Why do the desalination plants work at 50% if the reservoirs are already full?

BarcelonaThe harsh images of a Catalonia dry for three and a half years due to lack of rainfall and high temperatures have been replaced by those of full reservoirs, which currently exceed 92% of their reserves. But the water crisis was a wake-up call: it is no longer possible to live solely dependent on whether it rains or not, but rather it is necessary to transform the facilities that manage and produce water, whether they already exist or still need to be built or launched.

According to Generalitat sources, desalination plants must operate as much as possible – they are still working at 50% of their capacity and there is no plan to reduce the pace – more water must be generated and the maintenance of distribution networks must be promoted to prevent leaks. These are the bases of the preliminary report of the draft water transition law that the Government approved this Tuesday and which, on paper, must organize and establish timetables for launching the water planning and control measures and mechanisms.

The executive council gave the green light this Tuesday to the start of the processing of a regulation – which will now be subject to public consultation for two months – with the idea that it can become a reality during this legislature, indicate sources from the Department of Territory, Housing and Water Transition. "The fundamental horizon is to move towards a water security model", because "we cannot depend on rainwater and a regulatory framework must be generated to adapt Catalonia to the new reality" of climate change by 2050, stated the minister and government spokesperson, Sílvia Paneque.

Overexploited aquifers

If until now 70% of the water resource consumed in the country comes from reservoirs, rivers and aquifers and 30% from other sources of new water –regeneration, desalination, reuse and aquifer recharge–, these actions should reverse percentages. "In the long term, the law must allow the study and design of the water Catalonia of 2050; how it should be and what the various sectors and actors should do knowing that the climate for which the facilities were designed no longer exists", explain government sources.

Meanwhile, how could a new drought be faced? Aware that there is now a "truce", the authorities calculate that all the mentioned formulas will allow the contribution of about 300 hm³ of new water by 2030. For example, at the moment, desalination plants are working at 50% of their capacity, even though Catalonia has been strengthened hydrically by the rains of recent months and despite the fact that the energy consumption of desalination triples that of potabilization. Although these plants are intended to be a complement in case of emergency, government sources justify maintaining this power of use by the fact that some aquifers such as the Llobregat one – which can function as strategic water banks – have been overexploited and the groundwater level with respect to the sea plummeted to a level of -9; this means that seawater was entering. In these cases of saline intrusion, it is possible to opt for injecting water and giving them time to regenerate. Government sources add that they are considering increasing the number of injected reserves in the future, without specifying how many or when.injected in the future, without specifying how many or when.

Impulse to the Besòs

The future law will have to develop how two elements, highly demanded during the drought, can be made possible: the recovery of aquifers as "fundamental" water reservoirs, with programmed recharge, or hydro-sustainable urban design –buildings and vegetation–, and the fact of seeking a reduction in the consumption used by industry or agriculture. However, the Generalitat emphasizes, this modification will not start from scratch: the drought plan already set priorities in a kind of roadmap.

This draft memorandum of the water transition law includes planned infrastructures, such as the new desalination plants (Tordera II, Foix and Costa Brava), and new reuse projects in Besòs inspired by the Llobregat model. In fact, the future regulation pursues the objective of increasing water reuse to approximately 245 cubic hectometers annually by 2040 and advancing in the increase of desalination. However, in addition, the idea is to make the Llobregat and Besòs rivers the taps of the metropolitan area. Specifically, it is foreseen that 60% of the water consumed there will come from the Llobregat and the other 40% from the Besòs. "All this implies a change of model that can only be achieved with a law: moving from emergency management to preventive management," argue the same sources.

10% of actions on networks

Sources from the Generalitat also emphasize the improvement in efficiency in supply networks. 31% of the 130 million euros in aid granted by the Catalan Water Agency (ACA) to municipalities for repairing leaks and renewing pipes are already underway. "Global maintenance is at 73%, but there are still places where for every 100 liters, only 40 are utilized," they state. With more than 1,100 subsidized actions in municipalities with over 5,000 subscribers, the Government expects to reduce losses. For now, however, only 10% of the actions have been completed.