Local Irrigation Agencies

Local irrigation agencies are not centralized institutions with complete power over all surface and groundwater decisions in their basins. Instead, the three major types of irrigation agencies (public irrigation districts, mutual water companies and commercial water companies) have different and relatively limited power. Most importantly, with certain exceptions, they cannot directly control excessive groundwater withdrawals and have to resort to indirect methods to achieve this goal. Thus, the phrase Conjunctive management of surface and groundwater is very misleading. Conjunctive use models should only include in their proposed objective functions those decision variables controlled by the particular agency under study.