NOAA’s Office of Habitat Conservation is investing $9.5 million through the Bipartisan Infrastructure Law and the Inflation Reduction Act to restore salmon habitat for South Fork Nooksack River Spring Chinook. Projects led by the Lummi Nation and Nooksack Indian Tribe will install engineered log jams in the river.
These structures mimic the natural log jams in rivers flowing through old forests. They provide hiding places for young fish and resting places for adult fish returning to spawn. The careful placement of log jams can also reduce the risk of flooding to homes and other structures. This is becoming more important as climate change increases the likelihood of extreme weather events such as storms and floods.
The Lummi Nation and Nooksack Indian Tribe’s deep-rooted connection to the river informs their groundbreaking design and reconstruction of these ecosystems. They are coordinating with NOAA, local floodplain authorities, and many state and federal funders. Their leadership of this project is part of their effort to sustain the economic, social, and cultural well-being of their tribal communities and restore fisheries. Over the next 3 years, the projects will add more than 80 log jams to the watershed and conduct other actions to restore floodplain habitat.
In the past two decades, the Tribes have completed more than 30 log jam projects along the South and North Forks of the Nooksack River. Many were conducted with NOAA assistance. Each restoration project may include dozens of these structures.
Log Jams Help Salmon Populations Recover
Deploying log jams in the South Fork Nooksack River will help recover the Nooksack Spring Chinook, an essential part of the threatened Puget Sound Chinook salmon population. Without action, this sub-population may go extinct, further unraveling the genetic diversity of the Puget Sound Chinook population protected under federal law. Restoration in the South Fork bolsters Pacific salmon recovery and honors tribal treaties.
As a keystone species, Spring Chinook are essential for the river's productivity and biodiversity. When adults die after spawning, they provide vital oceanic nutrients to the river and its floodplain. Their young are a crucial part of the food web. The annual return of salmon has been a cornerstone of tribal life. When fish populations are strong, they boost the local fishing economy and culture.
The decline of salmon in this watershed due to:
- Historical overfishing
- Floodplain degradation
- Removal of large wood from the river
- Constriction of the channel
- Increased sedimentation from forest roads and eroding banks
Log jams are a critical part of floodplain river corridors. They redirect water flows, causing the river to split into multiple slower-moving channels that meander among forested islands. They create the habitat salmon need for spawning and the development of juveniles. River flows scour deep pools in front of log jams. These pools stay cool, providing respite for adult salmon during their upstream migration.
Log jams can also help reduce the impact of floods on fish and local communities. They spread the water across a floodplain, giving fish safe places to rest, and recharging groundwater in floodplain wetlands. Log jam projects are carefully engineered and designed in collaboration with local flood authorities.
The Nooksack effort is leading the way in developing efficient methods for evaluating flood effects of restoration projects, engaging both the Federal Emergency Management Agency and local flood authorities. Creating this integrated floodplain management is key to the federal response to climate change.