Regulation of Streamflow

the redistribution of the volume of streamflow over time, changing its regime to meet the needs of various economic sectors, particularly hydroelectric power production, irrigation, water supply, and water transport. Streamflow is regulated by storing excess water in reservoirs when the discharge exceeds need and releasing the accumulated reserves during periods of low water. Regulation may be seasonal, annual, or long-term depending on the length of the period of accumulation and release. Short-term (daily or weekly) regulation is employed when the pattern of water use changes by the hour or from day to day, for example, at hydroelectric power stations. In this case virtually no fluctuation in the natural flow occurs.