On Saturday July 15, Gilchrist Blue Spring suddenly turned brown and foamy with murky water and debris rushing from the vent in place of clear water.
The water turned brown and murky, the flow stopped, and the water level dropped by about one foot. It's likely that a sinkhole occurred beneath the spring, a collapse of the karst structure underground.
The spring was immediately closed to swimmers and springs lovers across social media expressed concern for the beloved spring as though a dear friend had been involved in an accident.
Thankfully it didn’t take long for the spring to run clear once again, as you can see in this series of photos taken about 24 hours apart.
Today, things look pretty much back to normal at the surface, though we don’t yet know the full story of how things have changed beneath the second magnitude spring.
What happened?
We can’t say for sure, hydrologists and cave explorers will need to weigh in on the details, but it seems to have been a sinkhole opening underground, a collapse in the karst beneath the spring.
Our science-based sister organization, the Florida Springs Institute, tells us that sinkholes like this can occur if when water levels in the aquifer drop, removing the support of the water for the karst. Our scientist friends at the Institute continue to look more closely at the cause and effects of this collapse.
Is a collapse beneath a well-loved second magnitude spring a cause for concern? We’re reminded of similar underground changes that manifest in our springs:
The browning of Wakulla springs, which has grounded their famous glass-bottom boats more days than not, is thought to be caused in part by the delicate balance in flow between Wakulla Spring and Spring Creek being altered by nearby pumping, causing tannic groundwater from a nearby forest to flow into the spring.
In 2020 a sinkhole opened near DeLeon springs that caused the spring itself to cloud up temporarily.
At some point in the last 20 years something in the complex system that joins the Rainbow Springs and Silver Springs basins flipped below the ground, around I-75, causing boundary changes in those springsheds, changing the flow of the aquifer between them.
It's a disturbing pattern. While we don’t know the full details of what happened beneath Gilchrist Blue spring, we do know that our overzealous water use above ground is changing the complex flow of water through the aquifer and compromising the stability of the underground karst. We DO know that overpumping makes sinkholes and karst collapses more likely.
The map above shows Gilchrist Blue spring in relation to BlueTriton Brands’ water bottling operation at Ginnie Spring. Seven Springs Water Co. pumps nearly 1 million gallons of water per day from the springs to sell to BlueTriton for bottling. The Florida Springs Council challenged Seven Springs Water Co.’s water-use permit in court to not only stop the permit but to challenge the lax water permitting system that is causing overpumping in the entire spring basin.
The overpumping of our aquifer not only overtaxes our precious water resources, it also has complex impacts on our springs that no one can currently predict.
How is Gilchrist Blue Spring after the collapse?
Update, August 11, 2023
On the surface things look back to normal. Even underwater, any changes might only be noticed by those who know the spring well. Our sister science organization, the Florida Springs institute has weighed in with some observations that can be found on their website.
From their report: "Based on evidence from photographs, there was likely a collapse of a cavern underneath the main
headspring basin. This collapse likely triggered a landslide, bringing mud and debris into vent #1. This mud and debris may have temporarily blocked the flow of one or both vents, leading to a drop in the water level, before being blown free and the flow returning."
In this photo provided by FSI, the white star denotes the inferred approximate location of the collapse. Red arrows denote inferred location and direction of landslide.
How did the spring change?
- Historically, Vent #1 contributed about 20% of the flow while vent #2 contributed 80% of the flow. These vents can be seen in this photo provided by the FSI.
- After the event, the majority of the flow is now exiting vent #2, and vent #1 has almost completely ceased flowing.
- The debris going into the left vent has almost entirely blocked the flow which appears to now be exiting through the right vent. Based on flow data, this event likely did not affect the total discharge level of the spring.
- There will likely be no long-term ecological effects from the collapse as flow and clarity have since returned to pre-event levels.