This indicator annually measures the percentage of rangeland streams with at least one day of no-flow (also referred to as zero-flow) in a year, and, of those, the percentage that have a duration of zero-flow for a given period that is substantially longer or shorter compared with a long-term average. Together, these two variables describe the frequency and duration of surface no-flow periods. Stream-flow is critical in sustaining the habitat necessary for many rangeland plants and animals. Increasing no-flow periods can lead to loss of streamside vegetation and wildlife habitat for many rangeland species. No-flow periods can lead to loss of fish and aquatic animals.