East Coast Hydrology + Biscayne Bay

The Atlantic Coastal Ridge (shown towards the right in light green) is an area of slight uplift that runs parallel with the Atlantic coast line and through the city of Miami. Before the canalization of South Florida, water flowed through low valleys that intersected this ridge system, and made its way into the Biscayne Estuary.

This Estuary was once predominanlty fresh water, fed by gushing springs which were supplied by groundwater that had been filtered for years as it passed through the Everglade ecosystem. As the area grew, the need to control flooding and create more usable land led to the development of the canal system we still see today. These canals lowered the water table, causing salt water intrusion into the aquifer system, corrupting the area’s main source of water, as well as increasing salinity levels in the bay.

Christian Langevin writes,

“tidal canals are focal points for ground water discharge, intercepting fresh ground water that would have discharged directly to Biscayne Bay.” He goes on to say,

“Field observations suggest that Biscayne Bay has changed from a system controlled by widespread and continuous submarine discharge and overland sheetflow to one controlled by episodic releases of surface water at the mouths of canals. The sole explanation for this change has always been that canals lowered the water table, and thus, submarine ground water discharge has decreased. Results from the numerical model, however, suggest that the interception ability of tidal canals is also an explanation for the decrease in submarine ground water discharge directly to Biscayne Bay and the redistribution of discharge to point locations.”

The impacts created by canals on the hydrologic cycle have impoverished the bay’s natural ecosystem as a marine estuary. By implementing new strategies to mitigate flooding while maintaining proper water flow into the bay, we may be able to reconnect the lowland everglades to the bay while creating public and ecological infrastructure that can act as a springboard for future development in coastal zone regions.

These strands will pose as environmental data collection sites, as well as gathering spaces for citizens, breeding grounds for fish and bird life, and water filtration systems.

The Atlantic Coastal Ridge is made up of upland pine and hardwood hammock communities, interspersed with wet praries and cypress domes which are dissected by finger glades (water courses that flowed from the Everglades to the coast). These finger glades now remain only in small and isolated patches that have been protected from urban development.

Quotes taken from GROUND WATER: Simulation of Submarine Ground Water Discharge to a Marine Estuary; Biscayne Bay, Florida.

The Desaturation of South Florida's Landscapes

Over the past century south Florida has seen a dramatic change in its ecological and hydrological cycles through the development of water management systems, leading to drought, dust storms, habitat loss, and dramatically reduced populations of various fish, plant, and bird species.

It began in the early part of the century, when prospectors and planners began to develop south Florida for residential and agricultural uses. After a series of catastrophic floods and hurricanes, the US Corps of Engineers stepped in and began construction on one of the world's most "successful" water management systems, made up of a series of canals, levees, flood gates and pumping stations. This system ultimately created a fragmented, piece-meal version of the wetlands that once freely flowed over 200 miles from central Florida all the way down into Florida Bay. With the canals diverting water from the Everglades into the cities, along with the disruption of sheet flow by the highways and roads that now sever east from west, and north from south, the Everglades ecosystem has become a crippled version of its former self.