STARKVILLE, Miss. (AP) — An inspection found a new sinkhole at a Mississippi lake where an earthen dam could fail because of high water levels linked to heavy rains, officials said Friday.

The sinkhole was discovered at Oktibbeha County Lake on Thursday after county supervisors approved a plan to drain the lake in an effort to keep it from breaching, the Starkville Daily News reported.

Measuring about 3 feet (0.9 meters) deep and 4 feet (1.2 meters) wide, the hole hadn’t gotten larger by Friday, but officials feared that could change with heavy rain predicted over the weekend.

County engineer Clyde Pritchard said the surface area of the lake already has doubled to about 900 acres (360 hectares), and he estimated it could take as long as 24 days to lower the water level by just 5 feet (1.5 meters) using pumps that move 25,000 gallons (94,600 liters) of water a minute.

The lake is about 10 miles (16 kilometers) northwest of Starkville, the home of Mississippi State University. A breach of the dam, which Pritchard said was built in the 1960s, would endanger about 130 properties and nine highways downstream.

Mississippi has one of the highest numbers of dams that pose dangers and are in poor or unsatisfactory condition, according to a two-year investigation by The Associated Press.