The D.C. Department of Housing has decided to put public housing for the first time in Ward 4, the sprawling community on the eastern edge of Rock Creek Park where many socially prominent blacks and black professionals live.

But, wary of this community's reputation for successfully guarding its property against liquor stores, halfway houses and apartment buildings, the city approved a relatively uncontroversial kind of public housing -- no families and no children, just 21 elderly persons.

They will have homes in a now-vacant apartment building at 5336 Colorado Ave. NW. that the federal government intends to sell to the city for $1. The building is expected to be ready for occupancy sometime next year.

Ward 4, characterized by a large percentage of homeowners, including many persons influential in city government, is the only one of the city's eight wards with no public housing or subsidized housing for families with low and moderate incomes.

A scarcity of vacant land, high land costs and a lack of offers for the city government to buy existing apartment bulildings are the reasons the ward has no subsidized housing, according to city officials.

Most of the city's 12,000 public housing units are located in large, sprawling projects east of the Anacostia River, in Wards 7 and 8. These often ill-kept projects are considered by some to be breeding grounds for crime. Homeowners often oppose the location of public housing in their neighborhoods for fear it will depress property values.

The purchase of the Colorado Avenue building is part of the city's ambitious program to scatter 2,000 new public housing units -- single family homes, cooperatives and small apartment buildings -- throughout the city because of the social problems spawned by large housing projects.

The city launched the expanded scattered-site program two months ago, when it purchased a small building in Southeast near Fairfax Village, and ran into a storm of opposition from many of the young, black middle-class professionals there.

The homeowners protested the use of the building at 3810 Southern Ave. for families, saying they feared large numbers of children and poor maintenance that would result in a neighborhood eyesore.

To blunt the community opposition, city housing officials were going to allow some of the homeowners to screen prospective tenants. But the federal government said such a plan was illegal.

Housing officials have apparently saved themselves from such opposition this time because the elderly are usually accepted in communities since they have no children and generally keep up their buildings.

"I don't approve of low-rent housing here," said a long-time homeowner who lives across the street from the Colorado Avenue building.

"It makes the neighborhood terrible because they don't keep it up. . . . Everybody around here tries to keep their property up, then they come in with low-rent housing." But, she added, "Senior citizens might be okay."

Charlie Black, president of the Brightwood Community Association, said that while the ward has a reputation for fiercely guarding its residential character, "I don't think they would overhwhelmingly oppose" public housing for the elderly.

The federal government took ownership of the three-story, tan brick building in 1975 after the Nineteenth Street Baptist Church tried to renovate the building for moderate-income families but abandoned its plan because of disagreements with the general contractor.