Cone Screen Riverine Baffle Design

Project ID: 3670
Principal Investigator: Leslie Hanna
Research Topic: Fish Passage and Entrainment
Funded Fiscal Years: 2012 and 2013
Keywords: None

Research Question

Can a baffle be designed for cone screens (designed for shallow depths), installed in a shallow riverine environment, that can reduce screen approach velocities on the upstream face and provide a uniform distribution of screen approach velocities around the circumference of the screen to meet resource agency fish screening criteria?

Need and Benefit

Fish screens are required on water diversion intakes in many locations to prevent entrainment of fish and other aquatic species (especially those that are listed as threatened or endangered). Resource agencies have adopted standards that require that screens meet a maximum approach velocity criteria ranging from 0.2 foot per second (ft/s) to 0.40 ft/s depending on the fish species residing in a given area (i.e., velocity measured perpendicular to the screen surface). This requires screen manufacturers to produce screen designs that provide uniform approach velocities in order to meet screen criteria guidelines while minimizing screen surface area or size required at a diversion. Cone screens have been designed to perform well for shallow water applications in areas where flow currents are minimal and cylindrical screens are not practical. However there is interest in using this type of screen in shallow river environments where river velocities are several feet per second. In order to accomplish this objective an effective baffle must be designed for the cone screens that will reduce the magnitude of approach velocities impinging on the upstream face of a screen and distribute them more uniformly over the total screen surface area.

Contributing Partners

Contact the Principal Investigator for information about partners.

Research Products

Bureau of Reclamation Review

The following documents were reviewed by experts in fields relating to this project's study and findings. The results were determined to be achieved using valid means.

ISI Cone Screen Riverine Performance_ External Baffle Design_PAP-1081 (final, PDF, 771KB)
By Leslie Hanna
Publication completed on March 10, 2014

Cone screens, which can be used under shallower conditions than typical cylindrical fish screens, are usually equipped with baffle systems that distribute flow over the entire screen area when installed in slack water locations; however the baffling system used in this environment was inadequate for approach velocities to meet fish screen design criteria in a riverine type setting. Research was conducted to develop a baffle design that would allow cone screens to be used effectively in this way.

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Last Updated: 6/22/20