In reviewing the likely causes of the collapse of Gilchrist Blue it was the consensus that, while over-pumping may have been a factor, it was the erosion from above and surrounding the spring that was the main cause. We need to take better care of our springs to prevent more issues such as this one.
Comments by OSFR historian Jim Tatum.
jim.tatum@oursantaferiver.org
– A river is like a life: once taken,
it cannot be brought back © Jim Tatum
The following was written by OSFR President Joanne Tremblay.
The collapse of a vent at Ruth B. Kilby Gilchrist Blue Springs Park on July 15th prompted Our Santa Fe River, Inc. to call a meeting for the scientific community to explore the event. We wanted to understand what caused the collapse.
We opened the discussion with footage that was taken by geologist Jake Berry who was on site when the event occurred. Next, geologist Jim Gross explained the physical and chemical processes that lead to sinkhole formation in our karst environment. Jim emphasized that though sink-holes are naturally occurring, they are sometimes preceded by significant drops to the aquifer.
Bill Hawthorne, Aquatic Ecologist with the Florida Springs Institute followed with their report which contained images and water flow readings taken the following day. The Florida Springs Institute published their report here. He added that though one of the two vents is currently blocked, the volume of water coming out has been steady. Conversations with cave divers also indicate that the overall cavern delivering the water has not been significantly altered.
Greg Owen, Senior Environmental Specialist with Alachua County, presented their springs protection plan which include shore stabilization, and replanting and stabilizing submerged aquatic vegetation (SAV). It was noted that Gilchrist Blue was lacking in both and had recently suffered from a great deal of erosion of its banks due to the recent removal of arsenic laden timbers which were terracing the slope . The absence of SAV is also endemic from high recreational use.
Merrillee Malwitz-Jipson indicated that Gilchrist Blue is within a mile of the wells which are extracting nearly one million gallons a day, suggesting that the extraction within the same cave system could be a factor leading to harm. She added that both the SRWMD which regulated water use permits and the Florida State Parks which regulate land use and management within the park system were invited but declined to attend.
Bob Knight closed by saying that springs are sinkholes that open to the aquifer, yet the clarity of their flow is dependent on aquifer levels. He added that the reduction of flow, brought on by overconsumption, is the true killer of our springs. Worthington was once clear and flowing, as was Santa Fe Spring above O’Leno, River Rise, Treehouse and Hornsby springs. One by one their flow has diminished, leading to backflow, and dark tannic waters. Gilchrist Blue is next in the series, will it join the line of failed springs?
In conclusion, the consensus seemed to be that the incident at Gilchrist Blue was likely a result of soil erosion above and around the spring. The overall reduction of flow offers a greater danger to the spring as it is in the line of failed springs along the Santa Fe. Over-consumption of our waters through large consumptive permits as well as residential landscape irrigation continues to accelerate flow reduction within the Santa Fe River and is the leading cause of death to our springs.
