Understanding the Rhythms of Rivers: Exploring Natural Hydrographs and the Impact of Dams on Watersheds
Dams create a number of issues for the overall health of a watershed. One of the primary issues is that they modify the volume (discharge) and timing of when and how water flows in the portion of the river downstream. Dams trap and store water in the wet periods of time, and then release additional water during the dry, hot periods of time to meet human need. The graph which shows the amount of water flowing past a point over time is called a hydrograph.