More Elevation for Coastal Construction?

BRADENTON – Florida's nationally-renowned statewide building code does not currently take sea-level rise into consideration. That could change this year, however, thanks to a new study commissioned by the Florida Building Commission.

The study, which was performed by Florida International University, recommends that all new construction along the coast be brought up an additional foot to mitigate potential floodwaters. This follows changes that were made in 2016 that required new construction along the coast to elevate buildings by one foot.

Florida did not have state building codes when Hurricane Andrew devastated its southern tip in 1992. The law creating the Florida Building Code was enacted by the state legislature in 1998 and became effective on March 1, 2002. It has never directly dealt with the idea of sea-level rise, which is predicted to hit two feet by 2060 due to global warming.

Another recommendation in the report calls for the review of groundwater maps prior to allowing septic tanks to be installed, because of rising groundwater from sea level rise, which has already caused septic failures across Miami-Dade County.

Many other states have implemented similar codes following disastrous floods, including both New Jersey and New York, which each instituted two-foot coastal elevation requirements following Superstorm Sandy in 2013. Some cities have even tougher criteria. Annapolis requires two feet, New Orleans goes up three feet, and Nashville requires four feet.

Developers have resisted increased "freeboard" requirements, because of additional costs that they say can further challenge affordable housing. That cost varies from the less expensive option of raising the home to the most expensive option of using fill only to increase the elevation of the foundation. However, proponents note that each foot provides for a significant flood insurance reduction, which could offset that cost over time.

One study by the Association of State Floodplain managers estimated that it tookaround 3.3 years for premium savings to pay for construction costs, creating significant savings over a 30-year mortgage. Proponents also note the much higher cost of rebuilding homes and other properties that are destroyed by flooding.