Mayor Marion Barry's Far Southeast Washington neighborhood has been thrown into an uproar by a city government proposal to build a 10-story, 2-million-gallon water tower at Alabama Avenue and 30th Street SE, barely six blocks from Barry's home.

More than 40 area residents turned out at a meeting of the Naylor Dupoint Advisory Neighborhood Commission recently to lobby against plans to build the bulky, silver colored, 107-foot-high tower, which they fear will dominate their quiet residential streets.

The tower would be constructed in a sloping corner of the Hillcrest Recreation Center grounds to alleviate what officials say is a serious shortage of water storage capacity in far Southeast. The unusually large crowd seemed firmly in opposition to the plan.

"What are we going to do when they take away the children's playground?" asked ANC Commissioner William J. Hickey.

"If they aren't going to put this thing on Foxhall Road [in a posh Northwest Washington street], then they shouldn't put it in any residential neighborhood," said Commissioner Barbara Hogan.

There was a general murmur of displeasure as D.C. Department of Environmental Services director William B. Johnson, also a resident of the area, showed the citizens a model of the Hillcrest area and then had one of his aides place a scale model of the proposed tower on its intended site.

"This plan is not poured in concrete," Johnson said midway through his two-hour presentation. "No final decision has been made to build this thing here." However, Johnson described circumstances indicating that the Hillcrest site was the most likely for the tower, leading one area resident to complain that holding the meeting was "like closing the barn door after the horse is out."

"What we're talking about is critically needed water storage," Johnson said. "I feel that this is my responsibility as a civil servant."

Barry, in his unofficial role as the neighborhood's First Resident, has taken no position on the water tower. He did go along with his neighbors in an earlier fight, signing a petition early last year -- in a losing cause -- to keep a Burger King fast-food restaurant out of the area.

Hogan said later in the week that the executive committee of the neighborhood commission sent a telegram to Barry expressing opposition to the plan. Four days later, they had received no response.

She said she had little faith that having the mayor as a neighbor would help keep the water tower from being built. "After all, he [Barry] has never been able to get anything done about 'God's Dump,'" she said, referring to an unsightly parcel of land that area residents have been trying to get cleaned up for years.

Johnson's presentation to try to drum up support for the tower included not only the intricate model, complete with inch-high trees and a tennis court marked off to scale, but also a 15-minute slide show describing in detail the history of the city's water system.

William Garlow, an environmental services aide, said the storage was needed to meet peak demand in the city's highest elevations east of the Anacostia River, a strip just inside the Maryland border.

The city already has 2.5 million gallons of storage capacity in the area, Garlow said, but does not believe that this is enough to meet peak summer demand. Without the tower, he said, the city would have to pump water uphill into the area during times of high demand, a process that is becoming prohibitively expensive because of the cost of fuel to run the pumps.

Johnson said the city had explored five other prospective sites for the tower. Two, in Fort Dupont and Fort Stanton Parks, were rejected by federal officials, he said. Two others, at Stanton and Garfield schools, have been denied by the D.C. Board of Education. The fifth potential site is at the Knox Dwellings public housing project, but city housing director Robert Moore objects to putting the tower there -- leaving the Hillcrest site.

Stanton School, at Alabama Avenue and Naylor Road SE, is already the site of a half-million-gallon water tower, and Johnson said he was still "actively pursuing" the possibility of building the new tower there. He cautioned the crowd, however, that "the school board has already turned me down twice." He said he would make yet another formal appeal before deciding that the Stanton site is lost.

Despite the city officials' assertion that the additional storage is needed, they acknowledged that they had not examined preliminary results of the 1980 census, which showed a general population decline throughout the city and seemed to indicate that population was shrinking east of the river as well. That data will be examined, Garlow said, before any final decision is made.