For the first time in four years, foster parents who care for 3,611 Washington children will get an increase in boarding fees, the D.C. Department of Human Resources announced yesterday.

The announcement by departmental director Albert A. Russo culminated a two-year campaign by foster home operators, who persuaded Congress earlier this year that more money should be provided to care for children who are wards of the city.

The monthly fee for children under age 12 will rise from $182.50 to $253. The fee for children 12 and older will rise from $196,75 to $265.

Russo said the increased payments will be made in checks to be mailed to 1,042 foster home operator next Friday, and will be retroactive to eh start of the fiscal year on Oct. 1,

"I think it is well needed and I think it should have been done a long time ago, with all the inflation we've had and all the food prices and utilities like they are," Mary Grayson, president of the D.C Foster House Association, said yesterday after hearing of the increase.

Last April, Grayson led a delegation of foster parent's who testified before the House D.C! Appropriations Sub-committee, headed by Rep. William H. Natcher (D-Ky) Congress had turned down a similar plea a year earlier.

In addition to the basic fees, Russo said his department's social rehabilitation fees to pay the costs of additional services to children with special needs, such as those with handicaps or emotional problems.

Russo said he was eager to let foster parents know of these special rates. "An increasing number of handicapped children, particularly those with emotional problems and mental retardation, are coming into our care because of parental neglect," Russo told a news conference.

In additon to the increases in monthly payments, the department approved higher payments for foster parents to buy clothing for the children when they first arrive in the homes.

The old payment was$63 regardless of the age of a child. The new payment will be $125 for a child under 12 and $150 for an older child.

Grayson, in asking for this increase, told the congressional committee last April that sometimes "the kids come entirely naked . . . In the winter we have to buy coats and boots and things . . . We find ourselves out $200 before the child gets in the house, plus we have to feed it six weeks before we can collect."

The old fees were last raised in 1974, and were based on living costs in 1973.

D.C. auditor Matthew S. Watson recently issued a report criticising the proposed increases, saying they were greater than the extent of inflation from 1973. Russo told reporters yesterday that he regarded Watson's report as "absolutely specious if not "roneous."