Elevating an Entire Island: Treasure Island’s Ambitious Multi-Billion Dollar Plan To Raise Elevation


Treasure Island is launching a proactive plan to counteract the threats of rising sea levels and severe storms by elevating the entire island by 2100. This initiative, known as the “Terrain Modification Program,” aims to lift homes, businesses, and infrastructure using external fill dirt, a practice currently restricted by local codes.

The city proposes to change these regulations to mandate the use of fill for establishing minimum building elevations.

According to the city’s website, “The Program consists of two parts: the Terrain Modification Manual and several corresponding code revisions. The Terrain Modification Manual is the rulebook for Builders, Engineers, Developers and City personnel on how to properly design and construct terrain modification projects within our community. The supporting code revisions rethink how we handle stormwater on the island in an environment of rising seas while ensuring that we maximize opportunities to reduce the risk of building flooding. These code updates will also serve to codify the principals and procedures outlined within the Terrain Modification Manual.”

The strategy specifically includes raising road elevations to an average of 5.1 feet, with some areas now under 2 feet. Buildings will need to have their lowest floors set at 7.6 feet above ground to mitigate flood risks, especially since Treasure Island, as a barrier island, is highly susceptible to hurricanes and “sunny day flooding.”

The city’s drainage system, connected to Boca Ciega Bay, complicates the flooding issue, pushing city leaders to seek solutions beyond simple water pumping. Approval from Florida state and city commissioners is pending for the plan, which has yet to be priced. The cost of elevating private properties will be covered by developers, aligning with the city’s goal to protect investments through proper elevation.

This elevation priority ensures effective drainage from properties to roads. Following a review that began in 2018, the city adopted a new Watershed Management Plan in 2021, paving the way for the fill dirt policy.