Project Description
One of the primary factors limiting Chinook production in the Stillaguamish watershed is fine sediment input before and during spawning and incubation. As stated by the Washington Department of Fisheries in the 1970's, "The principal factor limiting salmon production within the North Fork is sedimentation resulting from a major clay slide. Below that point, heavy silt deposits cover most of the gravel riffles, making them unsuitable for successful spawning and egg incubation. This condition also inhibits natural cycles of aquatic insect growth, reducing food production, and consequently lowering the holding and rearing capacity of the stream below." Sediment from the slide is filling pools, and shallowing and widening the overall channel network, resulting in increased temperature, brought about by reduced shading and groundwater interception. This habitat loss and water quality impact will continue until the sediment source is reduced and the channel storage is increased. The purpose of this project is to isolate the river from the landslide thereby eliminating the undercutting of the slide and creating channel storage behind a large wood revetment. The project goal is to build the revetment 500' from the toe of the slide, move the river south of the revetment and isolate the landslide from the river eliminating the direct sediment discharge. A feasibility report is complete (#99-1687N). Reducing sediment to a level the river can flush will be the measure of effectiveness, along with increased spawning and survival.
One of the primary factors limiting Chinook production in the Stillaguamish watershed is fine sediment input before and during spawning and incubation. As stated by the Washington Department of Fisheries in the 1970's, "The principal factor limiting salmon production within the North Fork is sedimentation resulting from a major clay slide. Below that point, heavy silt deposits cover most of the gravel riffles, making them unsuitable for successful spawning and egg incubation. This condition also inhibits natural cycles of aquatic insect growth, reducing food production, and consequently low...
Project Map
Publicly Accessible: No
County: Snohomish County, WA
Project Sites
-
Steelhead Haven Landslide Remediation (point 1) (Not publicly accessible)
Goals and Targets
Targeted Habitats:
No targeted habitats were identified for this project.
Targeted Species:
- Bull Trout - Coastal and Puget Sound Salvelinus confluentus pop. 3
- Chinook Salmon Oncorhynchus tshawytscha
- Chum Salmon Oncorhynchus keta
- Coho Salmon Oncorhynchus kisutch
- Cutthroat Trout Oncorhynchus clarkii
- Pink Salmon Oncorhynchus gorbuscha
- Rainbow Trout or Steelhead Oncorhynchus mykiss
- Sockeye Salmon Oncorhynchus nerka
Conservation Actions
Action |
Status |
Start Year |
End Year |
Manage sediment inputs |
In Progress |
2005 |
2009 |
Outcomes
Is the success of this project's actions being monitored? No/Unknown