Drought Management in the Urban Water Supply System of Canal de Isabel II, Spain

The availability of enough and suitable resources to attend the different kinds of water demands in the urban context represents the main basis of supply services. The maintenance of balance between availability and demand is subject to threats of different kinds, and when this balance is lost it has a major impact on and generates costs to citizens, entities and those responsible for the supply. The break-up of this balance represents one of the main risks with which urban water service must cope. The problem has not yet been posed or solved in a homogeneous way internationally, not even in contexts involving situations of hydric stress. The solutions described in this paper summarize the methodological and operational aspects followed in the Comunidad de Madrid in Spain by the supply system responsible for providing that service to 6 million inhabitants. From the methodological point of view a clear difference of setting has been established, with a clear separation between those related to the failure or normal situation and indicators and corresponding conventions to be used in planning, operating and solving contingencies. As for the operational aspects, a division into stages or phases is set with their corresponding impacts and cost distribution among the different parties involved. In both approaches, considering risk as a main factor in analysis and decision making is the main pillar for the efficient management of resources and commitments with society and the environment.