Water flow
What is it? Water flow is an indicator of the amount of surface water flowing measured at a particular point. Water flow rates are affected by stream width/depth and are often influenced by man-made structures (bridges, culverts, dams, etc.) or by natural features (vegetation, tree stumps, waterfalls, etc.).
Why Is it important? Water flow gives us important information on the source of our freshwater, helping to answer questions like: Is the water flow directly from seasonal precipitation (rainfall or snow), is the water flow lake-fed, or is the water flow from underground (groundwater) springs? Or from all of these…? Knowing where flowing water comes from is important in improving our understanding of an area's hydrological cycle (surface water and groundwater movements), freshwater availability, and associated freshwater riparian/aquatic habitats (and their sensitivity) to flow variability.
What does it mean?
- No water flow may mean that this location is likely entirely dependent upon seasonal rain or that someone/something has dammed the water flow!
- Year-round water flow - in drier locations (without summer rainfall), year-round flow indicates either an underground (groundwater) flow contribution and/or a surface lake inflow. Usually a surface lake inflow is easy to determine if you can see where the water flow is coming from (from a map).
- Seasonal water flow may indicate that flow at a location is likely entirely dependent upon seasonal rain or that there are man-made controls on water flow (e.g., dams or sluice gates). Man-made restrictions to flow are usually in place to preserve precious freshwater resources and habitats.