CHESTERTON, Ind. (AP) — For the second time in three years, a lifeguard shortage has prompted Indiana Dunes State Park to ban swimming beginning Saturday and until further notice.

Visitors can wade up to waist-deep in the waters of Lake Michigan but are not permitted to swim or go deeper into the lake, the park announced Friday.

Indiana conservation officers and park staff will be on hand to enforce the ban, it said.

Visitors interested in the weekend of August 27-28 or on Labor Day weekend should monitor the Indiana Dunes State Park Facebook page for notifications regarding beach status, it said.

Swimming is permitted at the beach at Indiana Dunes State Park only when lifeguards are present because of frequently changing conditions of the lake bottom and the unpredictability of dangerous rip currents that can occur along the shoreline at the southern tip of Lake Michigan, a news release said.

The park is located about 50 miles southeast of Chicago and is a popular summer recreational destination for the region.