Harbour Island — Tampa, Florida

Harbour Island began as Seddon Island, a pile of dredged sand that took shape after 1906 at the mouth of the Hillsborough River in downtown Tampa. For roughly seven decades the island served the railroad and the port. The name change arrived with a 1981 redevelopment plan from Beneficial Corporation, which proposed offices, hotels, shops and homes on the old freight yard, according to a history published by Tampa Magazine on May 19, 2020.

The rename marked a shift in purpose rather than a new piece of land. The same acreage that once held lumber yards and phosphate elevators became a planned district reached by bridge from Franklin Street and Channelside Drive. The island's story therefore runs through three eras: an engineered port island built by the Seaboard Air Line Railroad, a cleared industrial tract waiting through the 1960s and 1970s, and the mixed-use Harbour Island that opened in stages from 1985 onward, beginning with a hotel, the Shops on Harbour Island and an elevated People Mover from downtown Tampa.

Before 1906, Tampa Magazine reports, the site was mostly water plus part of an island commonly known as Little Grassy Island. Little Grassy and its bigger neighbor, Big Grassy Island, were delta islands at the river mouth that sat empty except for mangroves, crabs and rabbits. The change came when the United States Army Corps of Engineers dredged a shipping channel through Hillsborough Bay to reach downtown Tampa, and that channel sliced through Little Grassy Island.

The dredging left a large surplus of sand. Engineers piled it along the eastern side of the new channel, near and on top of Little Grassy Island, building a larger island for port use. W. L. Seddon, an engineer for the Seaboard Air Line Railroad, which was the main benefactor of the dredging, is credited with directing the work, and the island carried his name for most of the twentieth century.

Garrison Channel was cut in the same campaign and became part of the new Port of Tampa, leaving Seddon Island separated from the downtown Tampa shoreline by open water. Seaboard freight trains crossed to the island on a steel bridge supplied by the Scherzer Rolling Lift Bridge Company of Chicago and set in place in 1908, the link that turned a spoil island into a working rail terminal.

Rail service brought cargo almost immediately. Tampa Magazine records that the port's first phosphate shipment came the year after the 1908 bridge, and that docks, wharves, warehouses and phosphate elevators lined the downtown Tampa waterfront from then until the 1960s. Lumber yards shared Seddon Island with the elevators, and the whole riverfront down to the estuary that is now the Water Street district was industrializing around it.

Cleanup came slowly. Starting in the 1950s, under Mayor Curtis Hixon, the City of Tampa began clearing its industrial waterfront, a job expected to take a decade that stretched across almost half a century. The riverfront between Kennedy Boulevard and Cass Street was handled first, where a public library, a parking garage and a convention center named for Hixon replaced warehouses and rail tracks. The southern end of downtown, including Seddon Island, waited until the late 1970s, by which time the island was described as burnt out docks with feral pigs.

The public infrastructure of that era outlasted the elevators. The American Society of Civil Engineers reports that the 54-inch Harbour Island Force Main, a sewer pipeline that crosses the island toward the treatment plant near Port Tampa Bay, was placed in operation in 1951, long before anyone lived on the island.

Among the first private projects announced for the southern end of downtown Tampa, in 1981, was Harbour Island. Tampa Magazine describes the Beneficial Corporation plan as a mixed-use development of office space, hotels, shops and homes, most of them multi-family units ranging from two-story townhomes to tall apartment buildings. Many observers at the time considered a project of that scale so close to downtown a folly.

The retail piece struggled. The Shops on Harbour Island, a mall-like center meant to draw diners and shoppers day and night, opened before many residents lived on the island and faded once the novelty wore off, since few people from elsewhere in Tampa crossed Garrison Channel to support it. The housing plan, by contrast, broadened over time from mostly multi-family buildings into a mix of single-family homes, townhomes and high-rise towers, and the island came to house thousands of residents.

Tampa Magazine also credits Harbour Island with setting a pattern for the southern edge of downtown Tampa. The later public and private investments it lists along the channel include the Tampa Convention Center, the Florida Aquarium, Amalie Arena, the Tampa Bay History Center, three hotels and the Water Street Tampa development.

The People Mover was the transit link Beneficial built to tie the island to downtown Tampa. A 2018 conference paper archived by Michigan Technological University records that service began in June 1985, with President Ford taking part in the opening of the development and riding the inaugural trip. Otis Transportation Systems manufactured the system, which ran on a 2,500-foot elevated concrete guideway between a shopping center on Harbour Island and a parking garage beside downtown.

The original concept was even more unusual. Tampa Magazine notes that planners first proposed cable cars hung overhead, carrying passengers from the center of downtown over Franklin Street and Garrison Channel; the design changed to a single-track shuttle running high above the street from the Fort Brooke Parking Garage to the hotel building. Modern Cities identifies the downtown end as the Old Fort Brooke parking garage and gives the opening date as June 25, 1985.

Ridership never matched the ambition. The Michigan Tech paper states that ridership remained low while operating costs grew, and that Beneficial tried to sell the privately owned line to the Hillsborough Area Regional Transportation Authority (HART). Operations ceased in January 1999 and the guideway was torn down within the year. Money from the closure settlement went into an endowment for operating the TECO vintage streetcar line that serves downtown Tampa and Ybor City today.

Two City of Tampa projects reached Harbour Island after 2018. The Harbour Island Complete Streets project covered Knights Run Avenue, from South Harbour Island Boulevard to Beneficial Drive, and Beneficial Drive from Knights Run Avenue to Channelside Drive, four-lane collector roads carrying roughly 15,380 to 16,560 vehicles a day. The plan rehabilitated both roads, added two raised pedestrian crosswalks and bicycle lanes, narrowed lanes to ten feet, put a two-foot buffer on the bike lane across the Beneficial Bridge, and lowered the Beneficial Drive speed limit from 40 MPH to 25 MPH. The city held its public information meeting at the Tampa Bay History Center on October 2, 2018.

The second project concerned the 1951 sewer line. In 2017, during maintenance on the Harbour Island Bridge, contractors found leaks in the force main hung beneath the bridge deck, according to ASCE. When the city floated replacement routes, Bay News 9 reported on May 16, 2018 that island residents objected to a plan that would dig up sidewalks, roads and yards along the island's spine. The FOX 13 coverage of August 16, 2023 quotes the city's wastewater director saying the densely built island left no room for a new pipe, so the route went around it.

The answer was a tunnel under the water rather than a trench across Harbour Island. The City of Tampa reported on August 14, 2023 that the replacement began in August 2022 and that a 3,200-foot micro-tunnel had been bored 60 feet below the bay surface, with its receiving shaft in Cotanchobee Fort Brooke Park on Garrison Channel. On June 3, 2024 the city announced that all flow from the force main on Harbour Island had been diverted to a new 78-inch pipeline running about 13,700 feet to the Howard F. Curren Advanced Wastewater Treatment Plant, an $83 million job funded through the PIPES program; earlier 2023 reports put the cost at $79 million.