The Tennessee Valley Authority is completing temporary construction to raise the height of four dams in Tennessee.

Over the next few weeks, TVA will complete temporary work that will increase the height of the Tellico, Watts Bar, Fort Loudoun and Cherokee dams. The utility plans permanent construction later.

Chuck Bach, who heads river scheduling for TVA, said the utility wouldn’t be doing its job if it didn’t prepare to lessen floods coming down the Tennessee Valley.

Bach said the new work would prepare the dams for a “probable maximum flood” — an event that would occur once in 700,000 to 1 million years.