Agricultural Water Management 107 (2012) 112–121 Contents lists available at SciVerse ScienceDirect Agricultural Water Management jo u rn al hom epag e: www.elsevier.com/locate/agwat Optimal design of center pivot systems with water supplied from wells M.A. Moreno ∗ , D. Medina, J.F. Ortega, J.M. Tarjuelo Regional Centre of Water Research (CREA), UCLM, Ctra. de las Pe˜ nas, km 3.2, 02071 Albacete, Spain a r t i c l e i n f o Article history: Received 8 March 2011 Accepted 22 January 2012 Available online 17 February 2012 Keywords: Pumps Well Aquifer Characteristic curve Energy efficiency Center pivot a b s t r a c t Irrigation is one of the sectors in which energy consumption is increasing, mainly due to modernized systems designed to conserve water through the use of pressurized water distribution. Energy is one of the principle costs in irrigation. In this study, a new methodology is developed to determine the minimum total water application cost (investment + operation costs) in center pivot systems withdrawing water from wells. The proposed methodology optimizes the characteristic and efficiency curves for the pump as well as the types and diameters of pipes for pumping and distribution. In addition, the method accounts for hydrological variables (dynamic water table level and temporal variation), soil variables (infiltration parameters, surface storage capacity, surface impermeability), hydraulic variables (head losses in pipes, flow demand) and economic variables (energy costs, pump and pipe costs). In order to facilitate the technology transfer to managers and technicians, free software (DOP, “Dise ˜ no Optimo de Pivotes,” or Optimal Pivot Design) has been developed using MATLAB TM . Results show that the best options are timing irrigation to avoid periods of high energy costs as well as increasing pumping power and pipe size, with a greater system capacity (1.5 L s -1 ha -1 ), and shorter operation time (18 h day -1 ). The minimum water application cost is obtained in all case studies in this paper for center pivot systems irrigating 75 ha, with lateral pipes of 254 mm (10 in.). © 2012 Elsevier B.V. All rights reserved. 1. Introduction Efficient water and energy use have increasing importance in agriculture due to reduced water availability and increasing energy costs, which determine the viability of irrigated agriculture in many areas of the world. Currently, the projected effects of climate change and increasing energy costs have stimulated development of methods, tools, and actions aimed at optimizing the use of energy resources for environmental and economic benefits. Center pivot irrigation systems are among the most popular for irrigating field crops and are used on over half of sprinkler irrigated lands in the United States, Brazil, Argentina, and other countries (Allen et al., 2000). In Spain, 46% of the 3.4 Mha irrigated land are drip irrigation systems, with 14% set sprinkler irrigation systems and 8% mechanized sprinkler irrigation systems, mostly center pivot (ESYRCE, 2008). Application of this type of system requires consideration of energy issues in addition to water effi- ciency, which complicates the decision making process, especially from an economic point of view. Thus, the Spanish Ministry of Industry, through the Regional Energy Agencies, is implementing a ∗ Corresponding author. E-mail addresses: MiguelAngel.Moreno@uclm.es (M.A. Moreno), Diego.Medina@uclm.es (D. Medina), Jose.Ortega@uclm.es (J.F. Ortega), Jose.Tarjuelo@uclm.es (J.M. Tarjuelo). group of actions for improving energy efficiency in irrigable areas (IDEA, 2007; Abadía et al., 2008; Jackson et al., 2010; Rodríguez Díaz et al., 2011). Important economic savings have been observed after 20 energy audits in Irrigation Societies in the Region of Castilla- La Mancha (Moreno et al., 2010a). These actions are extended to privately owned farms, in response to a need to design irrigation systems and pumping systems such that energy usage is consid- ered. In Castilla-La Mancha (Spain), as in other Regions in the world, the main source of water is groundwater (more than 65% of irri- gation and urban water). Water is extracted by using submersible pumps and stored in a reservoir or injected directly into the irriga- tion system (Ortega et al., 2004a, 2005). Castilla-La Mancha is one of the Regions in Spain with the most center pivot systems for irriga- tion using groundwater extracted from different aquifers (Martín de Santa Olalla et al., 1999, 2007; Ortega et al., 2005). For large irrigation areas, the most common structure includes a reservoir to store water which is then pressurized for irrigation by pumping stations (Moreno et al., 2007). In small farms water is usually pumped directly to the irrigation system because of the high cost of reservoirs. An analysis of the main performance indicators and energy costs has been performed by Córcoles et al. (in press). Irrigation Advisory Services (IASs) are implemented to help farmers efficiently use resources, especially water, fertilizer, and energy. IASs provide farmers with adequate scientific and techni- cal support to increase agriculture sustainability and compatibility 0378-3774/$ – see front matter © 2012 Elsevier B.V. All rights reserved. doi:10.1016/j.agwat.2012.01.016