The decline in precipitation over the past five years, the gradual depletion of the subterranean reserves of the aquifer in Tenerife, and the loss of up to 50% in various sections of the island’s network due to the poor condition of the conduits have been three critical factors that prompted the Cabildo to declare a Water Emergency in May of last year. This declaration remains effective until February 28, pending a decision on whether the measure will be extended or allowed to lapse after an autumn and nearly two months of winter with rainfall levels significantly below average, particularly in South Tenerife, where precipitation has largely been absent.
In light of these circumstances on an island where demand continues to rise and the effects of climate change are becoming increasingly evident, rainfall has decreased by approximately 5% annually on average, which conversely hinders the recovery of the aquifers.
In this context, the island of Tenerife, which has historically relied on nearly 100% of its supply from galleries and wells, has seen its underground water resources diminish to below 70% of the overall water supply in recent years. This trend is reflected in the statistics provided by the Insular Water Council of Tenerife.
The Water Emergency includes 75 measures aimed at expediting the establishment of new infrastructure, such as seawater desalination plants, storage reservoirs, and purification and regeneration facilities. According to data from the Cabildo, the island consumes approximately 550,000 cubic meters of water daily, equating to around 220 Olympic swimming pools.
Deteriorating Quality
José León García Rodríguez, Emeritus Professor of Human Geography at the University of La Laguna, asserts that “the need for desalinated water is growing daily because the conventional aquifers, which consist of several deposits underground, are depleting.” In his view, this leads to an additional issue: the increased salinity of the water produced. “As the aquifer levels decline, the quality of the water extracted deteriorates, even necessitating treatment for high fluoride levels in areas like southwest Tenerife and La Guancha,” he explains.
The expert finds the situation in Tenerife over the past few years to be “concerning,” but he highlights seawater desalination powered by renewable energy sources (primarily wind and solar energy) as a potential solution to minimise reliance on oil. In this regard, García Rodríguez notes that the State has allocated specific funds to cover part of these costs. He also cautions about Tenerife’s “lag” in meeting deadlines to mitigate oil dependency. “If we do not yet have a clear plan for decarbonising electricity production, we will encounter serious issues,” he warns.
Finally, the Emeritus Professor from the University of La Laguna emphasizes the need for institutional campaigns to prevent water wastage, labelling the losses in the conduits affecting various municipalities across the island as “bleeding.” “This should be a concern not just for the municipalities, but for the Cabildo and the Government of the Canary Islands. How can we allow such significant losses of potable water through networks that are over 40 years old and essentially act as a sieve?” he stresses.