In the historic Bloomingdale neighborhood off North Capitol Street, as much as six inches of rain turned the streets into streams. In Dupont Circle, the deluge flooded basements and cost businesses two lost days.

Yesterday, city officials and residents began assessing the damage of what amounted to a very localized natural disaster, after Saturday's thunderstorms overwhelmed some neighborhoods of the 69-square-mile capital but left Capitol Hill, Georgetown and other southern areas of the city disaster-free.

Mayor Anthony A. Williams (D), inspecting the damage in several hard-hit areas, said he would ask federal officials today to declare the District a disaster area and apply for federal aid. He also made a plea for volunteers to help clean up homes in the Bloomingdale area that were left caked with a brown film and smelling of mildew and sewage.

"We need [to get] hundreds of people to come out here and help," Williams told D.C. Emergency Management Agency Director Peter G. LaPorte after the mayor emerged from a dank basement on U Street NW. "You've got a public health hazard" because of the sewage.

Residents in numerous flood-damaged neighborhoods called their insurance companies and mopped up the remainders of the mess.

About 1,160 households remained without power in the Washington area early last night, a Potomac Electric Power Co. spokesman said. In the District, 600 homes, the vast majority in Northwest, were without power. Gas and hot-water failures also were reported.

The Emergency Management Agency has logged more than 1,000 reports of water damage since the weekend, primarily flooded basements and, in a few instances, sewage backups from overwhelmed pipes. The D.C. Water and Sewer Authority has worked since Friday evening to address hundreds of reports of wastewater and storm-water flooding and obstructed drains.

Michael S. Marcotte, the authority's chief engineer, said the Bloomingdale area was particularly hard hit, partly because of a century-old sewer that runs under Florida Avenue NW to Robert F. Kennedy Memorial Stadium.

"There are good changes of elevation and low spots where water tends to pond," he said, explaining the severe flooding of homes, businesses, streets and intersections in the neighborhood.

Williams toured four homes with flood-damaged basements in Bloomingdale yesterday afternoon, listening to residents explain how floodwaters had forced open their basement doors and filled the rooms to a depth of four or five feet.

Wearing a knee-length coat, blue jeans and waterproof boots that came up to mid-calf, Williams promised residents that the city would seek to "make you whole" for flood damage.

"All you've got to do is go into these basements and you can see: It's a disaster," Williams said after leaving a home on Seaton Place NW. "I would be on the border of insanity if my basement were in [this] state."

As late as Saturday, Cleopatra Jones, president of the Bloomingdale Civic Association, had believed that cleaning the storm drain once a week outside the English-style basement of her home was sufficient. She doesn't have flood insurance.

Yesterday, bags of sweet southern onions and cans of golden kernel corn, perched on the top steps of the basement stairwell, were the only survivors of the deluge. Down below were the muddied remains of personal effects spanning three generations: papers, books, clothes, an oil painting, a table, foam padding, Christmas ornaments and toy vehicles.

"This is Washington, D.C.," she said. "We don't have natural disasters like hurricanes, tornadoes and volcanoes. The worst thing we have is snow blizzards."

As water began to seep in Saturday, Jones unplugged appliances, placed towels and quilts under the basement door and began rearranging computers and delicate items. It didn't help. "We had Lake Erie and Lake Ontario right next to each other, and the Mississippi flowed right into it," she said.

There were vast disparities in the rainstorms' effects. The city's northern sections experienced torrential downpours after a storm system from Maryland collided with another system already over the District, said Andy Woodcock, a meteorologist for the National Weather Service. Areas that were hit hard bore visible scars yesterday. Water pressure buckled saturated stretches of sidewalk and road pavement. Rhode Island and New York avenues, two major traffic arteries, were lined with soggy rugs, ruined electronic equipment and bags of wet trash. City crews in the 2700 block of South Capitol Street distributed hundreds of sandbags to help residents shore up their homes in anticipation of more showers late yesterday -- which did not appear to cause any new damage.

More than 400 people crowded into Mt. Bethel Baptist Church, on Rhode Island Avenue NW, for a community meeting last night with Williams and other city officials. The crowd was mostly supportive, but nearly everyone had a question or complaint, and near-chaos reigned at the end of the meeting as people lined up behind microphones and sometimes talked over each other about faulty drainage, flooded abandoned buildings and water still in their homes.

"Who's going to help me? Who's going to be responsible?" asked Seann King, who said his recording studio on 14th Street NW was filled with 18 inches of raw sewage.

The D.C. Division of Transportation closed parts of three small Northwest streets to nonresidential traffic: 44th Street between Edmonds Street and Forest Lane, 27th Street between Military Road and Broad Branch Road and 48th Place from MacArthur Boulevard to V Street. The roads will be closed for at least a week, an agency spokesman said.

Last night, another road was closed after a large tree fell across Missouri Avenue NW between Eighth and Ninth streets. Fire Department spokesman Alan Etter said the tree's root system appeared to have given way in the wet ground.

Starting tomorrow, D.C. residents can place flood debris at their regular trash collection points, the Department of Public Works said. Carpets should be rolled and other items bagged. Residents should call 202-727-1000 to put in a service request.

Susannah Quandt, 47, was away when the house she lives in, at 5320 Macomb St. NW, shifted about 12 feet off its foundation Saturday night. The shift created a massive hole, exposing the basement.

Yesterday, Quandt paced nervously as engineers studied the foundation to determine whether the house could be saved or needed to be razed. Quandt, a nurse, said the house belongs to her mother, who is in a nursing home. "I'm glad she's not here to see this," Quandt said. "This would break her heart."

Flooding was also reported in the Northwest neighborhoods of Brightwood, Petworth, LeDroit Park and Mount Pleasant.

Cici Mukhtar, owner of Polly's Cafe, a bar and restaurant on U Street between 14th and 13th streets NW, said the eatery lost electrical power about 8:30 p.m. Saturday.

With candles lighting up the place, "it was actually kind of fun. People wanted to hang out and drink, and it was sort of romantic. But by Sunday, we were really over it."

Saturday night's outage also shut down most of the commercial strip along 17th Street NW near Dupont Circle for almost a day and a half.

Pepco spokesman David Morehead said that flooding may have contributed to the underground fires that caused the power loss. The underground cable failure was more serious than crews originally believed, he said, which is why it took more than 24 hours to restore power.

The National Capital Chapter of the American Red Cross has provided emergency provisions to 80 flood victims, serving 200 meals and snacks and distributing 700 cleanup kits, a spokeswoman said.

In Maryland, Little Falls Parkway in Montgomery County was closed from River Road to Massachusetts Avenue because of heavy water damage. High water caused large chunks of pavement on a bridge to crack.

Staff writers Petula Dvorak, David A. Fahrenthold, Maria Glod, Serge F. Kovaleski, Allan Lengel, Phuong Ly, Sylvia Moreno and Steve Twomey and staff researcher Karl Evanzz contributed to this report.

Portions of Little Falls Parkway in Montgomery County were closed after high water caused chunks of pavement to crack.Mayor Anthony A. Williams discusses flooding with Roberta H. Bennett, of Northwest.