ST. PETERSBURG — Tampa Bay Rowdies owner Bill Edwards wants to more than double the capacity of Al Lang Stadium to 18,000 seats — enough for a Major League Soccer franchise.

Edwards' idea — he says he's drawn up preliminary plans — didn't come up in a nearly two-hour presentation recently at the University of South Florida St. Petersburg's Harbor Hall that drew a few hundred people.

Nor has it been a widely discussed topic in the past five months of public presentations.

But an expansion of some sort is included in the current plan being crafted to revamp the city's waterfront, city officials and consultants say.

The general concept of a bigger stadium has been represented in drawings in at least one previous meeting, but Pete Sechler, the consultant who has led most of the public presentations, couldn't remember if he'd ever mentioned aloud increasing capacity.

"I don't know if we've ever used the word 'expansion,' " said Sechler, community solutions group senior director at Gai Consultants, a subcontractor for AECOM, the global consulting firm in charge of drafting the plan.

Edwards says he has no interest in demolishing the historic stadium, but would like to add about 10,500 seats and boxes on empty land along the first base line overlooking Tampa Bay.

The draft waterfront plan doesn't include a specific number of seats to be built but does envision a possible expansion to be built in the same area as Edwards' plan, Sechler said.

"You're not going to retrofit a stadium and have everyone sit in the end zone," Sechler said. "To me, it was obvious."

Edwards said his ideas are preliminary, involve using vacant land on the western side of the stadium, and wouldn't increase the stadium's height or drastically increase its footprint.

Edwards said he didn't know how any expansion would be financed.

"It's just a pipe dream," he said in a phone interview.

Edwards' news wasn't the only waterfront blockbuster to surface recently. At a recent meeting, consultants unveiled a proposal to build a hotel and conference center near the Mahaffey Theater and the Salvador Dalí Museum.

In dozens of meetings and presentations, the idea of putting a hotel and conference center on the waterfront hadn't previously surfaced — at least publicly.

An expansion of Al Lang Stadium, along with the addition of a hotel and conference center, would transform a key stretch of waterfront — a change that would require a referendum or a series of them.

Leasing land for developers to build a hotel and conference center would bring in revenue for the city to pay for other waterfront improvements, such as stormwater drainage and erosion prevention. But it would also be a big change for a city that has fought previous attempts to alter the waterfront landscape.

City Council member Karl Nurse said his sense is that the crowd at Thursday's meeting greeted the news of a new hotel and conference center with guarded curiosity.

"I would describe it as interest with a degree of caution — sort of, 'tell me more about this,' " Nurse said.

As for a bigger, bolder Al Lang? Nurse recalled that the Tampa Bay Rays' bid for a waterfront stadium in 2008 didn't end well.

"If you build near water on public land, you should know it's an uphill sale," Nurse said.

Dave Goodwin, the city's planning and economic development director, said the public would have more opportunities to weigh in on the proposals. Public presentations will be held in the next few months before the draft moves to the City Council for action — probably in May or June.

Officials have said that, even after a formal adoption, the plan remains just a blueprint for the city moving forward, not a binding to-do list.

Contact Charlie Frago at cfrago@tampabay.com or (727) 893-8459. Follow @CharlieFrago.