(AP) — The Tennessee Valley Authority's board of directors voted Thursday to increase its base rate by 1.5 percent, the first increase by the nation's largest public utility in two years.

The board also approved a $10.5 billion budget for the new fiscal year that begins Oct. 1.

The rate adjustment will add about $1.50 to the monthly power bill of a customer using 1,000 kilowatt-hours of electricity. TVA provides power to about 9 million people in Alabama, Georgia, Kentucky, Mississippi, North Carolina, Tennessee and Virginia.

TVA's budget for the upcoming year anticipates 4.6 percent lower sales year over year and is about 6 percent less than 2013.

Earlier this month, the federal utility released its April-June financial results that showed power sales were off 4 percent in the third quarter. TVA officials said mild temperatures were the reason.

"It's a tough budget, but I think it's a good budget at a time when there's no growth," TVA chairman William Sansom said Thursday.

Early in the meeting, board members also heard about safety measures TVA is taking since a north Alabama man died on the Tennessee River. A bass boat the man was riding in struck a low-hanging wire near a TVA power plant, nearly decapitating him, according to authorities.

Officials said TVA crews were performing work on the line, and the Coast Guard said it had closed 1 mile of the river to traffic.

But the Coast Guard said it had no vessels in the water to warn boaters, and a coroner said the bass boat didn't have the type of radio the Coast Guard used to broadcast warnings about the hazard.

"TVA has been working with the Coast Guard and local agencies to improve coordination and communication between the agencies when future projects involve river crossings," TVA spokesman Duncan Mansfield said in an email to The Associated Press.