The Everglades' Water Pulse: How Flow Shapes a River of Grass

The Everglades isn't a swamp—it's a slow-moving river (100 miles long, 60 miles wide, inches to feet deep) where water flow writes the ecosystem's rules.

Natural Flow: The Sheetflow Engine

Historically: Lake Okeechobee overflow → broad, shallow sheet moving south ~30 m/day → Florida Bay. Seasonal pulse: wet season (May–Oct) floods the sawgrass; dry season (Nov–Apr) concentrates life in sloughs and gator holes.

Positive Impacts of Intact Flow

• Biodiversity cradle: 1,500+ plants, 350 birds, 120 herps, 50 mammals. Flow connects habitats.
• Water treatment: Sawgrass, periphyton, microbes filter N, P, pollutants. Natural kidney.
• Flood buffer: Stores wet-season surplus, releases slowly. Protects coasts.
• Estuary balance: Freshwater outflow calibrates salinity in Florida Bay (seagrass, shrimp, fish nurseries).

Disrupted Flow: The Engineering Legacy

1948: Central & Southern Florida Project — 2,100 km canals, 2,000 km levees, 700 structures. Goals: flood control, agriculture, water supply. Consequences:

• Compartmentalization: Water Conservation Areas (WCAs) fragment sheetflow.
• Timing reversal: Dry season drainage → wet season dumping (opposite natural).
• Volume loss: 50–70% less water reaches Everglades National Park.
• Quality decline: Agricultural back-pumping (phosphorus → cattail invasion, periphyton loss).
• Wildlife collapse: Wading bird nesting down 90%. Panther habitat fragmented. Gator holes dry.
• Fire regime shift: Drained peat burns catastrophically (muck fires, months long).
• Saltwater intrusion: Reduced freshwater head → salt creeps inland, kills freshwater communities.

Restoration: CERP and Beyond

Comprehensive Everglades Restoration Plan (2000): $23B, 68 projects, 30+ years. Key: raise Tamiami Trail (bridging), reservoir south of Lake O, seepage barriers, water quality treatment (STAs). Progress: slow, political, essential.

The Everglades teaches: water flow isn't plumbing—it's the circulatory system of a living landscape. Restore the pulse, restore the patient.