D.C. City Council Chairman David A. Clarke, concerned about the proposed closing of an 800-bed shelter and the impact of a new city law guaranteeing "adequate overnight shelter" for the homeless, has asked city officials to prepare by July 15 a comprehensive report on the District's contingency plans.

In a letter to City Administrator Thomas Downs, Clarke said he wanted to learn the District's "state of readiness" before the Council recesses for the summer July 15. Clarke said he feared that the proposed closing of the shelter at 425 Second St. NW, operated by the Community for Creative Non-Violence, coupled with Initiative 17, a law guaranteeing the homeless the right to shelter at city expense could result in a "tremendous infusion of more homeless individuals than previously cared for by the non-profit community."

Downs was out of town and could not be reached for comment yesterday.

Ever since the federal government announced two weeks ago that it plans to close CCNV's facility and give the $2.7 million that would have been spent on renovations to the city, District officials have been developing plans for those who would be displaced.

CCNV has sued the Reagan administration in an attempt to prevent the closing and to force renovation of the squalid facility President Reagan pledged to turn into a model. Crucial motions in the case are scheduled July 15 in U.S. District Court in Washington. If CCNV loses those motions, lawyers for the federal government have said they plan to close the shelter immediately.

Services to the homeless have become more urgent since March 14, when Initiative 17 became law. The referendum, overwhelmingly approved by the voters last fall, is the nation's first guaranteeing shelter to the homeless. The city, which has said it would cost $65 million to implement, has sought to overturn the ordinance in court. Since January the case has been pending before Superior Court Judge Annice Wagner.

In his three-page letter Clarke, one of the few city officials to support Initiative 17, asked Downs for a report that details housing plans and addresses the "critical issues of medical and mental health services, job training, social services and the ways which the government will move people toward self-sufficiency."