Placing “rockwads” into the Sacramento River to save salmon

Added: 2026-05-06

[00:00:02]People's use of the Sacramento River over the last several decades has left it fairly bare of debris. Debris that once acted as hiding spots for young salmon and trout trying to avoid larger predators. So to fix that, we're creating our own.

[00:00:15]>> Placing these large boulders in the very deepest part of the river so that juvenile salmon and steelhead can get in behind them and and feed and grow faster. And on top of that, we have the wood that's attached to it for escape cover from predators like trout.

[00:00:31]>> Funded by the Bureau of Reclamation, just over two dozen are being placed north of the Sundial Bridge near Turtle Bay. The hope is the juvenile fish will use the rockwats as their natural habitat until they're big enough when they'll likely make the journey to the Pacific. Although project lead Jeff Soua admits it's a new approach to the problem.

[00:00:48]>> We know that large wood is beneficial to salmon. Um, this is a very experimental project. It's very novel. So, the the the actual design is novel. It's the first time really anybody's tried this specific thing.

[00:01:01]>> Each one is being installed at a pre-planned point, using sonar to guide the rock wad into place once it's submerged, and they're not just dropping and forgetting them. Fishery biologist Keith Marine says they will be monitoring the project to measure its success.

[00:01:15]>> Doing follow-up surveys using sonar to quantitatively count fish that are using the structure or using the area in and around the structures. And then we'll compare that to surveys that we've conducted in the year preceding the construction installation of the rock walls.