The IVWA region is one of the most heavily irrigated areas in Illinois, accounting for over 30% of all of the irrigation water use in the state. To better account for water withdrawals, the USGS was contracted to develop an approach to estimating water use from center pivot irrigation. Using a formula based on power consumption, a method has been determined to estimate the amount of groundwater used by agricultural irrigation. Working together with the Menard Electric Cooperative, this approach provides an annual total of gallons pumped from the region. The variability in total gallons pumped from one year to the next reflect the differences in the amount and timing of rainfall in the area.