Monthly Meeting & Program
The Geology and Hydrology of Springs in West-Central Florida, and Future Land Use Visions for the State

David J. DeWitt, Senior Professional Geologist, SWFWMD
Monday August 3, 2009

Florida's springs are among its greatest treasures. For many years, a coalition of state agencies and conservation groups have worked to protect our springs from impacts such as introduction of fertilizers, pesticides and other pollutants. In this program, one of our state's foremost experts on springs will provide up to date information on how springs work, their status, and what can be done to preserve them for future generations.

David J. DeWitt, P.G. is a Senior Professional Geologist in the Resource Data and Restoration Department at the Southwest Florida Water Management District. He has over 20 years experience working on ground water resource in Florida, including aquifer delineation and groundwater characterization through test drilling and hydrogeologic data collection, monitor well design and construction. He also conducts water quality research on springs in west-central Florida with the District’s Water Quality Monitoring Program. Dave is a 1986 graduate of the University of South Florida, College of Natural Sciences, with a bachelor’s degree in geology, and has been a licensed Professional Geologist in Florida since 1994.

Read more on the threats to our springs below.

Monthly meetings and programs of the Hernando Chapter are held on the first Monday of the month, and are open to the public, free of charge. Meetings are held at the Hernando County Cooperative Extension Office – 19490 Oliver Street (next to the County Fairgrounds) in Brooksville. We gather for delicious food and fellowship at 6:30pm, meeting and program starts at 7:00pm. For more information about this program or the Florida Native Plant Society, contact the Hernando Chapter Board at hcfnps@gmail.com.

---

Garden Party Showcases Native Plants at Home

More of us than ever showed up at the annual Hernando Chapter July Garden Party ready to show off our efforts to establish and preserve native plants in our home landscapes. We saw examples of formal beds, urban meadows, natural areas preserved, and specimens nurtured. No one left uninspired. We are putting up some photos from the show soon...check back!

 

Florida's Springs Wait for Protection

This session, conservationists were excited at the prospect of meaningful legislation to finally protect Florida's freshwater springs, but it was not to be.

Florida has a greater concentration of high magnitude freshwater springs than anywhere else in the world. Today many of these special places are a mere shadow of their former selves, beleaguered by excess nutrients and losing in the competition for water with human consumptive use.

A number of springs protection bills worked their way through the legislature last session, only to die on the floor. For a summary of the legislative need, read analysis from Bruce Ritchie's blog. In short, SB 274 would have established "springs protection zones" in counties with major springs. The bill also would have set limits for nitrogen flowing from property with septic tanks and required that new developments with more than one home per acre be placed on central sewer. In short, the bill failed because of the cost of nonpolluting septic systems. Isn't that a pile of you-know-what?

For the best overview of the plight of our springs, and facts to use in conversation, we turn your attention to an article by Robert Knight and Sky Notestein, Special to the Times, July 31, 2008, entitled "The future of Florida's springs isn't eternal." Here are some sobering facts to explain why our springs are turning greenish, losing their natural aquatic plant communities to algae, and ceasing to flow.

Knight and Notestien offer, "Here's a look at what we know, what we don't know, and what we can do to begin to restore our precious springs." Read on.

Spring fact: All consumptive uses of groundwater in a springshed reduce spring flows to some extent.

Nearly every aspect of a spring, from the basin size and shape, to the fish, other wildlife, plants and public use, depends on a sufficient flow of pure water. The No. 1 objective of springs' protection must be protection of the volume of water flowing forth. Every human use of water in a springshed (the area of land that recharges water to a spring) — every domestic, agricultural, commercial, and public water supply well, shallow or deep, large or small — to some degree reduces groundwater flow to the local springs.

Spring fact: The concentration of nitrate nitrogen, a recognized pollutant in surface and groundwaters, is rising rapidly in most Florida springs in response to agricultural and urban development.

A continuing increase in nitrate nitrogen concentrations in groundwater is one of the most visible environmental consequences of Florida's agricultural and urban development. Throughout the karst (porous limestone) areas of North and Central Florida where artesian springs are common, groundwater nitrate nitrogen concentrations have increased by 50 to 350 fold, with localized hot spots greater than 10 parts per million — the EPA drinking water standard. These increases not only threaten drinking water but are also harming plants and other organisms. Even if all human-controlled nitrogen pollution sources were stopped today, nitrate pollution in our aquifers and in our springs will take decades to reverse.

Spring fact: Spring ecosystems are undergoing widespread and dramatic changes in natural flora and fauna, often evidenced by replacement of natural plant communities by filamentous algae and native fauna by exotic species.

Natural artesian springs in Florida are generally dominated by luxuriant growths of native submerged aquatic vegetation. Natural algal communities known as periphyton enhance the overall plant productivity that supports fish and other wildlife. Silver, Ichetucknee and Rainbow springs are prime examples of large springs with high flows that retain much of their former beauty and native plant and animal species. But trampling of plants during human recreation (for example, Wekiwa and Volusia Blue) and uprooting and physical damage by motor boat propellers and anchors (e.g., Weeki Wachee and Fanning) often result in the loss of these native plant communities in springs and spring runs, resulting in the predominance of less desirable exotic plant species and filamentous algae.

Spring fact: Relatively pristine springs with high flows help support local economies.

Visitation numbers at springs are influenced by clear, cool water and attractive plants and wildlife. Annual visits to the 100 largest springs in Florida are estimated at more than 7-million people, with an annual economic value in excess of $300-million. But springs become less attractive to visitors when the flow and water clarity are reduced and when excessive floating vegetation and filamentous algae predominate.

A time for action

Springs are Florida's canary in the coal mine: If we stand by while they continue to dry up and turn green, we'll have missed one more opportunity to preserve ourselves. What sorts of changes are needed? Primarily those that will lessen our human footprint:

• • Stronger water conservation measures in all springsheds and a hold on new consumptive use permits until existing human impacts on spring flow reductions have been quantified and adequate water resources are allocated to preserve the natural water resource values of springs.
• • Restrictions on nitrogen fertilizer sales and use in the karst areas of springsheds based on application rates that result in measurable declines in groundwater nitrate nitrogen concentrations.
• • Improved practices for treated municipal, agricultural and commercial wastewater reuse and disposal in the karst areas of springsheds by further limiting all groundwater discharges of nitrogen.
• • Re-evaluation of public recreational uses in all springs on Florida public lands to develop science-based management plans that ensure compatibility between appropriate recreational activities and sustainable ecological communities in these "crown jewels" of our parks, preserves and national forests.

Robert Knight is an aquatic and wetland scientist and has been conducting applied research in springs and wetlands for more than 30 years. Sky Notestein is an aquatic ecologist who has focused his academic and professional career on springs' restoration over the past 12 years. Both work at Wetland Solutions Inc. in Gainesville.

For more about protecting our springs, see: http://www.floridasprings.org/protection/