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Drought has settled in our territory. Catalonia suffers the most serious situation in the last 50 years, which has forced the Catalan Water Agency to decree the state of exceptionality, a measure that affects some 6 million people in a total of 495 municipalities. There has been no normal rainfall regime for more than two years. Drought is a recurring phenomenon in the Mediterranean basin, but with climate change there are more and more episodes and they are longer and more intense.
We are facing a challenge that requires a new management of the integral water cycle, the basic element for life. A change of model is necessary to redistribute and expand the sources of supply and ensure their supply on a continuous basis. It is time to make decisions and actions that make the management and use of an irreplaceable natural resource more sustainable. Climate change is turning the exceptional into the norm.
World Environment Day, which as every year is celebrated on June 5, is a good opportunity to reflect on the best solution and speed up its application. Aigües de Barcelona is firmly committed to an ecological transition towards sustainable, local and resilient models. Promoting the circular economy, protecting ecosystems and biodiversity is the way to fight the climate emergency.
The Catalan Water Agency estimates that climate change will cause a 22% reduction in the availability of water resources on the Catalan coast by 2050. Given this situation, Aigües de Barcelona considers that the best solution to deal with structural water scarcity and episodes of drought is the reuse of reclaimed water, that water that comes out of the treatment plants and undergoes additional treatment so that it can be reused according to a circular model.
Reclaimed water makes it possible to ensure the availability and quality of water resources without depending on rain or the extraction of water from surface and underground resources. In addition, it contributes to protecting and restoring biodiversity and ecosystems and reduces the human water footprint of the final uses of water because it is local, accessible and stable water. The reduction of the water footprint in the uses of water can reach 99% compared to other conventional sources thanks to the intrinsic circularity of this resource. At an energy level, the energy demand of reclaimed water is up to three times less than that of desalination. That is why it is the most sustainable option.
In 2022, Aigües de Barcelona regenerated a total of 50 cubic hectometres (hm3) of water, that is, the equivalent to the water consumption during a year of almost 1,250,000 people. Currently, reclaimed water is being directed from the Baix Llobregat regeneration station upstream of the river to Molins de Rei to be reused as pre-drinking water. In this way, reclaimed water is supplied to the river so that the Sant Joan Despí water treatment plant captures it downstream and treats it again to convert it into drinking water and continue the water cycle.
In a normal year, 95% of the water resources for the Barcelona metropolis are linked to the weather, that is, surface and groundwater, while 5% is desalinated seawater. In a situation of drought like the current one, 19% of consumption corresponds to surface water (rivers, mainly), 23% is groundwater (wells and aquifers), 33% desalinated water and 25% reclaimed water. This means that, in order to guarantee the water resilience of cities, it is necessary to diversify and find the most sustainable combination of the different water resources, undoubtedly incorporating reclaimed water.
To face this challenge, public-private collaboration is essential. This collaboration has been key in major developments in the metropolis throughout its history, such as the Cerdà plan and the management of wastewater from the Garcia Fària plan, which led to the reform of the sewage system.
For this reason, Aigües de Barcelona, together with the Administration, promotes essential actions based on the reuse of reclaimed water. A clear example is the Master Plan for metropolitan reclaimed water, in collaboration with the Administration and potential water users. A strategic piece to guarantee the water resilience of the territory. Likewise, under the umbrella of the Next Generation funds, the company has proposed a project to incorporate 180 hm3 of new resources with greater resilience into the metropolitan region (60 hm3 of reclaimed water, 45 hm3 of desalination and 45 hm3 of local resources from Llobregat and the Besós).
In addition, the company is distributing reclaimed water from the Baix Llobregat and Gavà-Viladecans treatment plants to different metropolitan town councils for urban uses, such as cleaning sewers, roads and containers, and irrigating green areas.
Climate change requires sustainable responses. Innovative solutions are needed. It is time to draw a future in which having water depends more on ourselves than on what falls from the sky.
