At least two of the state's biggest water systems, those serving Atlanta and DeKalb County, weren't able to meet Gov. Sonny Perdue's mandate to cut water production by 10 percent, water authority officials said Wednesday.

The state Environmental Protection Division hasn't decided what penalties those utilities — and their customers, in turn — face, though officials have said before that fines are likely. In fact, the state won't make an official determination of who made it and who didn't until the week of Dec. 17, after it gets the final November figures and compares them to usage from December 2006 through March 2007.

David Tulis/AJC (ENLARGE)

The state's historic drought is taking a toll on Lake Lanier.

• Photos: A shallow Lake Lanier can be hazardous DEALING WITH THE DROUGHT: • Can I water? Here are the rules • 10 tips to save water • Map: Heavy demands on our water RELATED: Rain coming! Look for it Tuesday night, Wednesday  Georgia drought persists, but not panic  Atlanta water use down 20 percent from August 2007  Lake Lanier 2.4 feet fuller, southwest Georgia flooded  Twisters damage Hall County schools, Commerce homes  • More on coping with the drought

The forced reduction will continue indefinitely.

The Cobb County-Marietta Water Authority met the governor's order, but just barely, according to their calculations. A Fulton County spokeswoman didn't provide the daily production data to back up the assertion that Fulton also made it just under the new target.

And Gwinnett County officials are interpreting the rules differently than other

counties, making it difficult to judge how much they've cut back.

Responding to the state's extraordinary drought, Perdue in October said utilities in 61 counties had to cut water production 10 percent, compared to the average for four months last winter, when usage is at its lowest.

In November, the Cobb system had to scale back water usage to about 74.45 million gallons per day. They finished the month averaging 74.32 million gallons per day, said Glenn Page, general manager for the Cobb County-Marietta Water Authority.

"We are very pleased because it was a tall order," said Page. "It really came down to the last couple days of the month for us to come into compliance."

Atlanta reduced water production by about 7 percent, said Janet Ward, spokeswoman for Atlanta's Department of Watershed Management. DeKalb reduced water usage by 8.3 percent.

"We were very close," said Francis T. Kung'u, director of DeKalb County Department of Watershed Management.

Kung'u said his department tried everything to get customers to conserve and even had water employees patrol at night to catch watering ban violators.

"We tried many, many things," he said. "But there is only so much we can do because we can't control how much water people use in their home."

Ward, of the Atlanta Water Department, said she does not know what type of penalty, if any, Atlanta will receive for not reaching the goal.

"What you have to understand is that we have been conserving since May, since before the governor's order went out," said Ward. "We had already cut our usage, so it was hard to find new ways to conserve."

When Perdue made his reduction order, he said the state would monitor monthly usage and levy punishments for noncompliance. EPD director Carol Couch has said the fines will be "appropriate and severe."

What might complicate issues is a growing confusion by public water official regarding what numbers they need to provide to the state.

For example, documents provided to The Atlanta Journal-Constitution by the Gwinnett County Water Department suggest that the county has not reached the 10 percent reduction.

But Gwinnett representatives argue that they are allowed to subtract the amount of water they sell to smaller cities from their total. Water officials from DeKalb and Atlanta disagreed with that and have included water sold to cities in their totals.

EPD spokesman Kevin Chambers said each agency may be right and the EPD is working with them to determine which figures to use.

Issues such as this may present the state with a hodge-podge of data to sift through and compare.

"I think one of the things that is happening here is that we just have never done this before," Ward said. "We are all trying to figure out what we need to send to the state."

Perdue has not heard of any confusion in the process, spokesman Bert Brantley said.

"We really think the point is getting across that we need to conserve," he said. "We are leaning on the EPD to evaluate the numbers. Our hope is that it would not get to the point that there needs to be sanctions or fines."