Tenerife is drying up. The Island is heading towards an unprecedented water supply crisis in the short to medium term unless more drastic measures are taken following the solutions already adopted after the declaration of a water emergency on 29 May 2024, which has been extended ever since. This warning comes from the Insular Water Council (CIATF), which is part of the Cabildo of Tenerife, in a report for the drafting of the Hydrological Plan 2027-2033.
This analysis, which will serve as the basis for preparing the document that governs the integral water cycle and is renewed every six years, clearly outlines with numerous data that demand is continually rising, while reserves continue to decline. It concludes that there must be a commitment to desalination, regeneration, savings, and public awareness.
An island without rivers
On this island, where its inhabitants have historically had to engineer solutions to extract water from deep underground, due to the lack of surface streams because of the rugged terrain, the recent drought has further disrupted the situation and limited the recharge of the aquifer.
The reduction in rainfall has had such a significant impact that galleries and wells, which provide 70% of the water consumed in Tenerife, will have reduced their flow by 2033 –just eight years from now – by 60% compared to what they provided in 1985, which is 48 years ago.
The decline is more pronounced if 1965 is used as a reference, when the Island reached the peak of production with 1,500 galleries and wells –currently, 589 galleries and 180 wells are active–, as noted by public works engineer and hydrologist Juan José Braojos in his book Alumbramientos, agotamientos y fracasos. That year marked a record, with subterranean operations extracting 255 hectometres of water (255 billion litres), the volume equivalent to filling 102,000 Olympic swimming pools. By contrast, in 1985 it was 212 hectometres and now it stands at 188.
An aquifer under strain
This water source will be halved by 2033 –meaning reduced to 127 hectometres – according to the projections of the Insular Water Council, signalling that the island’s aquifer is suffering a considerable decline and that the precipitation –becoming increasingly sporadic and erratic– are insufficient for its regeneration.
Thus, the diagnosis from the Insular Water Council is clear-cut. “The trend towards a sustained decrease in the availability of groundwater,” the report explains, “is due to the historical dependence on groundwater abstractions, in a territory with hydrogeological complexities, marked rainfall irregularity, and limited natural recharge capacity.” This progressive reduction of the ‘mana’ from the mountains highlights, according to the CIATF, “a transition towards a water model increasingly reliant on the increase of desalination and reuse.”
Control measures
Nevertheless, the public entity that manages the integral water cycle in Tenerife makes it clear that the conservation of the aquifer “remains strategic”, thus “specific control and protection measures are required, alongside management that ensures the sustainability of the groundwater resource in the context of climate change and increasing demand.”
Tenerife is increasingly thirsty but possesses less liquid. According to the study by the Insular Water Council, the demand is 10% higher than it was 25 years ago, spurred by the rise in population and also the increase in tourists. In fact, by 2033, the year chosen for future projections in the document –as it is the last year of the upcoming cycle of the Insular Hydrological Plan–, the Island will have surpassed one million inhabitants –currently numbering 955,000–, indicating a growth rate of 6,624 people annually. Additionally, there is the influx of over seven million tourists.
Consequently, the total water demand on the Island –for consumption, irrigation, tourism, and industrial activities– is projected to increase from 186 hectometres in 2010 (186 billion litres) to 203.2 hectometres in eight years, a volume that cannot be met with current availability of supplies from deep aquifers, as well as through purification and desalination processes. And herein lies the major challenge if the current system is maintained and measures initiated under the water emergency are reinforced: soon there may not be enough water to meet such demand.
Population, tourists, and agriculture
The CIATF clarifies how this demand is distributed by sector. The population and tourists will consume by 2033 –in proportions very similar to the current ones– 48.2% (98 billion litres), while agriculture and livestock will account for 45.3% (92 billion litres), the industry will require 2.4% (5.4 billion litres), and golf courses will use 2% (4 billion litres).
It also details the sources of this supply, which constitute a unique market globally, primarily due to the expertise of farmers who, over 175 years ago, invested their resources in drilling into the mountains in search of the elusive ‘gold’ of hydrogen and oxygen.
Today, these galleries and wells –which originated from private initiative and remain privately held– account for 70%, while desalination of seawater has increased to exceed 40% and the rest comes from springs and regeneration systems.
Changes to the Water Law
The problem could deepen if the water communities owning these cavities –it is estimated that 20,000 Tenerife residents share the shares of about 200 communities– withdraw their investments in maintaining these activities as the deadline stipulated in the Water Law of the Canary Islands approaches for preserving the concessions. This expires in 2040 –only 15 years from now – and it is then that these galleries and wells will be transferred to public ownership.
In light of the concern that this uncertainty might further diminish their water contribution, as well as the decrease in aquifer reserves due to drought, the Cabildo of Tenerife has initiated the process to request a change in this Water Law –established in 1990– to maintain the private model and extend the authorisations’ duration. The Island Corporation has begun discussions with parliamentary groups to advance a request it deems “vital” to ensure supply in the medium and long term.
Declining water yields
Blanca Pérez, councillor for Natural Resources at the Cabildo, has noted that some communities are already beginning to reduce their investments, which could lead to “decreases in yields that would create a significant problem compounding existing issues affecting this essential resource.
Engineer Juan José Braojos predicts that the continuous decline in groundwater flow will persist in the coming years “as it has been since 1965.” He attributes this to “overexploitation” and “the succession of years with below-average rainfall.” The hydrologist clearly sees, based on the data he has gathered and in his book Alumbramientos, agotamientos y fracasos en los 175 años de historia de las galerías de Tenerife that “the aquifer is not recharging at the same rate as it is being exploited.”
Volcanic ‘intestines’
The pockets contained in the volcanic ‘intestines’ of the Island will only begin to recover, clarifies a researcher who worked at the CIATF, when the percentage provided by water mines to the entire Tenerife supply system drops from the current 70% to around 45-50%.
Even in the hypothetical case that the subterranean operations maintain a high contribution in the coming years, with the consequent risk of accelerated depletion, the upcoming water crisis will compel administrations to increase desalination of seawater. For the 2033 projection conducted by the CIATF, the Island will need 203 hectometres of water (remember that one hectometre is one billion litres), while galleries and wells will have diminished their contribution to 127.
More desalinated water
To meet the demands of the entire population and the productive sectors, desalination plants –Tenerife has five major desalination plants– will have to double their output and increase from the current approximately 40 hectometres to at least 76, which is 36 more.
If this does not happen, the figures will not add up, and there will need to be an increase in savings measures and levels of regeneration, with the latter being a limited solution as that flow is only suitable for irrigating fields and urban gardens.
The measures implemented following the declaration of a water emergency in May 2024 are inadequate. These include the installation of portable desalination units throughout the island –with limited production–, efforts from local and municipal governments to eliminate losses in generally outdated and degraded distribution networks –in Icod de los Vinos, for example, it reaches 60%– and mayoral decrees –especially during summer, when demand spikes– urging the public to make every effort to save water and implementing restrictions such as not filling swimming pools or avoiding garden watering and car washing.
An island declared a water emergency
The declaration of a water emergency, the Insular Water Council reminds us in its report, “requires the implementation of efficiency measures by authorities to ensure potable water supply and preserve water resources, including, if necessary, declaring public utility or social interest whenever the adoption of measures requires the expropriation of goods or rights.”
However, based on the projections from the same report, there is a need to strengthen these actions to be curative rather than palliative. The time frame for reaction is minimal –just eight years –considering, for example, that the estimated time to construct a large desalination plant is five years.
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