What is a water budget?

A “water budget” is the accounting of the total groundwater and surface water entering and leaving a basin, including the changes in the amount of groundwater stored in the basin. Basic components of water budgets are:

  • Precipitation (rain)
  • Evapotranspiration (a combination of evaporation from the soil and transpiration by plants)
  • Surface water flow (streams and lakes) infiltrating or leaving the groundwater basin
  • Groundwater flow (aquifers) into and out of the groundwater basin
  • Change in groundwater storage
  • Groundwater pumping and consumed or exported from the basin.

Show All Answers

1. Is groundwater quality currently being monitored?
2. Is there a link between groundwater and surface water, and if so, how will it be managed?
3. What is a water budget?
4. What is irrigation system efficiency and what factors affect the efficiency?
5. What is the current status of the Napa River for impairment under the Clean Water Act?
6. How is climate change taken into account in considering and planning for groundwater sustainability?
7. Return to the Groundwater FAQ page