When Bill Beningfield got his water bill this month, the bottom line didn’t look right.

The city wanted him to pay $100; he had expected the tab to be closer to $60. A little research turned up the cause of the discrepancy: Meter readers didn’t get to his house during the November billing cycle, so they estimated his bill based on the prior three months.

“We were all pouring water on our lawns during August, September and October,” he said. “I’m a mathematician; it seemed inappropriate to me.”

He’s not the only one who thought so. City Finance Director Ed Mullins said this week his department had received “quite a few calls” complaining about high water bills. The department is adjusting water bills for customers whose usage was overestimated.

The city tries to read all the water meters during every billing cycle, Mullins said, but the five-person staff was shorthanded in November. The bills of about 5,000 customers were based on their average use over the previous three months.

“We like to avoid estimation,” Mullins said. “We don’t want to do it if we don’t have to.”

Beningfield, a retired engineer, didn’t mind the estimation as much as the method.

“If they had asked somebody with a proper statistics background,” Beningfield said, “they could’ve been told how to do a proper estimation.”

Water use is seasonal, he said, so a better method would be to take the average water usage of a household during the same month of previous years.

“You’d probably get a much closer call than the method they used,” Beningfield said. “They really didn’t do a very good job of it.”

Mullins said his department will change the method of estimation when a meter reading is unavailable. The usage from the same month the previous year will be used to calculate the customer’s bill, he said.

To inquire about water bills, call the city’s Finance Department at 832-7878.