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HomeMy WebLinkAbout20080915 Ver 2_More Info Received_20101207PkI Duke Energy. Carolinas December 7, 2010 Ian J. McMillan, PWS, GISP NCDENR/Division of Water Quality Acting Supervisor - 401 /Wetlands Permitting and Oversight Unit 2321 Crabtree Blvd. Suite 250 Raleigh, NC 27604 Ms. Amanda D. Jones, Project Manager Asheville Regulatory Field Office U.S. Army Corps of Engineers 151 Patton Avenue, Room 208 Asheville, NC 28801-5006 og-oql? TJEC 0 7 200 WETLA, DE R- s QUALITY », ATER BRANCFI Re: Catawba-Wateree Hydroelectric Project FERC Project No. P-2232 Linville Dam Embankment Seismic Stability Improvement (ESSI) Project Update Dear Mr. McMillan and Ms. Jones; Duke Energy Carolinas, LLC (Duke) appreciates the actions of the North Carolina Department of Environment and Natural Resources (NCDENR) and the United States Army Corps of Engineers (USACOE) to issue Water Quality Certification No. 3838 and Individual Permit SAW-2008-02753 for the subject project. Duke wishes to update NCDENR and the USACOE regarding enhancements to project activities. Project Updates Disconnecting the penstock from the old powerhouse and connecting it to the new powerhouse will be done in two separate, shorter phases rather than one longer phase as previously planned. The total duration of the two shorter phases does not exceed the originally planned duration. The project update is described more fully in the following public information materials that have either been mailed, distributed electronically, or posted to Duke's lake information web site: • Bridgewater Fact Sheet (Attachment 1) • Community Notification and press release (Attachment 2) • Message Posted on Duke Energy website and phone line (Attachment 3) Project Enhancements This two-phase approach creates the following benefits compared to the original approach: www.duke-energy.com • The first phase is planned to begin in mid-March 2011 and last for approximately 60 days. This is earlier than the originally planned start date of late May 2011. During this time Lake James will fill (the rate of fill depends on actual rainfall), allowing Lake James to potentially recover to its normal elevation prior to Memorial Day and the 2011 prime summer recreational season. • Duke will be able to make flow releases from the existing powerhouse from approximately mid-May 2011 to August 2011 while maintaining normal lake elevations (depending on actual rainfall). Under the original plan, there would have been no flow releases from the powerhouse from late-May through September and lake levels would have to have been drawn down to 10 ft below full pond or lower just prior to the 2011 Memorial Day holiday. • In preparation for the second phase, Lake James' level will be lowered to 5 ft below full pond during August. The second phase is planned to begin in September 2011 and last approximately 30 days. During this time Lake James will fill (the rate of fill depends on actual rainfall). There will be no flow release from the powerhouse during this outage, but the cumulative duration is much shorter than the 90 days of no flow release that would have occurred from May through September under the original plan. This significantly reduces the stress on aquatic organisms in the river section below the powerhouse. • The new powerhouse is expected to begin operating in October 2011, as originally planned. Compliance with Water Quality Certification and Individual Permit Duke has reviewed both the Water Quality Certification and Individual Permit and can find no conflict between these documents and the enhanced plan described herein. The enhanced plan reduces potential impacts to natural resources as well as to the public. Duke will follow all Water Quality Certification requirements and Individual Permit requirements during both project phases. Thank you for the opportunity to update you on our project activities. If there are any questions or if additional information is needed, please contact Jon Wise (828-391-6754; jon.wise@duke- energy.com) or James McRacken (704-342-7373; james.mcracken@hdrinc.com). Sincerely, lj c". !l (Vt1% - onathan R. Wise, Project Director Bridgewater Powerhouse Replacement Project Duke Energy Carolinas, LLC Attachments cc: CS Goolsby GA Galleher 2 BT Keaton EB Culbert JG Lineberger John Dorney, NCDENR Mark Cantrell, U.S. Fish and Wildlife Service Chris Goudreau, North Carolina Wildlife Resources Commission 3 Attachment 1 Duke Bridgewater Hydro Station Work Pahmnergy. New Plan Minimizes Impact to Lake James in Summer 2011 Steer Clear: Minimum Flow Valve The Bridgewater Hydro Station, located at the toe of the Linville Dam, has to be relocated to facilitate construction of the seismic improvements on the dam. Construction of a new powerhouse further downstream is under way. After completing the new powerhouse, the old powerhouse will be removed. Repairs needed on the existing intake structure and connecting the new powerhouse require Duke Energy to operate Lake James at lower levels in late 2010 through spring of 2011. Duke Energy recognizes this will impact businesses and recreation on Lake James. We have been working hard to develop a plan that lessens this impact. By separating the 90-day powerhouse outage into two shorter outages, we can complete the work while maintaining normal lake levels in the summer. We appreciate your understanding of this federally-required project. • Intake work (January to mid-March 2011) - Lake James will be at about 85 feet (with 100 feet being full pond). Duke Energy will continue gradually lowering the lake in December 2010 and early January 2011 to achieve that level. • Connecting new powerhouse (mid-March to mid-May 2011) - The Bridgewater Hydro Station will be out of service, and Lake James will immediately begin refilling in mid-March 2011. The lake will fill depending on the amount of rainfall received; this may result in spilling over the Paddy Creek and Catawba Dam spillways. • Normal lake levels (mid-May to August 2011) - Duke Energy will operate Lake James at its normal target level (98 feet, depending on rainfall) during the summer. • Switching to new powerhouse (September 2011) - Duke Energy will need to lower Lake James in August 2011 to 95 feet for a brief outage in September 2011. Again, the lake will begin refilling based on rainfall. This will complete the transition to the new powerhouse, which is expected to begin operating in October 2011. Dock and Boat Preparations Lake residents and businesses often elect to conduct dock, slip or shoreline improvements during times of lower lake levels. Please contact Duke Energy Lake Services at 800-443-5193 to obtain permits required to conduct work inside the lake boundary. At 85 feet, Lake lames will be one foot lower than in December 2007 during the drought of record. Be thinking now about any arrangements needed for boat storage or transportation. Please be mindful how lower lake levels may affect your dock, and take precautions to protect it. Contact your pier contractor for advice. continued on next page During the two outages at the Bridgewater Hydro Station in 2011, Duke Energy will provide supplemental flow downstream to minimize impacts to aquatic life and to support downstream water user needs. We will operate the Minimum Flow Valve on the Catawba Dam, which flows at 75 cubic feet per second. Because this water is flowing at high pressure, please heed signage and avoid this area for your safety. Duke Energy Corporate Headquarters 526 South Church Street Charlotte, NC 28202-1802 www.dyke-energ.y.com 12110 To comply with revised federal guidelines, a program is under way to make improvements to the three dams that form Lake James. This is part of a nationwide effort by the Federal Energy Regulatory Commission (FERC) to increase the safety of dams during severe earthquakes. Construction of seismic improvements is complete at Paddy Creek Dam and Catawba Dam; construction is scheduled to begin on Linville Dam in early 2012. Frequently Asked Questions Duke Why is a draw-down of Lake James necessary? 1warEnergy, Duke Energy is preparing for a federally-required construction project on the Linville Dam in 2012 to enhance stability in the event of a severe earthquake. A new powerhouse, which contains the turbines for hydroelectric power, is under construction now. Repairs needed on the existing intake structure and connecting the new powerhouse require Duke Energy to operate Lake lames at lower levels from late 2010 through spring of 2011. During the intake repair work (January to mid-March 2011), a depth of 85 feet is needed to perform concrete repair work above water from a barge and to increase the safety of divers as they perform deeper gate repairs. While connecting the new powerhouse (mid- March to mid-May 2011) and while switching to the new powerhouse (September 2011), a drawdown is needed to provide storm runoff storage in Lake James to decrease the risk of flooding for lake residents and businesses. Is the Linville Dam safe? Yes. The Linville Dam and all other Duke Energy dams are inspected regularly and are safe. This federal program is intended to improve the performance of existing dams during severe seismic events. It is unlikely our region would experience an earthquake the size of the ones used in FERC evaluations, but public safety is our top priority for communities surrounding our reservoirs. Will downstream municipal water intakes be impacted by this project? Water released through the Minimum Flow Valve (MFV) on the Catawba Dam will supplement rainfall and natural stream flow downstream of Lake James and through the Upper Catawba River Basin to ensure municipal water intakes are not affected by lowering Lake James. How will Duke Energy manage high-water events while connecting the new hydro station? Another benefit of conducting this work in two, shorter outages is that it reduces the risk of high water events. The existing powerhouse will operate from mid-May until it is taken out of service in September 2011, meaning Duke Energy will have a greater ability to manage lake levels during the summer months. Duke Energy's Hydro Operating Center is staffed around the clock and expertly manages the Catawba-Wateree lake system as a whole by continually monitoring conditions and keeping the safety of downstream residents an utmost priority. What provisions are you making for fish and other aquatic life during lower lake levels? We will operate the Minimum Flow Valve (MFV) on the Catawba Dam to provide additional flow downstream. The water Lake Level Updates flowing from the MFV is at high pressure; please be cautious and heed signage for safety. The new powerhouse provides a unique opportunity to improve aquatic habitat long term as well. The state-of-the-art for updates during this turbines that will be installed are designed to increase dissolved oxygen and provide a continuous flow of water through duke-energy.com/lakes/ the hydro station. levels.asp or call 800- Will I be able to have boat access through marinas, public access points or my own personal dock/pier? 829-LAKE (5253) for Unfortunately, boat access on Lake James will be limited from December 2010 through spring 2011. Some public special messages. access points and deeper marina docks may be usable in spring once the lake begins to refill. Boaters with shallower access points should be prepared for the boat storage or transportation arrangements you may need. Please be mindful how lower lake levels may affect your dock, and take precautions to protect it. Contact your pier contractor for advice. Duke Energy will monitor lake levels at public access ramps carefully and will temporarily close those that cannot support safe access. Canoe, kayak and small boat access should remain unaffected. Do 1 need to take any special safety precautions while on lake James? Duke Energy Since lower lake levels from late 2010 through spring of 2011 may expose hazards normally covered with water, please Corporate Headquarters use caution while recreating on Lake James. 526 South Church Street Charlotte, NC 28202-1802 Please note, time frames and lake levels are approximations, as weather may affect construction progress and lake management decisions. www.duke-energy.com #100717 12110 Attachment 2 t P&Duke Ener `Important News - About Lake James Dec. 7, 2010 Lake James Expected to be at Normal Levels Next Summer A revised Bridgewater Hydro Station construction plan will reduce the duration of Lake James' lowering, allowing for a more robust business and recreation season next summer. The next phase of construction at the Bridgewater Hydro Station at the Linville Dam requires the continued lowering of Lake James in December 2010 and early January 2011 to about 85 feet (15 feet below full pond). This will allow crews to repair the intake structure in January and February. That depth is needed to perform concrete repairs above water from a barge and to increase the safety of divers while performing deeper gate repairs. While that portion of the project hasn't changed, Duke Energy has adjusted the construction plan so the original 90-day hydro station outage can be separated into two, shorter outages. The existing hydro station will not operate from mid-March to mid-May 2011 while crews connect the intake pipe to the new hydro station. The lake will begin refilling in mid-March based on rainfall and should be at a normal target level of 98 feet through next summer. Duke Energy will need another brief outage in September 2011 to finish the transition to the new hydro station. The lake will be lowered to 95 feet in August for that work, but it will begin to refill immediately based on rainfall. "By dividing up the outage time needed into two different periods, the lake has an opportunity to refill starting in mid-March with expected spring rainfall," said Carol Goolsby, vice president of Duke Energy's hydro fleet. "We've been exploring other alternatives for the complex construction of the intake pipe to lessen the impact to businesses and recreation, while protecting downstream water users and aquatic life. This is a good solution that better meets the needs of the community while meeting our project needs as well." Those wishing to conduct dock or shoreline improvements may contact Duke Energy Lake Services at 800-443-5193 to initiate any lake use permitting requirements. Duke Energy will update messages throughout this project at www.duke- energy.com/lakes/levels.asp or 800-829-LAKE (5253). An updated fact sheet also is available at www.duke-energy.com. Attachment 3 PDuke ., VEnergy- Important News Y. About Lake James Two-Outage Web and Phone Messages Upper Catawba phone message: To complete the next phase of construction at the new Bridgewater Hydro Station at the Linville Dam, Duke Energy will need to gradually lower Lake James in December and early January to 85 feet. This depth is needed to perform repair work on the intake structure from barges in the lake and to increase the safety of divers performing deeper repairs. When intake work concludes in mid-March 2011, the hydro station will be taken out of service until mid- May to allow further construction. The lake will immediately begin to refill in mid-March based on rainfall. This could result in spilling over the Paddy Creek and Catawba Dam spillways until the hydro station returns to service in mid-May. Duke Energy will operate Lake James within its normal target range throughout the summer. Lookout Shoals Hydro Station continues to have one unit out of service. Initial attempts to repair the unit while still assembled were unsuccessful. A more extensive repair is needed, and Duke Energy believes that Unit 1 will be returned to service by April 1, 2011. As always, we encourage those living along lakes, streams and other low-lying and flood-prone areas to pay special attention to changing weather conditions and take any necessary precautions. The Catawba-Wateree Basin continues to be in Stage 1 drought conditions, which calls for voluntary water and energy conservation. Please conserve to protect our shared water resources. Lake James web message: To complete the next phase of construction at the new Bridgewater Hydro Station at the Linville Dam, Duke Energy will need to gradually lower Lake James in December and early January to 85 feet. This depth is needed to perform repair work on the intake structure from barges in the lake and to increase the safety of divers performing deeper repairs. When intake work concludes in mid-March 2011, the hydro station will be taken out of service until mid- May to allow further construction. The lake will immediately begin to refill in mid-March based on rainfall. This could result in spilling over the Paddy Creek and Catawba Dam spillways until the hydro station returns to service in mid-May. Duke Energy will operate Lake James within its normal target range throughout the summer of 2011. The Catawba-Wateree Basin continues to be in Stage 1 drought conditions, which calls for voluntary water and energy conservation. Please conserve to protect our shared water resources. Attachment 3 *These messages will be updated as needed to reflect the second outage in September 2011 and to communicate any changes due to inclement weather, etc.