Three Decades of Channel Change on the Jordan River, Utah

The Jordan River in Utah has been highly regulated for many years through intense irrigation, channelization, and managed releases from Utah Lake. As the only outlet of Utah Lake flowing north into the Great Salt Lake, it is important to the health of not only the riparian ecosystem but the surrounding human population as well. The river has a long history of mixed-uses, but it is emerging as a popular recreation site for the numerous adjacent communities. Human interaction both on the individual and commercial scale plays a role in the overall health of the system. Both the chemical characteristics of the water and the physical characteristics of the river and its riparian zone can be used as measures of system health. In this study, we focus on the physical channel of the river. We use GIS and aerial imagery to quantify channel change on the Jordan River over approximately the last 30 years. We assess changes in channel size and shape, as well as sinuosity, by comparing channel polygons. While there are areas where change is observed, the large areas of little or no change suggest that the dynamics of the river has been reduced. This has implications for the overall health of the river ecosystem and needs to be considered in future restoration efforts.