Circularity and adaptability as possible approaches to mitigate urban drought

Abstract

From 2018 to 2020, the city of Breda (NL) faced drought, with significant economic losses and water scarcity problems. The water board within which the city is located began to consider new possible water management practices, due to the unsustainability of the current ones. This study aims to investigate how a change of the current paradigm can improve the current approach in water management, shifting from a linear to a water management circular approach, and from command-and-control to adaptive. Starting from the case scenario of Breda, the study considers how through the reuse of management wastewater treatment plant effluent and stormwater, and the application of sewer mining units, it may affect the circularity and adaptability of the system. Then, based on Breda's experience, an attempt is made to investigate the concepts of circularity and adaptability. \\To be able to understand the current water situation and approach in the city of Breda, a water balance for the year 2020 was drafted. The water balance for 2020 for the city of Breda shows a positive value of 50 mm/year. The definitions of circularity and adaptability for a water management system were determined, and for each of the concepts a framework has been developed, to assess the level of circularity and adaptability before and after the interventions. Then, a workshop with local experts in the field was organized. Different strategies of interventions were proposed to them, in order to evaluate their suitability. Then, a final strategy was formulated, where wastewater effluent is employed as irrigation water for agriculture in the south of the municipality, stormwater discharge into wetlands to recharge aquifers and three sewer mining units in the rural area of Breda. These interventions showed a positive effect on the water system, since the volume of water stored in the system has increased, giving an overall better performance of the circularity and adaptability indicators. Moreover, the final strategy shows a better water balance of 100 mm/year. This research aims at creating a better understanding of concepts like circularity and adaptability. The study shows that there is a potential for re-using water to enhance the overall performance of the water system under certain conditions.