The federal government agreed to hold more water in Lake Lanier this winter, a potential one-foot boost to the lake’s level.

In a decision announced Friday, the U.S. Army Corps of Engineers said sending less water down the Chattahoochee River through metro Atlanta “was determined to have no long-term significant environmental or human impacts.”

Georgia Environmental Protection Division Director Carol Couch last month asked the corps to reduce the required minimum amount of water flowing down the Chattahoochee at Atlanta by 13 percent to keep as much water in Lanier as possible. But Lanier still could reach a record low level next month. On Friday, the lake was more than 18 feet below full pool, lower than it has ever been this time of year since it was built in the 1950s.

Lanier — either directly or indirectly via the Chattahoochee — provides the water for about 3 million metro Atlantans.

“We can assure Georgia citizens that this is an important step to conserve a significant amount of water,” Couch said of the corps’ decision, which takes effect Saturday. “The cumulative impact of this flow reduction, plus the level of reductions Georgians relying on the lake continue to make could allow us to retain as much as two more feet” of water in Lanier.