STREAM BANK STABILITY AND TURBIDITY OF DRY RUN CREEK, CEDAR FALLS, IOWA

The Iowa DNR considers Dry Run Creek in Cedar Falls to be an impaired watershed, and some portions of Dry Run Creek have projects underway to improve stream bank stability and the general health of the stream. Bank stability and turbidity of the stream are important indicators of stream health, and finding the main cause(s) is necessary to begin to remedy the health of the stream. The intent of this study is to assess the stream corridor by observing bank conditions, predominate land use, degree of hydrologic variability of the stream channel, turbidity, bank materials and dominate substrate. In addition, water chemistry analysis is being conducted by measuring pH, dissolved oxygen, chloride, sulfate, temperature, and nitrate levels in the stream. Preliminary findings indicate that stream bank erosion appears to be the main cause of turbidity in the stream. Field observations have located a high number of storm drains emptying into the stream, and channelization of the stream’s headwaters are causing a rapid increase in flow during rain events. These conditions amplify natural stream channel changes of erosion and undercutting. Continued improvements to the stream's health through bank stabilization projects, creation of rain gardens and detention ponds, and identifying and remedying point-source pollutants are needed to remove Dry Run Creek from the DNR’s list of impaired waters.