ISU officials warn students should not walk across Lake La-Verne, even if it looks frozen.

The lake used to freeze over each winter. However, ice no longer covers the lake in the winter months due to the addition of aerators.

Cathy Brown, campus planner for facilities planning and management,said the university began a project to improve the water quality of Lake LaVerne in 1995.

This included adding submerged aerators that supply oxygen to the accumulated bottom sediments and keeps the ice from freezing over.

John Downing is a professor of ecology, evolution and organismal biology and animal ecologist who has done extensive studies on lakes, including Lake LaVerne. When the lake was first built, Campus Creek ran straight though the lake.

“Campus Creek often carries a lot of sediment and nutrients that caused a buildup of sediments,” he said. “Even after the creek was routed around the lake, the lake received a lot of nutrients from the campus through storm drains.”

Downing said since the lake has a long history of receiving nutrients from the creek and campus, the rich sediments that have built up use all of the oxygen under the ice, which can cause problems with the water.

“The aerators help to control these problems and allow bacteria in the sediments to convert the organic muck to carbon dioxide that leaves the lake,” Downing said.

“Eventually aeration will lead to positive changes in the lake’s water quality.”

Another positive effect from the aerators is they allow the lake’s swans to stay on the lake year round.

“This is healthier for the swans,” Brown said. “Swans naturally live in an arctic or colder climate and they want to be on the water.”

She said the Facilities Planning and Management department puts out bales of straw to protect the swans from harsh winds.

Downing said sometimes the lake will freeze solid all the way across, but it us not safe to walk on due to the aerators.

“There are probably several very thin places that look frozen over, so caution is warranted,” he said.

ISU Police Patrol Captain Rob Bowers said he tries to keep people off the ice.

“To my knowledge, no one has fallen through the ice, but that doesn’t mean it’s never happened,” he said.