Hydrology and Hydraulics of South Florida

The ecological and physical characteristics of South Florida have been shaped by years of hydrologic variation. South Florida hydrology is driven by continuous balance of rainfall and evapotranspiration reflected in surface water runoff, surface and subsurface storage, flows through the low relief features, dry-outs and wildfires. Generally, the region is a wet region with a regional average annual rainfall of 134 cm. The general hydraulic gradient is north-to-south, where under the natural system excess surface water flows from Upper Kissimmee Basin in the north to the Everglades in the south. The current hydraulic and hydrologic system is composed of lakes, impoundments, wetlands, canals and numerous water control structures that are managed under various water management schedules and operational decisions, based on flood control, water supply, water quality and environmental restoration objectives. Lake Okeechobee is the center of the South Florida hydrologic system with the largest storage and it plays a critical role in flood control during wet seasons and water supply during dry seasons. Hydrologic extremes are exemplified by flooding and excess water during wet years and wildfires and water shortage during drought years. The development of the region required a complex water management system to manage flooding, occasional drought, and hurricane impacts. Excess water is stored in lakes, detention ponds, wetlands and impoundments or discharged to the coast. Currently, as part of a major environmental restoration program, reservoirs are planned and are under construction to increase storage for water quantity and water quality improvements.