Officials in Wythe County warned residents of a potential dam failure earlier Thursday.
Here is the statement from Appalachian Power:
Water conditions have improved throughout the day on many of the rivers on which Appalachian Power operates hydroelectric facilities in Virginia. An earlier potential dam failure emergency condition has been lifted.
· Around 2:30 p.m. Appalachian downgraded the emergency conditions on a portion of the New River to a non-failure emergency condition. Earlier today the company notified emergency officials in proximity to the company's Byllesby and Buck hydroelectric facilities near Ivanhoe that there was a potential failure situation. That situation has been removed. Flashboards, oak boards atop the dam structure designed to give way, had to be manually removed. With the flashboards in place, water pressure was building up to potentially unsafe levels behind the dams. After their removal engineers inspected the dams and determined that the structures were stable.
· At Claytor Dam on the New River the company inflows have decreased and spillway gates are able to be closed. The water released from the project has been cut from 72,000 cubic feet of water per second (cfs) to 68,000 cfs. The water level behind the dam has decreased from 1848.4 to 1846.5. Normal full-pond elevation is 1846. Downstream water levels should continue to subside. Residents in this area should watch the Radford USGS for current information.
· Some tributaries feeding the Smith Mountain Project have crested, while the Pigg River flows continues to climb. The current water level at Smith Mountain Dam is about 795 feet above sea level. The company does not anticipate the elevation exceeding 795.5 at this time.
· At Altavista, downstream of Leesville Dam, flood conditions have improved slightly. The company is holding water in Leesville, and will release inflows in a manner that does not increase downstream flooding conditions.
· At Reusens Dam on the James River near Lynchburg flows continue to increase and are now at approximately 43,500. Flows are expected to increase throughout the night. The company is releasing inflows through the spillway gates and will monitor conditions closely.
Appalachian Power reports the water level at some of its dams is still rising.
The utility is warning people who live downstream from the Buck and Byllesby dams on the New River in Carroll County to be alert. Water is pouring over the top of the dam and more water is expected to flow out of North Carolina.
Appalachian expects the level at Smith Mountain Lake to top out at no higher than 759.5 feet in elevation later in the day. Flow out of Claytor Dam in Pulaski County is expected to remain heavy but should not go higher.
Here is the complete news release from Appalachian Power:
ROANOKE, Va., January 31, 2013 – Heavy rainfall overnight in the Appalachian Power territory in Virginia resulted in high water conditions this morning on many of the rivers on which the company operates hydroelectric facilities. In some areas river flow increased a multiple of 10 times in just 12 hours. Where necessary, Appalachian Power officials notified emergency services organizations of water releases that are affecting downstream and lake conditions. None of the company’s facilities are constructed for flood control. However, efforts are being and have been made to attempt to assist in controlling flows downstream.
- On the New River near Ivanhoe in Carroll County flows have increased dramatically. These flows are affecting the company’s Buck and Byllesby hydroelectric facilities. Water is currently going over the dam and flashboards at both facilities. Local flooding is inhibiting access. As soon as the dams are accessible flashboards will be removed. This will increase flows immediately downstream of the dams, but should dissipate further downstream. Because water is overtopping the dam, as a precaution the company has notified officials in accordance with its emergency action plan procedures. Additional water volume from North Carolina will increase flows late this evening. Residents in low-water areas downstream should monitor the US Geological Survey (USGS) Ivanhoe gauge on the New River. This information is available at http://waterdata.usgs.gov/nwis.
- At Claytor Dam on the New River the company is releasing approximately 72,000 cubic feet of water per second (cfs) and the company does not anticipate increasing this release amount or that the reservoir level will increase further. The reservoir elevation is currently 1848.4 feet above sea level, normal full-pond elevation is 1846. The current water release plan should maintain heavy flows downstream but should help avoid a higher crest. Residents in this area should watch the Radford USGS for current information.
- Tributaries feeding the Smith Mountain Project are expected to crest later in the day. The current water level at Smith Mountain Dam is 795 feet above sea level. Additional inflows may require Appalachian to increase the water level at the dam. The company does not anticipate the elevation exceeding 795.5 at this time.
- At Altavista, downstream of Leesville Dam, approximately 20,000 cfs water flows are creating a flood condition. The company is holding water in Leesville, and will release inflows in a manner that does not increase downstream flooding conditions.
- At Reusens Dam on the James River near Lynchburg the current flows are approximately 36,600 cfs. The company is releasing inflows through the spillway gates.