Development of a Surface-Water Index of Permanence to assess surface-water availability for ecohydrological refugia

First posted October 13, 2023 For additional information, contact: Director, Wyoming-Montana Water Science CenterU.S. Geological Survey3162 Bozeman AvenueHelena, MT 59601 Surface-water availability has major implications for the environment and society in the 21st century. With climate change, increased drought severity, and altered water and land use, future water availability is predicted to continue to decline in many areas, including much of the western United States. An understanding of where and when water will be available at multiple scales is crucial for the planning and management of wildlife health, recreation, and energy development. Currently, indices describing water presence and permanence exist for specific surface-water components (for example, streams and wetlands); however, a general surface-water permanence index that includes all major surface-water components is lacking. Developing a Surface-Water Index of Permanence can provide a reliable metric to understand future river reach- to region-scale surface-water permanence and availability and inform land management and policy decisions.