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The drought has settled in our house. Catalonia is suffering from the most serious situation in the last 50 years, which has forced the Catalan Water Agency to declare a state of emergency, a measure that affects around 6 million people from a total of 495 municipalities. There has been no normal rainfall 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 needed to redistribute and expand the sources of supply and ensure their supply on an ongoing basis. It is time to take 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 like every year is celebrated on June 5, is a good opportunity to reflect on what is 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. Faced with this situation, Aigües de Barcelona considers that the best solution to deal with the shortage structural water and in drought episodes is the reuse of regenerated water, that water that leaves the sewage treatment plants and undergoes additional treatment so that it can be reused in accordance with a circular model.
Regenerated water ensures 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. In terms of energy, the energy demand of regenerated water is up to three times lower than that of desalination. That is why it is the most sustainable option.
Aigües de Barcelona regenerated a total of 50 cubic hectometres (hm3) of water in 2022, i.e. the equivalent of the water consumption of nearly 1,250,000 people for a year. Regenerated water is currently being sent from the Baix Llobregat regeneration station upstream to Molins de Rei to be reused as potable water. In this way, regenerated water is brought to the river so that the Sant Joan Despà water treatment plant captures it downstream and treats it again to turn it into drinking water and continue the water cycle.
In a normal year, 95% of the water resources for the metropolis of Barcelona are linked to climatology, that is, surface and underground water, while 5% is desalinated seawater. In a drought situation like the current one, 19% of consumption corresponds to surface water (mainly rivers), 23% is underground water (wells and aquifers), 33% desalinated water and 25% regenerated water. This means that, to guarantee the water resilience of cities, it is necessary to diversify and find the most sustainable combination of different water resources, undoubtedly incorporating regenerated water.
To face this challenge, public-private collaboration is essential. This collaboration has been key in major developments of the metropolis throughout its history such as, for example, the Cerdà plan and the waste water management of the Garcia Fà ria plan, which led to the reform of the sewer system .
For this reason, Aigües de Barcelona, ​​together with the Administration, promotes major actions based on the reuse of regenerated water. A clear example is the Master Plan for metropolitan regenerated 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 in the metropolitan region 180 hm3 of new resources with greater resilience (60 hm3 of regenerated water, 45 hm3 of desalination and 45 hm3 of local resources of Llobregat and Besòs).
In addition, the company is distributing, to different metropolitan councils, regenerated water from the Baix Llobregat and Gavà -Viladecans treatment plants for urban uses, such as cleaning sewers, roads and containers, and watering areas green
Climate change requires sustainable responses. Innovative solutions are needed. It’s time to draw a future where having water depends more on ourselves than what falls from the sky.
