The reservoirs of the Ter and Llobregat rivers, which supply the regions of Barcelona and Girona, currently accumulate half of the flow necessary to leave behind the risks of drought. The reservoirs are currently at 29% of their capacity, which is why they present the same percentage as they showed at the beginning of February this year. It is the evidence of a globally very dry spring, despite the recent downpours, very localized geographically. “What is expected in a normal spring would have been to have double the volume of water we currently have”, says Enrique Velasco, head of the water resources management department of the Catalan Water Agency (ACA).
After the recent rains, the Barcelona area has seen the risk of domestic restrictions recede, as explained last week by the president of Agbar, Ángel Simó. Nevertheless, the entire central area of ??Catalonia still remains in a situation of exceptionality, which means that there will continue to be limitations for various uses of water (agricultural irrigation, in industries, irrigation of parks and gardens , and urban cleaning). Therefore, the situation is not normalized yet.
The five large reservoirs of these Catalan rivers accumulate 176 cubic hectometres, while to definitively remove the dangers of drought it would be necessary to have 341 cubic hectometres (55% of the total). This is the threshold that marks the entry into a pre-alert situation (and which entails the first special measures: increased desalination, activation of wells, first controls).
After the rains, the Sau reservoir has recovered (it reaches 24% and dropped to 7% in April), but the Ter-Llobregat system as a whole continues at very low levels continuously, which proves a persistent drought. In four months the reservations have only been maintained.
If you analyze what normally happens in a spring (the time of the year when there is more rainwater input) it can be seen, for example, that on March 1, 2018 the Ter and Llobregat reservoirs were to 49% (302 hm3) and that in the summer (June 21) reached 95% (581 hm3).
These figures illustrate the seriousness of the situation, considered “critical”. “To have an optimal volume of reserves to face the summer months with guarantees, we should be between 48-50%”, say ACA sources. With this level (about 100 hm3 more than we currently have) demands (urban, agricultural irrigation and environmental flow) could be guaranteed. The months of March and April were very dry and only in May and June have they started to rain. But they have not been widespread episodes of several days, extensive and continuous, but specific and geographically localized, although they have the virtue of soaking the ground.
In the current phase of exceptionality in which the Barcelona region finds itself, the restrictions are focused on the agricultural, livestock and industrial sectors (with restrictions of 40%, 30% and 15% respectively); and, in addition, the use of potable water for the irrigation of parks and public and private green areas, among others, has been prohibited. In the domestic sphere, the water supply in municipalities is 230 liters per inhabitant per day.
In addition, an emergency has been avoided thanks to desalination and reuse, which are now the main pillars of the supply (constitute 58%) in the 23 municipalities in the Barcelona area served by Aigües de Barcelona. Desalination constitutes 33% of the demand while 25% is regenerated flows (the rest is water from the river and wells).
After yesterday’s rains, scattered showers are expected today, although not as intense. “We expect extensive, but scattered, rain. We don’t expect it to rain everywhere at the same time”, says Santi Segalà, SMC’s head of forecasting. Between Thursday and Saturday, three days of peace are expected, without precipitation and with rising temperatures. And between Sunday and Tuesday a new disturbance will arrive that could cause storms, but not widespread ones.
