The Floridan Aquifer System: A Vital Water Source
Did you know that the Floridan aquifer system stretches over 100,000 square miles and reaches into parts of Alabama, Georgia, and even South Carolina? The upper Floridan aquifer contains about one-fifth the amount of water in all the Great Lakes and is the main source of drinking water for northern and central Florida.
What Is an Aquifer?
An aquifer is an underground layer of rock or sediment that holds groundwater. It's essentially a natural reservoir that’s typically made of permeable materials like sand, gravel, or fractured rock. These permeable materials allow water to flow through and be stored within their pores and fractures.
What Is the Floridan Aquifer Made Of?
The Floridan aquifer system is mostly made of layers of limestone and dolomite. These types of rocks have pores that store water and are often riddled with cracks and crevices that allow even more water to flow through them.
How the Aquifer Is Divided
However, there are also layers of rock in the Floridan aquifer system that have low permeability. This means water cannot easily flow through them, dividing the system into separate aquifers — including the upper Floridan aquifer and lower Floridan aquifers.
The Upper Floridan Aquifer
The upper Floridan aquifer is the primary source of water for northern and central Florida. It’s used for public supply, agriculture, and industry. It’s also the source of water for many of Florida’s springs and is connected to surface water bodies like lakes and rivers.
The Lower Floridan Aquifers
The lower Floridan aquifers are deeper and may contain brackish, or slightly salty, water. They can be used for water supply, but it takes more effort and resources to withdraw and treat the water for use.
How the District Monitors and Protects the Aquifer
At the Southwest Florida Water Management District (District), we continuously monitor rainfall and the water levels within the upper Floridan aquifer to ensure water supplies remain adequate and natural ecosystems stay healthy.
How the Aquifer Gets Recharged
Rainwater that soaks into the ground is the primary way the Floridan aquifer system gets recharged. Depending on where you are in the District, anywhere from 2% to 38% of total rainfall will end up in the aquifer. Recharge is greatest in the northern areas of the District, where the upper Floridan aquifer is close to the surface and there is little to no geologic confinement.
Learn More
Visit our Floridan Aquifers Frequently Asked Questions to dive deeper into aquifers!