California Environmental Flows Framework

Multiple local, regional, and State agencies share responsibility for managing environmental flows, defined as the water required to protect the ecological health of California streams while balancing human uses and other water management objectives. The process of developing environmental flow recommendations is complex, often involving multi-component technical studies and lengthy public discussions that can take years to complete. Although many environmental flow assessment tools exist, managers are often constrained to using either time-intensive, site-specific studies or a limited set of rapid desktop and regional approaches that have not been tailored to California. Furthermore, environmental flow assessments have not always been consistently designed and implemented in a way that allows data to be aggregated and shared, making it difficult to accelerate learning and improve the effectiveness of environmental flows in supporting the ecological health of California’s rivers and streams. Water managers need a consistent statewide approach that can help transform complex environmental data into scientifically defensible, easy-to-understand environmental flow recommendations that support a broad range of ecosystem functions1 and preserve the multitude of benefits provided by healthy rivers and streams. Having a consistent statewide approach would also improve statewide data compatibility and promote coordinated regional flow assessments that would benefit multiple agency programs working to improve the scale and pacing at which environmental flow protections can be extended to rivers and streams across the state.