Agricultural Engineering

Case Study

Project:     Imperial Irrigation District, California
Client:       Imperial Irrigation District

    Imperial Irrigation District (IID) is located in the Imperial Valley of Southern California, and constitutes one of the nation’s largest irrigation districts.  IID is in charge of ordering and distributing approximately 3.2 million acre-feet of water from the Colorado River each year, to serve roughly 475,000 acres of farmland and several municipalities.  NRCE has been working with IID since 1997, and has completed studies focusing on following areas: (1) consumptive water use analyses, (2) water use efficiency and conservation studies, (3) mapping, inspection, and inventory of irrigation systems, (4) beneficial use evaluations, and (4) system performance and service evaluations.
    Consumptive water use analyses were completed based on a combination of field measurements, historical diversion data, and calculations of theoretical crop water requirements using climate data.  Water use efficiency and conservation studies investigated the past projects IID has undertaken to conserve water, and estimated the volume of water conserved for each project.  In addition, NRCE evaluated how efficiently IID uses water, in comparison to other irrigation districts in the region (shown in the figure below).



    As part of a system improvement study, NRCE completed an inventory of the district’s conveyance and distribution system; identifying all major control gates, canals, reservoirs, and current levels of system automation.  In addition, the complex nature of IID water operations were inventoried and evaluated.  The study used the system inventory to evaluate the level of service provided to farmers, and explored variations in system performance and service between crops, months, farm locations, and the types and purposes of the water delivery.  Recommendations were made to IID to address specific variations in service and performance.  A detailed beneficial use investigation was conducted for IID to defend the rates of water use practiced in IID.  Site visits and field measurements confirmed that IID contains unique irrigation conditions due to the nature of its soils, and the study analyzed the distribution of water applied at the farm headgate (shown in Figure IV-3 below).  To further support the rates of water use in IID, water use efficiencies were calculated at the on-farm and conveyance/distribution levels.





Return to Service:  Agricultural Engineering