Already under construction in the Water Street development is the University of South Florida’s Morsani College of Medicine and Heart Institute, a 325,000-square-foot facility that is set to open next year.

“We’re filling the hole in the middle of the doughnut,” said James Nozar, Strategic Property Partners’ chief executive, referring to the Water Street project’s position in a sparsely developed area in the heart of the city, which includes Amalie Arena, home of the Lightning. One of the aims of the project, he said, is to “reconnect downtown to the waterfront.”

To support the outside investment, officials from Tampa and Hillsborough County have agreed to split the roughly $100 million cost of a revamped street grid in and around the Water Street project. Planned improvements include new parks, sidewalks, storm drains, underground utility and communications pathways, as well as lines connected to a cooling plant that will provide chilled water to the air conditioning systems of the buildings.

The streets are being designed with driverless cars in mind and parking structures that could be converted to other uses. Renderings of the project show wide, verdant sidewalks, with bustling businesses, cafes, shade trees and children running through fountains. The developer estimated that 23,000 people will fill the Water Street area every day, as residents, visitors or workers.

“I’ve been dreaming of this for a long time,” said Bob Buckhorn, who has been Tampa’s mayor since 2011. “We’ve changed our economic DNA. I knew that if we were going to invest in intellectual capital, we had to create a built environment and an urban core that was attractive to young people, which meant completely transforming downtown Tampa on the waterfront.”

There was much that needed changing. Tampa, incorporated in 1849, was long known for little more than phosphate mining, cigar factories, mobsters and corrupt politicians. It was sometimes derisively referred to as Sin City or Little Chicago.

There was an extensive streetcar system beginning in the 1890s, and the city erected its first skyscrapers in the 1920s, said Gary Mormino, a former professor of history at the University of South Florida. But by the late 1950s, he said, the city center had gone into a “death spiral.”