Reclamation Information Sharing Environment (RISE)

This research aims to develop a science-based, numerical approach for fish passage to assist the design and evaluation of ways to reduce juvenile salmonid entrainment into or enhance passage through diversion channels at river junctures. Three current state-ofthe-art are adopted: (a) multi-dimensional flow models; (b) fish track models; and (c) knowledge of fish behaviors in response to flow features. Two flow models are updated to provide the flow variables to which juvenile fish respond: 2-D hydraulic model SRH-2D and a 3-D computational fluid dynamics (CFD) model. Two fish track tools, one in the Eulerian framework and the other in the Lagrangian framework, are developed so that fish entrainment at diversion channel junctures may be evaluated. A third sophisticated tool ELAM, a fish track model developed by Army Corps of Engineers (USACE), is further adopted through a collaboration with USACE. These flow and fish track tools have been applied to several diversion junctures, including Reclamation projects; valuable knowledge has been gained in understanding the ways to alter the flow features to increase or decrease fish entrainment. The research has led to the following outcomes: (a) a science-based, defensible approach for fish passage evaluation; (b) development and/or extensions of modeling tools that are linked for fish entrainment modeling studies; (c) guidelines for conducting fish passage simulations; and (d) knowledge about geometric and flow features of a diversion channel that are important for attraction or rejection of migrating Juvenile salmon passage.