Streamflow is a critical cornerstone to aquatic health. Rivers and streams are naturally dynamic in many ways, and this dynamism is shaped by variations in how much water flows through the stream. For example, spring floods give fish critical access to floodplain wetlands; moderately high flows move sediment, seeds, and other organic materials through the system; and low flows allow plant species to grow in areas that would otherwise be covered in water. Variability in streamflow ensures a variety of physical habitats form within and along a river; these habitats in turn support a wide range of aquatic species. The natural timing of high or low flows cue many species to make important life cycle transitions – for example, they may trigger fish to spawn or migrate, or plants to flower or disperse seeds. Alteration of natural flow patterns may improve the likelihood of non-native species invasion. These are just a few examples of the numerous and complex relationships between natural streamflow patterns and thriving aquatic ecosystems.
For those interested in further reading, we suggest a limited number of papers to get your feet wet:
The RIFLS program began in 2002, when many across the state were raising the call for deeper examination of streamflow alteration in Massachusetts. Our staff first contacted people around the state regarding observed and/or measured flow alterations in streams large and small. The resulting Low Flow Inventory file size 1MB was developed to enable individuals, communities, and state agencies to access information and observations about streams with unnatural flow problems and to summarize the extent of streamflow alteration and depletion on a statewide basis.
Moving from this effort to educate the public about the extent of the flow alteration, we began gaging specific streams, in partnership with local groups, to document and address specific cases of flow alteration. The data collected by RIFLS volunteers to date may be found here.