Enhancing Instream Flows in the Mattole Headwaters

Walker Wise, Water Program Director, Sanctuary Forest

The Mattole River flows in a northwest direction for 62 miles from Northern Mendocino to its mouth in Petrolia, making it the longest undammed river wholly within California.  At its headwaters, near the village of Whitethorn, the river bends westward towards the cooling influence of the Pacific Ocean. Here, coastal fog drifts over rugged mountains through towering redwoods into flat valleys where cold air settles each morning. In these upper reaches, salmon and steelhead, including nearly all the river’s remaining coho, end their long journey upstream where there are gentle gradients and waters that remain cool enough for their offspring to over-summer.

Modernity has brought many challenges for these highly adaptable creatures. Once abundant runs in the Mattole headwaters have been decimated, some, such as coho salmon, to the brink of extirpation. Several waves of logging liquidated over 90% of the forests in the watershed. Sprawling road networks altered the watershed’s hydrology and changed the sediment regime. Large wood was removed from streams by the restoration community due to well-intentioned, but mostly misguided, concerns about fish passage. And changing ocean conditions and overfishing have undoubtedly taken their toll.

In the 1970s and 1980s, several grassroots organizations sprung up that were focused on fish recovery. The Mattole Restoration Council (MRC) worked to address roads, culverts, and stream sediment loads. The Mattole Salmon Group (MSG) focused on fish habitat and hatchery operations. Sanctuary Forest (SFI) was dedicated to acquiring or otherwise protecting the last remaining old growth from being cut. The engagement and collaboration between Mattole residents and these three groups was unprecedented in the restoration movement.  

While these efforts found many successes, new challenges continued to arise. In 2002, Mattole Salmon Group fish enthusiast, Ray Lingel, reported widespread fish mortality when the headwaters completely dried.  That same year, Whitethorn Junction residents saw the mainstem Mattole run dry for over a month, leaving them unable to pump water to keep their homes and gardens hydrated.  A meeting was held with residents and the Mattole organizations, and it was decided that something had to be done to protect summertime flows in the Mattole Headwaters.  In keeping with the collaborative division of work between the organizations, it was decided that Sanctuary Forest would spearhead the effort.

Storage and Forbearance

The idea for a storage and forbearance program began to take shape.  Bob McKee, at Whitethorn Construction, had enough water stored that he did not need to pump during summer months.  Bob’s daughter, Tasha McKee, decided to pursue a grant-funded Storage and Forbearance Program. She found an ally with Gary Flosi at the California Department of Fish and Wildlife (CDFW), who helped drum up support and find the first state funding for this program.  Two storage systems were built near Whitethorn in 2007, and the first organized Storage and Forbearance program was formed.  

This program now includes 31 residences as well as Whitethorn Elementary School and Whitethorn Construction.  Participants agree to forbear from diverting water during the summer months in exchange for a grant-funded water storage and delivery system being installed on their property. This program directly improves streamflow, benefits residents, and provides work to local contractors. There is also a community engagement component – I love it when folks tell us they abide by our ‘stop pumping dates’ even though they aren’t enrolled in the program.  

Unfortunately, storage and forbearance alone are not sufficient for restoring healthy summer flows for fish and people in the Mattole headwaters. There is an abundance of evidence that tributaries with no homesteads or cannabis cultivation sites, such as Vanauken Creek, are still suffering from historically low flows. It is likely that changes in forest age and composition due to logging, and the suppression of lightning-caused fires and cultural burning, have profoundly and negatively impacted summer water yield in the Mattole. In addition, climate change has led to more erratic rainfall patterns and hotter summers.

Sanctuary Forest now engages in an ‘all of the above’ approach to improving summer streamflows and drought resiliency in the headwaters. Guided by technical advisors across agencies and private companies, strategies include groundwater recharge through ponds, floodplain reconnection using sealed log weirs, riparian and upland forest thinning, and recently, direct flow augmentation using ponds that provide metered flow directly to a stream. 

One of several significant projects being implemented in the summer of 2025 is the Vanauken Ponds project.  Designed by Joel Monschke and his team at Stillwater Sciences, and inspired by Salmonid Restoration Federation’s Marshal Ranch Project, this project will construct two ponds totaling 6 million gallons that will provide at least 15 gallons per minute base flows into Vanauken Creek; enough to prevent the creek from completely drying in drought years.  

For more information: sanctuaryforest.org

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