State Of Western Rivers

Rivers are crucial to supporting biodiversity and providing ecosystem services such as clean drinking water and recreation opportunities, offering far more value to people, wildlife, and ecosystems than might be expected given their small global footprint. Yet rivers are under increasing threat as the climate warms and our populations grow, placing greater stress and demand on freshwater resources. Despite their life-giving importance, few rivers and streams are currently protected from human impacts to their integrity and flow. For example, less than 0.5% are protected nationwide under the federal Wild and Scenic Rivers Act. To support greater awareness of and protection for the nation’s most ecologically important rivers, The Pew Charitable Trusts commissioned Conservation Science Partners to conduct assessments of the rivers in six western states: California, Colorado, Nevada, New Mexico, Oregon, and Washington. We focused in particular on identifying rivers and streams throughout each state with the highest potential for state Outstanding National Resource Water (ONRW), although we anticipate the data provided to be valuable for supporting river protection through other mechanisms, such as the federal Wild and Scenic Rivers Act. We connected each state’s designation criteria to statewide data regarding, for example, ecological value (e.g., at-risk aquatic species diversity), water quality, cold water refugia potential, and recreation potential, among other values, to identify rivers with the greatest potential to achieve formal protection via ONRW designation. We summarized our key findings and map these rivers statewide to help visualize the “best of the best” river segments and other ecologically important places to seek new protections. The reports found tens of thousands of waterways that possess a wide range of ecological values and ecosystem services worthy of protection, whether through state-level designations, federal Wild & Scenic designation, or other available mechanisms. These assessments and the accompanying data offer scientifically grounded support for identification of the values associated with rivers, streams, and watersheds across the West that can inform and support efforts to ensure those values persist.