water budget

The water budget refers to the balance between water inputs and outputs for a lake or lake system. This balance is crucial for the existence of lakes and is influenced by factors like precipitation, evaporation, streamflow, and groundwater. Understanding a lake's water budget helps in managing water resources, especially during droughts or floods.1

Key inputs of water to a lake include streams, rivers, precipitation, and groundwater. Precipitation directly on the lake's surface can be a major input, as can precipitation that reaches the lake through surface or groundwater flow. Evapotranspiration, the loss of water to the atmosphere through evaporation and plant transpiration, is a significant output.123

Human activities, such as dam construction or dredging, can alter a basin's water budget, potentially affecting the lake's ecology and hydrology. These alterations require careful consideration of the entire watershed's water balance.14