The mortgage finance crunch in metropolitan Washington is getting more intense almost daily, and lenders see no end in sight. Rates on home loans now exceed 15 percent at most lending institutions still in the market, with only a handful offering funds in the 14 percent range. The departure of the area's largest savings and loan association, Perpetual Federal, from the market this week -- after it established a 17 1/4 percent floor on new conventional mortgages -- was symbolic of the distress being experienced by the lending community.

Martin Wiegand, chairman of Metropolis Federal Savings and Loan Association and president of the Metropolitan Washington League of Savings Associations, warned that if money market trends continue on their present course into the spring, "We've got one hell of a crisis coming.

"Our back is to the wall," said Wiegand, who has closed his institution's doors to new mortgage borrowers, including depositors. "WeVe got deposit money flowing out of here like we've never seen before, and we've got absolutely nothing available to lend out" for home buyers or builders, he said. a

Metropolis lost $3 million in deposit assets in January and February -- a sharp 60-day decrease for an S&L with $100 million in total assets.

Virtually all other local S&Ls also saw depositors pull out funds in large chunks in the past two months. Perpetual, for instance, lost $2.25 million in February alone, according to chairman Thomas Owen. Perpetual's assets total $1 billion, making it the 85th largest in the U.S.

Washington Federal Savings and Loan Association, another major home lender for the District and the suburbs, lost $2 million in net deposits last month, said Howard Orebaugh, senior vice president. Its assets total $285 million, but it services nearly $500 million worth of mortgages.

The rapid outflows of funds are occuring here, S&L executives say, despite record interest rate yeilds offered depositors through the S&Ls' insured, six- and 30-month money market certificates. The latest yield permitted on six-month, $10,000 minimum certificates is 14.8 percent, up from 13.7 in February. The yield on 30-month certificates was capped administratively by federal regulatory agencies at 12 percent last month.

A high proportion of the S&L outflow is ending in a private money market mutual funds, which gained $6.8 billion in new deposits nationally last month alone. The thrift institution-based housing finance system in areas such as Washington -- which has high demand for real estate -- is being wrung dry of lendable funds.

The S&Ls still actively in the market are selling almost all their new loans to large secondary mortgage market investors such as the Federal Home Loan Mortgage Corp. at yields of 15 percent or more.

The record rates have also drastically reduced loan requests by consumers here. Local S&Ls have no precise data on the drop in loan and demand during the past two weeks, but industry estimates go as high as 50 percent.

"No one wants to pay 15 or 16 percent for a 30-year loan," says Metropolis' Wiegand. "People aren't even trying to buy -- not since rates started going over 14 percent."

The impacts of the sudden sharp reductions in mortgage fund availability on the real estate industry as a whole are only beginning to be felt, but in the words of one S&L executive, "We're very, very worried for our customers" -- home buyers, sellers and builders. CAPTION: Illustrations 1 through 4, THE MORTGAGE DILEMMA -- When mortgage rates reach 17 percent, a two-income family making $50,000 a year can only qualify for a $62,000 loan, using the standard lending guidelines regarding income and monthly payments. At 10 percent, the family can easily qualify for a $100,000 mortgage, but at 14 percent, only $75,000. By William T. Coulter for The Washington Post