project. We look forward to
reviewing the additional information. If we can be of further assistance, please contact our office at (336)
449-7625.
cc: Cyndi Karoly, DWQ (09-1242)