Protecting the Santa Fe River in North Florida

Be Informed.

Accounting for our Groundwater Inheritance


The Gainesville Sun on May 20, 2016 has published an editorial by Dr. “Robert Knight, OSFR advisor and director of the Florida Springs Institute, with his thoughts on the Floridan aquifer.Scrollbobkinight


Robert Knight: Accounting for our groundwater inheritance

By Robert Knight

Special to The Sun

Published: Friday, May 20, 2016 at 6:01 a.m.

Last Modified: Thursday, May 19, 2016 at 12:29 p.m.

Donald Trump has nothing on today’s Floridians. Like Trump, Florida’s residents and tourists were born with a silver spoon in their mouths. Trump’s nest egg was millions of dollars from his successful father. Florida received a much greater bank balance in the form of trillions of gallons of pure, fresh groundwater, literally just below our feet.

There is really no comparison between what was handed to us versus Trump’s inheritance. At a current delivered cost of about $3 to $5 per 1,000 gallons, the clean water in the Floridan Aquifer is worth as much as or more than all of the real estate in Florida, including Miami Beach!

Any sharp businessperson can tell you that capital equates to income. An endowment of $1 billion generates an annual income of about $50 million in today’s markets. Squandering an endowment for short-term needs is bad business. Diluting an endowment with bad debts is just plain stupid.

The public at-large owns the water in the aquifer. It supplies many of our personal needs for drinking, bathing and food production. Moreover, the water supports Florida’s economy through permitted access for public utilities, farmers, water bottlers and industry. And just as importantly, the aquifer supplies water for our 1,000-plus springs and the rivers, estuaries and wildlife they nourish.


LIMIT THE USE of fertilizers and pesticides in your environment. Remember that because of our Karst Topography, chemicals used on your lawn and garden can drain quickly into our aquifer and then flow back up into our springs and rivers. Click here for more ideas.

Every one of us living in North Florida has a stake in preserving this natural bounty for the future. The aquifer is a public trust to be used wisely for ourselves and the public good. With our legal right to a share of this groundwater resource, tapping the aquifer becomes a responsibility.

We must be vigilant of our own impacts on the aquifer and the impacts of our neighbors. Good stewardship is dependent on knowledge. We need to know our personal aquifer footprint as well as the footprint of the people and businesses around us. By having a quantitative scale for comparison, we can make ethical judgments to moderate excessive groundwater impacts by a few.

The Howard T. Odum Florida Springs Institute has initiated the Blue-Water Audit Project. Utilizing best available data, institute scientists are developing a program to estimate everyone’s aquifer impacts. The audit will allow entities to estimate the amount of groundwater they consume and the amount of nitrogen pollution they contribute to the groundwater.

For example, the 2010 average domestic daily water use in Florida was 85 gallons per person. Up to 70 percent of groundwater pumped from the aquifer was returned in the form of recharge in some inland areas such as Gainesville, while as much as 100 percent was consumed where there was no recharge (for example in the Jacksonville area).

For more precise water-use values, city residents and many businesses will be able to use their utility bill coupled with a map of aquifer recharge rates to estimate their impacts. Many farms and country residences that rely on private wells do not measure their daily water use. In these cases water use can be approximated based on specific land uses, such as forest vs. row crops and whether landscaping is irrigated.

We also contribute nitrogen to the environment in the form of wastewater, fertilizers and other manufactured products that contain nitrogen. Location is even more important when looking at our specific nitrogen aquifer footprint. If we live and work in an area where the aquifer is confined by clayey sediments, then very little excess nitrogen reaches the underlying aquifer. But if we live and work in an area that has sandy soils directly over the limestone aquifer, the aquifer is vulnerable to nitrogen contamination. Our nitrogen aquifer footprint is typically much higher in these areas.

In my book “Silenced Springs,” I estimated the current combined aquifer footprint of approximately 9 million residents, thousands of businesses and millions of tourists. Based on observed declines of spring flows, our combined aquifer water quantity footprint (excluding South Georgia) is about 2.6 billion gallons per day, for a combined per capita consumption of about 290 gallons per day. Our current combined nitrogen footprint is about 32 million pounds per year or 3.5 pounds per person per year.

Keep your eyes on the springs institute’s website ( to find out how you can conduct your own Blue Water Audit. This knowledge will make you a more conscientious citizen with a stake in protecting your priceless groundwater inheritance.

— Robert Knight is director of the High Springs-based Florida Springs Institute.

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