Hall County is once again seeking approval from the U.S. Army Corps of Engineers to build Glades Reservoir.

But this time, the proposal is for a much more productive source of drinking water.

The corps confirmed Friday that Hall County officials have applied for a permit to build a reservoir that could provide as much as 80 million gallons of water to Hall and Forsyth counties each day.

The county's original permit application called for a yield of 6.4 million gallons per day. County officials quickly scrapped that plan when a federal judge's ruling in 2009 threatened Georgia's use of Lake Lanier as a primary source of drinking water for much of metro Atlanta.

Though state officials have appealed the ruling, Board of Commissioners Chairman Tom Oliver said in a statement Friday that the revised plan is a way for the county to "control our own destiny."

"Our future water supply for the next 50 years depends on this permit," Oliver said in the statement.

Yet the leader of the Upper Chattahoochee Riverkeeper, an environmental advocacy group, says she is "leery" about the project. Sally Bethea says her organization thinks it is more prudent to raise the full pool water level of Lake Lanier and implement more conservation measures.

Bethea said her organization would review the county's application closely, and plans to submit detailed comments to the corps. The Upper Chattahoochee Riverkeeper already is in talks with the federal Environmental Protection Agency about the project, she said.

"From what we know, this reservoir project is extremely expensive," she said.

At this point, county officials estimate the cost of the reservoir at $138 million, which would largely be offset by user fees, according to a statement from Public Information Officer Nikki Young.

County officials are hopeful that they will have the permit in hand in the coming year so they can begin design and the construction of the 850-acre reservoir in North Hall County.

The public will have a 30-day chance to comment on the application shortly after corps permitting officials ensure the application is complete, said Billy Birdwell, a spokesman for the corps' Savannah district.