Gerald Donovan is a deal maker. He owns a thriving restaurant, marina and bingo hall in the town of Chesapeake Beach. He is a savvy real estate developer with plans to build a 60-room waterfront hotel nearby. And as a Democratic power broker and town mayor for 16 years, Donovan has cobbled together federal, state and county support for local projects from affordable housing to a boardwalk.

But Donovan's latest proposal--a simple land swap between the town and Calvert County--is causing more waves than the tidal pool in the town's popular water park.

And the turbulence, expected to peak Thursday evening at a public hearing, suggests Donovan's famous power base may be fraying in both the county and his home town, where his father and grandfather served as mayor before him.

"The climate is changing," said Ginger Crawley, who has been the town's treasurer and Donovan's right-hand aide since he hired her 15 years ago. "There are a lot of newcomers in town, people who don't know Gerald, who don't know what he's about. . . . There are a lot of people who are jealous of Gerald, because he's so successful."

At issue is the Kellam ballfield, a piece of county land in the heart of the town's recreational complex off Route 261. The ballfield sits next to the town's $2.3 million water park, which has been growing in popularity and revenue since it opened five years ago.

The town wants ownership of the three-acre Kellam field. In exchange, the town is offering to give the county a lot of similar size just east of Kellam field. To sweeten the deal, Donovan said the town will create a new ballfield, playground and tot lot on the land it gives to the county.

Donovan said he wants to build new parking spaces on part of Kellam field and preserve about a third of it--60,000 square feet--for "future improvements." The town is considering a range of uses, including a community swimming pool, a year-round recreational facility and an expansion of the water park, he said.

"People want to believe this is about the water park, but how's this about the water park when I'm telling people I have no plans, I just want to keep all options open?" Donovan said.

He said he can't understand the opposition to his land swap proposal, which he says will solve existing parking problems, position the town to take advantage of future development of Kellam field and give the county more than $500,000 worth of improved recreational land. "It's a win, win, win situation for everybody," he said.

But critics--led by Town Council member Patrick J. Mahoney--are convinced Donovan intends to use Kellam field to expand the water park. They point to a design for an expanded water park prepared last year by Paddock Pools, the Rockville-based company that designed and maintains the current park.

Earlier this year, the mayor formed a committee to explore possible uses for Kellam field but then disbanded it abruptly. "I opened it up [to the community] and made a mistake in my opinion," Donovan said. "The decision makers on this are the Town Council and that's who should be discussing it."

Critics say the committee was killed because members didn't support an expanded water park or other similar ideas. "He held two meetings to try to ramrod the water park idea through and then he disbanded the planning committee because there were objections," said Susan Haynes, who lives in the Winward Keys condominium complex across the street from the water park.

"We were told to use our imagination, but that the end result should look like a water park," council member Mahoney said.

Donovan took a road trip with town engineer John Hofmann and several others to Fredericksburg, Va., to check out Funland, an indoor-outdoor family amusement park that features a "bumper boat" pool, go-cart course, miniature golf and batting cages. Donovan now dismisses Funland as "too commercial" to be replicated in Chesapeake Beach.

But the leaders of the town's two largest condominium complexes, which are across Route 261 from the water park and flank Donovan's Rod 'N Reel restaurant, say the mayor clearly wants to build something on Kellam field. And any expansion of the water park or new attraction will create a raft of problems, they say.

"We have no roads and if we had the expansion of the water park, it would take you all day to drive four miles through the center of town," said Chuck Quinlan, president of the Chesapeake Station Homeowners Association, which represents owners of 108 condominiums. "Look, he's done some very good things. Kudos to him for the water park, but this is a small town and we need to really to discuss what is going on. He doesn't make anything public, doesn't tell you much about Chesapeake Beach until it happens."

Complicating the local dispute between Donovan and the condominium owners is the fact that the mayor needs the approval of the county commissioners for the land swap.

So far on that issue, Donovan has only one clear ally on the board, Commissioner Patrick M. Buehler (D-St. Leonard). Commissioner John Douglas Parran, an independent, has indicated he might also back Donovan. But the three other commissioners--Barbara A. Stinnett (D-At Large), Linda L. Kelley (R-Owings) and David F. Hale (R-Owings)--are sympathetic to the homeowners.

And they have demanded that Donovan present his plans for the land swap in writing and then hold a public hearing on the matter--orders that make Donovan bristle. "I have been elected six times," said Donovan, 50, referring to his two terms as Town Council member and four as mayor. "I am a public official just like them. I serve the community of Chesapeake Beach. David Hale does not dictate to Gerald Donovan. Period. . . . We're not in Bosnia or Serbia. This is Calvert County."

Donovan has scheduled a 7:30 p.m. hearing on the land swap Thursday in Town Hall. The county commissioners say they will schedule their own public hearing on the proposal in the weeks ahead.

Donovan said he wants community input but he won't be deterred from his vision for the town. "All of this boo hoo hoo about the water park is just petty politics," he said. "I'm on my course, and that is about improving what's there."

But changing demographics in the tiny town of 3,500 mean the end to carte blanche for the mayor, Quinlan said.

"There's a whole influx of people from Virginia, the D.C. corridor coming into town and they're younger, more aggressive, more active and they're taking a good look at the town itself," he said. "It's a beautiful town and they want to keep it that way. They don't want to turn it into Ocean City."