Foot Lake's sediments disturbed by dredging that uncovered mystery
WILLMAR -- The decision to drill a sediment core on Willmar Lake was done in part because of knowledge that sediment in Foot Lake was disturbed by years of dredging, according to Robert Palmer, Willmar High School science instructor.
He led local students who joined Dr. Kate Pound, geologist with St. Cloud State University, in a project to collect sediment core samples from Willmar Lake and Eagle Lake on Feb. 17.
Kandiyohi County and the City of Willmar had operated a dredge on Foot Lake during much of the 1970s and 80s.
The dredging led to the creation of the beach on Robbins Island and an expansion of the island.
In 1985, the dredging also uncovered a mystery. A pair of underwater walls was discovered in the southwest section of the lake. According to Tribune files, the walls run east and west, are situated some 100 feet apart and are parallel to each other and to Ella Avenue.
The newspaper accounts describe the walls as between two and three feet in thickness and four to five feet in height. They were estimated to be 100 feet long and consist of granite-type rocks but covered by layers of sediment. Scuba divers later said they believed the walls were made of gravel.
The walls made for great coffee table talk, and all kinds of theories were proffered. Were they fish traps built by the original Dakota inhabitants? Are they an abandoned defensive structure built by frontier troops? Or, did a hapless settler build them as a foundation for buildings during a dry period only to see them flooded?
The suggestion termed most plausible in the 1980 newspaper accounts is the possibility that railroad tracks were laid on the supporting walls each winter. A box car could be rolled on the tracks and filled with ice cut from the lake.
Or, could the walls have been the intended foundation for a bridge to be erected during low water?
The local students found no such surprises or mysteries when they drilled into the sediments of Willmar Lake. As they anticipated, they found that Willmar Lake, like its twin Foot Lake, has a bottom covered by a homogenous, organic muck with a not-so-pleasant odor, said Palmer.
He said they had hoped to locate a 14-foot hole in Willmar Lake to conduct the drilling. They were unable to find the hole depicted on a Department of Natural Resource topographic map of the lake. They drilled in nine-feet of water.
He said they do not know if sediment has filled the 14-foot hole, or if they just were unable to pinpoint its location.