A Living Project: The Continuous Effort to Restore Sausal Creek
- Friends of Sausal Creek
- Mar 26
- 4 min read
If you’ve volunteered at a Friends of Sausal Creek (FOSC) restoration site, you’ve experienced firsthand the immense challenge of restoring urban greenspaces. Since FOSC’s grassroots beginnings in 1996, when efforts first focused on the section of Sausal Creek in Dimond Canyon, the vision has broadened to encompass watershed-wide stewardship. While guided by this wider perspective, restoration efforts must strategically target specific sites, requiring ongoing assessment of where to allocate time and resources.
Dimond Canyon and Park have remained a focus for FOSC’s work, and as the site of two major restoration projects over the years, serve as a valuable case study in both long-term challenges and evolving strategies of this ecological restoration.
In 2001, FOSC partnered with the City of Oakland to restore two acres of riparian habitat in lower Dimond Canyon, boosting native vegetation, biodiversity, and preventing erosion. However, the canyon’s long, narrow shape—with a large perimeter alongside private property—made it particularly vulnerable to invasion by species rooted in neighboring yards. For many years, the restored area held steady, with native plants thriving. Eventually, however, invasive species like Himalayan blackberry, and English and Cape ivy came to dominate portions of the understory, creating monocultures that crowd out diverse native plants. As time passes, many of the original alders, oaks, and willows in the canyon have been pulled down by ivy in windstorms, or have reached the end of their natural lives. The thick invasive understory has prevented natural seedling germination, so our staff and volunteers have been working to grow these native trees in our nursery to outplant in the canyon and rebuild the canopy.
A second major effort took place in 2016, when FOSC, the City of Oakland, and Alameda County Flood Control removed the culvert in Dimond Park, below Wellington Street, unearthing a long-buried creek section and widening it to create a naturalized riparian corridor. Native alders and willows, key species for this habitat, along with understory plants such as pink flowering currant, ceanothus, and Pacific rushes, were planted along the creek during the project. The willows were planted quite densely, as the banks needed to be stabilized immediately and it was expected that many willows would not survive to maturity. A decade later, nearly every willow did survive, and we find ourselves with an overabundance of willows that shade out the more diverse native understory vegetation. Now, volunteers are thinning out some of these limbs to allow more sun into the understory, and diligently removing emerging invasive species to prevent the overwhelming establishment of them like we see in Dimond Canyon.
While these large-scale projects have brought significant benefits, restoration is never a one-time effort. As FOSC Board President and ecologist Dr. Robert Leidy explains, “The real work begins after major restoration projects are completed—or even in their absence—through ongoing care and adaptation.” Managing invasive species, supporting native plants, preventing erosion, and mitigating pollution require continuous effort, and resources are limited. The enduring stewardship of FOSC’s site leaders and volunteers is at the heart of restoration, ensuring these spaces are cared for in perpetuity.
FOSC’s Restoration and Nursery Manager, Ella Matsuda, describes the current restoration strategy in Dimond Canyon as focusing on the most critical and manageable areas. She prioritizes work between the trail and the creek, and has found that working in patches is most manageable with the available volunteers and resources. “We will work intensively in an area to clear invasive species, plant the area, and then return with experienced volunteers to weed and maintain the plantings. This allows us to create ‘defensible spaces’ around our projects, and create spaces where less experienced volunteers can work and learn without fear of damaging new plantings.” For instance, when a large patch of poison hemlock near the trail was identified, Ella and volunteers worked intensively to remove it, then immediately replanted the space with a variety of native species. With those plants now established, volunteers are shifting their focus to pushing back the surrounding thornless blackberry. In some cases, Ella has discovered newly introduced invasive species and quickly mobilized efforts to eliminate them before they can take hold the way more established invasives have.
Sausal Creek will never again be fully “wild.” As Oakland has grown, a once meandering creek has been confined to a static area. In the past, a fallen tree shifting the creek’s path by a few yards would have been unremarkable; today, it could threaten nearby homes. We’ve displaced many of the people, plants, and animals that have shaped the ecology of this watershed for millennia, and introduced a host of new species that each leave a unique footprint on the landscape. We will likely never eradicate invasive species or fully daylight the creek. Instead, our goal is to work with communities to create inclusive, beautiful, and thriving habitat corridors along Sausal Creek—safe, healthy, and accessible for all, with improved water quality and diverse plant life to support all life throughout this vital watershed.
Looking ahead, as we approach our 30th anniversary as an organization, community priorities will continue to guide FOSC’s work, ensuring that efforts align with the needs and desires of those who live in and around the watershed. To address ongoing challenges—such as the persistent invasive species takeover—another large-scale project may be necessary, and FOSC will continue pursuing large grants to enable such significant restoration initiatives. As Leidy puts it, “It keeps me up at night, thinking about all there is to do. But we’re not going back in time. That’s why it’s so important to manage expectations and get creative.” Ultimately, the success of FOSC’s restoration work isn’t just about major projects but is largely defined by the consistent dedication of our staff, Board, and volunteers working with the land. Week after week, year after year, they put in the hours, ensuring that the long-term care and attention needed to sustain and improve the health of the watershed remains a priority.
