Flow features just below the low head dams that are used as sea lamprey barriers can represent a public safety concern under some flow conditions. In this project, an improved barrier design will be developed to mitigate these dangerous flows, while maintaining the efficacy of the barrier at blocking lamprey. To do this the existing flow must be first studied to better understand the flow behavior and to allow quantification of drowning risk at the site. Scale models of four existing barriers (Salmon River, Wolf Creek, Duffins Creek, and Little Otter barriers) and will be tested in a laboratory flume to evaluate the flow behavior at the structures. Flow visualization will be first used to identify the conditions of flow when a dangerous submerged hydraulic jump forms. Then, detailed flow measurements will be made of these flows using an Acoustic Doppler Velocimeter. After gaining a better appreciation of flow at the structures, a retrofit design for barriers will be developed that results in mitigation of the potentially dangerous flow features, while maintaining the necessary vertical drop between the dam crest and tailwater to block lamprey migration. This retrofit design will then be tested in the laboratory flume to assess the improvement in drowning risk.
Phase I Development of an Improved Sea Lamprey Barrier Design
Scope of Study
Scale of Phenomena
Research & Development
Surveillance and Monitoring
Impact of water quality and AIS on fish and wildlife populations and habitats