D.C. Police Chief Maurice T. Turner said last night that his department will fall about 35 officers short of attaining a congressionally mandated force of 3,880 uniformed officers next year under the budget proposed by Mayor Marion Barry.

Turner also differed sharply with several of Barry's proposed policy changes affecting the police department, including the closing of Cedar Knoll, a detention facility in Laurel for District youths, and the closing of the police and fire clinic.

Turner, responding to questions from City Council members during a hearing on the department's proposed $139.5 million operating budget for fiscal 1984, also said that the budget was not adequate to fund a proposed four-year program to hire 292 civilians to take over some administrative tasks now handled by uniformed officers.

"There's no money . . . for it," Turner said.

Turner told the council members during the hearing at Ballou High School in Southeast Washington that the police department has 3,870 officers, 10 short of the minimum set by Congress in previous budgets.

He said the department will begin hiring about 35 officers next week, but that attrition during the fiscal year beginning Oct. 1 would drop the number to 3,845. "I don't know what Congress will do" about that level, Turner said in response to a reporter's questions after the hearing.

He said the department was keeping the higher figure as a "goal."

Turner also revealed at the hearing that the city's month-old ban on the sale of drug paraphernalia is not being enforced. He said his department is working out prosecution standards, and that a letter is being sent to businesses that sell such items warning that the city would soon begin forcing compliance with the ban.

Police, prosecutors and court officials have questioned the city's ability to enforce the law, which is based on a difficult standard that requires merchants to know that purchasers of paraphernalia intend to use the items with illegal drugs.

Asked by council member John Ray (D-At Large) about Cedar Knoll, Turner said juvenile crime increased 10 percent in the city last year, although the overall crime increase was only 4 percent.

He said preliminary plans to place the youths in community shelters or halfway houses was "inappropriate." He said that with "juveniles free to roam, there will be an increase in crime."

The chief said closing the police and fire clinic would amount to a paper savings of about $2 million a year, but that costs actually would rise if officers were allowed to use private physicians to determine the extent of injuries.

"I think the police clinic is valuable and useful," Turner said. "I would have some grave concern if it were closed."