Climate change and the increase in the number of residents in Barcelona and its area of influence are two of the reasons that warn of the possible lack of availability of the water resources needed to supply the population within 30 years. The most pessimistic projections estimate the drinking water deficit at 43 hm3 per year starting in 2050. Far, but not too far, from the most optimistic forecasts, which point to a deficit of 11 hm3 per year in the same horizon.
Given this situation, the Barcelona Metropolitan Area (AMB) has developed a strategic plan for the integral water cycle that constitutes the roadmap to reduce the water deficit suffered by the metropolis of Barcelona. The plan foresees acting comprehensively on the entire water cycle, with estimated investments by all public administrations that would be between 2,100 million and 2,400 million euros. Of the total, 740 million would correspond to the Catalan Water Agency (ACA), 1,300 million to the AMB and 410 million to the metropolitan municipalities.
This project includes saving and efficiency measures, largely through adequate network maintenance and the use of alternative water resources to drinking water, but also the development of new infrastructures. Of the 43 hm3 deficit, half could be covered by simply better managing water, according to Eloi Badia, Vice President of Ecology at the AMB.
The other half would correspond to the improvement of the network with the development of three new hydraulic infrastructures that will require an investment of 132 million euros. Specifically, the AMB plan proposes the construction of a new drinking water treatment plant (ETAP) and a water regeneration station (ERA) in the Besòs river, similar to the one already operating in the area of the El Prat de Llobregat wastewater treatment plant. This facility would allow obtaining higher quality water, suitable for being pumped upstream of the Besòs, to maintain its ecological flows. The third infrastructure proposed would be a pipeline to transport regenerated water between the channels of both rivers to guarantee hydraulic availability in the metropolis.
"This means that action would be taken in the natural basins of the metropolitan area, Besòs and Llobregat, and that the volume of investments is smaller than in other plans," while the plan represents "greater use of another major metropolitan waterway, the Besòs, and, therefore, the pressure between both systems is balanced," highlights Badia.
The AMB reminds that at this moment, the metropolitan territory annually has 806 hm3 of water, while the demand for the entire territory amounts to 397 hm3. However, several factors will cause these figures to worsen year after year, and the availability of water resources in the metropolitan area will be reduced. In fact, by 2050, it is estimated that resources will be 745 hm3, but demand will have increased to 501 hm3.
Climate change is expected to decrease surface resources and the internal basins of the Ter and Llobregat by 12%, and groundwater resources by 9%, while increasing the demand for water for agricultural uses. The agreements of the Ter Table have reduced, starting in 2023, the flow of this basin destined for the metropolitan area to a maximum of 54 hm3/year, and several periods of drought could reduce the quantity and quality of water bodies.
The Vice President of Ecology of the AMB, Eloi Badia, and the technician of the AMB Water Cycle Services Directorate, Maria Indurain, have indicated that the strategic water plan will be initially approved by the Metropolitan Council on March 22 ---coinciding with World Water Day--- and that, after all the necessary administrative procedures, it would obtain final approval in December 2022.