Concurrent Sessions C: Multi-Dimensional Modeling and Fish Passage Restoration - Modeling Fish Passage for American Shad in a Steeppass Fishway Using a Computational Fluid Dynamics (CFD) Model

The Alaska Steeppass is a type of chute fishway used extensively on coastal streams in the east and in remote locations of the U.S. Typically prefabricated out of ¼ aluminum plate into 27-inch-high, 18-inch-wide, 10-foot sections, these chutes are highly portable and relatively inexpensive. The Model A Steeppass, a derivative of the modified Denil No. 6 developed by McLeod and Nemenyi, is the most widely used variant because it reduces flow velocities to magnitudes negotiable by many salmonid and alosa species. The results of the CFD model will be briefly described and thefocus of the presentation will be to demonstrate how the CFD model was used to estimate the probability ofpassage for American Shad in a steeppass fishway for a selection of swim paths. Passage efficiency can be estimated using optimal swim speeds for the target species (Castro-Santos 2005) allowing for variation in water velocity (Castro-Santos, 2006). The results will be compared to experimental results for passage efficiency published by researchers at the S.O. Conte Anadromous Fish Research Center (Haro, et al, 1999) to demonstrate that water velocity alone does not limit ascent of the fishway by American Shad