The D.C. and federal governments and a Georgetown developer yesterday agreed on an elaborate plan for the Georgetown waterfront that by 1984 could transform the current tawdry industrial landscape into an area including a public park and terraced, luxury town houses.

However, the estimated $60 million development plan the culmination of years of public and private feuding and a protracted court fight over the use of the scenic and extraordinarily valuable Potomac River shoreline was immediately denounced by militant Georgetown residents who want only a park along the riverfront.

The agreement yesterday was a crucial first step toward eventual construction of a 160-foot-wide strip of national park along the river from just west of Key Bridge to Rock Creek, as well as development of 375 townhouses costing between $200,000 and $300,000 offices and retail stores.

The National Park Service would construct the park at a cost expected to range from $7 million to $12 million. A joint venture of Chessie Resources and Western Development Corp, would build the residential and commercial complex between the Whitehurst Freeway and the strip park west of Rock Creek. It would cost "well in excess of $50 million," according to Herbert S. Miller, Western's president.

He predicted that construction would start in the fall of 1980 and be completed in three to four years. But the development plan still has important hurdles to clear before the first bulldozer can roll. The federal Commission of Fine Arts has the authority to advise the city government on the design of the project, while the city council has to approve removal of the extensions of Thomas Jefferson, 30th and 31st streets, from K Street to NW to the Potomac that now exist only on city planning maps.

Such people as Interior Secretary Cecil D. Andrus, city planning director James O. Gibson, National Capital Planning Commission chairman David M. Childs and Miller sat at a table along the Potomac River at Thompson's Boat Center in a broiling morning sun to sign the 11-page pact outlining the terms of the development of the 17.7-acre riverfront tract.

They, along with Sen. Charles McC. Mathias Jr. (R-Md.), extolled the virtues of the development plan, the product of a group formed by Mathias called the Georgetown Waterfront Task Force.

As jets roared overhead on their way to National Airport, Mathias called the pact "a workable solution to a very difficult problem." Andrus said the development would be "a final jewel in the necklace" of parkland along the Potomac that runs 184 miles from Cumberland, Md., to East Potomac Park in the District.

The tract now would probably stand an excellent chance of winning an award as one of the ugliest riverfronts in America. The Super Concrete Co.'s massive concrete-making machinery dominates the waterfront skyline. It is flanked by a public parking lot, a lumberyard, a garage truck parking lot, and a lot where the District impounds cars.

All of that would be removed if the development plan becomes a reality. As part of the plan, the Inland Steel Co, will sell 3.7 acres it owns along the riverfront to Chessie, which also owns some of the land, and to Western for an amount that Miller would describe only as "in eight figures, well in excess of $10 million."

After signing the development pact, the officials and many of their aides viewed the tract while they cruised up the Potomac and underneath Key Bridge.

But the controversy surrounding the development was not far removed from the idyllic boat trip. Several Georgetown residents who oppose any development other than for a park along the waterfront waited at a dock for the boat to return to give reporters their side of the dispute.

Caren Pauley, one Georgetown advisory neighborhood commissioner, plaintively asked a reporter, "Do you think a 160-foot strip is a park? The traffic, nosie and pollution in Georgetown) have become unbearable."

As Miller and other development officials pulled away in the boat from one dock, Pauley shouted at no one in particular, "Take him away and don't bring him back!"

Miller smiled and waved at her.

The Citizens Association of Georgetown, which spent $50,000 in a court battle unsuccessfully fighting the mixed-use zoning approved by the city for the Georgetown waterfront, said, "We want a park not a pathway." The group said it supports a bill introduced in the Senate Thursday by Sen. Mark O. Hatfield (R-Ore.), a Georgetown resident, calling for the federal government to buy the Chessie and Inland Steel lands and turn the whole tract into a park.

Mathias made a similar proposal at one point, but the idea went nowhere. The cost of such a purchase is estimated at between $20 million and $25 million, a figure that several people connected with the proposed development think Congress would be reluctant to approve.

But Pauley was adamant, saying "By hook or crook we're going to get that money."

Miller said the town houses would all face the river in a terraced layout in which the roof of one town house would be the garden for the one above. He said the housing units, while all contained in one building would have a "textured look" in that some would be set back from others and the heights would vary so that the sameness of ordinary town house developments would be eliminated.

He said the structure would range in height from three to six stories and at one point would shield the Whitehurst Freeway from the Virginia shoreline across the Potomac.

The housing units would range in size from 1,200 to 1,800 square feet, he said, and would go on sale when construction starts. Miller said he expects the first buyers could move in within two years. CAPTION: Map, Georgetown Waterfront, The Washington Post; Illustration, Plan for Georgetown waterfront shows park flanked by town houses rising to Whitehurst Freeway.