The Everglades Water Cycle: A Seasonal Heartbeat Now Interrupted

The Everglades runs on a pulse: wet season flood, dry season concentration. Engineered drainage broke the rhythm. Restoration aims to reset the clock.

Natural Cycle (Pre-Drainage)

Dry Season (Nov–Apr)

• Rainfall: <50 mm/month
• Evapotranspiration > precipitation
• Water recedes → concentrates in sloughs, alligator holes, cypress domes
• Wading birds feast: wood storks, ibis, herons, egrets, spoonbills
• Fire: lightning-ignited, sweeps sawgrass, resets succession

Wet Season (May–Oct)

• Rainfall: 150–250 mm/month (convective + tropical systems)
• Lake Okeechobee rises → sheetflow south begins
• Water depth: 30–90 cm across 100+ km width
• Fish/invertebrates disperse → breed in flooded marshes
• Predation pressure drops (prey diluted)
• Nutrients flushed to Florida Bay → seagrass, shrimp, fish nurseries

Food Web Coupling

Dry concentration = predator bonanza. Wet dispersal = prey recovery. This oscillation drives population cycles. Disrupt timing → decouple predator/prey → collapse (wood storks: 90% nesting decline).

Engineered Disruption (Post-1948)

• Canals drain wet season fast → no sheetflow storage
• Levees block flow → WCAs impound, park starves
• Back-pumping (EAA) → phosphorus → cattails replace sawgrass
• Dry season over-drainage → peat fires, salt intrusion
• Flow timing reversed: wet when should dry, dry when should wet

Restoration Targets (CERP)

• Quantity: 1.7B gal/day additional flow south
• Quality: 10 ppb phosphorus (STAs treating)
• Timing: Mimic natural hydrograph
• Distribution: Reconnect sheetflow paths (bridges, spreaders)

Progress

Tamiami Trail bridging (6.5 mi done, 2.6 mi funded). EAA Reservoir (STA + storage) — groundbreaking 2023. C-44/C-43 reservoirs (St. Lucie/Caloosahatchee relief). 20+ years in. 30+ to go.

The Everglades doesn't need water managed. It needs water released — on nature's schedule.