Raleigh's supply is about as dire. Durham's is worse at 69 days -- if there's little rain between now and late January.

But Duke Energy, which manages the Catawba River basin, and Charlotte-Mecklenburg Utilities, which delivers the county's drinking water, won't say how many days Charlotte has left. Duke Energy officials said such predictions are often unscientific.

Yet, at a time when the city has ordered water restrictions, some officials say Duke and county officials need to give clearer information about the severity of the drought.

Charlotte City Council member Anthony Foxx said Friday he'd like Charlotte-Mecklenburg Utilities to track the daily water supply.

"If we're tracking the information then there will be a point in time in which the public is alerted to the level of risk that confronts us," he said. "But at present, I can't even find out if we are."

Next week, after repeated questions by the Observer, Duke plans to give more details and provide a time frame for when greater water restrictions could start, Mayor Pat McCrory said at a news conference Friday.

"It's a bleak picture," said Maeneen Klein, the utility's water conservation manager. "The danger will come when we head into spring and next summer from a damaged position -- where we are right now."

Duke guards info

The planned announcement is a change for Duke, which earlier declined to give any forecasts.

Quantifying Atlanta's and Raleigh's water supply can be easier, Charlotte officials say. Those other cities draw drinking water largely from a single lake and rain.

"They have more of an ability to look at finite numbers," said Denise Foreman, the utility's assistant director.

The Charlotte region's water system is more dynamic, because Duke manages 13 hydroelectric dams on a chain of 11 lakes, which allows Duke to move water where it's needed most.

Duke, a private company, controls water-level information. Most area utility departments refer water supply questions to Duke.

The power company holds weekly drought-management meetings with representatives from Mecklenburg and other water users along the Catawba. The meetings are closed to the public. Duke spokeswoman Marilyn Lineberger said that sensitive information about the supply is discussed and that it must be kept private for security reasons.

The company says it hasn't operated in the dark. It posts information about the meetings on its Web site and the public is represented by local officials.

"I feel like we're very up-front and transparent," she said. "The public is well represented."

The advisory group formed as part of Duke's application for a new federal license to manage the river.

Ed Cross, Gastonia's longtime chief of water supply and treatment, said that the advisory group needs to protect some information but still should be more open.

"It's not panic, it's not fear, it's knowledge," Cross said. "And with knowledge comes solutions."

McCrory, who works for Duke as an economic development consultant, defended the process, saying it is more open and coordinated than in the past. He said he treats Duke as he would any other corporation doing public business.

Stage 3 restrictions

The region currently is gripped by "exceptional drought" -- the most severe category -- and is under Stage 3 conservation measures, which require cutting normal consumption by as much as 20 percent.

Most of the Charlotte region is under mandatory water restrictions. Usage in Mecklenburg has dropped 23.5 percent since August, McCrory said Friday.

Numbers supplied by Duke for the Catawba River basin show falling levels of usable water.

Duke said earlier this month that the water supply in the basin was shrinking 2 to 3 percent a week. If levels continue to fall -- and there's strong reason to think they will -- Stage 4 restrictions, the most severe, could be near. Those restrictions would eliminate all outdoor watering and seek to reduce water use by up to 30 percent. That would include urging businesses and industries that require a lot of water for manufacturing to reduce their use.

Foxx, the council member, said the utility told him that even now, levels are so low that water is coming to the utility department dirtier than normal.

"They're having to work harder to clean it," he said.

Little rain foreseen

Significant rain would stave off more severe restrictions, but the chances are slim.

Forecasters say a pattern settling into the Pacific Ocean will bring the region a warmer and drier winter, when water supplies in streams and lakes are normally replenished.

The Charlotte region's rain deficit is 13.5 inches. To improve conditions to a moderate drought would require 16 to 20 inches over three months. To break the drought, Charlotte needs 20 to 24 inches, said Mike Moneypenny, a National Weather Service hydrologist. Chances of that much rain are about 10 percent, he said.