Improving irrigation system performance through scheduled water delivery in the Middle Rio Grande Conservancy District

Department Head: Luis A. Garcia.2010 Spring.Includes bibliographical references (pages 265-275).This dissertation examines improving irrigation system performance in the Middle Rio Grande Valley in central New Mexico. Historically, the Middle Rio Grande Conservancy District practiced continuous on demand water delivery, which resulted in large diversions from the Rio Grande. Due to pressure related to the endangered Rio Grande silvery minnow (Hybognathus amarus), the Middle Rio Grande Conservancy District has been forced to manage water more effectively. To reach this goal while still providing farmers with adequate supplies, the Middle Rio Grande Conservancy District has employed scheduled water delivery. Scheduled water delivery introduces significant management challenges that can be addressed using Decision Support Systems (DSS). This dissertation presents the development, validation and implementation of a DSS in the Middle Rio Grande Conservancy District to facilitate scheduled water delivery. The development of the DSS represents a four year effort during which data were collected throughout central New Mexico to develop a real time model capable of predicting crop water demand and distributing irrigation water. This research verified the hypothesis that real time modeling using a Decision Support System is capable of predicting crop water demand and developing water delivery schedules to meet those demands. The field study conducted during the validation effort defined input parameters for the DSS and also had the contribution of quantifying farmer practices in the Middle Rio Grande Valley, which prior to this research were poorly understood. The implementation of the developed DSS was successful during the 2009 irrigation season and improved water delivery operations, while reducing the required water supply by 27%. Overall, the DSS provides the Middle Rio Grande Conservancy District with a powerful tool that can be used to schedule water delivery, determine legitimate water use, improve reservoir operations and sustain irrigated agriculture in the face of future water management challenges