Fish Passage Toolbox: Approaches to Solving Fish Passage Problems

APPROACHES TO FISH PASSAGE

Geomorphic and Hydraulic approaches are the basic classifications of fish passage solutions used in California Department of Fish and Game’s new Fish Passage Design & Implementation Manual (CDFG PART XII, 2009).

Solutions based on geomorphic principles mimic natural conditions and are flexible and resilient, while solutions based on hydraulic principles are more rigid and accommodating of site constraints. Many fish passage solutions combine both approaches and each site is unique, and conditions will lead to individual fish passage designs.

A Hydraulic solution is based on the premise that a structure with appropriate hydraulic conditions will allow target fish to swim through it.

A Geomorphic solution is based on the premise that a channel that simulates characteristics of the natural channel presents no more of a challenge to movement of organisms than the natural channel. 

This poster presents an overview of these approaches. The limitations and design considerations for each type of approach are given with examples of how baffles, fishways, drop structures, channel regrade, roughened channels, restored profile and stream simulation can be used to provide fish passage.

Part XII of the Fish Passage Design and Implementation Manual is intended to be a guide for the designer through the general process of selecting a design approach for passage improvement. It provides concepts, a design framework, and procedures to design stream crossings and fishways that satisfy ecological objectives, including the passage of fish and other aquatic organisms.  

A link to download the guidelines can be found at: http://www.h2odesigns.com/resources/publications-2/