Overview
Willow Creek is a tributary to the lower Russian River in coastal Sonoma County. The Willow Creek watershed drains an area of approximately 8.7 square miles, nearly all of which is owned and managed by State Parks as part of Sonoma Coast State Park. The lower Willow Creek valley within the park contains significant, undeveloped wetland and riparian habitats. The upper watershed is primarily forested land, with intermixed grasslands.
In 2001, Stewards joined with many agency and nonprofit partners to embark on a ten year journey to restore the Willow Creek watershed. At that time, approximately 4,600 feet upstream from its confluence with the Russian River, Willow Creek was filled in with sediment. In certain segments of the creek, no bed or banks remained. These conditions limited the upstream migration of spawning salmonids to periods when the valley was flooded. Downstream migration of juveniles in spring was blocked.
The filled channel condition of Willow Creek upstream of the second bridge was attributed to channel modifications that were begun before 1953, as well as increased sediment yield from land use practices in the watershed. Prior to 1953, Willow Creek was relocated, straightened, and probably widened, apparently to facilitate agriculture. Such channel modifications often create a condition that traps sediment as is illustrated by the fact that unmodified reaches of Willow Creek upstream and downstream are not filled with sediment to the same degree. The increased sediment yield from the watershed is attributed to road construction, timber harvesting, and livestock grazing beginning before 1900. Sediment supply derived from landslides and surface erosion has decreased since the 1960s.
In 2011, a new 43 foot span bridge was installed near 2nd Bridge. This successful endeavor has re-established fish passage in the watershed.