Lake Cushman Floating Surface Collector

To improve fish migration habits at Lake Cushman, Tacoma Power moved forward with the Cushman Hydroelectric Project to safely guide and restore fish populations. This project included the installation of a 50-foot wide and 100-foot long floating fish collector attached to Cushman Dam No. 1.

One of the challenges was making sure the lighting fixtures installed on the surface collector were sufficient enough to accurately measure the fish. Furthermore, it was proposed that the lighting caused a negative affect on fish migration patterns dissuading them from entering the collector.

Tacoma Power wanted enough light output that wouldn’t result in shadows. Based on the application, the biologist concluded the shadows may be diverting the fish away from the collector. The lumen output and optics of a light fixture were deeply considered in choosing a light that would be effective. The environment was also an issue, as the fixtures would need to sustain a wet environment.