Severe weather in the area served by the Tennessee Valley Authority caused serious damage to the utility's transmission system today, with power outages and high voltage lines down in Alabama, Tennessee, Kentucky and Mississippi.

Eleven high-voltage transmission lines were out of service this afternoon and TVA crews are working to restore service, according to a news release from the utility. Only one local power company, Cullman Electric Cooperative in Cullman, Ala., was directly affected by the TVA transmission outage. Several other power companies sustained damage, the news release stated.

Additional severe weather, including high winds and possible tornados, is expected later tonight. Strong storms could damage transmission lines and structures and cause power outages, TVA said in the release.

TVA's service region includes most of Tennessee; southwestern Kentucky; the northern areas in Mississippi, Alabama, and Georgia and parts of western North Carolina and southwest Virginia.

Rainfall in the western portion of the TVA service area was four to seven inches from Tuesday to Wednesday.

Eight of the nine dams on the Tennessee River were generating at full power to move water through the river system and help control flooding.

"The unusually strong storms we're experiencing have caused damage resulting in power outages," said Rob Manning, TVA executive vice president of Power System Operations, who also urged caution around damaged electrical equipment.

"Never approach power lines or transmission structures that are lying on the ground," Manning advised. "Call your local power company to report downed power lines."