The overall changes to the Everglades, including both the C&SF Project and other alterations, can be summarized in five areas:
- Reduced areal extent: The Everglades has been reduced to about 50% of its original size and connected to a flood control system so that it does not provide as much water storage as the original system. These changes make the ecosystem more vulnerable to damaging effects of both flooding (use for flood control) and drought (less storage, more competition for water). Important wildlife has dwindled as a result—most notably wading birds.
- Fragmentation: The Everglades has been divided into compartments, some of which are “off line” with respect to the remainder, notably WCA-2B, WCA-3B, and Northeast Shark River Slough. Connecting overland flow, including ridge-and-slough landscape that characterized the original ecosystem, has been essentially lost, with major obstacles being canals, control structures, and levees.
- Changes in the quantity, timing, distribution and quality of water: Rerouting of water primarily as a flood control system has damaged freshwater Everglades functions and the coastal estuaries, some of which originally received very little water from the Everglades system and now get frequent overloads (Caloosahatchee, St. Lucie, Lake Worth Lagoon), while others get less fresh water (Loxahatchee River, Florida Bay) or have deliveries generally reduced and changed to point sources (Biscayne Bay).
- Changed fire regimes: The natural effects of fires have been changed. Reduced water levels caused soil fires that greatly changed the system. Fire breaks represented by roads and canals have diminished the areal extent of many fires that regulated the ecosystem.
- Spread of invasive exotic plants: The altered ecosystem has facilitated the spread of many exotic species. Disturbance has aided the spread of Brazilian pepper. Reduced water levels have facilitated the spread of melaleuca. These and other species have degraded natural plant communities and their support of wildlife.