Lake bed crack raises fears about dam
By ALEX LEARY, Times Staff Writer
INGLIS -- In the still water below the Inglis Dam, bubbles rise from the dark green depths like an ancient spring.
It has been like this for decades, but now, officials are paying close attention, worried that the simmering surface represents a potentially disastrous situation.
The source of the bubbling is not an aquifer. It is, recent tests have confirmed, a 40-foot-long crack in the bottom of the 3,600-acre Lake Rousseau, which the Inglis Dam holds back.
"It may be just a small seep that is no concern," said Gary Kuhl, director of operations for the Southwest Florida Water Management District, which operates the dam.
But if the fissure, located 2,000 feet from the dam, were to expand, it could cause the structure to shift, crack or, worst of all, collapse.
The mere flow of water from one side to the other illustrates that the rock below the dam is not entirely solid, Kuhl said.
"It's a serious problem that needs to be addressed," said Al Coogler, a member of Swiftmud's governing board. "It doesn't seem to be getting any smaller."
During its meeting last month, the governing board was asked to appropriate $139,000 for an emergency action plan for the dam.
The money would later be reimbursed by the Department of Environmental Protection, which owns the structure.
The board tabled the issue, however, prefering to wait until Gov. Jeb Bush makes a decision whether to carry over unspent DEP money into the new budget cycle.
DEP officials are confident the funding will be available. It would be used to continue a study on the effects of a dam failure, particularly flooding downstream, toward Inglis.
URS Corp. of Tampa, which is conducting the study, has mapped the area but needs to more precisely identify which homes would fall into a flood zone, Kuhl said. URS officials were on vacation last week and could not be reached.
With the knowledge gleaned from the study, officials can develop an emergency notification plan. The options range from a simple phone chain to a more complicated and expensive "reverse 911' system in which authorities could deliver a recorded message to dozens of homes in a matter of minutes.
That would cover the symptoms but not the condition.
Mindful of the looming questions, DEP is considering asking for $500,000 in the 2003-04 budget to continue with investigations of the crack and how it could be fixed. For instance, cement or another substance could be poured into the crack.
"There is no way to know what solutions there are until we do a study to find out exactly what the subfeatures are," said Jena Brooks, director of the DEP's Office of Greenways and Trails.
She noted that the issue is not new and DEP has been monitoring the crack for a while. Every six months for the past five years, for example, divers have made the plunge.
So why the new concern?
While it has long been suspected that the "spring" on the other side of the dam is really water seeping underground from Lake Rousseau, the matter has never been investigated in-depth.
To test the relationship, researchers recently placed dye in the water near the crack. About five hours later, the colored water was noticed on the other side of the dam.
"The issue now is how deep are those cracks?" Kuhl said. "Is there a chance something could collapse? (The dam) could sit there for another 1,000 years and nothing could go wrong. But we want to be ready in case something does happen."
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