The Potrero power plant once generated electricity. Now it may produce something else that is vital to San Francisco: housing.

Five years after the plant’s 300-foot-tall smokestack spewed its last exhaust over the Dogpatch neighborhood, the owners of the 22-acre property are preparing to file plans for a mixed-use development that could add more than 1,000 units of housing and 1 million square feet of commercial space to the southern waterfront.

District Development, which is leading the redevelopment for property owner NRG Energy, plans to transform the shuttered power plant, which was one of the most-polluting in California, into a 3 million-square-foot project. Although the exact mix will depend on market demand and community input, it’s likely the plan will call for between 1,000 and 2,000 residential units, along with shops, offices and space for small manufacturers and artists.

Seth Hamalian, District’s managing principal, said a preliminary application will be filed with the city this fall. He said the goal is to integrate the Potrero plant property into the adjacent Dogpatch neighborhood as well as Pier 70, a 60-acre property to the north, which is in the early stages of redevelopment.

“Dogpatch is one of the most unique and amazing neighborhoods in the city,” Hamalian said. “You walk down a single street and you have a combination of everything. You’ve got residential, office workers, retail, people working at making things, PDR (production, distribution and repair). All on one block.”

Closed in 2011

The power plant was closed in 2011 after the Trans Bay Cable project was completed, allowing power generated in Pittsburg to be sent under the bay to San Francisco.

Although the plant property has been seen as a potential development site since it closed, the decision to include residential buildings is relatively new. Originally, a 1999 deed restriction prohibited a number of uses on the site, including open space and housing. Recently, the previous owner, Pacific Gas and Electric Co., and the current owners agreed to lift the deed restriction, opening the door for housing.

PG&E is responsible for cleaning the property up to the state’s commercial standards, which are less stringent than residential standards. The developers have to undertake additional cleanup to make it safe for housing, Hamalian said.

“The goal is to make sure the site is cleaned up and safe for a variety of uses,” he said.

Building boom

The proposal comes at a time when Dogpatch and Potrero Hill are being inundated with construction, fueling resistance from residents who say the new housing isn’t coming with the public transportation and parks needed to handle the new residents.

More than 800 units will be completed in the neighborhood over the next year, with another 2,000 units coming over the next two years. That doesn’t include Pier 70, which will add 1,000 homes.

“It’s tripling the population of (the ZIP code) 94107, and we are still waiting for even one additional bus line,” said longtime Potrero Hill resident Tony Kelly, a past candidate for city supervisor.

J.R. Eppler, president of the Potrero Hill Boosters neighborhood association, said the power plant plan needs to be coordinated with the Pier 70 planning process and other development proposals.

“Each major project in our neighborhood has its own transportation plan,” he said. “Coordination among these transportation plans to achieve a neighborhood-level solution has still not taken place.”

But residents also welcome an opportunity to open up a piece of waterfront land that has been closed off behind a tall fence for decades. Hamalian said that “providing direct access to the waterfront will be a top priority.”

Bruce Huie, president of the Dogpatch Neighborhood Association, said people in the area would benefit from opening up the waterfront. Huie has lived three blocks from the plant for years and has never set foot on the property.

Bay access

“I’ve looked over the fence from Warm Water Cove — that’s the closest most of us have come,” he said. “We are all looking forward to it opening up access to the bay.”

Today, the site is one of the quietest places on the waterfront. Vegetation sprouts from the plant’s 66,000-gallon tank. Stray cats and opossums prowl the property. Only a handful of NRG employees remain, most of whom work on green-energy projects.

Facility manager Dave Hansell, who rides a bicycle around the now-unused tanks, pipes and cables to make sure everything is OK, said the level of activity is a far cry from the days when 33 workers staffed the place around the clock.

“I was kind of the last man standing when they closed the doors,” Hansell said.

But over the next few months the site will become more active. The developer has hired the brokerage Colliers International to attract investment partners for what is likely to be a $2 billion project. This month, District Development will start offering tours to residents.

The site offers flexibility that others on the waterfront don’t, said Gabriel Metcalf, executive director of the urban think tank SPUR. For one thing, unlike most of California’s waterfront, it isn’t under the jurisdiction of the State Lands Commission — which means the developer won’t need state legislation to use it for nonmaritime purposes.

Also, because the property isn’t owned by the Port of San Francisco, the developer won’t need voter approval to exceed waterfront height limits, though it would need to get the OK from city government.

“It’s a really neat site. It’s going to have those incredible views of the bay, but also be an extension of Dogpatch and Pier 70,” Metcalf said. “For a site this big, they should try to develop an extension of the neighborhood that feels like it’s a part of San Francisco, not a separate enclave.”

So far, outreach into the neighborhood has made one thing clear: Residents overwhelmingly want to see the smokestack remain.

Beloved smokestack

“A lot of us see it as a landmark, an icon of the Dogpatch, that should stay on the waterfront,” Huie said. “We don’t want it to be a smokestack per se, but want to see it remain and reused as something different.”

Hamalian said the development team would like to retain the smokestack along with one or two other existing buildings.

“I’m realizing now how many different parts of the city you can see the stack from,” he said.

J.K. Dineen is a San Francisco Chronicle staff writer. Email: jkdineen@sfchronicle.com Twitter: @sfjkdineen