Authorities in Florida are evacuating about 345 inmates from the first floor of a county jail amid concerns over the potential collapse of a local reservoir, according to reports on Sunday.  

The Manatee County Central Jail is at the corner of an evacuation zone surrounding the old Piney Point phosphate mine, where about 300 million gallons of wastewater is threatening to breach a reservoir there and flood the surrounding area. 

Manatee County Administrator Scott Hopes said the models show the area could be covered with one foot to five feet of water. The second floor of the jail is 10 feet above ground.

On Sunday, Manatee County Sheriff Rick Wells declined to share what location the jail is taking the inmates, as they were still being moved. He said the county's original plan -- moving all the inmates to the second floor -- would be too much of a security risk, according to the Tampa Bay Times. 

FLORIDA EXPANDS EVACUATIONS AHEAD OF POSSIBLE 'CATASTROPHIC' 340M GALLON BREACH AT PHOSPHATE PLANT

This photo shows a reservoir near the old Piney Point phosphate mine, Saturday, April 3, 2021, in Bradenton, Fla. (Tiffany Tompkins/The Bradenton Herald via AP)

This photo shows a reservoir near the old Piney Point phosphate mine, Saturday, April 3, 2021, in Bradenton, Fla. (Tiffany Tompkins/The Bradenton Herald via AP)

The jail was home to 1,063 inmates Sunday. The remaining inmates and staff on the first floor of the jail will be moved to the second floor, along with medical equipment, the paper reported. 

"The first floor will be vacant," Wells said.

Florida state Rep. Michele Rayner-Goolsby, a Democrat, said she was OK with Wells' plan.  

"I’ve spoken with Sheriff Wells and he has assured there is a plan in place to make sure inmates at the jail are protected and evacuated safely," Rayner-Goolsby wrote on Twitter. "As I am able to share the full plan, I will. But know- I am good with the plan."

On Sunday, Florida Gov. Ron DeSantis said crews were working to prevent the collapse of the reservoir while evacuating the area to avoid a "catastrophic flood."

Officials said it has the potential to gush out 340 million gallons of water in a matter of minutes, risking a 20-foot-high wall of water. The pond held about 480 million gallons last week. As of Sunday, it held about 300 million gallons.

LEAK AT WASTEWATER POND PROMPTS EVACUATIONS IN FLORIDA

"What we are looking at now is trying to prevent and respond to, if need be, a real catastrophic flood situation," DeSantis said at a press conference after flying over the phosphate mine.

County and state officials are currently working to pump water out of the reservoir to reduce the quantity in the event of a breach. Authorities closed off portions of the U.S. Highway 41 and ordered evacuations of 316 homes. Some families were placed in local hotels.

Crews have been discharging water since the pond began leaking in March. On Friday, a significant leak was detected that escalated the response and prompted the first evacuations and a state of emergency declaration on Saturday.

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Currently, about 22,000 gallons of water are being discharged per minute, but Hopes said he expects the risk of collapse to decrease by Tuesday. 

The Associated Press contributed to this report