SYMP 24-1
Setting the stage: The challenges and opportunities for adaptive management of an urban riparian floodplain
The City of Sacramento contains large-scale managed ecological infrastructure—built at the confluence of the Sacramento and American Rivers, it is one of the most flood prone cities in the USA. A major dam, pump stations, canals and an interconnected series of levees/dykes protect approximately 400,000 residents and nearly $50 billion of property and infrastructure from flooding. These rivers also provide water supply directed to Los Angeles and Central Valley farmers, important terrestrial and aquatic habitats, and recreational opportunities. In response to major flooding in 1986, the Sacramento Area Flood Control Agency (SAFCA) was established as a regional joint powers agency in 1989. All of SAFCA’s work focuses on the riverine ecosystems of the metropolitan Sacramento region to ensure protection of the region from devastating floods. These ecosystems—also classified as designated floodways—are strictly managed and regulated with overlapping authorities by Federal, State and local agencies responsible for flood conveyance, endangered species, and ‘wild and scenic’ river obligations.
Results/Conclusions
SAFCA’s management of a complex ecological infrastructure has embodied a key principle of its enabling legislation requiring the Agency to: “have at its highest priority the protection of life, property, watercourses and public highways…in ways which provide for the optimum protection of the natural environment, especially riparian habitat and natural stream channels.” SAFCA’s practical experience in carrying out this mission will be presented along with an overview of challenges and opportunities for balancing flood protection and ecosystem values within a developed urban floodplain. This includes the restoration and conservation of more than 900 acres of habitat for the Natomas Levee Improvement Program. Restored landscapes included landside woodlands, native perennial grasslands, extensive freshwater marsh complexes designed to support giant garter snakes, and forb plantings designed as habitat for pollinators and other beneficial insects. In addition we will discuss regulatory obstacles to restoration, and the role that scientific research can play in shaping policy and practice. The revised policy guidance issued by the US Army Corps of Engineers in 2009, for example, prohibits most woody vegetation on federal levees. This decision prompted the formation of the California Levee Vegetation Research Program, which aims to scientifically quantify the effects of woody vegetation on levee reliability and safety.