Possible Water Withdrawals from St. John’s and Ocklawaha

This story is about the UF Water Institute and St. Johns River Water Management meeting that took place last week in Gainesville, FL at the Hilton.   Fred Hiers published this in the Ocala Star-Banner on Sept. 19.  Continue reading for this story, or click HERE to see the original piece in the Star-Banner.

 Consensus inches toward tapping two nearby rivers

By 
Ocala Star-Banner
Published: Friday, September 19, 2008 at 11:45 p.m.
Last Modified: Friday, September 19, 2008 at 11:45 p.m.

The St. Johns and Ocklawaha rivers moved a little closer last week to becoming prime potable water sources for thirsty Central Florida.

More than 100 scientists, St. Johns River Water Management District engineers and environmental experts met in Gainesville on Wednesday and Thursday to discuss the rivers as two potential water sources in 2013, when the state turns off the taps to Central Florida countries seeking to draw additional groundwater from the aquifer.

The two-day symposium was the first time so many experts in the field of water use met to share basic data that they’ve collected about the rivers with the goal of determining whether it’s safe to siphon water from the two.

Both rivers run north and meet near Palatka.

Most of the studies centered on the St. Johns River and initially indicated withdrawing water from the Ocklawaha and the St. Johns would not do any harm. But most of the scientists were quick to say much more would have to be done before concluding that taking water from either river would be safe.

One study presented at the meeting showed that siphoning 262 million gallons per day from both rivers, 107 mgd from the Ocklawaha and 155 mgd from the upper St. Johns River, would decrease the water level in the central St. Johns River only 2 centimeters (less than an inch) and less than 2 centimeters further downstream.

But what isn’t fully understood is the effect of lowering the water table by that depth.

What is known, scientists at the meeting agreed, is that salt concentrations from the Atlantic Ocean increases in rivers like the St. Johns when water levels drop. Scientists also showed that as salinity increases, it reduces the number and diversity of invertebrates that fish rely on to live and that more salt in the water can hurt vegetation.

Another unknown is how much the salinity would increase in the St. Johns River.

Ed Lowe, the St. Johns Water Management District’s director of environmental services, said the purpose of the symposium was to give lawmakers as much information as possible before they make decisions on whether to withdraw water from the two rivers.

He said most of the studies discussed at the meeting were about the St. Johns River and not the Ocklawaha, because the St. Johns was a much more complex system that included a large estuary. In addition, the Ocklawaha has a series of dams that could be used to regulate its depth, while no such dams exist on the St. Johns.

Before researchers shared their findings, Lowe painted a bleak picture of Florida’s water needs and resources in the future. The St. Johns River Water Management District’s population, which includes half of Marion County, is expected to grow to 5.9 million people by 2025, a 67 percent increase from 1995. The demand for water in the district will almost double to 836 million gallons per day during the next 17 years.

Lowe said a balancing act was needed to meet the state’s water demand while protecting its water resources. The state’s 2013 deadline means that many Central Florida counties will not be able to siphon more water from the aquifer than they already are.

But demand can’t be met using just groundwater, which is largely the case today, Lowe said.

Lowe said the data presented last week was preliminary and recommendations about withdrawals won’t be ready for at least two years.

 

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