Every December, the Contra Costa County Flood Control and Water Conservation District’s (District) together with The Restoration Trust and the Contra Costa Resource Conservation District holds it's annual Giving the Natives a Chance volunteer planting event. This annual event focuses on restoring native plants to local creeks and flood control channels. Efforts have been focused on the Clayton Valley Drain off Solano Way in Concord, which drains to the Walnut Creek Channel, Carquinez Strait, and then to the Pacific Ocean.
Due to the COVID-19 pandemic, the District has not held a volunteer event for 2020 and 2021. The plantings were instead performed by a contractor. The work in 2020 included planting 5,000 native creeping wild rye grass plugs and valley sedge on the north creek bank, pulling invasive weeds, and removing a pick up truck’s load of garbage out of the creek. When the event returned to the public is 2022, 6,200 native plugs were planted. Prior to our first event in 2013 and the restoration work, the site had less than 5% native cover. Native cover is now over 55% and is likely to continue to increase as the native vegetation grows and expands.
Past events have including planting the creek with Santa Barbara sedge, Baltic rush, and creeping wild rye. Each species has different environmental needs and has beneficial effects on separate parts of the channel. These species are native grasses or sedges that provide erosion control, fire suppression, and are compatible with flood control objectives. They spread from underground rhizomes that anchor the soil and are all perennial species, meaning they stay green all year. They do not have woody stems, so during floods, they lay down on the slope, which does not impede the flow of water during high-flow events. These species also provide carbon sequestration, unlike non-native annuals, and remove as much as 500,000 gC/acre a year or about ½ ton of Carbon per acre per year.
The District would like to thank all the past volunteers for their support including the City of Concord, County Public Works Department staff, Contra Costa Resource Conservation District, Pleasant Hill Boy Scout Troop 239, Outside The Box 925 and EarthTeam for bringing students from Antioch High School, Pinole Valley High School, and Pittsburg High School, our partners at The Restoration Trust, and many other community members who were generous enough to donate their time.
