Office of the Delta Watermaster

A Comparative Study for Estimating Crop Evapotranspiration in the Delta

In the most recent drought (2012-2016), lack of accurate and timely insight about crop water use in the complex setting of the Delta hampered both water resource management and water use regulation.  In response, in 2015, several State agencies organized the first rigorous scientific effort to compare and improve seven emerging methods for estimating crop water use in the Delta.  The study was organized by the State Water Resources Control Board’s Office of the Delta Watermaster.

The scientists who conducted the research have now released the report on the three-year study.  The study—along with technical appendices and the publicly accessible supporting data—points the way toward significant improvement in understanding and management of California’s most precious resource within the Delta.

During the study, seven crop consumptive use measurement techniques were compared against standard datasets in the Delta environment, and the study provides a basis for evaluating results derived from different approaches to crop water measurement.  Application of this research promises to improve the water community’s response to and ability to manage through future droughts.

Study Resources:

• Summary of Study - Prepared by the UC Davis Center for Watershed Science.
  The Complete Study and Technical Appendices can be found in the Summary under “Project Documents and Datasets".
• California Water Blog about the Study - Blog Title: Modeling, Measuring, and Comparing Crop Evapotranspiration in the Delta.
• SWRCB Media Release about the Study

State Water Resources Control Board Meeting Presentation - May 1, 2018

• Crop Study Presentation Slides (05/01/2018)
• Crop Study Presentation Video (05/01/2018) - Starts at 2:19:18.