The Fine Arts Commission yesterday proposed two parks and an underground parking garage as an inexpensive solution to the perennial problem of the Georgetown Waterfront.

The Commission, in an unusual shift from its role as watchdog of the city's design, suggested the parks to replace sanitation trucks, construction materials, a parking lot and an abandoned incinerator now on the sites.

An urban park would be developed on city-owned land between K Street and the Potomac River, running from 31st Street to Key Bridge.

To replace the lost parking spaces, the Commission recommended a parking garage be set into Brickyard Hill, the site of the old District incinerator. The steep hillside would be terraced and topped with the small overlook park.

Long-range planning for the area move or improve Whitehurst Freeway has been held up pending plans to reand develop a comprehensive plan for the land. The Commission in its letter suggests that "without complicated plans or great expense" the city would have a park that would not impede any grandiose ideas for the area's future.

J. Kirkwood White, assistant director of the Municipal Planning Office, said the city has already taken the first steps toward implementing the proposal. "We are trying to find places now to put the trash trucks, the large pile of salt and the bridge construction material. We're working to sort it all out and it really isn't too difficult.

"The beauty of the commission's plan is that it is relatively simple. If all goes well -- and a way is found for the city to legally build and lease the parking garage -- the whole project could be finished and in use in two years."

Some problems in implementing the plan were brought up by Ben Gilbert, director of Municipal Planning. "We don't want to deal with the Georgetown Waterfront Piecemeal," he said. "We've been studying alternate solutions to the waterfront, including the problem of the Whitehurst Freeway. We have decided its removal is not practical in the near future and maybe never. So we are looking for ways to make it acceptable."

One of the difficulties with the commission's proposal is that the District is forbidden by Congress to build parking facilities. However, it might be possible for the District to lease Brickyard Hill to a developer who would build the garage according to the District's requirements.

The Fine Arts plan would have the entrance to the garage on K Street.The overlook on top would be at South and 31 Streets.

The proposed garage site is now occupied by the District's abandoned incinerator. A proposal to use the building for a dinner theater was one factor in sparking the Fine Arts plan.

In the letter to Mayor Washington, Fine Arts Commission chairman Carter Brown said the small overlook park "could open up one of the most magnificent views in all of the District of Columbia while eliminating industrial and automobile impact to some of the very historic structures in this vicinity. Since we understand that the District is currently considering proposals for renting or adaptively reusing the old incinerator, we thought it would be an appropriate time to make an alternate suggestion which may have higher public value.

"If properly designed, terraced, and landdscaped, such a structure could eliminate the need for all parking on the water's edge and easily double or triple the existing 300 commercial parking spaces along K Street. The annual income to the District from such a structure may well make it a profitable venture."

The Fine Arts proposal, according to Don Myer, assistant secretary of the commission, would also include removing a commercial garage presently in the area.

A proposal by Inland Steel to build a Washington marina (to be called Georgeton marina (to be called Georgetown Harbor) on the site now occupied by Super Concrete Co. at 3040 K St. is currently blocked by a suit filed by the Georgetown Citizens Association.

The marina for small pleasure craft would adjoin the proposed park. Inland Steel owns the only land along the waterfront in private hands, according to Arthur Cotton Moore, the architect who designed the marina for Inland.

The suit against the District Government calls for the waterfront to be zoned according to a comprehensive plan. The suit has been heard but no judgment has been handed down yet.

Olcott Deming, president of the Citizens Association of Georgetown, said he had not yet seen the Fine Arts Commission proposal, but in general his group was in favor of parks, though more dubious about parking. "We are very much opposed to commercial development of the waterfront," he said. "The area is very historic, it was the old port of Georgetown. Our organization, the Advisory Neighborhood Council and the Committee of 100 on the Federal City have all favored a park on the waterfront flood plain."

For some time now, the city has been discussing proposals for the area with the National Capital Planning Commission, the Park Service and Georgetown citizens groups. A $250,000-study by the Georgetown Planning Group (requested by the National Capital Planning Commission) has been circulating among interested agencies since February 1975. That study also champions a park along the area, while recommending low and medium-rise developments south of M Street instead of the high-rise buildings now permitted by zoning regulations.

Myer said the Fine Arts Commission would like to see tennis courts, benches, walkways and perhaps a cafe, but at least quiche vending wagons, in the park.

Brown, whose own Watergate apartment view narrowly misses the Georgetown Waterfront, said he feels the "whole image of the city is determined by the waterfront. And since so many people come into the country through Dulles and National Airports, the first view they see of the country is the beauty of the palisades, Roosevelt Island and Hains Point. Now the Georgetown Waterfront is the visual blight in what could be an aesthetic triumph. The time has come to change it."

There is just on more problem. Mayor Washington has yet to receive Brown's letter, sent by messenger yesterday morning.