Lower Walnut Creek (Contra Costa County, CA) and its surrounding landscape have undergone considerable land reclamation and development since the mid-nineteenth century. In 1965, the lower 22 miles of Walnut Creek and the lower reaches of major tributaries were converted to flood control channels to protect the surrounding developed land. In the recent past, sediment was periodically removed from the lower Walnut Creek Flood Control Channel to provide flow capacity and necessary flood protection. Due to the wildlife impacts and costs associated with this practice, the Contra Costa County Flood Control and Water Conservation District (District) is now seeking a new channel management approach that works with natural processes and benefits people and wildlife in a cost-effective manner. Flood Control 2.0 project scientists and a Regional Science Advisory Team (RSAT) worked with the District to develop a long-term management Vision for lower Walnut Creek that could result in a multi-benefit landscape that restores lost habitat and is resilient under a changing climate.
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Flood Control 2.0 is an ambitious regional effort aimed at helping restore stream and wetland habitats, water quality, and shoreline resilience around San Francisco Bay. The project leverages local resources from several forward-looking flood control agencies to redesign major flood control channels so that they provide both future flood conveyance and ecological benefit under a changing climate. This timely project will develop a set of innovative approaches for bringing environmental benefits and cost-savings to flood protection efforts at the mouths of creeks that drain to San Francisco Bay.
During the mid-19th century, the lower Walnut Creek watershed was a landscape dominated by extensive wetlands, meandering creeks, and grassy plains. The marshes, sloughs, and meadows provided habitat and food for a huge number of wildlife species ranging from grizzly bears and elk to clapper rails and steelhead. Over the past 150 years, urban development, diking and filling of wetlands, and channelization of streams has resulted in dramatic changes to the watershed, and much of the historical habitat has been lost.
SFEI recently released a resilient landscape vision for lower Walnut Creek that incorporates habitat restoration actions into flood risk management. The vision, developed in coordination with a team of regional science experts, highlights opportunities for restoring and sustaining vital tidal wetland habitats around lower Walnut Creek while supporting a high level of flood protection under rising San Francisco Bay water levels.
The Resilience Atlas is a compilation of cutting-edge science, creative visions and relevant spatial data to support planners, designers, policy-makers, and residents in the creation of the healthy cities, shorelines and surrounding landscapes of the future. The main goal of the Resilience Atlas is to make the science of resilience more accessible to help communities successfully adapt and thrive in the face of climate change and other challenges.