The impact of a natural disaster can cause contamination of water, breaking pipelines, structural damages, water shortages, and collapse of the entire system. In emergency or disaster situations water supply are imperative for the rapid return to normalcy. In this paper, water supply planning for emergency response after natural disasters has been studied. Multi Criteria Decision Making (MCDM) has been used as a tool for incorporating decision maker preferences for water supply planning in emergency conditions. Analytical Hierarchy Process (AHP) as a well-known MCDM method was utilized for prioritizing water resources alternatives. For this purpose, the quality and quantity of water for living in emergency conditions after natural disasters were reviewed. Different water resources alternatives which are possible to use for emergency response were identified. Water resources availability, water quality, cost, affected population and delay in service were used as criteria for ranking the water resources alternatives. The proposed methodology was used for Pardis City in the vicinity of Tehran metropolitan in Iran, which is highly vulnerable to earthquakes and floods. The developed methodology provides an opportunity for further incorporation of decision makers' preferences in preparing an Emergency Response Plan (ERP) to improve respond to provide necessary water in disaster situation.