CRIDE: A case study in multi-criteria analysis for decision-making support in rainwater harvesting

This paper aims to develop a multi-criteria decision analysis (MCDA) tool for rainwater harvesting (RWH) on a university campus in Bogota, Colombia. The specific type of MCDA our research proposes is known as CRIDE (multi-CRIteria DEcision support tool), which allows us to study various methods of RWH. In order to account for uncertainties such as the variability of expert opinions and imprecision stemming from the different criteria required, we have designed this tool to incorporate ELECTRE II and the Monte Carlo method. For this case study we apply a methodology that evaluates the performance of six RWH scenarios. These six input scenarios emerged from an ideal one, wherein all rainwater throughout the campus is successfully harvested and treated until potable. From there, reality sets in: the other five scenarios are varying degrees of deviance from the ideal one, both in terms of water quantity and quality. In regard to collection and treatment we used sustainable urban drainage systems (SUDS). As for the evaluation of each of the scenarios, we outline eight criteria, which include hydraulic performance, compatibility with the University's Master Plan and financial aspects. Our research concludes that CRIDE as a means of support during the decision-making process generates a complete view of possible solutions, in addition to ranking these solutions. The CRIDE-based approach allows for the proposal of a methodology that evaluates the relevance of an established criteria set, using robustness, redundancy and sensitivity.