You've taken to heart Gov. Mike Easley's appeal to shorten your showers, do fewer loads of laundry and let the toilet bowls mellow to conserve water in this severe drought.

But you might not be able to figure out how many gallons you're using and saving by looking at your water bill.

Raleigh measures water use in units -- 100 cubic feet. Durham does the same, and although each unit equals 748.1 gallons, the bills don't show that. The Orange Water and Sewer Authority shows consumption to the nearest thousand gallons, an even less precise number.

On top of that, all three utilities round the consumption numbers down, then, without showing it, carry over the extra to the next bill.

"Right now, this unit stuff just doesn't work for me," said Rita Hayes, 65, a Wake Forest resident who is baffled by Raleigh's billing system.

Hayes has been trying to conserve more water in recent months, but her bills keep showing her use as two units of water.

"It's like I'm on an easy pay plan," said Hayes, who doesn't understand why water can't be measured as accurately as electricity.

With all the confusion, Raleigh and Durham are considering changing their billing systems to make them more user-friendly. This week Raleigh Mayor Charles Meeker said the city would begin showing each customer's average daily water consumption in gallons in the upper right-hand corner of the bills.

"When water was cheap, a lot of people didn't pay that much attention," said Jeff Hughes, director of the Environmental Finance Center at the UNC-Chapel Hill School of Government. "Quite frankly, a lot of systems weren't designed with the idea of conveying conservation information to customers."

Like many Durham residents, Meredith Emmett now wants to know how well she is conserving. It took stumbling across a city booth at a community event before she learned how to convert a "consumption unit" into gallons.

"Seems like it ought to be reasonably simple for the city to do the calculation for us and print out average water consumption per day in gallons on our bill," she said. "It's just math."

Making sense in Cary

Cary's monthly water bills are among the more customer-friendly in the Triangle. The town shows a customer's total consumption down to the tens of gallons.

Cary's bills also include a bar chart showing how a customer's water use has changed over the previous 13 months.

OWASA, which serves most Chapel Hill and Carrboro households, charges its customers for each thousand gallons used, but the only way to find out precisely how much came through the pipes is to go out and read the meter, often under a cover out by the street. OWASA also includes bar charts on the monthly bills.

"We do have a rather educated, erudite consumer base in southern Orange County that we think is capable of reading a meter," said Kevin Ray, OWASA's finance director. "A thousand gallons is clearly a mark. It may not be down to the exact gallon, but it certainly is a good tool and indication in terms of consumption."

Raleigh and Durham bill for water in hundreds of cubic feet. Each 100 cubic feet is a unit, or 748.1 gallons.

Both cities round down their meter readings, meaning a customer who uses 199 cubic feet of water would be billed for 100 cubic feet, or one unit. The cities carry the extra 99 cubic feet over to a customer's next bill.

Though Raleigh has promised to start converting a customer's average daily use into gallons, that amount will not include water that was carried over to the next bill -- up to 11 gallons per day.

Dale Crisp, Raleigh's utility director, said that until recently water meters were read manually and the city decided to bill in hundreds of cubic feet to help prevent errors. Raleigh is switching to automated meter readers, and Crisp said that may allow the city to begin reading meters to the tenth of a cubic foot.

As for why the city doesn't use meters that can be read in gallons, Crisp said Raleigh has too many older meters that measure water in cubic feet.

"With the infill development in the city, it would be impossible for us to differentiate between old and new meters on the same street without ultimately causing billing errors," he said.

By this summer, Durham also will include gallons used on water bills when it begins using new billing software. Deputy City Manager Ted Voorhees said bills also will start being issued monthly, allowing residents to keep closer tabs on their water use.