Environment — Miami, Florida

Miami sits at the southeastern tip of the Florida peninsula on a low-lying coastal plain bounded to the east by Biscayne Bay and the Atlantic Ocean and to the west by the Everglades wetland system. The U.S. Geological Survey documents that the Greater Everglades Ecosystem reaches only a few meters above sea level, making the coastal urban population around Miami particularly vulnerable to sea level rise and storm intensification. These conditions define the city's environmental profile as distinctly acute: a densely settled metropolitan area — with a city population of 446,663 as of the U.S. Census Bureau ACS 2023 — pressed between two of the most ecologically significant natural systems in North America.

Environmental governance in Miami is divided between the City of Miami, which operates under a mayor-city commissioner form of government, and Miami-Dade County, which administers the county-level Office of Resilience and coordinates the regional Sea Level Rise Strategy. The National Park Service, the U.S. Army Corps of Engineers, and the Southeast Florida Regional Climate Change Compact are additional institutional actors whose mandates intersect directly with Miami's environmental conditions.

The most significant natural feature immediately adjacent to Miami is Biscayne National Park, administered by the National Park Service and situated directly south of the city within Miami-Dade County. The NPS Geodiversity Atlas documents the park as encompassing approximately 172,971 acres (69,998 hectares), of which 95% is water. The park protects Biscayne Bay, the longest continuous stretch of mangrove forest along Florida's Atlantic coast, and a portion of what the NPS identifies as the world's third-longest barrier reef ecosystem.

To the west, the Greater Everglades Ecosystem forms a contiguous boundary with Miami's urban edge. The USGS Florence Bascom Geoscience Center characterizes this ecosystem as reaching only a few meters above sea level across its extent, a condition that concentrates the effects of saltwater intrusion, flooding, and storm surge across both the natural landscape and the built urban environment. Miami's tropical climate produces a pronounced wet season from May through October and a dry season from November through April, with the wet season coinciding with peak hurricane activity.

Miami is widely documented in federal scientific literature as one of the most exposed urban areas in the United States to sea level rise. The USGS identifies the Greater Everglades region, which directly abuts Miami, as sitting only a few meters above sea level, a condition that amplifies the effects of both gradual inundation and episodic storm surge. Miami's porous limestone geology — an oolitic limestone substrate underlying much of the coastal plain — allows saltwater to migrate upward through the ground rather than being blocked by conventional flood barriers, a physical characteristic that distinguishes Miami's exposure from other coastal cities.

The combination of high tidal flooding frequency, hurricane storm surge risk, and the low elevation of surrounding natural systems means that environmental planning in Miami addresses not only ecological preservation but the structural habitability of the city itself. As of the U.S. Census Bureau ACS 2023, 69.3% of Miami's housing units are renter-occupied, and the median gross rent stands at $1,657, concentrating climate risk within a predominantly renting, lower-to-middle income population — the city's poverty rate is documented at 19.2% in the same dataset.

Miami-Dade County administers the primary institutional framework for environmental resilience through its Office of Resilience, which oversees the county's Sea Level Rise Strategy. That strategy is implemented in part through the Resilient305 Strategy, a collaborative framework, and through U.S. Army Corps of Engineers Coastal Storm Risk Management Studies, including a Back Bay feasibility study and a Beach Reauthorization project, both documented by the Miami-Dade County Office of Resilience.

A key mechanism within the Sea Level Rise Strategy is the designation of Adaptation Action Areas (AAAs) — geographically defined zones where coordinated land use, infrastructure, and investment decisions are intended to reduce long-term flood exposure. According to the Miami-Dade County Office of Resilience, the first AAA was established in the Little River area of Miami-Dade County. The Southeast Florida Regional Climate Change Compact, a multi-county collaborative documented through the county's resilience pages, provides a regional governance structure linking Miami-Dade, Broward, Palm Beach, and Monroe counties in coordinated climate planning.

At the city level, the City of Miami operates under the mayor-city commissioner plan documented in City Attorney legal opinions, with the five-member City Commission exercising legislative authority over local land use and environmental ordinances. Mayor Eileen Higgins, documented by the City of Miami as the first female mayor of Miami, assumed office in 2025.

As of 2025 and 2026, Miami-Dade County continued active implementation of its Sea Level Rise Strategy under County Mayor Daniella Levine Cava, whose office identified an ongoing affordability crisis as a strategic priority in the FY 2025–26 Adopted Budget materials. That framing reflects the convergence of environmental risk and socioeconomic vulnerability that characterizes Miami's policy environment: displacement pressure from flooding, insurance cost increases, and housing cost escalation are treated within the same strategic frame.

The first Adaptation Action Area in the Little River neighborhood represents the county's initial implemented geographic application of the AAA framework, as documented by the Miami-Dade County Office of Resilience. The U.S. Army Corps of Engineers Back Bay feasibility study and Beach Reauthorization, both components of the Coastal Storm Risk Management program, are documented as ongoing processes. PortMiami, which the county documents as contributing $61 billion annually to the regional economy, operates adjacent to Biscayne Bay, situating a major piece of economic infrastructure within the same environmental zone subject to resilience planning.

Miami's environmental circumstances are embedded in a regional and federal system involving multiple overlapping jurisdictions and agencies. The Southeast Florida Regional Climate Change Compact, documented through Miami-Dade County's Sea Level Rise Strategy pages, links Miami-Dade County with Broward, Palm Beach, and Monroe counties in a coordinated adaptation planning structure. This compact represents one of the larger multi-county climate collaboration frameworks in Florida and directly shapes how regional sea level projections are translated into local land use and infrastructure decisions.

At the federal level, Biscayne National Park is managed by the National Park Service as a protected marine and coastal ecosystem within sight of Miami's downtown skyline. The park's protection of mangrove forests and coral reef systems represents a federally maintained ecological buffer directly contiguous with Miami-Dade's developed coastline. The USGS Florence Bascom Geoscience Center's ongoing research on sea level rise and climate impacts in the Greater Everglades provides the scientific baseline informing both county and regional adaptation planning. Taken together, these federal and regional institutions form the environmental governance architecture within which the City of Miami and Miami-Dade County develop local policy.