Location

UMass Amherst

Start Date

28-6-2011 4:25 PM

End Date

28-6-2011 4:45 PM

Description

The planning and designing of steep channels suitable for fish passage has become increasingly common as an alternative to structural fish ladders at dams. They are found at dam removal sites, naturalistic bypass channels that allow fish to swim around and past dams, and at created fill ramps that allow fish to swim over dams. Each of these three steep channel types have unique features such as entry and exit needs; partial or full river flow design criteria; and rigid, threshold, or mobile beds. All three types of steep fish passable channels have a common feature in the main channel segment. To be fish passable, the depth of flow, velocity, and cover must be scaled to the swimming and biological characteristics of one or more fish species or assemblages. Steep channels have the potential for high velocity and high turbulence flow, plus supercritical conditions that are difficult to analyze. A design protocol is presented, drawing upon classic hydraulics; use of analog reference reaches with similar slopes; and geomorphic relationships between slope, discharge, and profile type. Steep mobile bed channel types are also discussed with basic techniques to analyze sediment continuity. Numerous examples of constructed steep fish passable channels are used to illustrate the discussion.

Comments

Jim MacBroom earned BS and MS degrees in Civil Engineering from the University of Connecticut and is a registered Professional Engineer in five states. He is Vice President of Milone & MacBroom Inc, a Civil and Environmental Engineering consulting firm located in Cheshire Connecticut, and he developed and teaches graduate courses in River Processes & Restoration and Applied Hydrology at Yale University. He has over 35 years of experience in watershed management, open channel hydraulics, dam repair and removal, fish passage, computer modeling, fluvial morphology, stream restoration, and tidal systems. Jim is a member of the ASCE Stream Restoration Committee, American Rivers Technical Advisory Committee, and a speaker at the annual University of Wisconsin continuing education course on dam removal. Jim has planned, designed, and inspected numerous river restoration, flood control, and dam removal projects including earth, timber crib, and concrete structures, with a special interest in sediment management, channel evolution, and design of natural-like bypass channels.

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Jun 28th, 4:25 PM Jun 28th, 4:45 PM

Session A6- Design of Steep Channels for Fish Passage; Dam Removals, Bypass Channels, and Rocky Ramps

UMass Amherst

The planning and designing of steep channels suitable for fish passage has become increasingly common as an alternative to structural fish ladders at dams. They are found at dam removal sites, naturalistic bypass channels that allow fish to swim around and past dams, and at created fill ramps that allow fish to swim over dams. Each of these three steep channel types have unique features such as entry and exit needs; partial or full river flow design criteria; and rigid, threshold, or mobile beds. All three types of steep fish passable channels have a common feature in the main channel segment. To be fish passable, the depth of flow, velocity, and cover must be scaled to the swimming and biological characteristics of one or more fish species or assemblages. Steep channels have the potential for high velocity and high turbulence flow, plus supercritical conditions that are difficult to analyze. A design protocol is presented, drawing upon classic hydraulics; use of analog reference reaches with similar slopes; and geomorphic relationships between slope, discharge, and profile type. Steep mobile bed channel types are also discussed with basic techniques to analyze sediment continuity. Numerous examples of constructed steep fish passable channels are used to illustrate the discussion.