Tending to landscape means making space for the local wildlife that depends on it. But when that wildlife is a group of industrious beavers determined to turn your water management system into their dream pond, things get a little more complicated.
Once labeled as pests, beavers are now being recognized as powerful allies in ecosystem restoration. That shift in perspective is playing out firsthand at International Bird Rescue’s Cordelia Slough Youth Education Program site in Suisun Marsh, where our work increasingly centers on finding ways to share this environment with the wildlife that calls it home.
When access to the property was first granted to Bird Rescue in 2022, there was only a single beaver dam. Over the past two and a half years, the beavers have constructed four additional dams, and their activity has transformed the site into a thriving wetland. The dams have created a slow-moving water channel lined with willows and other vegetation and flooded a once-dry area, which now attracts an abundance of wildlife. This includes birds, river otters and other mammals, reptiles, and insects.
Searching for Balance with Nature’s Engineers
This past spring, beavers had recently targeted one key feature: a vertical water control device known as a riser. Meant to drain excess water during heavy rainfall, they persistently plug the riser with sticks and mud in an attempt to create a standing pond. While this behavior is natural – and their engineering skills impressive – the consequences can be costly, including flooding out the levee road and blocking access to the wildlife education site.
Bird Rescue learned how to maintain the system and respond when beavers block the flow, thanks to early
guidance from the California Waterfowl Association. During the rainy season, staff and volunteers play a vital role in managing this delicate situation. By regularly removing beaver debris and monitoring water flow, they help maintain access and protect the integrity of the habitat. They often had to unblock the riser twice a week to prevent flooding.
To better understand and monitor beaver activity, a motion-activated camera – generously donated by volunteer Glen Lewis – was installed near the riser in April. Beavers have been sighted on numerous occasions, especially at night, since they are primarily nocturnal animals. This monitoring helps volunteers respond quickly to blockages and better understand beaver activity patterns.
“As a Land Maintenance Volunteer, I’ve embraced the unofficial role of ‘beaver watch,’” said Karen Sheldon, long-time volunteer. “On every visit to the Cordelia Slough property, I notice changes – new beaver chew on trees, altered water levels, or restructured dam areas. Beavers are persistent and efficient, capable of cutting limbs of impressive diameter and dragging them significant distances to reinforce their dams.”
Despite this progress, beavers are remarkably efficient and can completely block the riser overnight, so regular checks are key to keeping the area safe and usable. As we prepare for the upcoming rainy season, we’re actively seeking a more long-term solution that reduces the need for constant manual intervention and allows the riser to function as intended while respecting the ecological role of beavers.
The California Department of Fish and Wildlife (CDFW) has worked to reframe beavers not as nuisances but as vital contributors to ecosystem health. Through the launch of its Beaver Restoration Program in 2023, CDFW is promoting nature-based solutions that use beaver activity to protect biodiversity, restore habitat and build wildfire-resilient landscapes.
Bird Rescue is proud to be part of this evolving dialogue – where even a blocked riser becomes a chance to rethink how we share space with wildlife.
Volunteer with our Land Maintenance Team
Bird Rescue’s land maintenance volunteers are the backbone of keeping the Cordelia Slough site healthy and accessible for wildlife and visitors. Their tasks include trimming overgrowth, removing invasive plant species, and thoughtfully managing the landscape to keep it wild and welcoming.
If you’re passionate about conservation and want to make a direct impact – plus enjoy working outdoors alongside a caring community – we’d love to have you join us! To get involved with the Cordelia Slough land maintenance team, click here. For other volunteer opportunities at our wildlife centers or remote roles, visit our Volunteer page.
About the Cordelia Slough Youth Education Program
The Cordelia Slough Youth Education Program has a simple yet powerful mission: to connect students with the beauty around them in greater Solano County. Through volunteer support and regular school and youth events, the program was implemented to train and inspire the next generation of wildlife stewards.
The Cordelia Slough is a part of the Pacific Flyway, a superhighway for migratory birds. The Pacific Flyway Fund granted Bird Rescue the long-term use of 55 acres of stunning riparian and marsh habitat to bring wildlife and environmental literacy to the next generation of advocates for nature.
These field trips also serve as a lead-up to “The Walk in the Marsh,” an educational experience that will take place at the nearby Pacific Flyway Center. To request a field trip for your school group, please fill out this form.