In April, the Port Commission of San Francisco will issue a request for qualifications to redevelop Pier 70, one of the city’s last major pieces of waterfront. The plan for the 65-acre site south of Mission Bay is to restore its historic buildings but maintain its working industrial shipyard, the oldest in continuous operation in the U.S. “Once upon a time, there were 30,000 workers here banging out ships,” said David Beaupre, the Port’s senior waterfront planner. “We want to reactivate this area at that level.”

It’s the second time in recent history that the Port has tried to rejuvenate the site, which is known by many San Franciscans as the location of the police impound lot. But the area is no longer so isolated from downtown, thanks to all the building in Mission Bay and the Third Street light rail. Still, the costs of the project are daunting: Just restoring the buildings and infrastructure is estimated to cost $660 million.

Proposition D, passed in 2008, allows the Port to act as a redevelopment agency and put money raised from property and payroll taxes back into the project. Even so, as the draft master plan states, “the financial complexities of the project—developing 65 acres of infrastructure, three million square feet of new buildings, 700,000 square feet of rehabilitation of historic buildings, associated parking, and 20 acres of open space—require a sophisticated real estate development partner to fashion a development program acceptable to the real estate and capital markets.”

Because of the working shipyard, the plan for the rest of the site calls for commercial and light industrial uses, but no residential. The port also hopes to create a destination attraction. Among the 20 historic buildings in this adaptive reuse project, the architectural jewel is the 1886 Union Iron Works Machine Shop. Built before steel framing, the brick-and-concrete building is seventy feet high and longer than a football field, with arched windows and no internal columns.

“It’s like a cathedral,” said Beaupre. “We really think the public should be able to enjoy the grandeur of it, so we’re looking for a cultural use.” A few potential partners—including the Exploratorium and the National Maritime Museum—considered moving in but decided not to go forward.

The Port has spent the last couple of years working out a master plan, bringing in ROMA Design Group for the urban planning and Carey & Co. for the historical analysis. With the plan in place, the Port hopes to attract commercial developers with a taste for tricky projects; Wilson Meany Sullivan, the developer of Treasure Island, is among those who have expressed interest. A team, including architects and engineering, is expected to be selected by the end of the year.