Water footprint in the water cycle of the Canary Islands

Resumen

Islands are territories with limitations when it comes to exploiting their natural resources, due to the quantity of these resources and the possible vulnerability that can be caused to the ecosystem if this is not done in a sustainable manner. The Canary Islands are an archipelago in the Atlantic Ocean, belonging to Spain, with a high demand for water resources mainly due to urban, tourist and agricultura! use. The orographic characteristics of the islands and their capacity to capture the trade winds determine the greater or lesser aridity of the islands, which means that each island has its own water model, where in sorne there is a greater contribution of desalinated water and in others a greater contribution of groundwater. This article presents a study of the water footprint of the different drinking water collection and wastewater treatment facilities in the Canary Islands, in order to determine the blue, green and grey water in each case. The results confum that water galle11es are environmentally friendly facilities in terms of both water and energy, while water treatment plants have a greater impact on discharges into the natural environment, as well as desalination plants, which are very common in the archipelago.