Near the city of Eureka in Humboldt County, a large restoration project was completed to restore the estuarine reach of the Cochran Creek watershed. The tidal marshes of the Cochran Creek estuary once provided important brackish water habitat for coho, Chinook, cutthroat, and steelhead, and supported a broad array of birds and other wildlife. However, beginning in the early 1900s, almost all of these tidal marsh lands surrounding Humboldt Bay, including Cochran Creek, were diked off and converted to ranch lands. As a result of these activities, the Cochran Creek estuary became disconnected from the spawning grounds in the upper watershed, and no longer provided quality fish habitat or a connection to Humboldt Bay.

To address these problems, CalTrout implemented the Cochran Creek Fish Passage and Habitat Rehabilitation Implementation Project. In summer 2021, CalTrout’s North Coast program launched the construction phase of the Cochran Creek project. In July 2021, fish passage was ensured through the replacement of the “top-hinged” tidegate with a “side-hinged” tidegate technology. Another component of the project was restoration of the wetland and riparian vegetation zone. The wetland plants, riparian trees and understory shrubs provide critical habitat to numerous bird, amphibian, and small mammal species. Revegetation of the area included over 45,000 wetlands plant “plugs”, and many hundreds of redwood, Sitka spruce, and alder trees.

Since project completion, there has been a significant increase in use of the creek by coho salmon. Hundreds of coho salmon have been observed migrating from adjacent creeks to into the newly restored creek – a big change from the few fish that were previously observed in Cochran Creek. Post construction monitoring will continue to take place for three years following restoration.