Restoring Florida’s Old Tampa Bay
For the past 14 months, Volkert has been working with the Florida Department of Transportation (FDOT) to design and construct a bridge addition for the State Route 60/Courtney Campbell Causeway along Old Tampa Bay. This bridge project, however, serves a different purpose from most projects that Volkert undertakes.
Rather than focusing on traffic flow, the new Courtney Campbell Causeway was designed to improve tidal flows in the northeast portion of the Bay. “The goal of this project was to create a channel below the causeway to increase water circulation and, as a result, improve the water quality of Old Tampa Bay,” says Volkert’s Project Manager Joe Hitterman. “It is a transportation project that serves an environmental purpose.”
History of the Causeway
Originally opened in 1934, the Causeway provided a more direct route between Tampa and Clearwater across Tampa Bay. At the time of its completion, the causeway was the longest over-water land fill across an open body of water in the United States, stretching approximately 9.9 miles.
Because of the panoramic water views, the Causeway was designated an official scenic highway by the state of Florida in 2005. In 2015, FDOT completed a recreational trail system that allows pedestrian and bicycle access along the entire scenic Causeway.
Improving Water Quality and Environmental Restoration
FDOT’s Water Quality Improvement Project was created to improve water quality in Old Tampa Bay—the body of water north of the Causeway—and restore habitats and other natural resources, specifically seagrasses.
Prior to this project, this portion of the bay often became stagnant and had an overall lower water quality than the remaining areas of Tampa Bay. Stormwater runoff and other pollutants were often being trapped because of less than adequate tidal flushing, preventing the natural treatment process from occurring.
“By essentially cutting a hole through the Causeway, the bridge provides an inventive solution to this environmental issue,” comments Hitterman. “Volkert’s goal was to harmonize infrastructure improvements with Tampa’s multifaceted natural environment.”
With the channel opened under the bridge, tidal flushing is restored to improve water quality, circulation, and generate seagrass growth.
Designing and Constructing the Bridge
Volkert teamed with construction firm Johnson Bros. Corporation, part of Southland Holdings, to complete the design-build project. The project required an accelerated four-month design phase from November 2017 through February 2018. Construction began in January 2018.
“We truly maximized the benefits of the Design-Build method by working closely with Johnson Bros. staff who specialize in marine construction techniques,” says Hitterman. “The sharing of ideas and customized approaches enhanced the overall project.”The bridge addition replaced 229 feet of the existing causeway over Old Tampa Bay. The completed bridge boasts three 12-foot eastbound lanes, two 12-foot westbound lanes, 10-foot outside shoulders, 8-foot inside shoulders, and a 16-foot access road on the westbound side. It also continues the 12-foot Courtney Campbell multi-use trail on the eastbound side.
“Throughout the construction process and various phases, we have ensured a high degree of safety within the travel lanes and multi-use trail,” says Hitterman. “By using innovative structural approaches in our bridge design, we have decreased the likelihood of future maintenance of the bridge and walls.”
Volkert also implemented a temporary traffic control scheme during construction that maximizes safety. SR 60 and the pedestrian/bicycle trail remained open for use during construction, making site safety a critical factor throughout construction.
The traffic control plan included roadway shifts and trail alignments. Both directions of traffic and the pedestrian trail were shifted to the northern portion of the new bridge in September 2018. North and south dam removal was completed in November 2018 to allow full tidal flow through the new channel.
The project is on track to be completed on time and within budget while achieving all goals and objectives. The project recently hit its major milestone with the opening of the channel. Construction and finalizing traffic alignments will be completed April 2019. The environmental benefits of this project will be seen for many years to come.
“We are confident that this project will benefit Tampa, its residents and visitors, and the adjacent natural environment,” Hitterman says. “Volkert is honored to be able to use our talents to better our community.”