Presented in this paper is a methodology for a spatially based multi-criteria evaluation of land suitability for irrigation (IR). A group of experts use the analytic hierarchy process (AHP) and the consensus convergence model (CCM) to define weights of factors relevant in validating areas of land as suitable for IR and to develop IR suitability maps in the geographic information system (GIS) environment. Then, using those maps, a group of policy-makers apply voting methods to identify districts with priorities for installing new IR systems. The presented methodology has several benefits. Group decision can aggregate the wisdom of the different domain experts involved in the process while effectively coping with the risk inherent in any decision problem. In CCM, cooperation among experts is rewarded and non-cooperation yields the risk of being excluded from the process or having very little impact on the group decision. The presented methodology is more precise than previously published methodologies, which is more helpful for policy-makers. Finally, sometimes experts’ opinions are not comprehensive enough to formulate an objective decision, as they are based on scientific facts whereas real-life decision-making is often based on economic or political factors. Owing to that, policy-makers are included in the presented methodology.