Army Corps of Engineers floats $4.6 billion flood protection plan for Miami

Miami Virtue

Army Corps of Engineers floats $4.6 billion flood protection plan for Miami

Downtown Miami and Brickel. The city’s flat topography and nearness to the water’s edge presents a unique challenge to flood mitigation measures. (Ryan Parker/Unsplash)

Miami-Dade County is uniquely vulnerable to climate change-induced sea-level rise, and although climate resiliency projects across America have been endangered by the coronavirus pandemic, the U.S. Army Corps of Engineers has drafted a feasibility study for a massive flood protection plan for Florida’s most populous county.

The Draft Integrated Feasibility Report and Programmatic Environmental Impact Statement (EIS) for the three-year, $3 million Miami-Dade Back Bay Coastal Storm Risk Management Feasibility Study was released to the public for comment on May 29. Because of the area’s strategic and trade importance, and because 2.8 million residents are at risk over a huge distance, the report stuck to making recommendations for the county’s seven most vulnerable areas.

In the Corps’ Tentatively Selected Plan (TSP) for Miami-Dade, $4.6 billion in coastal flooding mitigation was proposed, including a mixture of hard and soft infrastructure, natural-based installations, and the increased hardening of existing, but threatened, infrastructure.

That includes the construction of levees, seawalls, storm surge gates, and pumping stations in strategic locals around the Miami-Dade area, but due to the interconnected, crisscrossing waterways, this precludes a single, wraparound levee. Because of the enormous potential this would have to disrupt local wildlife, especially native mangrove trees in the county’s endangered coastal wetlands, if the TSP plan is implemented, the Corps will have to examine ways to mitigate their loss or reclaim an equal amount of wetlands elsewhere. However, as part of the plan’s Natural and Nature-Based Features, these mangrove trees (which already provide soil erosion control and some measure of flood prevention on their own) would ideally be integrated or expanded along Cutler Bay.

The draft EIS will remain open to comments from the public until July 20, 2020, and the feasibility study is set to conclude in September of 2021. If Congress approves the final plan and everything remains on track, the project is scheduled to begin design work in 2022, but due to the wide scope, the Corps will build everything out in phases over a number of years. Miami-Dade County will assume 35 percent of construction costs and will be required to operate, maintain, and potentially rehabilitate the final project for the next 50 years.