Historic channel change along Soldier Creek, northeast Kansas

To assess historical channel change along Soldier Creek, northeast Kansas, available information from eight U.S. Geological Survey streamflow-gaging stations was analyzed. At each gaging station, channel change was assessed using channel-bed elevation as the primary indicator variable. Changes in channel-bed elevation were inferred from changes in the stage associated with the mean annual discharge at each station. The variables channel width, channel area, and streamflow velocity were used as additional indicators of change.

Results indicated that the most substantial channel changes occurred downstream from Rocky Ford at the Soldier Creek streamflow-gaging stations located near Topeka and Delia. The available evidence indicated that the channelization of Soldier Creek, completed in 1961, was likely the primary cause of the channel changes at these locations. The decreasing base level provided by the Kansas River also may have contributed to the channel changes at these locations. At the Soldier Creek gaging station near Topeka, immediate effects of the channelization included a decrease in channel-bed elevation of about 5 feet and an increase in channel width of about 35 feet. The instability introduced by the channelization caused channel-bed degradation that moved upstream at the rate of about 0.7 to 1.2 miles per year. At the Soldier Creek gaging station near Delia, located about 12 miles upstream from the upstream end of the channelized section, channel-bed degradation began during the 1970s and resulted in a net decrease in channel-bed elevation of about 5 feet by 1999.

The available evidence indicated that Soldier Creek at and upstream from Rocky Ford has not been substantially affected by the upstream-progressing channel-bed degradation as of 2001. In this part of the basin other causes of channel change, such as land use and floods, may be relatively more important.