A second sinkhole has been discovered at the imperiled Oktibbeha County Lake dam in Mississippi as officials move ahead with plans to drain the lake and ease pressure on the dam.

One sinkhole was found during an inspection on Thursday afternoon, the Starkville Daily News reported. It's approximately 4 feet wide and 3 feet deep. The dam remains in danger of collapsing, but an inspection Friday morning showed that neither the sinkhole nor an area of sliding ground that's being watched had changed overnight.

An editor for the newspaper tweeted on Saturday that a second sinkhole had been found.

Meanwhile, pumps arrived at the lake Friday afternoon as part of the county's effort to drain it and prevent failure of the dam.

The work could take weeks or months and the road running over the dam will be closed during that time.

On Tuesday, emergency management officials urged nearby residents to evacuate, saying the dam was in "imminent" danger of breaching and flooding 17,500 acres of nearby land.

Officials in neighboring Clay County have also said 50 structures, about 40 of which are residential, could also be impacted in that county if the dam fails, the Starkville Daily News reported.

Water in the lake rose at least a foot from Tuesday night to Wednesday morning, putting even more pressure on a dam.

County officials said Wednesday morning that mandatory evacuations could be issued if conditions continue to worsen, according to the Daily News.

Workers have installed four 8-inch siphons to transport water from the lake over a spillway to a nearby stream, the Associated Press reported. A county official said the normal surface area of the lake is 426 acres, but as of Wednesday morning, it was covering about 900 acres.

Oktibbeha County EMA Director Karen Campanella told WTVA a county engineer on Tuesday found extremely high water levels in the lake, which is about 112 miles northeast of Jackson, Mississippi.

Clyde Pritchard, the engineer, also found that water has apparently gotten between the dam and the ground beneath it, which endangers the structure's integrity, a reporter with the Daily News tweeted.

Campanella said residents living along Riviera Road and Walter Bell Road should evacuate immediately.

Oktibbeha County emergency managers held a press conference Tuesday evening to update the public and said only one person had evacuated so far. Should the dam fail, an estimated 130 homes are in the inundation zone, they also said.

In September, the county sought federal funds to replace the dam.

At that time, Campanella warned that if the dam breaks, 17,500 acres of nearby land would flood to some extent, and about 250 people would have to evacuate at least 112 households, according to the Commercial Dispatch.

The county has limited the amount of water in the lake, which was built in the 1960s, since a 2016 state inspection confirmed the levee needed repairs, the Dispatch reported.

At least 1.37 inches of rain fell Tuesday morning in nearby Starkville, Mississippi. Nearly 8 inches of rain has fallen this month on the Mississippi State University campus in Starkville.

It has been the wettest start to January there since 1989, weather.com senior meteorologist Jonathan Erdman said. The average for the month is 5.12 inches.

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