District employes, their young children in tow, showed up at a City Council hearing yesterday to lend visible support to proposed legislation that would provide low-cost child care facilities in District government buildings and agencies that employ 300 or more city workers.

The bill, sponsored by council member William R. Spaulding (D-Ward 5), seeks to set up on-site child care services similar to those provided city government workers in Los Angeles and New York. In the District, according to Spaulding, there are 41,000 city employes who need some form of day care for 25,000 preschool children and 45,000 school-aged children.

"The benefits produced by strategically placing these child care facilities in the buildings where the parents report to work will be enjoyed by both our employes and the agencies for which they work," said Spaulding, chairman of council's Committee on Government Operations, who conducted the hearing on the measure.

The council member said convenient child care would cut down the commuting time between home, the baby-sitting service and the job and would increase worker productivity and morale.

Addressing the situation in the Washington area, Diane Flanagan Montgomery, who heads the legislative committee for the D.C. Commission for Women, said 55 percent of mothers with children under 6 work.

And nearly 71 percent of women with children between the ages of 6 and 17 are employed, she said.

"One survey has shown working parents lose an additional eight work hours per year because of early departure or late arrivals to the job," said Montgomery. She noted that the lack of affordable child care often prevents low-income women from finding employment.

Testifying on behalf of the mayor, William B. Johnson, director of the Department of Administrative Services, said the city's executive branch strongly supported the intent of the proposed legislation. It would apply to new and renovated property owned or controlled by the District and where 300 or more District employes work.

But Johnson, who identified 10 buildings owned or leased by the city and having worker populations exceeding 300 and no day care facilities, said it would be too costly and disruptive to refit each building for individualized day care services. Instead, he suggested a "magnet" approach, with the District providing child care "in one building rather than two or three buildings which are geographically in close proximity to each other."

A Spaulding aide said later that child care facilities would be designed to be self-supporting and would be run by the employes, by other nonprofit organizations or as profit-making services set up through competitive bidding.