As you can see in the chart above from yesterday, flows in and out of Prineville Reservoir are very high and gas bubble disease is sure to occur. If you look at the details this morning, it is even worse.

This morning flows into the Crooked are above 3,000 cfs. This is the level where gas bubble disease has created significant fish mortalities in the past, especially for fish over 12″. This is bad news for resident fish and the record number of steelhead currently in the river. Also note that at high flows the fish ladder at Opal Springs dam must be closed. (For more background, here is a post on this topic from 2019 and one from 2024. There are more if you do a search in this blog.)

There is nothing that can be done about this. The reservoir is nearly full, inflows are very high (over 7,000 cfs this morning), and water must be released. Rain on snow events led to flooding in the City of Prineville in the past which is why Bowman Dam was built.

A final comment, in a naturally free-flowing river these high water events are good things. They flush the river, recharge riparian zones, and transport gravel to create spawning beds. Dams largely interfere with these processes. As in the past, the much of the gravel below Bowman Dam that creates spawning beds will likely be washed away with no replacement from new gravel from higher up the system. Let’s hope there are funds to artificially recreate these spawning areas as has been done in the past.