Florida Sea Grant is partnering with the U.S. Geological Survey and the Florida Center for Environmental Studies to provide information to water managers on how climate change may affect future water in south Florida.
The availability of water is always a concern in populous southern Florida, both for the people who live there and the natural ecosystems that have evolved there over thousands of years.
Now, people and ecosystems in South Florida must contend with the growing threat posed by increased amounts of saltwater seeping in from the ocean and changes in the amount of freshwater delivered to the region.
At a recent workshop in South Florida, water managers and scientists discussed how the availability of freshwater for people and ecosystems might change in future years as a result of climate change, focusing in particular on climate models that have been scaled down to local levels, and what the models project for future rainfall, evaporation and runoff to the Everglades and lower east coast urban area.
The Challenges Ahead
Many of the state’s coastal aquifers are already experiencing some degree of saltwater intrusion. The South Florida Water Management District, for instance, spends millions of dollars annually to offset the effect of saltwater intrusion on the Biscayne aquifer.
Normally, the Biscayne aquifer is recharged by rainfall and the flow of the Everglades, but as the area’s population has grown in the last several decades, more and more water has been withdrawn. At the same time, flood control structures have diverted freshwater flow that once replenished the southern Everglades and the aquifer, allowing seawater from the coast to push in.
As sea level continues to rise, and as rainfall and evaporation rates change, researchers predict that access to sufficient supplies of freshwater will challenge Florida’s coastal residents and its unique ecosystems for generations to come.
“One of Florida Sea Grant’s program goals is to improve knowledge about the impacts that climate change will have on businesses, infrastructure and natural resources in the coastal zone,” said Florida Sea Grant director Karl Havens.
“This meeting was a first step in a process to help water managers explicitly incorporate information about future rainfall and runoff into planning models and decisions about the greater Everglades restoration.”
One goal of the Comprehensive Everglades Restoration Plan is to better capture runoff, and redirect it where needed in cities and natural systems.
Florida Sea Grant co-sponsored the workshop with the U.S. Geological Survey and the Florida Atlantic University Center for Environmental Studies. The audience included 50 water managers and scientists from the Everglades National Park, the South Florida Water Management District, USGS, and private consulting firms.
On the first day of the meeting, experts in climate modeling described various methods that are being used to ‘downscale’ the global climate model to the region of South Florida, so predictions about future rates of rainfall and runoff can be made.
The second day focused on the physical processes that determine the amount of rainfall, evaporation and runoff in the Everglades region. Accurate information about these processes is key to predicting how much water will be available for natural systems and the urban coast under future climate change scenarios.
After a series of technical presentations, facilitated discussions were held among the attendees to identify information gaps, as a way of guiding future research to reduce uncertainty in climate model projections.
“Changes in climate and rainfall patterns could make things worse on a regional system that already has issues with providing adequate water for cities and natural systems,” Havens said.
“This meeting was critically important to begin a discussion on how Florida is going to handle these issues, beginning with us understanding what we do and do not know, what research is still needed, and how this all can be factored into Florida’s water management planning.”