Suspended sediment behavior within an urban river watershed in Owatonna, Steele County, Minnesota

The purpose of this study was to determine the impact of the storm water runoff from the City of Owatonna on total suspended solids in the Straight River and its tributaries. Water samples were collected from fifteen sites along the Straight River and its three tributaries. The water samples were analyzed for turbidity and total suspended solids (TSS). The TSS samples were characterized for percent organic matter and grain size. Sediments collected from three sedimentation basins on the system were analyzed to determine if there was a relationship between those sediments and the TSS collected downstream from the sediment basins. Runoff from the City of Owatonna during the two storm events in 1992 impacted the Straight River and its tributaries as documented by turbidity, TSS levels and the nature of grain size and percent organic matter of the TSS. In the sediment basins, it was determined that as the organic matter and percent fines increased, the amount of heavy metals also increased.