Suspended Sediment Conditions to Hyporheic Dissolved Oxygen and Fine Sediment Deposition in Salmonid Spawning Habitat Below an Irrigation Dam, Park County, Wyoming

We quantified the effects of dam sediment management operations on downstream salmonid spawning habitat during two fall water-level drawdown periods: an experimental drawdown leading to sediment release or a typical slower drawdown intended to minimize release of sediment. The experimental drawdown increased deposited fine sediment and decreased hyporheic dissolved oxygen levels. However, the typical drawdown did not increase fine sediment deposition or decrease hyporheic dissolved oxygen. We quantify the immediate impacts of dam operations using a number of water column and substrate metrics including total suspended sediment concentration, hyporheic dissolved oxygen concentration, and deposited sediment data from sediment infiltration bags.