Restoring vibrant life in Sonoma Valley’s Stuart Creek

Imagine a life well-lived in the estuaries and open ocean off the California coast and then swimming over one hundred miles to the place where you hatched, where you plan to bring forth the next generation… only to find it barricaded by concrete. This was the experience for many steelhead trout traveling in the tributaries of upper Sonoma Creek, where for decades small dams, culverts, and road crossings have impeded the natural flow of life for an array of fish and amphibians — including steelhead, California red-legged and yellow-legged frogs, species that are federally listed as threatened. 

Now a plan for the removal of the last dam on one of the most important tributaries, Stuart Creek, is in the works and, with it, the hope that new generations of juvenile steelhead may be attracted to its ideal habitat upstream from the defunct dam. 

Waters that feed wetlands, rare plants, and wildlife

Stuart Creek in the Sonoma Creek watershed is within the traditional home of the Coast Miwok, Wappo, and Pomo peoples. The creek runs for five miles from its headwaters in the Mayacamas Mountains near Cavedale Road, making its way west through Bouverie Preserve and lands held by Sonoma Land Trust before it merges with Calabazas Creek for a short run then joins Sonoma Creek in Glen Ellen and continues south to San Pablo Bay. 

Prior to colonialization in the early 1800s, lower Stuart Creek sediments settled as an alluvial fan and the stream braided through wetland areas. The creek was once a major steelhead spawning and rearing ground within the Sonoma Creek watershed — the second-largest steelhead run in the San Francisco Bay Area.  

A creek rides out an extractive era

Beginning in the latter 19th century, a railroad berm built across the valley channeled the stream. Additional sections were straightened and moved. The upper reaches of the watershed saw shale mining, logging, and even “dynamiting for steelhead.” Livestock grazing and agriculture dominated the lower reaches.  

Englishman David Pleydell-Bouverie arrived in the Sonoma Valley in the late 1930s and purchased the first 140 acres of what would become Bouverie Preserve, adding parcels encompassing much of Stuart Creek during the next ten years. 

Bouverie constructed a concrete dam in the early 1950s to provide irrigation and pipe water to the houses until a well was drilled later in the decade. Although the dam has not been in use for decades, winter flows hemmed in by the dam have left behind a deeply scoured basin, preventing young fish and amphibians from ascending the creek in search of cool upstream reaches during the summer months. 

In the lower creek, road crossings and culverts, and other small dams were built on neighboring properties, further hindering access.

Promising results from infrastructure removal and streambed enhancement 

In 2014, Sonoma Land Trust removed three human-constructed barriers on the lower reaches of Stuart Creek and restored a 900-foot stream channel along Stuart Creek Run. Although no migratory steelhead have been observed yet, recent surveys have counted rainbow trout population in line with historic estimates, so the conditions are ripe for their return. A good canopy of alder, ash, willow, and maple provides beneficial shade and cool water to encourage the fish to move upstream.  

Joe Plaugher, stewardship program manager at Sonoma Land Trust, shares the project’s success: “In the time since the restoration project was completed, the plantings have become well established and the restored stream channel is fully functioning — the reconstructed channels have easily handled large rain events without flooding and fish would be able to move upstream easily.” 

The last dam

The final barrier to unimpeded fish passage is the 45-foot-wide concrete dam built by Bouverie in the 50s. The dam runs the streambed’s full span and is a barrier for juvenile salmonids and a variety of other fish and amphibians that migrate up and downstream.  

With a strategy developed by Prunuske Chatham, Inc., Audubon Canyon Ranch hopes to soon replace the dam with a section that mimics natural streams. This new section will have the right water flow and sediment movement to help fish and other aquatic life access the newly accessible half-mile of upstream ‘refugia’ pools — safe, cooler refuges for aquatic life during periods of warm weather or drought — where fish can grow before heading out to sea and where other fish and amphibians can live. 

Environmental Scientist Ryan Watanabe from the California Department of Fish and Wildlife advocates for removing the dam to help wildlife cope better with climate change. This includes making it easier for fish to move through their migration routes, especially in areas where drought has split up their habitats. 

The project may also increase the effectiveness of downstream efforts to restore places where fish lay their eggs by improving the flow of sediment into the greater watershed, Watanabe adds. 

Jennifer Potts, resource ecologist at Bouverie Preserve, dreams of the potential once the dam is removed: “It’s a rare opportunity to make an impact like opening safe shelter to steelhead in the cool shaded waters of Stuart Creek. It feels good as a conservation organization to be taking better care of our lands and waters by removing this dam.“ 

In addition to the positive ecological outcomes, waterways inherently connect us to our neighbors. The restoration will be an opportunity to share the promise of land stewardship with the nearly 3,000 Sonoma County students and families visiting Bouverie Preserve annually. 

Improving conditions for a diversity of life to thrive is some of the most important work we do

Removing a small dam and reworking a section of creek bed requires state and often federal oversight and the expertise of licensed engineering and landscape contractors who specialize in ecological restoration. We are fortunate to have completed the project design thanks to a grant from the California Department of Fish and Wildlife’s Fisheries Restoration Grants Program and are now awaiting approval of implementation funding. Look for updates on this project in early 2025.   

Stewardship work that addresses degraded or lost ecological function is some of the most important work we do…and is ongoing! To support stewardship projects such as the Stuart Creek dam removal, donate, become a member, or get involved.