Image: Road inundated with flood waters in the Florida Keys
Monroe County has completed its Regional Roads Adaptation and Capital Plan study, which provides information on which of the county’s more than 300 miles of roadways need to be elevated or have drainage added in order to adapt to projected sea level rise (SLR). The study outlines when and how the roads would need to be elevated or adapted, along with cost estimates, conceptual designs, an implementation plan and a schedule. The study, conducted by HDR Engineering Inc., indicates that in order to ensure long-term community resilience, $1.6 billion will be required to adapt the Florida Keys’ roadways, at a cost of $9.6 million per mile.
The study projects that 53% –166 miles – of the 311 miles of county-maintained roads are anticipated to be affected by sea level rise inundation by 2045. These roads service 76% of the county’s population. The criteria for ranking the road projects include population and critical infrastructure such as fire stations that reside along the roads. Ninety-seven neighborhood areas in total are affected and recommended for road adaptation projects, of which 49 neighborhoods are recommended for action by the year 2025 at a cost of $888 million. The projects identified range in size from 207 linear feet to 3.63 miles and range in cost from $75,000 to $64 Million.
Many roads are planned to be elevated high enough to avoid sea level rise inundation, only. Additional flooding caused by high tide will instead be mitigated through the use of pump stations and stormwater conveyance features. The roadways not requiring such storm water management features (only requiring elevation) significantly reduces the overall cost of the adaptation initiative by $200 million. The county will also have to cover an ongoing operation and maintenance costs of the pumps to the tune of $3 million per year.
Securing funding to implement the $1.6 billion plan is a considerable challenge for a county of 82,000 residents. The county applied for 15 road adaptation projects with a cost of $384 million in September 2022 under the Resilient Florida grant program and officials are researching all available funding options. Monroe County has experience advancing large and expensive infrastructure upgrades recently completing a $1 billion wastewater program. Such experience in working collaboratively with residents, state and federal elected officials positions the county favorably to rise to this next challenge.
The next steps include a review of county policies to determine if changes need to be made to facilitate additional private residential and commercial adaptations, such as the potential elevation of yards and living shorelines.