D.C. Water’s board of directors voted Thursday to lower a new fee that would have resulted in some residents paying an additional $1,000 annually for water.

Those customers will now be charged the same fee — $10 monthly, or $120 annually — as many other District residents. Some residents will be charged $6 monthly.

As previously structured, the utility’s new “water system replacement fee” would have hit District residents in newer houses and townhomes disproportionately hard — some would have been charged 10 times more than most other residents — because their homes were required by D.C. code to have sprinklers in case of a fire.

The fee, which will go toward repairing and replacing the city’s decades-old water pipes, is based on pipe size, so customers who use the most water will pay the most to upgrade the system.

Most homes have pipes with a diameter of one inch or less. But those with sprinkler systems must have larger pipes, resulting in the higher charge, because they need to be able to handle a sudden burst of water if the sprinklers are triggered. Residents complained that they shouldn’t be penalized for having mandated sprinkler systems they’ll likely never use, particularly when some of their newer, more energy-efficient homes use less water. The problem affected about 2,100 households, the utility said.

Board members, who approved the change 6-0, said they reconsidered the fee after the utility received dozens of complaints as customers began receiving a letter from D.C. Water explaining the new fee, which takes effect Oct. 1.

“They obviously made a good point,” said Matthew Brown, the board’s chairman. “We believe people shouldn’t face a higher fee because they have fire-suppression systems.”

George S. Hawkins, D.C. Water’s general manager, said the utility hadn’t realized the new charge would have a disproportionate impact on this relatively small subset of residents.

“Their reasoning made sense,” Hawking said of the complaints.

For residents with smaller pipes — about 90 percent of D.C. Water’s 105,000 residential customers — the fee will amount to $6 to $10 monthly, or about $72 to $120 annually. Under the initial plan, those with larger pipes to accommodate sprinklers would have been charged about $41 to $84 monthly, or $496 to $1,005 annually. Under the change approved Thursday, they will be charged $10 monthly.

Resident Bill Shively said his water bill would have almost doubled, to $97 monthly, with the original fee, and some of his neighbors in the Capitol Quarter townhouse development near Navy Yard would have seen their water bills triple.

“This was a significant win for our community,” said Shively, president of one of the development’s community associations. “Often, government doesn’t move that fast, so I’m a little surprised that in two weeks, they took it to heart and acted on it.”

Sprinklers have been required for new District houses and townhouses since late 2008. New apartment and condominium buildings have had to have sprinklers since at least 1987, according to the District’s Department of Consumer and Regulatory Affairs.

The system-replacement fee also will be applied to condo and apartment buildings based on pipe size. A five-story building with 140 units, for example, likely would have a four-inch pipe, which would result in a monthly charge of $561, according to D.C. Water. Building owners could divide that cost among tenants, based on their leases.

The D.C. Water fee, which is set to raise $40 million annually, follows a national trend. Water utilities traditionally have charged based on the amount of water used. However, federally required low-flow appliances have resulted in water usage — and, in turn, utility revenues — dropping, just as aging water mains have begun to fail more frequently.

Fairfax Water, which serves much of Northern Virginia, doesn’t have a separate infrastructure fee. The Washington Suburban Sanitary Commission, which serves Montgomery and Prince George’s counties, recently imposed an “infrastructure investment fee.” Residential customers in houses and townhomes, including those with sprinkler systems, pay $5.50 to $7 quarterly. Apartment and condo buildings are charged more based on the size of their pipes.