No one disputes that the Georgetown waterfront is a mess.

There is the cement factory, a grimy hulk that dominates the narrow strip of land. There is the D.C. Department of Transporation parking lot, a holding pen where disgusted drivers come to pick up cars the city unceremoniously snatches off the streets. And looming over it all is the Whitehurst Freeway, casting much of the strip into perpetual shadow.

It is hard to remember, sometimes, that there's a river nearby.

The waterfront has been in this sad state for years, and prospects for change are still clouded. It is still far from certain that Western Development Corp. will get to build a hotel/office/condominium complex anytime soon.

But some observers sense a change in mood, a strengthening of Western's hand and a weakening in the position of the coalition of community groups that hopes to turn the entire area into a federal park.

"I think the larger community has the momentum now," said City Council Chairman Arrington Dixon. "I mean the broader community outside the Georgetown. I think people view (the development) as important in terms of land use, revenue, jobs and housing."

Dixon said he does not anticipate the kind of council fervor against the development that was evident last year to resurface. "This thing is vital to the whole city," he said. "It's the kind of revitalization the city needs."

Mayor Marion Barry has changed his tune as well. Barry, who received support from historic preservationists in his 1978 race, continues to maintain that his "personal preference" would be for the entire 18-acre Georgetown waterfront parcel to be turned into a park. But two weeks ago, his planning director, James O. Gibson, told a hearing on the plan that the city "strongly supports" Western's project.

In his new stance, Barry tells potential re-election supporters that he tried to keep big-time development off the waterfront, while at the same time he assembled resources of the city are hard at work to secure the millions of dollars in tax and tourist revenue the development would bring into District coffers.

The fate of the plan is now with Carol B. Thompson, Barry's agent for historic preservation. She must decide whether the proposed development fits into the "historic character" of Georgetown. If she decides that it does not, the city cannot issue a building permit. if she decides that it does, the city can proceed to grant the necessary permits and approvals.

The proponents of the development came to Thompson's series of hearings, which ended last week, with a slew of attorneys and an assortment of consultants including Robert Mendelsohn, a former Carter administration official who ran the as-yet unfruitful effort to spruce up Union Station.

Even if Thompson rules in favor of the development, the opponents have a number of options, including trying to get the City Council to revive a bill proposed last year that would declare the area part of the floodplain of the Potomac River. The council was considering a moratorium on floodplain building, and that kind of tactic could effectively kill the development.

That bill was introduced by Polly Shackelton (D-Ward 3), who represents Georgetown and has been one of the council's strongest supporters of the all-park idea.

But because of the Reagan administration's statement that it will not consider adding any new parks, even Shackleton believes the all-park idea is now shaky. And there has been little interest in resurrecting the floodplain moratorium.

Donald H. Shannon, president of the Citizens Association of Georgetown, acknowledged that many people "just hear about all the revenues that will be created, and say, 'Well, all right.'" But Shannon disputes the revenue figures, and says that parking and other problems will outweigh the possible benefits of the project.

But Shackleton speaks with less confidence. "All things being equal, I support the park," she said. "But there are going to be some problems. I think it looks less possible than in the past."