Peak Flows

The flow regime throughout the Willamette River system is disrupted by 13 dams built to mitigate and control downstream flooding by reducing the magnitude of peak flood flows. Reduction in the magnitude and frequency of peak flows has altered ecological communities and lead to a variety of negative geomorphological consequences in the Willamette River.

This indicator measures the difference between current and historic peak flows.

This indicator assesses the annual variation of peak flow at Salem and Albany, in comparison to calculated naturalized flows that would have occurred at these sites without reservoir regulation or irrigation demands. Photo courtesy of Dave Herasimischuk (Freshwaters Illustrated).