The District must do a better job eliminating wasted and unbilled drinking water, especially given a proposal to increase utility rates by 19 percent over the next four years, Mayor Anthony A. Williams said yesterday.

Williams (D), responding to a Washington Post report that the city loses track of nearly a quarter of the drinking water it handles each day, said he will ask the D.C. Water and Sewer Authority for a briefing within the next two weeks on its strategy to prevent leaks in the 1,288-mile water system and to speed the pace of repairs on broken water mains.

"We must eliminate as much as possible, not only fraud and abuse [in city government], but waste," Williams said. "This kind of leakage is something we have to work very, very hard to get a handle on."

The water authority has proposed a series of rate increases over the next four years that would cost a typical household a combined total of about $82 a year. The first rate increase--5.1 percent--would occur on April 1, costing about $20.90 a year. Currently, the average annual bill, paid on a quarterly basis, is about $408.

Water authority General Manager Jerry N. Johnson agreed yesterday that the agency needs to improve its water-loss prevention program, an effort he said already is underway. Recently, he said, the agency has placed an even higher priority on drinking water quality improvements, in response to a 1996 agreement with the federal government after a series of violations of drinking water standards that summer.

Johnson did commit yesterday to eliminating a backlog of repairs to city water lines by next winter to avoid dangerous leaks. In January, ice resulting from a water main break on Reno Road NW that went unrepaired for 11 days was blamed for a car accident that left a woman with permanent brain damage.

The water authority will work over the next year to reduce to 20 percent the share of so-called unbilled water. In recent years the city, on average, has not issued bills to customers for 33 million gallons a day of the 135 million gallons it handles, or 24 percent.

Williams said he wants the city to follow the example set in many other cities such as Boston, New York, Chicago and Denver that have a regular program to look for undetected leaks in water lines, instead of just waiting for leaks to be called in by the public.

Johnson agreed that the water authority should have a comprehensive leak-inspection program. A consultant has been hired to begin such an effort, he said. But Johnson said he is convinced a major part of the unbilled water problem can be traced to malfunctioning or missing water meters, meaning customers are not charged for all the water they actually use.

Over the next five years, Johnson said, the water authority intends to spend $14 million to install new meters, $19 million on water storage facilities, $38 million on water pumping stations and $158 million on repairing or replacing water lines.

It is in part because of this investment, he said, that the rate increase is needed. There was a 42 percent rate increase in 1997.

Williams did not endorse the proposed rate increases--5.1 percent in 2000, 5.4 percent in 2001, 4.4 percent in 2002 and 3.9 in 2003. However, he said part of the reason the water system is troubled is because of the failure in past years to maintain it properly.

"Part of being unsure of where the water goes is the end result of years and years and years of neglect," Williams said yesterday. "Part of that neglect was under investment in all the infrastructure it takes to maintain a good water and sanitary system."