ity officials yesterday announced a rezoning plan that would open the crumbling East River sections of Williamsburg and Greenpoint in Brooklyn to housing and recreation.

The plan is the first concrete step that the Bloomberg administration has taken since it announced last month that it would oppose a proposed 1,100-megawatt power plant on the Williamsburg waterfront. The city's plan calls instead for housing and open space on the 1.6-mile stretch of Brooklyn riverfront between the Williamsburg and Pulaski Bridges, and increased residential and commercial zoning in a 170-block swath inland.

Community groups that had long opposed the power plant applauded the city's plan, which includes zoning for residential towers along the waterfront and provisions for low-income housing among market-rate apartments.

"It's historic," said Adam Perlmutter, a lawyer for the Greenpoint-Williamsburg Waterfront Task Force, which opposed the plant. "It's an opportunity to put a waterfront out there worthy of Sydney, Seattle, and San Francisco."

The area has been largely zoned for manufacturing for 42 years. In recent decades, as waterfront industries were replaced by residents and stores, the area took on a patchwork of uses.

"We walked block by block, street by street, and it became clear that a standard rezoning was inappropriate," said Amanda M. Burden, the chairwoman of the City Planning Commission.

The commission's 18-month study used community input to come up with a combination of residential, mixed use, and commercial zoning. The proposed zoning map is full of indentations where the zoning was fine-tuned to fit in with current use. The proposal includes low-to-middle-income housing, legalization of lofts, extensive public access to the waterfront, and a riverside esplanade with adjacent recreational space. In line with a request to protect existing industry, the plan preserves manufacturing in currently industrial areas like the Domino's Sugar factory. The most striking change would be the erection of 150- to 350-foot-high residential towers in a landscape that is nearly as flat as it was a century ago.

Community groups and elected officials praised the plan yesterday. "They seem to be determined to make this a centerpiece of a very unique waterfront community," said Christopher Olechowski, the chairman of Community Board 1's rezoning task force.

Supporters cited the plan's designation of a state park at an 8-acre riverfront site at North 12th Street where TransGas Energy has applied to the state to build a power plant. David Flanagan, a spokesman for the State Public Service Commission, said that it is very early in the state approvals process but that " zoning will be a key issue for the case."

The park would be financed by the Olympics and used for beach volleyball and archery if the Games come to New York in 2012. A few blocks south, New York University plans to build playing fields, which would also be used for the Games. A spokeswoman for the City Planning Commission said that the plan calls for open space on the site, even without the Olympics.

Daniel L. Doctoroff, deputy mayor for economic development and rebuilding, said that the area should remain recreational space. The TransGas application, he said, is not consistent with the city's proposal.

Over years of industrial use, parts of Greenpoint and Williamsburg have suffered from environmental contamination. Adam Victor, the owner of TransGas, said it would cost at least $35 million to clean the North 12th Street site enough to use it as a park. But Mr. Doctoroff said there was no study to back that figure and added that cleanup would be paid for by corporations that had caused the contamination. The city also plans to offer up to $200 million to help developers clean up the sites.

Last night the city presented the plan to a Community Board 1 zoning task force, and on Tuesday it will present it to the public. In coming months, the department will review the plan with Community Board 1, business, neighborhood and civic groups, and elected officials, with final approval required by the City Council.

Some residents have fought new industrial plants and new residential towers. But Steve Hindy, owner of the Brooklyn Brewery on North 11th Street and a member of Community Board 1, said allowing towers was necessary. "There's a pretty large number of people in the community that are opposed to anything above five or six stories," he said. "But 30 years of saying no to housing proposals on the waterfront is what brought us the proposal for a garbage transfer station, which we were very lucky to defeat, and it's what brought us the proposal for the power plant, which we hope to defeat. So I hope people realize that they've got to say yes to something here."