Proposal of the “Wastewater Use Basin” Concept as an Integrated Sewage and Rainwater Management Unit in Semiarid Regions—A Case Study in the Southeast of the Iberian Peninsula

Urban Farm DB summary

This paper proposes the concept of a "wastewater use basin" as a smaller-scale working unit than a traditional river basin, aimed at better managing sewerage-network water and urban stormwater in semi-arid and arid regions where water scarcity drives competition among urban, agricultural, industrial, and tourism demands. It is a geographically-focused proposal for integrated management of wastewater and stormwater that ultimately reaches a treatment plant for treatment and reuse. The study area is the southeastern Iberian Peninsula, Spain — the Campo de Cartagena–Mar Menor district (Murcia) and the Vega Baja district (Alicante). Analysis of recent torrential rainfall episodes in the Segura river basin found a clear tendency for these episodes to occur in coastal and pre-coastal areas, meaning the water does not reach the headwaters where the reservoirs are located. Based on the capacity of existing and planned environmental tanks, the study estimates that four cubic hectometers of additional water could be incorporated into the hydrological planning of the Segura basin. It concludes that rainwater collection adds a supplementary water volume that complements resources from treatment plants, serves as an adaptation measure to climatic extremes such as droughts and floods and to climate change, and supports circular management of water resources.