Yolo Bypass Offers Proof That Nature-Based Solutions Can Work at Scale

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The Yolo Bypass, a 60,000-acre floodplain in California's Central Valley, is an overlooked example of a highly effective Nature-based Solution (NbS) that has been protecting the city of Sacramento from floods for over a century. Despite its long track record of success, the Bypass is rarely identified as an NbS, likely because it so dramatically shatters the common perception that NbS are limited to small-scale, stakeholder-driven projects with uncertain efficacy. The Bypass uses natural floodplains to safely convey over 80% of the volume of floodwaters during major events, while also providing critical habitat for wildlife and other benefits to people. Proponents of NbS should highlight the Bypass as a prime example of how these ecosystem-based approaches can be implemented at a massive scale to address societal challenges.

Why it matters

The Yolo Bypass challenges the common perception that Nature-based Solutions are limited to small-scale projects with uncertain effectiveness. As one of the largest and most successful NbS in the world, the Bypass demonstrates that these approaches can be implemented at a massive scale to provide reliable flood protection and multiple other benefits. Highlighting the Bypass could help overcome the hesitancy of funders and decision-makers to commit to NbS, which is often based on concerns about scalability and evidence of efficacy.

The details

The Yolo Bypass is a 40-mile-long, 59,000-acre engineered floodplain located parallel to the Sacramento River in California's Central Valley. It is a key component of the Sacramento River Flood Control Project, designed to keep the city of Sacramento and surrounding areas safe from floods. During major flood events, more than 80% of the floodwaters from the Sacramento River are diverted into the Bypass through a series of weirs and levees. Once in the Bypass, the floodwaters spread out across the vast natural floodplains, providing flood protection downstream while also creating critical habitat for native birds, fish, and other wildlife. The Bypass has been functioning in this capacity for nearly a century, demonstrating its long-term effectiveness and reliability.

• The Yolo Bypass has been a key component of the Sacramento River Flood Control Project since the early 1900s.
• During the record-breaking floods of 2017, the Bypass conveyed over 80% of the floodwaters from the Sacramento River, keeping the city of Sacramento safe.

What they’re saying

What’s next

Proponents of Nature-based Solutions should highlight the Yolo Bypass as a prime example of how these approaches can be implemented at a massive scale to provide reliable flood protection and multiple other benefits. Showcasing the Bypass's long track record of success could help overcome the hesitancy of funders and decision-makers to commit to NbS.