MARTINEZ -- Antioch's plan to annex 678 acres to its northeast took a significant step forward this week, as no one protested the largest piece of a complex package becoming part of the city.

The lack of protest gave Contra Costa's Local Agency Formation Commission the green light Wednesday to annex 481 acres of industrial waterfront that includes two natural gas-fired power plants.

Now, all but 94 acres of waterfront land used mainly for marina and storage have been brought within city limits.

The second of three land swaths in question -- 103 acres near Viera Avenue -- was annexed last month, when commissioners from the agency that oversees local government boundary changes determined the area met the state's "land island" criteria and waived the right for the near 110 property owners to vote on the matter.

As for the marina land, the commission decided in a 6-1 vote that more community meetings are needed to address any concerns. It will reconsider the annexation next month.

"I would certainly like to see this commission provide that level of outreach and community engagement," Commissioner Mary Nejedly Piepho said.

Piepho, a county supervisor from Discovery Bay, said similar meetings in the Viera area helped educate and inform those residents.

"Otherwise, we would be pursuing an unfair action prematurely," she said.

Land zoning and taxes in the area would be the same following an annexation, city and county officials said. Antioch would also try to pursue grant funding to help residents with the cost of sewer line connections, Tina Wehrmeister, the city's community development director, said.

Views were mixed among those who spoke at Wednesday's meeting.

Don Wilson, commodore for the Sportsman Yacht Club, said his 200- member group opposes annexation. The city at one time didn't want to annex the area and things "have gone full circle," he said.

"We've peacefully coexisted with the county for 80 years. We'd like to continue that relationship," Wilson said. "If it's not broke, don't fix it."

Steve Klee, one of the owners of the New Bridge Marina, urged annexation.

Using a septic system for sewage is not an ideal solution, while having Antioch's police patrolling the area could stop drug sales at the nearby regional park and reduce boat burglaries, he said.

Antioch first applied for annexation of the industrial piece of land in 2007, but was later directed by the formation commission to include the Viera area, which drew international attention in 2009 because of the Jaycee Dugard kidnapping.

Local leaders see the area as a golden opportunity to boost its economy, estimating it could yield nearly $1 million in net tax revenue each year and provide other economic opportunities on the waterfront.

Contact Paul Burgarino at 925-779-7164. Follow him at Twitter.com/paulburgarino.