Florida’s aquifers — drinking water

Florida has historically been gifted with water — lots and lots of water! But there is a limit to how much water is available in the form of drinking water, also called potable water. Climate change, droughts, and increasing water use are taxing our water supply. The St. Johns River Water Management District has imposed a Level III Drought Water Restriction on Nassau County, along with all the counties in the district.

Let’s look at the aquifer system that provides Amelia Island with drinking water. 

Florida has a maze of different aquifers, a complex system that includes the Floridan aquifer system (statewide), the intermediate aquifer, the Biscayne aquifer (South Florida), and the sand and gravel aquifer (western Panhandle). Regionally, there are layered subdivisions and localized aquifers.

An aquifer is made up of ancient marine rock layers that are permeable, meaning water can move through them, and porous, meaning water can be stored. In the case of an artesian aquifer, the water is held under pressure by a cap rock, such as clay, which is impermeable and holds the pure artesian water in place. When drilling into an artesian aquifer, water is under pressure and comes to the surface naturally, and with thousands of years to purify, the artesian water is potentially pristine. 

In Northeast Florida, we rely on the Floridan aquifer system, one of the largest, deepest, and most productive aquifers in the world. It spans 100,000 square miles, including the entire state of Florida, and parts of Georgia, South Carolina, Alabama, and Mississippi. This aquifer is divided into the Lower and Upper Floridan aquifers, with the Upper Floridan being our main source of drinking water. 

The Floridan aquifer system provides drinking water for nearly 10 million people across the southeastern U.S. According to the U.S. Geological Survey, total withdrawals often exceed 3.5 to 4 billion gallons daily, with the heaviest demands driven by agricultural irrigation (49%), public drinking supplies (33%), and industrial or power needs (18%).

So how can we protect the Floridan aquifer system and our drinking water? The obvious answer is to conserve water. 

Wasting fresh water is a real concern. A Florida Climate Institute study conducted with homeowners in Central Florida found that, on average, 64% of the drinking water used by homes went to irrigation. In the summer months, this percentage increased to 88%. As the population increases, conservation of fresh water becomes increasingly important.

The aquifer does not have a fixed amount of water that will eventually run out, provided it can recharge and is not depleted to the point of structural collapse. It is a perfect system of renewal. The Floridan aquifer system, along with other aquifers in Florida, can be recharged as surface water collects and filters into the aquifer's layers, transforming it into drinking water. It is vitally important that we not only conserve water but also protect the system that is actively creating it in real time. This is a process we want to protect. 

In a previous article, "The salt marsh, our provider, protector, and purifier," I wrote about the services it provides for us. Florida’s aquifers are another example of how nature provides us a resource that is vital to humans — clean water. These natural systems, such as the aquifers and the salt marsh, are trying their best to provide for us. Nature can provide the most cost-effective solutions for sustainable potable water, seafood production, clean coastal water, and flood control when natural systems are honored and protected.

South Florida has depleted a majority of their aquifers, the soft limestone cavities that held the water collapsed and the purification system and water storage facility have closed. This system operated at no cost to South Florida and provided them with clean water. Their aquifers are not just empty; they are no longer able to serve as a water-purifying system or hold water, because their storage capacity has been lost. 

Let us not meet the same fate; let us manage our valuable aquifer system responsibly, in gratitude for the service it provides us, and in awe of its perfect design. 

Stay tuned for "Florida’s aquifers — A perfect design" (part 2 of 4)