They are the few and the brave who fought for the many. Following a week when America celebrates patriots who sacrificed their lives to fight tyranny, we all should thank the Rainbow Five for their heroic actions.
Rainbow Springs currently has the highest average flow of any spring system in Florida and probably in the United States. While this distinction is noteworthy, it does not compensate for the fact that long-term average flows at Rainbow have already declined by about 20%, due largely to regional groundwater pumping.
Science shows that significant harm to the environmental health of Rainbow Springs is evident with just a 5% decline in flow. In other words, the health and aesthetics of Rainbow Springs are already impaired due to permitted wells extracting several times the acceptable quantity of groundwater.
While the Southwest Florida Water Management District agrees that average flows at Rainbow Springs have declined by about 20%, they claim that groundwater use is only causing about 1% to 2% of the observed decline. This conclusion is based on the same flawed mathematical model that allowed the St. Johns River Water Management District to continue to issue new groundwater consumptive use permits near Silver Springs.
Ironically, Silver Springs as recently as the 1980s had the highest flow of any U.S. spring. Currently it has lost over 32% of that long-term historic flow and now ranks considerably lower than Rainbow Springs.
Groundwater is literally the lifeblood of Florida’s artesian springs. The quantity of pure water flowing out of a spring is the most important factor affecting springs health. More flow correlates with higher aquatic plant productivity, greater wildlife habitat, and maximum recreational and aesthetic benefits for humans.
Reduced flows at Silver and Rainbow have been linked to increased dominance of noxious filamentous algae, lower populations of aquatic insects, and fewer fish and other wildlife. Highly elevated nutrient concentrations in these two spring systems exacerbate these biological impairments.
The Florida Springs Council provided technical and financial support for the legal challenge to the proposed minimum flows for Rainbow Springs. At the administrative hearing, Springs Council experts with technical expertise in hydro-geology and springs ecology presented a holistic assessment of factors responsible for spring flow declines, and the consequences of allowing additional harm to Rainbow Springs.
Specifically, the council’s scientists highlighted the uncertainty associated with the district’s groundwater flow model predictions. While the model can predict flows at Rainbow with some accuracy, it incorrectly predicts groundwater levels by four to 10 feet, equivalent to a loss of 50% to 100% of the flow at the springs.
The Springs Council experts presented the judge with four lines of evidence that contradicted the district’s claim that pumping is not significantly affecting flows at Rainbow Springs. Based on these multiple lines of evidence, the petitioner’s experts concluded that groundwater pumping is responsible for most of the observed flow decline, and lower average rainfall accounts for less than one third.
In the past, the water management districts’ technical staff were free to pursue their science without political interference. Under recent state environmental leadership, this reliance on the facts has been severely compromised.
When the draft Rainbow Springs minimum flows were proposed in 2016, a peer review panel provided these recommendations to the Southwest Florida Water Management District:
- “The District’s allowable flow reduction is not protective of most of the water resource values.”
- “Current flows are substantially below the minimum and there is nothing in the report that assures recovery.”
- “In the absence of key supporting data, the District should consider capping withdrawals at current levels.”
The district’s response was to reduce the allowable flow reduction from 7% to 5% with no adjustment to their prediction that current pumping is only reducing flows by less than 2%.
The state’s administrative hearing officer has until mid-September to make his ruling. The testimonies of the Rainbow Five were convincing — they have seen with their own eyes that Rainbow Springs is already suffering an unacceptable level of harm.
The water management districts need to stop the bleeding. Our springs are too important to lose.
Dr. Robert Knight is executive director of the Howard T. Odum Florida Springs Institute. Visit the North Florida Springs Environmental Center in High Springs.