Every river draining the western Sierra Nevada mountains has a major dam, with the exception of the Cosumnes. As the last free-flowing river in the region, the Cosumnes’ 809,600-acre watershed harbors native habitat types and species found in few other places in California, including the largest oak riparian forest in the state.
While many scientists and conservationists laud the Cosumnes River as a model basin for ecological processes, the watershed has been highly modified over the past 150 years. Much of its natural habitat has been converted to agricultural and grazing land; the upper watershed has been extensively logged; the Cosumnes has been channelized and leveed in several sections; and the basin’s groundwater overdrafted.
Despite these challenges, the watershed presents a big opportunity for restoration.
In fall 2014, six people formed the Cosumnes Coalition to restore and steward the river watershed’s hundreds of thousands of acres and 80 miles of waterway. This marked the first on-the-ground attempt in the basin to steward the entire river – from the headwaters to its confluence with the Mokelumne River in the eastern Sacramento-San Joaquin Delta. With no roadmap for such a basin-scale restoration, the coalition is creating a new framework for watershed stewardship.
Since what happens in the upper watershed affects downstream users and the entire watershed’s ecosystem, the coalition works with that scale in mind, engaging stakeholders and communities across the basin in the process of promoting sustainability and promoting watershed health. This means collaborating with growers on sustainable projects, partnering with water agencies, spearheading land acquisitions, restoring meadows, proposing increased recreational opportunities, holding river cleanups and multiple other engagement initiatives.
For decades, environmental groups and agencies ranging from the Bureau of Land Management to the United States Fish and Wildlife Service to the Nature Conservancy and American River Conservancy (ARC) have worked in the Cosumnes watershed, but their projects have been disparate and isolated geographically.
Now the coalition is helping to consolidate and coordinate efforts.
Melinda Frost-Hurzel, Cosumnes Coalition facilitator and ARC Cosumnes River monitoring coordinator, pointed out that most river conservation and restoration efforts in California operate on relatively small scales because of the cost, the legal jurisdiction boundaries and the isolation of river segments by dams, or regulations on those dams imposed by the Federal Energy Regulatory Commission (FERC), among other factors.
But because the Cosumnes is free of hydroelectric dams, it is exempt from FERC regulations, meaning that the river is not managed for the purpose of water supply and energy generation. For that reason among others, the Cosumnes can maintain a relatively natural flood regime that sustains rare native species and types of habitat. Considering the river’s uniqueness, the coalition’s founders were disheartened by the lack of government funding and stakeholder coordination in the watershed.
“We really started [the Cosumnes Coalition] because we felt there was a need to galvanize work that needed to still be done,” said Elena DeLacy, ARC stewardship director and a founding member of the coalition. “A lot of the time the Cosumnes River gets left out of the conversation because it is a smaller river system … By having a stronger voice and getting agencies and organizations together, [we] could get more people together and advocate for the Cosumnes River.”
The coalition’s overall vision is to create a healthy watershed that can support both humans and native ecosystems by promoting economically attractive stewardship options, creating connectivity for terrestrial and aquatic species, preserving key landscapes and habitats, protecting cultural resources and restoring pivotal ecological functions. By November 2016, the coalition had written a comprehensive stewardship plan and proposed and implemented more than 18 projects, ranging from land acquisitions to monitoring programs.
Frost-Hurzel attributed the coalition’s quick success to its structure and dedicated volunteers. At its core are five partners – the ARC, the Fishery Foundation of California, Trout Unlimited, Cosumnes Culture and WaterWays and Landmark Environmental, Inc. – each bringing a specialty to the table. A range of collaborators, such as the Sacramento Valley Conservancy and U.C. Water, work with the partners on many of the projects, while a technical advisory committee guides the coalition’s work. The coalition relies on a hodgepodge of different funding sources, including grants, donations of various kinds, memberships and the partners’ and collaborators’ financial support.
One of the coalition’s programs, the Cosumnes River Monitoring Program, epitomizes the scope of collaboration needed to steward the 809,600-acre watershed. Established in 2015 by Frost-Hurzel in partnership with Trout Unlimited, the program relies on a range of professional and volunteer help including: about 50 citizen scientists checking more than 21 monitoring sites across the watershed, 10 landowners and partners who allow monitoring on their properties; and the technical advisory committee that helps interpret the copious amounts of data. The results help the coalition understand the metrics of a healthy river, diagnose problems and identify opportunities to address them.
The coalition seeks projects that “are economically sustainable and support watershed health and ecological function” as a way to engage people with different agendas who live in the basin. Since the watershed is predominantly agricultural, that approach often includes finding ways to preserve uses of ranching and farming land that are compatible with wildlife needs. For instance, the coalition’s partners pursue conservation easements on some grazing land parcels, which can serve as a habitat for the state-listed threatened Swainson’s hawk. When the cattle are transported to other pasturelands and the hawks migrate away in the fall, the land can also be intentionally flooded to facilitate groundwater recharge and sustain base flows in the river throughout the year.
With the passage of the Sustainable Groundwater Management Act in 2014, the coalition aims to help landowners and water agencies maximize the recharge on their properties for the benefit of urban and rural water users and the environment.
A local water agency, the Omochumne-Hartnell Water District (OHWD), for instance, is implementing a multi-partner, groundwater recharge project on vineyards totaling 900 acres adjacent to the Cosumnes river. The coalition has contributed expertise and connected this project with critical partners, including researchers from University of California, Davis and U.C. Water, who will help monitor the project’s benefits, water quality and impact on fish runs, to name a few.
Michael Wackman, general manager for the OHWD, hopes to launch the project this winter with the goal of diverting “between 2,000 and 2,500 acre-feet of water this year if we get everything in line. We’ll take that water from storm flows, so we’re not affecting the river.”
In partnership with U.C. Water, the coalition is also creating a program that will study the interactions between surface water and groundwater in the Cosumnes watershed to identify ways to enhance recharge overall.
“Almost everything we do has some impact or potential impact on humans and ecosystems,” said Graham Fogg, professor of hydrogeology at U.C. Davis and a member of the technical advisory committee, who hails the effort to manage the groundwater stores across the watershed as “unprecedented” for the Central Valley.
“What makes us successful is [the] people at the core of the effort who are very passionate about the river itself and have a tie to the place,” said the ARC’s DeLacy. “There is a lot of knowledge and skill that is coming to bear.”