More than 200 persons were evacuated from their homes in the predawn hours yesterday after a water main burst near 12th and K streets SE, sending thousands of gallons of water into the streets and nearby residences, flooding some basements to a depth of 6 feet.

Henrietta Green, who lives at 921 12th ST. SE., said she was awakened at 3:45 a.m. by the shouts of a neighbor that water was spewing from the broken pipe. She said she ran to the basement, where the water "was pouring in like a river."

Clara Faulk awakened shortly after 3 a.m. to see her 1978 blue Grand Prix submerged in the parking lot of her apartment building at 1000 12th ST. SE. "It floated back from the curb and I just prayed it would stop." It finally did, in the middle of the parking lot.

Some residents complained that their personal belongings could have been saved from damage or destruction if city officials had reacted sooner.

"I want to know what took them [city workers] so long" to cut off the water, said Sally Patterson, who lives at 1311 K St. SE. Patterson said she called the city water department at 2:30 a.m. to report the rupture, but the water oficials did not get workmen to the scene until 5 a.m.

According to water department officials, the department received the report of a possible water main break at 3 a.m. Then at 3:19 a.m., the fire department workers to report to an area between 11th and 13th streets on K Street.

Officials said it took workers until 6 a.m. to determine the precise dimension of the rupture, and what the proper procedure was to cut off the spouting water without unnecessarily disrupting service. The water was cut off at 6:21 a.m., officials said.

"You can't shut it off at one time," said George Stryker, an official in the water department. "We did it as quickly as possible."

The water main rupture added an additional headache for early-morning commuters who found traffic tied up by the closing of several streets. At one point, police had part of the Southwest Freeway closed because flooding a parking lot overlooking the freeway was pouring onto the freeway. Also police closed I and K streets between 11th and 13th streets and 11th Street between I and M streets.

Stryker said officials do not know how much water was lost. He said the 30-inch main has the capacity to handle 130,000 gallons of water a minute.

He said that service was not interrupted to any customers during the course of the emergency. Police said there was no mass evacuation of the neighborhood.

Stryker said that once a rupture occurs, pressure in the main drops sharply, thus reducing the force of the outpouring of water.

Stryker said the main pipe that ruptured was put in the ground in 1904. He said officials were replacing the ruptured pipe with a 10-foot length of new 30-inch pipe.