Economic index for inter-annual water management: the case of Irrigation District No. 041, Río Yaqui, Mexico.

Abstract

In the agricultural system of Irrigation District No. 041, Rí­o Yaqui, the volume of water for agricultural purposes is supplied by the reservoir system and the aquifers in the region. The efficient operation of this irrigation system is extremely important for the economic, political and social activities of the Yaqui Valley. These activities have had a negative impact in the period from 1996 to 2006, in which the Yaqui River watershed faced a severe drought. The objective of this research is to develop, present, and validate an index for the inter-annual water management in this agricultural system. This index, which tries to attenuate the drought effect, includes information about the economic efficiency of the operation rules employed in the Irrigation District. For the development of the index, the Yaqui River simulation-optimization model developed by Minjares et al. (2008) from CONAGUA's Northwest Watershed Organization was used. Results show that this index is a very useful tool during the irrigation planning process (for short- and long-term planning) and allows administrators to make the important decision whether: 1) to maintain water stored in the reservoir system for future use and drought event prevention, or 2). to use the water in the system in the present agricultural year in the most profitable crops.