Streambank Erosion Inventory Study

RWP's 2017 Streambank Erosion Inventory Report is available here. 

In 2017, IRWP with support from Walton Family Foundation undertook a "streambank erosion inventory" to understand the extent of streambank erosion along impaired reaches of the Illinois River and its tributaries. Using the BEHI modeling method, the study estimated erosion rates and quantities of sediment and phosphorus loading from 923 stream segments. Some key findings include: 

  • Across the 45 mile study area, an average erosion rate of 5.2 feet per year.

  • Estimated sediment loading of 37,500 tons per year

  • Estimated phosphorus loading of 56,250 pounds per year.

To put the phosphorus loading number into perspectice, the four largest wastewater treatment facilities in the watershed cumulatively load just over 24,000 pounds of phosphorus per year. This result indicates that streambank erosion presents one our greatest challenges in lowering phosphorus concentrations in the watershed.