The State Lands Commission has approved the boundaries for Marina Park, bringing the Balboa Peninsula public waterfront development one step closer to construction.

By overcoming this hurdle, the city can now complete its California Coastal Commission application and restart the long-stalled project.

Park advocates, city officials and others decided on a plan for the development more than three years ago, but it has been stuck in bureaucratic morass. In the meantime, residents of the 57 mobile homes have been afforded more time on public land, while others have protested the slow progress.

"This is a really positive step," said Deputy Public Works Director Dave Webb. "It is a little bit of a battle any time you deal in the harbor with all [the public agencies] involved."

The city struck a deal last week with the State Lands Commission on the tidelands boundary, the demarcation of state property that must be used for aquatic purposes. The negotiated line snakes around the Marina Park drawings to exclude proposed tennis courts, a community center, the historic Girl Scout House and some parking spaces.

The city will own that land, while the remaining property — with a beach, sailing center, marina and other parking spaces — will be placed in state tidelands that are controlled by the city. Any revenue derived from tidelands property would have to be spent on similar water-related projects.

Advocates and residents who successfully passed a 2004 ballot measure to create a park say they are pleased with the progress.

"It's just exiting to know that this site will someday soon allow that much-needed public access," said Tom Billings, a member of Protect Our Parks.

But not everyone is overjoyed.

Resident Karen Whitaker, who has lived in one of the mobile homes since 2003, said her neighbors are expecting their 90-day notice to vacate in coming months.

"They want to just demolish us," she said.

Before then, the City Council will have to agree which phases to build first, and the Coastal Commission process could take as long as six months, Webb said.

mike.reicher@latimes.com

Twitter: @mreicher