Selected for FY24 funding under PLCI umbrella project.
The goal of the project is to improve adult Pacific lamprey passage at Prosser Dam in the Yakima River. The specific goals include the following.
1) Install a volitional passage system (using 4-inch flexible hose, or solid PVC in some locations) for all the existing adult lamprey passage structures on the Center and Right ladders (three total) so that lamprey can pass these two ladders volitionally and efficiently without the need for YNFPLP staff to collect and transport lamprey on a daily basis. This will make all three ladders fully volitional, given that the Left Ladder has already been converted.

2) Install laser photoelectric sensor monitoring systems (similar to the technology used for garage door opening) to count adult lamprey passing through all the 4-inch clear PVC counting stations at all three ladders (similar to the counting system at Bonneville Dam, which has been very successful).

3) In order to help reduce the amount of sediment buildup and maintenance work required, attach a small add-on for the trap box (a perforated screen that sits just above the trap box bottom to allow fine sediment to deposit underneath, so lamprey stay clear of the fine sediment (this design has worked well for the new structure built at Lyle Falls fish ladder on the Klickitat River (in 2022).