The U.S. Army Corps of Engineers has agreed to cut back on the amount of water it’s releasing from Lake Lanier.

But don’t start celebrating yet; the agreement is only valid for two weeks.

From now until May 31, the minimum amount of water flowing through the Chattahoochee River at Peachtree Creek in Atlanta will be 650 cfs (cubic feet per second) instead of the usual 750 cfs.

Georgia Environmental Protection Division officials say a certain amount of flow is necessary in order to dilute sewage that’s discharged into the Chattahoochee as it moves through Atlanta.

But the EPD is equally concerned about Lake Lanier’s low level, which could threaten the entire region’s water supply. Though the lake has risen 7 feet since it hit a historic low in December, it’s still about 13 feet below normal full pool.

In February, EPD director Carol Couch asked the corps for a reduction to 650 cfs at Peachtree. That request was granted for March and April.

Couch sent the corps a letter on April 25 asking for an extension of the reduction, which was set to expire on April 30. The corps approved the extension Wednesday, giving the lake about 16 days to retain a little extra water.

In a statement, Couch acknowledged that the reprieve was temporary, but said that "every amount will help."

EPD spokesman Kevin Chambers said Couch has not yet decided whether she’ll ask for another extension after May 31.

Lanier has benefited from a relatively cool, wet spring. But the lake is expected to start losing water rapidly once the hot summer weather sets in.

Lisa Coghlan, spokeswoman for the corps in Mobile, Ala., said decisions about how much gets released from Buford Dam are a separate issue from what’s going on at the other end of the Apalachicola-Chattahoochee-Flint river system.

On June 1, the U.S. Fish & Wildlife Service is expected to render an opinion on whether to reduce flow through Woodruff Dam, on the Apalachicola River near the Georgia-Florida line.

Cutting down on water releases there, from the current 5,000 cfs to a possible 4,500 cfs, could also help keep more water in Lanier. But reducing the flow too much could threaten the survival of endangered mussels in the Apalachicola.

Coghlan said the corps has to comply with all federal laws, such as the Endangered Species Act. But once those requirements are met, the corps tries not to drain its reservoirs unnecessarily.

"Any water we’re holding back anywhere in the system is a good thing," Coghlan said.