Degree Name

Master of Science (MS)

Semester of Degree Completion


Thesis Director

Leonard Durham


Polecat Creek is an occasionally intermittent stream which drains approximately 18,368 acres in eastern Coles County, Illinois. It travels 15.2 miles through cropland and a partially wooded valley before it enters the Embarrass River 3 miles upstream from Lake Charleston. The stream ranges from 0.5 foot to 5 feet deep at a normal water level, with an average depth of 16 inches. It averages 12 feet wide, with a range from 4 to 20 feet.

A water quality study with 5 stations along the stream was conducted from January 1971 to July 1971. A qualitative benthos study at the same 5 stations was conducted from April 1971 to July 1971. The purpose of the study was to determine the physical and chemical conditions present in Polecat Creek. The water quality tests covered dissolved oxygen, B. O. D., total dissolved solids, alkalinity, hardness, and the more important soluble compounds normally present in the water, such as nitrates, phosphates, iron, and nitrites. The benthic samples were taken from several different points in the stream at each station and were not quantitative. A selected literature review of general water quality criteria for running waters was also written.

Polecat Creek was found to be a fairly clean stream. The fact that it conforms with water quality standards set up by government agencies for surface waters indicates that it is a suitable environment for aquatic organisms. The benthic population is composed of both pollution-tolerant and intolerant species at most of the stations. This situation indicates that there is a lack of inhibiting factors present in most of the stream. If a model stream were selected for comparison with streams of lesser quality, Polecat Creek would be a good choice.