Parham Environmental

Lower Yellowstone Diversion Dam Project

Dr. Parham and Dr. Peters served on a Science Review Panel at the request of the Bureau of Reclamation to provide a critical evaluation of the science surrounding the Lower Yellowstone Diversion Dam Project. The objective of the project is to provide both fish passage and a fish screen at the Lower Yellowstone Diversion in the Yellowstone River near Intake, Montana.

This review specifically considered whether the information provided in the Draft Environmental Assessment (DEA), Biological Assessment (BA), and responses to Missouri River Restoration Implementation Committee (MRRIC) Questions use the best available science and support a conclusion that the Intake Project is a viable alternative with benefits for recovery of pallid sturgeon in the Great Plains Management Unit. Questions of whether the project is the best choice from the range of possible management actions within the Management Unit are outside the scope of the review.

This review concluded that the information effectively supports hypotheses that:

1. The project will provide passage and enhance upstream migration for adult pallid sturgeon.

2. Suitable spawning habitat exists upstream of the project.

3. Conditions at the potential upstream spawning sites are suitable for the development and survival of pallid sturgeon eggs.

4. There is sufficient downstream drift distance for larval development for at least a portion of the larvae in some years for some level of natural recruitment might occur.

5. Proposed fish screens will effectively decrease entrainment of adult, juvenile, larval, and embryonic pallid sturgeon and other fish species.

6. Conditions in the Yellowstone and connected sections of the Missouri River are suitable conditions to support completion of the pallid sturgeon life cycle.

Dr. Parham was further contracted to provide additional modeling to assess downstream drift distances under historic flow conditions to help better understand the potential benefits of the project.


The entire report can be found here: