Lake Level Update

Published: March 17, 2011

Catawba Dam valve to operate during hydro outage

By McDowell News Staff

Duke Energy plans to open a valve on the Catawba Dam Monday, March 28 to provide additional downstream flow from Lake James when the current Bridgewater Hydro Station temporarily stops operating for construction work.

This will provide added protection to aquatic life and Morganton’s water intake downstream, according to a news release from Duke Energy.

The valve, called a “minimum flow valve” (MFV), will continuously send 75 cubic feet per second of water downstream while water cannot be passed through the hydro station. The current hydro station will not operate for about two months as crews work to connect the existing 20-foot water pipe (penstock) to the new hydro station.

“This is a prudent action since our region is expected to continue seeing dry conditions this spring,” said Carol Goolsby, vice president of the hydro fleet. “While this volume of water is small compared to the amount stored in the lake, it will be leaving the valve at high pressure, so residents should be cautious and avoid this area.”

Lake James will begin refilling Monday, March 28 based on rainfall and will be operated in its normal operating range this summer. Recent rain increased the lake level to about 89 feet from the 85 feet where Duke Energy had been operating it to perform repair work on the intake structure since early January. Construction crews and divers will continue intake work until Monday, March 28.

Duke Energy has posted safety signs and has installed wire cabling to restrict access to the area at the Catawba Dam where the valve will be operating. Sheriff’s deputies will patrol this area periodically while the valve is open.

Once the penstock work is completed by early June, the existing hydro station will go back in service through the summer. In August, Duke Energy will lower the lake to about 95 feet in preparation for a shorter outage to finalize the conversion to the new station. This lake level will have a very minimal impact to recreation. Testing for the new turbines is expected to begin in October.

Lowering the lake prior to both outage periods reduces the risk of spilling if the Lake James area receives significant rainfall. However, without the ability to pass as much water downstream when the station is out of service, there is a possibility of spilling over the Paddy Creek and Catawba Dam spillways.

“We will continue to monitor weather conditions and construction progress and may need to adjust lake levels or the schedule accordingly,” Goolsby said. “Striking the right balance between reducing flood risks for lake residents and not overly impacting recreation is important to us.”

The Mcdowell News © Copyright 2011 Media General Communications Holdings, LLC. A Media General company.

Duke Energy to Lower Water Level at Lake James

to Facilitate Dam Strengthening and Hydro Station Move

MORGANTON, N.C. – Duke Energy will lower the water level at Lake James by up to 15 feet starting later this year, with less impact continuing through next spring and summer.

Duke Energy is notifying lake residents and businesses this week so they can begin making any necessary arrangements for their boats or properties during lower lake levels.

The lake lowering is prompted by requirements from the Federal Energy Regulatory Commission (FERC) that Duke Energy strengthen the three dams it operates on Lake James to increase dam stability in the event of a severe seismic event.

Duke Energy has completed work on two of the dams – Paddy Creek Dam and Catawba Dam. Construction is scheduled to begin in 2012 on improvements to the third dam – Linville Dam.

“The Linville Dam remains very safe today, but this federally required project will further reinforce its durability and reliability for those living downstream,” said Carol Goolsby, vice president of Duke Energy’s hydro fleet.

To facilitate the strengthening work on the Linville Dam in 2012, the dam’s existing electricity generating station (Bridgewater Hydro Station) must be permanently removed. A replacement hydro station is being built several hundred yards downriver. At the peak of construction, the new hydro station project will employ a workforce of more than 150 people, coming largely from the local area.

The work includes repairs to the station’s intake structure, which will require Duke Energy to gradually lower the lake level in November and December to about 85 feet (15 feet below full pond).

After completing the intake work in February, Duke Energy will allow the lake to refill to about 92 feet (eight feet below full pond) through the spring to support walleye fish spawning and limited recreational access.

In May 2011, Duke Energy will again lower Lake James – this time to about 90 feet (10 feet below full pond) to begin the process of connecting the new hydro station to the intake pipe. Since neither the old nor the new, under-construction hydro station will be operating from late May through September 2011, one of the normal outlets that moves water downstream will be temporarily closed during this five-month construction period. Once at 90 feet, the lake will begin to immediately refill based on rainfall.

Substantially lowering Lake James’ water level – in advance of the hydro station work – will reduce the amount of water that otherwise could spill over the lake’s Paddy Creek and Catawba dam spillways during the temporary closure of the normal Linville Dam outlet.

This action will provide added protection against potential high water for downriver residents and businesses in the event of lengthy periods of heavy rain during the May to September 2011 construction timeframe.

“We do not take the decision to temporarily lower Lake James lightly, but it is necessary to complete the required dam and hydro station work,” Goolsby said. “We understand this work impacts residents, businesses and others who enjoy recreational activities on the lake, so we wanted to provide them as much advanced notice as possible,” she said.

Lake residents and businesses often repair docks and make shoreline improvements during periods of reduced lake levels. Those interested in doing so can contact Duke Energy Lake Services at 800-443-5193.

During the construction project, updates on lake levels will be available at www.duke-energy.com/lakes/levels.asp or by calling 800-829-LAKE (5253). For more details, please visit our fact sheet with frequently asked questions.