Fish Passage Improvement Program
     Software

FISHPASS

FISHPASS provides the analytical capabilities to assess whether a culvert or a battery of culverts will pass weak swimming fish efficiently and safely. The application uses hydraulic formulas describing profile drag (velocity), non-Archimedean buoyant (gradient) forces, and virtual mass forces to quantify the hydraulic conditions within a culvert that weak swimming fish can sustain without exhaustion. This design is not based on acceptable cross-section culvert velocities. Rather, the design method evaluates the component hydraulic forces within a culvert against a fish's available power and energy capabilities. The application can further differentiate between the red muscle (aerobic) propulsive mode typically used by fish within the culvert and the white muscle (anaerobic) propulsive mode used under most flow regimes at the culvert inlet and outlet. Power and energy evaluations are particularly useful in steep culverts, perched culverts and culverts with significant inlet contraction where virtual mass and gradient forces become significant relative to profile drag (velocity).

The FISHPASS computer modeling program and background documentation are published in:

Behlke C., Kane D., McLean R., and Travis M. 1991. Fundamentals of culvert design for passage of weak-swimming fish. Alaska Dept. Trans. & Pub. Facil. Rpt. No. FHWA-AK-RD-90-10. Fairbanks, AK.

Before using FISHPASS, we recommend that users read and become thoroughly familiar with the Behlke et al. publication. The required data inputs and design results will be more meaningful if the underlying theoretical concepts and assumptions are fully explained and understood. The FISHPASS program does not require that culvert inverts be embedded. However, routinely depressing culvert inverts increases culvert roughness, increases the tailwater depth, and provides greater assurance that, over time, downstream channel degradation will not result in a perched culvert. Subsequent updates of the FISHPASS computer-modeling program are expected to refine the equations for additional fish species and to enhance the modeling capabilities of the program. Current collaborative efforts include merging the FISHPASS program with the U.S. Forest Service's FISHXING computer modeling program.

System Requirements

• Minimum: DOS 3.31 or higher with an 80286, 8088 or 8086 processor with 640 KB of RAM and a monochrome monitor is required. A math co-processor will speed the computations up, but be aware that the program will run very slowly on an 80286, 8088, or 8086 processor.
• Preferred: An 80386 processor, with a math co-processor, or an 80486-DX2 processor with a color monitor is recommended. The program is mouse-supported but can be run directly from the keyboard. Disk Space: The FISHPASS.EXE file occupies 181,728 KB of disk space.

Download

• FISHPASS.ZIP - This is a "Zip" file that contains both the Executable program (FISHPASS.exe, 177 KB) and the Documentation for program (FISHPASS.doc,734 KB) in Word format.

If you would like more information concerning Fish Passage, please contact Gillian O'Doherty, Habitat Biologist, Alaska Department of Fish and Game.