A water balance is an accounting of all water volumes that enter and leave a 3-dimensional space over a specified period of time.  A complete water balance is not limited to irrigation water, but includes all water that enters and leaves that space, including irrigation, rainwater, groundwater, etc.

Water balances are essential for making wise decisions regarding water conservation and water management.  ITRC conducts water balances at the on-farm and district level, in order to facilitate future planning and water conservation efforts.

ITRC has performed water balance studies for numerous irrigation districts, including Westlands Water District, Imperial Irrigation District, and Klamath Basin irrigation projects.  Past projects in California have included:

• Crop and soil evapotranspiration

• Evaporation from irrigated agricultural land in California

• Estimation of project water diversions from the Sacramento River. 

In addition, in 2003 ITRC completed a hydrologic assessment of the upper Klamath Basin, Oregon, which was intended to provide decision makers and stakeholders with a scientific framework for understanding the realistic potential for water conservation from agricultural land and wildlife refuges, as well as for management of the water resources for other purposes, such as improving water quality.