A general methodology for adaptative planning of urban water systems under deep uncertainty

ABSTRACT Urban Water Systems (UWS) operate under a broad list of uncertainties. They usually depend on large amount of investments requiring long-term planning for a future full of changes with high degree of uncertainties (climate, social and economic). Many of these uncertainties do not have analytical representation neither they count on agreement among experts or decision makers concerning their influence in the performance of the UWS. The literature has named these changes as deep uncertainties (DU). This work presents a general approach to incorporate the influence of DU on planning and management processes of three types of UWS: 1) Water Supply Systems; 2) Drainage Systems and 3) Rainwater Harvesting Systems. The proposed framework defines steps toward the selection of the best policies and their evaluation in a broad set of scenarios. The particularities of each urban system led to adjustments in some steps of the general methodology. The approach proposed in this work was applied to a practical case, the Rainwater Harvesting Systems in the city of Ipameri, located in the State of Goiás, Brazil. The results highlight the impacts of DU factors on the system performance and reinforce this type of approach as a contribution towards adaptive planning for UWS.