D.C. Police Chief Maurice T. Turner Jr. told a City Council panel yesterday that the city's largest drug raid, which was conducted before dawn on Saturday and netted far fewer arrests than police had expected, had been delayed two days after police were told that their plans had been leaked to drug dealers.

After the raid, several people, including a former D.C. police lieutenant, accused police of mistakenly raiding their houses. Yesterday, during a budget hearing held by the council's Committee on the Judiciary, council member Wilhelmina J. Rolark (D-Ward 8) asked Turner to explain the circumstances surrounding the raid.

Turner said police had planned to conduct the raid, called "Operation Caribbean Cruise," on Thursday, but rescheduled it for Saturday after learning that an alleged group of Rastafarian drug dealers was aware of the raid.

"In my opinion, the word on the street had inhibited us from accomplishing what we intended to accomplish," said Turner, adding that an investigation of the police operation is under way.

Turner said the police had planned the raid on 69 locations in Northwest and Northeast Washington for about 18 months, and to establish a case, had purchased $40,000 worth of drugs, twice the value of the drugs confiscated during the raid.

The money for the drug purchases came from a $320,000 police "confidential fund," according to police officials. Although Turner said police have spent as much as $200,000 for a single drug purchase, such purchases were made when police planned an immediate raid to recover the money.

Regarding "Operation Caribbean Cruise," Turner told the panel, "I wanted to know when it was going to end because we were running out of money to buy drugs."

The police department's fiscal 1987 proposed budget is $158.1 million, an increase of $9.9 million above last year's request. Turner said he plans to intensify a crackdown on narcotic organizations and to seize more personal property obtained from illicit activities.

After testimony on the D.C. Fire Department's fiscal 1987 budget, department officials also discussed a new dispatch system they began a month ago that allows the department to respond quickly to life-threatening situations and delay response to less serious calls.

Victoria Countee, the fire department's medical director, said that under the new system callers are questioned to determine whether an injured person is conscious, breathing and behaving normally before units with advanced life-support equipment are dispatched.

As a result, the fire department can vary its response time from two minutes for the serious calls to 20 minutes for victims with minor injuries, Countee said.

She said the new dispatch system was not a cost-saving measure but was designed to make sure the emergency equipment is available when and where it is needed the most.

The department's proposed operating budget for fiscal 1987 is $68.4 million, which represents an increase of $8.2 million. Fire Chief Theodore R. Coleman said that 57 vacant firefighter positions will be filled by March, a move to reduce the department's overtime budget. The department spent $7 million for overtime in fiscal 1985 and $3 million in the current fiscal year, Coleman said.