Concurrent Sessions D: Designing Roughened Channels for Fish Passage - Designing Fishways Based on the Natural Morphology of Steep Streams
Location
Agriculture Science Theater, Oregon State University
Start Date
27-6-2013 1:50 PM
End Date
27-6-2013 2:10 PM
Description
Numerous types and configurations of nature-like fishways, constructed primarily of rock and other natural materials, have been employed throughout North America, Europe, and Australia. Design of nature-like fishways focuses on producing hydraulic conditions that satisfy passage criteria for target fish species, but seldom incorporate the stable morphology of natural channels into their design. In recent years, designers have employed new geomorphically-based approach to engineer and construct fishways, founded on mimicking the bed morphology and composition of steeper natural channels. These geomorphically-based fishways are presumed to more likely satisfy broad fish passage objectives if constructed with a morphology and slope similar to natural channels that the target fish species and life-stages are known to reside and traverse. Additionally, natural bedforms found in steeper channels are more persistent due in part to their ability to dissipate energy efficiently over a wide range of streamflows. These geomorphically-based fishways have been applied to fish passage at small dams and road-stream crossings on smaller waterways. They are typically channel-spanning and receive the entire streamflow. The authors have described an approach to designing these types of geomorphically-based fishways in two recent publications (CDFG, 2009; USFS, in press). The approach is founded on using the Montgomery and Buffington (1997) channel classification system, which focuses on relationships between channel bed form and channel slope.
Concurrent Sessions D: Designing Roughened Channels for Fish Passage - Designing Fishways Based on the Natural Morphology of Steep Streams
Agriculture Science Theater, Oregon State University
Numerous types and configurations of nature-like fishways, constructed primarily of rock and other natural materials, have been employed throughout North America, Europe, and Australia. Design of nature-like fishways focuses on producing hydraulic conditions that satisfy passage criteria for target fish species, but seldom incorporate the stable morphology of natural channels into their design. In recent years, designers have employed new geomorphically-based approach to engineer and construct fishways, founded on mimicking the bed morphology and composition of steeper natural channels. These geomorphically-based fishways are presumed to more likely satisfy broad fish passage objectives if constructed with a morphology and slope similar to natural channels that the target fish species and life-stages are known to reside and traverse. Additionally, natural bedforms found in steeper channels are more persistent due in part to their ability to dissipate energy efficiently over a wide range of streamflows. These geomorphically-based fishways have been applied to fish passage at small dams and road-stream crossings on smaller waterways. They are typically channel-spanning and receive the entire streamflow. The authors have described an approach to designing these types of geomorphically-based fishways in two recent publications (CDFG, 2009; USFS, in press). The approach is founded on using the Montgomery and Buffington (1997) channel classification system, which focuses on relationships between channel bed form and channel slope.