Keeping it cool on one of California’s best coho salmon strongholds.

The South Fork of the Eel River—roughly 200 miles north of San Francisco, in southern Humboldt County—sustains one of the strongest wild coho salmon populations remaining in California (as well as abundant runs of Chinook and winter steelhead). A challenge for coho in the South Fork is the lack of streamflow for rearing juveniles during dry summer months. While low summer streamflows are a natural occurrence, this stressor is being compounded by the cumulative effects of water diversions for agricultural and domestic uses. WSC has supported efforts on the South Fork to understand the minimum cold water flows necessary to sustain coho during summer months. Once those needs are understood and a standardized flow assessment developed, CalTrout, Trout Unlimited, and several local project partners hope to use the information to establish minimum streamflow objectives in the South Fork Eel, while working with private landowners to implement voluntary water conservation projects.

Maintaining cold water flows is a core strategy of the stronghold program in California, and partners there view the South Fork Eel as a pilot that may be replicable throughout the state’s strongholds. According to Darren Mierau with CalTrout, “Our science-based approach developed in the South Fork Eel will provide a strong foundation for securing the health of other salmon strongholds as they face continued pressure from drought, climate change, and increasing water demands.”

The salmon stronghold initiative has helped us jump start a program on the South Fork Eel that could have profound benefits to salmon and steelhead throughout California’s coastal watersheds.”
Curtis Knight, Executive Director, CalTrout

Curtis Knight, Executive Director, CalTrout