SPRING HILL — When the earth opens up and swallows part of a major county thoroughfare, the existing sinkhole is only part of the concern.
In the worst-case scenario, the void is a telltale sign of unstable ground in the area that needs to be shored up before traffic can flow again.
Hernando County officials were happy to learn that was not the case with Mariner Boulevard. On Thursday afternoon, they reopened a section of one of the county’s busiest roads, 10 days after a large sinkhole opened there after Tropical Storm Debby.
The sinkhole — one of at least 30 that formed on county property — remained confined to the southbound lanes of Mariner near its intersection with Little Street, and the ground in the area is stable, said assistant public works director Steve Whitaker.
Crews filled the hole and repaved the road, which sees about 21,000 vehicles per day, according to county traffic studies.
“We were fortunate it was isolated to the area we repaired,” Whitaker said.
The county contracted the work, and the purchase order to repair the sinkhole was issued for $155,000. Whitaker said he expects the final bill to come in under that.
Two smaller sinkholes on nearby Claymore Street will be repaired soon, Whitaker said.
County airport officials are hoping for the same kind of geo-technical report for the area where three sinkholes formed, said Mike McHugh, the county’s manager of business development. The hole that swallowed part of an airport taxiway, as much as 75 feet wide and 15 feet deep, is the largest known to have formed in the county in Debby’s wake. Two smaller holes formed on either side.
Engineers drilled in the area and used ground-penetrating radar this week, and a report outlining a repair strategy is expected Monday, McHugh said.
“I don’t think they came across anything of great concern,” he said.
The airport has remained open, and operations have not been affected.
Elsewhere, the main entrance to the Hernando County Detention Center and a portion of Spring Hill Drive, submerged by Debby’s floodwaters, are now dry.
Both Spring Hill Drive and the jail entrance opened Monday, but the jail access road was closed again Tuesday after it appeared to be settling. Crews discovered a void underneath the surface, filled it with grout and repaved the area. The road is expected to reopen today, Whitaker said.
Normal prisoner visitation, suspended since the storm, likely will resume Monday, said Sheriff’s Office Capt. Michael Page.
Sinkholes that formed in drainage retention areas throughout the county also will have to be repaired eventually, but they are low on the priority list, Whitaker said.
As the repairs are checked off the to-do list, the bills mount. County officials still are awaiting word from Washington that President Barack Obama has signed a public assistance disaster declaration that will qualify local governments for federal reimbursement to cover repair costs.
The threshold for a county to be eligible for damage assistance is $587,000. Hernando’s current tally is about $700,000, but that is sure to increase significantly, said emergency management director Cecilia Patella.
“I expect it will be in the millions (of dollars),” Patella said.
The repairs to the Peck Sink stormwater project on Wiscon Road southwest of Brooksville are expected to cost hundreds of thousands of dollars. And the tab for overtime costs for county staffers to repair and clean up after Debby is mounting. An itemized list will be submitted to the federal government.
“It adds up quickly,” said County Administrator Len Sossamon. “Our people were alerted up front to keep very good records.”
The public assistance declaration is distinct from the disaster declaration that makes individuals and businesses affected by the storm eligible to seek aid from the Federal Emergency Management Agency. That declaration came this week. The deadline to register is Sept. 6. For information, visit disasterassistance.gov or call toll-free 1-800-621-3362.