Integrated Fish Protection System to Address Entrainment and Impingement

Extensive research has been conducted on various fish protection systems in an attempt to reduce both entrainment and impingement. Since the technology for impingement reduction is often different from entrainment technologies, integrated systems are often used as retrofit designs to address the different life history stages of fish, notably larvae, juvenile and adult fish. The proposed system at BayShore involves a unique “reversed” louver array to address impingement and debris (and to a lesser extent entrainment), fine mesh screens in the pumphouse to address entrainment and residual impingement, and a fish return system involving fish pumps and a transport system. The “reversed” louver array is critical as the initial component of the proposed fish diversion system and includes specific design features such as frame angle, slat angle, slat length, slat spacing and a bottom overlay. The primary function of the louver is to divert juvenile and adult fish which may eventually become impinged on the traveling screens. Another function of the louver is to divert or minimize debris so that less material ends up on the traveling screens. Fine mesh screens are another critical component of the integrated system at BayShore. It’s main function is to divert organisms which include eggs and larvae unharmed towards the transport system. The final component of the integrated system is a fish pump and transport system. Factors considered important include location, type of pump, size, impeller speed, expected fish densities, sweep velocity along louver to pump, attraction velocity (if required), and quantity of flow. A pilot project was carried out in the field from April to October 2010 on the louver array, and a fine mesh screen component. Results on entrainment, impingement and biofouling will be presented including a discussion of how the proposed unique system will operate at the BayShore Plant.