Int. J. Water, Vol. 4, No. 1, 2008 25 Copyright © 2008 Inderscience Enterprises Ltd. A model for integrated water resources management in water-scarce regions: irrigation with wastewater combined with desalination processes Nava Haruvy* Netanya Academic College, 1 University Street, Netanya 42365, Israel E-mail: navaharu@netvision.net.il *Corresponding author Sarit Shalhevet SustainEcon, 126 Thorndike Street, Brookline, MA 02446, USA E-mail: sarit.shalhevet@gmail.com Yehuda Bachmat Hadassah Academic College, 37 Haneviim St. Jerusalem 91010, Israel E-mail: ybachmat@vms.huji.ac.il Abstract: We have developed a model for planning water supply from diverse sources, including groundwater, the National Water Carrier, wastewater and seawater. The model integrates hydrological, technological and economic considerations, and estimates the economic and environmental impacts of alternative water management policies; it was implemented in a case study of the Emek Heffer and northern Sharon regions in Israel. A unique hydrological database was constructed and a hydrological model was developed for planning water resources use and forecasting the chloride concentration in the aquifer. The costs of desalination processes and of the water supply to the region under various scenarios were estimated. The results include recommendations for the water treatment level and for desalination of different water sources, and forecasts of the implementation costs. We conclude that the economic cost of improving the quality of the supplied water and of the aquifer water should be considered in decision making. Keywords: groundwater salinity; multi-disciplinary model; economics; desalination; wastewater. Reference to this paper should be made as follows: Haruvy, N., Shalhevet, S. and Bachmat, Y. (2008) ‘A model for integrated water resources management in water-scarce regions: irrigation with wastewater combined with desalination processes’, Int. J. Water, Vol. 4, No. 1, pp.25–40. Biographical notes: Nava Haruvy is a Senior Professor of Economics in the Netanya Academic College, and Deputy Dean of the College’s School of Insurance. She received her PhD in Economics from the Technion in Israel. She has conducted extensive research, teaching and consulting, managed