Thank you to everyone who joined us for the ninth State of the San Lorenzo River Symposium on April 13 at Felton Community Hall! This symposium holds special significance as the only recurring public event focused solely on the San Lorenzo River. This year included discussions on the dynamic and varied history of the watershed, a look at fish passage challenges in the San Lorenzo River and Branciforte Creek, and updates on conservation activities for salmon, steelhead, and the Western Pond Turtle. We will update this post when recordings of the talks become available on the SOSLRS website! 

While CWC has helped organize the symposium for many years, this was our first time giving a presentation as well! Education Coordinator Sam Adelson and Communications Manager Erin Loury co-presented on the benefits of flooding to the San Lorenzo ecosystem, as well as CWC’s efforts to improve flooding resiliency through our work in the Santa Cruz community. The presentation was adapted from a talk Sam gave last year at the Felton Library, which was inspired by 2023’s highly destructive winter storms. In the wake of that wet winter, many people wanted to know: is flooding good or bad for the watershed?  

CWC Education Coordinator Sam Adelson prepares to present at the 2024 State of the San Lorenzo River Symposium

The answer is that while flooding brings both positive and negative consequences, floods ultimately create a net benefit to watersheds in many ways. These benefits include recharging groundwater, rejuvenating soil fertility, dispersing seeds and increasing aquatic habitat, among others. Native plants and animals have evolved alongside floods for millennia and are able to respond to them. However, CWC recognizes that floods can seriously impact people who live alongside rivers, and that flood control must remain central to the City of Santa Cruz’s relationship with the lower San Lorenzo River. Our presentation covered several of CWC efforts to improve community flood resiliency in concert with river health. We highlighted efforts to mobilize community members to clean up the lower river after big storms, our push for flood control to be included as a guiding principle of the San Lorenzo Park redesign, and our advocacy for habitat-friendly vegetation management for flood control. We also spotlighted public art projects CWC has supported to raise flood awareness in the Beach Flats community, including the creation of storm drain murals and the work of our Artists in Residence, The Jams, to improve flood emergency preparedness through a comic book 

Other talks at the symposium included the cultural history of the San Lorenzo River watershed presented by Lisa Robinson from the San Lorenzo Valley Museum. Her talk touched on several periods of the watershed’s history, including the Indigenous era, the Spanish/colonization era, the Industrial era, and the Victorian era. The watershed has been highly modified throughout time, particularly during the Industrial era: as one example, the California Powder Works, established in 1864 to manufacture blasting powder for mining and railroad construction, regularly diverted the entire flow of the San Lorenzo River every summer for its operations! This presentation set the stage for the rest of the talks by underscoring the historical challenges that create the backdrop for today’s ongoing watershed recovery. Another interesting historical tidbit: many silent movies were filmed in the San Lorenzo Valley, including the 1922 film “Soul of the Beast,” which brought an elephant on location!   

Lisa Robinson’s presentation highlighted the Aulintoc storm drain mural supported by CWC

Several of the symposium’s talks touched on the ability of fish to migrate freely in the river, known as fish passage. Kristen Kittleson, newly retired from the County of Santa Cruz, shared the results of a multi-year study to evaluate historic structures in the San Lorenzo River that can create barriers to fish migration, like the remnants of flashboard dams used to create swimming holes in the river. When there is too little stream flow, these structures make the river too shallow for fish to pass, but when the flow is too high, the velocity of the water channeled through the structures is too fast for fish to migrate. A total of 37 such structures were evaluated on the mainstem San Lorenzo, and 26 of them posed some challenges for fish migration, with 18 being rated as “high severity” barriers. Fortunately, now that these structures have been identified, efforts can be made to remove them. The Resource Conservation District of Santa Cruz will start removing some structures in the fall of 2024, while CalTrans is currently redesigning the Highway 9 culvert at Waterman Gap, which was identified as one of the most serious barriers. Since all of the structures are passable under some conditions (none pose a permanent barrier to fish), Kittleson noted that removing any of them will create a net benefit for fish migration in the river.  

A presentation by Justin Gragg of Environmental Science Associates highlighted a study to improve fish migration in the Branciforte Creek flood control structure near the confluence with the San Lorenzo River. The water in this concrete channel often moves faster than steelhead can swim against it, and under high flows, fish get too tired to swim to the top of the channel – models suggest they can make it as far as Water Street. Since the Army Corps of Engineers does not allow any major modifications that would decrease the channel’s ability to convey flood water, some proposed designs to include fish passage include adding pockets or cone-shaped baffles to the channel to slow water down and provide resting spots for fish. The current cost estimate of these improvements is $15-20 million, so it will take time for them to become reality.  

CWC Communications Manager presents on activities related to flood control at the State of San Lorenzo River Symposium

Chris Berry from the City of Santa Cruz provided some milestones for salmon and trout recovery in the San Lorenzo River. He noted that the river ran dry at one point in 1991, which was a “huge wakeup call” for the need to improve water management. Evidence for such improvements can be seen in 2020, when a good amount of flow was kept in the river despite a years-long drought. Berry noted that a Habitat Conservation Plan for salmon and steelhead in the San Lorenzo River that has been in the works since 2001 is finally nearing completion – this plan includes a long-term permit for the city’s water operations in exchange for extensive restoration and monitoring activities. For example, $60 million is allocated for monitoring over the 50-year life of the permit. Future plans include rehabilitating the fish ladder at the inflatable Felton diversion dam.  

Chad Mitcham of the U.S. Fish and Wildlife Service presented on the Western Pond Turtle, which was proposed to be listed as “threatened” on the Endangered Species List in 2023 and is currently under consideration for listing. These turtles can live to an impressive 55 years and don’t reproduce until 7-12 years of age, meaning their populations can be slow to recover from disturbance. Potential threats in the San Lorenzo River include illegal camping, ice plant that covers their sunning and nesting habitat near the water’s edge, and vegetation management practices like mowing and riverbed discing that could disturb turtles. Mitcham highlighted CWC’s ice plant removal activities during our River Health Days as an important activity for benefiting Western Pond Turtle habitat! 

The newly renovated Fall Creek Fish Ladder

The symposium also included a presentation by Assemblymember Gail Newall, who lauded the resilience of Santa Cruz county residents for enduring challenging storm and drought conditions, and talked about environmental legislation currently being considered by the state. The talks were followed by a tour of the Fall Creek fish ladder, where renovations are nearly complete to improve fish passage for steelhead trout and lamprey. We want to thank all of the organizers, presenters, and attendees for a successful State of the San Lorenzo River symposium, as well as The Grove Bakery, the Bagelry, Verve Coffee, Pacific Cookie Company, and Trader Joe’s for providing generous food donations for the event. We’re already looking forward to the next symposium, and hope to see you there! 

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