D.C. Water officials are reconsidering a fee that would leave some residents paying up to $1,000 more annually for water.

Beginning Oct. 1, a new “water system replacement fee” would go toward repairing and replacing the city’s aging water pipes, many of which date back 80 or more years and some to before the Civil War. Utility officials say they based the fee, which is expected to generate $40 million annually, on the sizes of pipes serving homes and businesses. Customers who use more water via larger pipes will contribute more toward upgrading the system.

The fee would amount to $6 to $10 monthly — or about $72 to $120 annually — for 90 percent of the utility’s 105,000 residential customers because their homes’ pipes are one inch in diameter or smaller.

But homes built in the District since late 2008 are required by code to have sprinklers for fire suppression, according to the District’s Department of Consumer and Regulatory Affairs. Such systems must be served by larger pipes, either 1  1/2 or 2 inches in diameter. Facing fees of $41 to $84 a month, customers in newer homes could end up paying as much as 10 times more than other residents, even if they use less water.

About 2,100 households are in this category, D.C. Water said.

The utility said it has received a couple dozen complaints about the proposal. The board of directors is expected to consider the fee’s impact on newer homes with sprinkler systems at its meeting Thursday.

George S. Hawkins, D.C. Water’s general manager, said the utility did not realize that the fee would disproportionately affect newer homes with sprinkler systems.

“We want to be as fair and thoughtful in the rate structure as we can be,” Hawkins said. “We think this merits further attention.”

Marisa Madigan said the new fee would cause the average water bill for her family’s townhouse in the Navy Yard area of Southeast Washington to almost triple, from about $56 a month to $140. Madigan said she and her husband, Dan, did not know they would be paying an additional $1,000 a year for water when she recently decided to cut back her work hours to spend more time with their toddler.

“It’s a hit,” said Madigan, 38, a recruiter for a law firm. “We’ll have to make other sacrifices to make up the difference. To be surprised by such a big number will have an impact on the rest of our expenses.”

Madigan said she is particularly upset because the townhouse that she bought in 2012 with help from the city’s workforce housing program is LEED-certified, so her environmentally friendly appliances use less water than if she had bought an older home.

She said she is fine with paying to replace aging pipes but thinks it unfair to make some residents pay more simply because their homes were required to have sprinklers.

“In all likelihood, those sprinklers will never go off” and use more water from the bigger pipe, she said.

The new fee follows a national trend among water utilities charging flat fees to keep up with the costs of aging infrastructure as revenue that is traditionally based on the amount of water used is dropping because of federally required low-flow toilets, shower heads and faucets.

The Washington Suburban Sanitary Commission, which serves Montgomery and Prince George’s counties in Maryland, recently imposed an infrastructure fee of $6 per quarter. Fairfax Water, which serves much of Northern Virginia, has newer pipes, no infrastructure fee and no immediate plans to institute one, a spokeswoman said.

Nationwide, the cost of replacing decades-old pipes, valves and other underground equipment crumbling from age or neglect is expected to exceed $1 trillion by 2035, according to a 2012 report by the American Water Works Association.

Because of the complaints to D.C. Water, a board committee has recommended that the $83.75 monthly fee for homes with two-inch pipes be discounted to the $41.35 monthly fee for homes with 1  1 /2-inch pipes.

The board could endorse that recommendation or consider charging all customers with sprinkler systems the lower fee that most residents with smaller pipes pay.

Customers who feel unfairly penalized by the new fee raise “a fair point,” Hawkins said.

About half of the 600 homes facing the highest fee for two-inch pipes are in the recently built Capitol Quarter townhouse development near the Navy Yard.

Mike Hess said his family’s water bill would double with the new fee, from about $40 per month, because of the sprinkler system.

He said a neighbor, who has an even larger pipe, would have to pay three times more.

“We understand we have 100-year-old infrastructure and in some cases infrastructure older than that,” said Hess, 39, a vice president for a trade association. “But why are we paying 100 percent more or in some cases 200 percent more just because we have a fire suppression system?”