A rash of water main breaks flooded District streets and left behind bone-dry faucets this spring as the Water and Sewer Authority struggled to contain a new series of gushers.

This latest soaking isn't all bad news, however. Many recent eruptions are probably tied to a series of capital improvements to the entire system, according to WASA officials. While beneficial in the long run, the work can temporarily wreak havoc on the water pressure in miles of aging and corroding cast iron pipes, causing them to burst.

There were main breaks at 190 locations in the city from January to June this year, a steady stream that peaked with a massive eruption May 21, when a 24-inch main burst and left five hospitals and tens of thousands of residents and businesses in Northwest Washington without running water.

The District has been bedeviled by water main breaks for years, as 1,300 miles of cast iron water mains, some dating to the 1800s, crack, buckle and burst, seemingly all at once.

The issue came to a head in fiscal 1999, when a calamitous winter logged 376 breaks and the city held hearings and investigations into the problem. WASA pledged to start a 10-year, multimillion-dollar improvement plan for the entire system, and the agency says the plan is running on schedule. Since then, the water main breaks have never reached the contemporary low of 197 that happened in fiscal 1997, according to WASA records.

So far, 306 breaks have occurred during this fiscal year, from October to May 20, according to WASA. Most breaks happen in the winter months, but this spring was unusually problematic, said WASA spokesperson Michele Quander-Collins.

"In April and May, we had a rash of main breaks," Quander-Collins said. "We believe a lot of that was because of increased pressure in our system."

The spring episodes have bumped up the fiscal year's numbers, which seem to be close to the pace of 1999, when 578 breaks both flooded and parched neighborhoods all over the city. Because WASA looks at the totals by fiscal year, officials believe the worst is behind them, with only three more summer months to go before they have to assess the water main damages for the year, said D.C. Councilmember Carol Schwartz (R-At Large). She held a public works committee hearing on the recent water main breaks earlier this month.

"I was worried that we were going to have another bad year, but with the winter months behind us, it may not be so bad," Schwartz said. "I really think WASA is trying hard. They're dealing with an aging system and iron pipes that are more than 100 years old in some places."

The most recent main breaks from this spring were linked to the $40 million rehabilitation project at the Bryant Street Pumping Station, which delivers potable water to about 500,000 residents and to commercial and government customers in the northern quadrants of the city. It is also WASA's principal pumping station, Quander-Collins said.

The station, originally constructed in 1905 near the McMillan Reservoir in Northwest, was last renovated in 1954. Before the most recent renovations began, WASA warned customers that they might experience low water pressure during the work. The opposite happened, and unusually high pressure triggered a spree of 68 water main breaks the last two months, most in Northwest and Northeast, Quander-Collins said. The most extensive one was discovered at 4:15 a.m. on May 21, when water began appearing at the corner of 12th and U streets in Northwest, said Kerry Payne, deputy operations chief at WASA, during Schwartz's hearing.

Within the next few hours, crews pinpointed the break at 13th Street and Florida Avenue NW, in a two-foot-wide water main line that was installed in 1895. When they realized how many neighborhoods feed off the 4 million gallons that come through that water main every day, they figured out that five area hospitals would be affected, Payne said.

The fire department was asked to send tanker trucks to the hospitals to provide high-pressure water should a fire break out in any of the facilities while crews repaired the main, Payne said.

Businesses all over Adams Morgan, Columbia Heights and Dupont Circle were hit hard. Many had to close for much of the day.

Tryst Coffeehouse in Adams Morgan had no water from opening time at 6:30 a.m. until about 3, said general manger David Fritzler.

"That Saturday was a beautiful day; it would've been a great day for sales," Fritzler said. But no water means no coffee, and all they could sell was bottled drinks. He estimates that the losses that day totaled at least $6,000. And the business has been forced to close because of water problems several times in the last few years, he said.

Service was restored to the hospitals and to some residents and businesses, including Tryst, by that afternoon, but others were dry until the next day, after debris from that water main broke another, smaller line. Major repairs on the 13th Street and Florida Avenue main began June 20 and are expected to be complete July 11.

Council member Jim Graham (D-Ward 1) said he was particularly dismayed that so many hospitals were affected. Each hospital has an emergency supply of water, so patients were not in danger, but Graham is asking them to reevaluate and augement their supplies. "It could've been a catastrophe," Graham said. "It wasn't, because everyone acted efficiently, but it's a good time for us to look at the hospitals and their reserve supplies."

The exact cause of that break is still under investigation, but crews suspected it was the result of more than 100 years of corrosion aggravated by water pressure thrown out of equilibrium by major renovations, Quander-Collins said.

The city's topography is a challange, with a 410-foot differential in high and low points throughout the District. Those elevations are divided into seven different pressure zones. This year's water main breaks have been concentrated in the northeast and northwest quadrants of the city, areas that have had wild fluctuations in water pressure thanks to the Bryant Street pump renovations, she said.

Jerry N. Johnson, general manager of WASA, told Schwartz's committee the main break emphasized the need for continued investment in the ongoing improvements of the aging system.

"With 1,300 miles of water pipes under our streets, some over a hundred years old, water main breaks are unavoidable," Johnson said last week. "The difference between the break numbers for 1999 and the numbers for today is attributed to the virtual elimination of repair backlogs and WASA's investment in a $570 million capital program to replace and rehabilitate pumps, water lines and valves in the distribution system."

To help fund some of those improvements, WASA proposed a 5 percent rate increase last year, but that was met with howls from residents and elected officials who were still reeling from the lead crisis in District's water. That rate hike didn't pass, but another one, 6 percent this time, was proposed this spring.

The rate increase, which would add about $2.40 per month to the typical water bill, is needed to help pay debt service on bonds that are funding improvements to the utility's distribution system, WASA officials said. Officials will hold a series of public meetings to explain the rate increase and solicit input from ratepayers. WASA's board of directors will vote on the proposal later this year.

A lesson was learned from the May 21 episode, Johnson said in his testimony at this month's hearing: "The authority's effort to evaluate the status of existing infrastructure is critically important. . . . We must continue to ensure that we allocate resources to this area accordingly. It must remain among our highest priorities."

Schwartz agreed that the water authority cannot let those improvements go to the back burner and that they must be done continuously, on a piece-by-piece basis.

That was not what Johnson said was happening in 1999, when a 40 percent shortage in street crews and a backlog of more than 100 breaks left the city with ice patches and buckled roads all winter.

When he had to answer for that at a committee hearing that year, Johnson told Schwartz: "Let me be candid. We have not had a system of repairing breaks in a timely manner."

After the hearing this month, Schwartz said she was convinced that Johnson has changed that.

"I think they're working hard to put linings in the pipes; they're trying to replace the joints, trying to find minor leaks and breaks before they become major," she said. "But it's an aging system, with old, cast iron pipes from around 1900. This will take some time."

Workers survey the damage created by a break in a two-foot water main at 13th Street and Florida Avenue NW in May that disrupted service to five area hospitals and tens of thousands of residential customers. Workers respond to a massive early-morning water main break on May 21 that disrupted service in the Adams Morgan area.Workers are still repairing a massive water main break at 13th Street and Florida Avenue that occurred in May.Repair work on a water main break at 13th Street and Florida Avenue will continue until later this month.