Citing a projected $166 million shortfall next year, Astorino called for shared sacrifice and said layoffs for hundreds of county workers was a last resort but "likely."
He said short-term cuts will include closing the Croton Point Park pool, ending bus service to New York City and eliminating the police mounted unit.
There will also be a later opening time for the county-owned Rye Playland Amusement Park — with more changes looming next year for the historic shoreline park.
"The land is county-owned and it's parkland, so we would not seek to de-dedicate it," he said. "You're never going to see condos at Playland. That would never happen.
"But the way we operate it, everything is on the table with regard to the ice casino, to the amusement park, to the beach," Astorino said. "All of that is in discussion right now, including the management of Playland."
The first-term Republican vowed not to raise property taxes in 2011, but said the price will be steep.
He will make $16 million in cuts this year, and make up the gap by slashing nonvital services, leaving positions vacant, reviewing existing contracts and consolidating county departments.
He said long-term cuts would address the projected 2011 gap. If enough can't be cut, the difference will be made up with layoffs.
"Basically we're looking at a structural problem in county government," Astorino said. "In the past, what has happened is we have used one-shots and rosy projections to get to where we are, and it's just continuing to kick the can down the road.
"Well, the day has come where that can is no longer able to be kicked," the county executive said. "We have to deal with reality, and we will deal with a responsible budget starting in 2011."
Andrew Spano, a three-term Democratic incumbent before Astorino ousted him in the November election, could not be reached for comment.
But Westchester County Board of Legislators Chairman Ken Jenkins, a Yonkers Democrat, said Astorino's assessment of the coming budget was premature.
"The county executive's budget deficit pronouncement for (fiscal year) 2011 is premature, given that the 2009 fiscal year hasn't closed yet, we have not received actual revenue data for the first three months of 2010, and the administration has no idea how cuts in our state aid will impact the county," Jenkins said in a statement released Tuesday.
Jenkins noted that the current budget, approved in December, was a balanced spending plan.
In a separate statement, Legislator Thomas Abinanti of Greenburgh, the board's Democratic majority leader, cited Astorino's recent move to hike the salaries of two top aides by $18,000 each.
"I am concerned about County Executive Astorino's credibility in asking for sacrifice to control spending when he has already set the wrong example by increasing the salaries of his top aides," Abinanti said. "It is cause for watchful, extra careful management, not panic."
Still, the Business Council of Westchester commended the county executive, saying in a statement that he "has acted responsibly in acknowledging the difficult financial environment that confronts Westchester's residents."
Legislators approved the current $1.8 billion budget by a 9-8 vote.
That budget, the last submitted by Spano, raised county property taxes by 2.9 percent. The increase would have been nearly 5 percent had legislators not cut $1 million before approving the budget package.
But the 2011 budget promised to be both fiscally and politically challenging for Astorino — he heralded his Election Day victory over Spano as a mandate from voters to trim county spending.
Astorino said he entered office believing the county faced a $60 million deficit in 2010. He maintained that a review of financial records revealed the larger gap.
"It started not two years ago with the economy," he said. "But really this was unrestrained spending for many, many years."
He said spending rose 46 percent since 2001, while personnel costs rose by 48 percent and the tax levy by 53 percent. Over the same time span, the consumer price index rose only 29 percent.
Without significant cuts now, Astorino said, the deficit would rise to $266 million in 2012 and $355 million by 2013.
He said consolidation of county properties and county departments, including public safety and emergency services, were among the options being considered.
Astorino said job cuts were a last resort, but are on the table.
"Unfortunately, it is likely that there will be elimination of some jobs, that there will be layoffs at some point, whether that's this year or next year," he said. "I don't see how we can get to plug this hole of $166 million without it.
"How many will be determined by the choices that people make," he said. "At this point, people have to manage their own careers."