Lake Thompson

LAKE THOMPSON, S.D. -- Some residents of Lake Thompson in east-central South Dakota have taken to social media to ask the state of South Dakota to help them with access to their homes on the flooded lake.

In a series of Facebook posts, Kathy Heither of Sioux Falls--who says she is a former resident of Lake Thompson--says residents are parking along roads and on vacant lots because they can't get to their properties.

Some farms, homes, and trailers sit surrounded by water.

"I think it is a sad day when our State can’t help it’s taxpayers," Heither writes on her Facebook page. "This area has been under water with NO ACCESS in to their homes for more than two months."

The owner of the Lake Poinsett Estates Campground Facebook page also noted the problems--and frustration--by some Lake Thompson residents.

"I know there are friends and relatives of Governor Noem that follow this page and can you pass some of these concerns on to her," the campground page noted. "They (lake residents) feel like their voices haven't been heard for several months now."

The state of South Dakota says they're working on the problem.

“Access issues like this are common in many areas where it has flooded this year," said Tony Mangan, a spokesman for the South Dakota Department of Public Safety. "The state is willing to work with the county and affected townships to find a solution to the issue.”

The S.D. Department of Game Fish and Parks lists a couple of areas in and around Lake Thompson that are closed or restricted:

Lake Thompson/Lake Henry Lakeside Use Area on 211th and 212th St.

Lake Thompson (Kingsbury County) No Wake Zone with 300 feet of shore.

Heavy snowfall and rain last winter and spring are not the only culprits causing problems at Lake Thompson and other glacial lakes.

According to the U.S. Geological Survey, the area's lakes have been expanding for decades.

Many lakes in eastern South Dakota have expanded during the Landsat record that began in 1972. Lake Thompson is one that has displayed remarkable change in recent decades.

This part of South Dakota is in what is known as the Prairie Pothole Region (PPR). Numerous depressions in the land were left behind there after the most recent glacial retreat. These depressions are termed potholes and collect rainfall and snow melt to form wetlands and ponds of varying size.

A wet period in the 1980s and several years in the 1990s resulted in dramatic filling of Lake Thompson, located west of Brookings, SD, along with other nearby lakes and sloughs. Lake Thompson is now South Dakota’s largest natural lake. According to GF&P, "In the 1930s, the lake (Thompson) was completely dry and used for pasture. In the 1980s, the area was a 9,000-acre marsh." KELO-TV chief meteorologist Jay Trobec says Lake Thompson goes through cycles.

"Lake Thompson varies greatly over the years," Trobec said. "It is very susceptible to droughts and floods."