Tenerife dries up
Tenerife is drying up. The island is heading towards an unprecedented water supply crisis in the short to medium term unless more drastic solutions are implemented beyond those already adopted following the water emergency declaration on May 29, 2024, which has been repeatedly extended since. This stark warning comes from the Island Water Council (CIATF), under the authority of the Tenerife Island Council, in a report prepared for the drafting of the 2027-2033 Hydrological Plan.
A clear and concerning diagnosis
This analysis, which will form the basis for the document governing the island’s entire water cycle (renewed every six years), clearly and data-richly exposes a critical imbalance: demand keeps rising while reserves keep falling. It concludes that the future must rely on desalination, water regeneration, conservation, and public awareness. On an island where inhabitants have historically had to ingeniously extract water from deep within the earth due to a lack of surface streams caused by its rugged terrain, the drought of recent years has finally tipped the scales, severely limiting aquifer recharge.
The dramatic decline of groundwater
The reduction in rainfall has had such a profound impact that the water galleries and wells, which supply 70% of the water consumed in Tenerife, are projected to see a 60% reduction in their flow by 2033—just eight years from now—compared to their output in 1985, a span of 48 years. The decline is even more pronounced if 1965 is taken as a reference, a year that marked the peak production from Tenerife’s 1,500 galleries and wells (today, only 589 galleries and 180 wells remain active).
As documented by public works engineer and hydrologist Juan José Braojos in his book “Alumbramientos, agotamientos y fracasos” (“Water Findings, Depletions, and Failures”), that record year saw underground extractions reach 255 cubic hectometers (255 billion liters), a volume equivalent to filling 102,000 Olympic-sized swimming pools. By 1985, this had fallen to 212 cubic hectometers and now stands at 188. Projections from the Island Water Council indicate this vital spring will be halved by 2033, to just 127 cubic hectometers—a clear symptom that the island’s aquifer is suffering a considerable depletion and that increasingly sporadic and irregular rainfall is insufficient for its regeneration.
A necessary transition in the water model
The Council’s diagnosis is therefore unequivocal. “The trend of a sustained decrease in groundwater availability,” the report explains, “is a response to the high historical dependence on underground sources in a territory with hydrogeological complexities, marked rainfall irregularity, and limited natural recharge capacity.” This progressive reduction of the mountainous ‘manna’ highlights, according to the CIATF, “a transition towards a water model increasingly supported by the expansion of desalination and reuse.”
Nevertheless, the public entity that manages Tenerife’s integrated water cycle makes it clear that aquifer conservation “remains strategic,” and thus “specific control and protection measures are required, along with management that guarantees the sustainability of the underground resource within the framework of climate change and growing demand.”
Rising demand meets shrinking supply
Simply put, Tenerife is getting thirstier but has less liquid to quench it. According to the Island Water Council’s study, demand is now 10% higher than it was 25 years ago, driven by both population growth and an increase in tourist arrivals. By 2033—the end year for projections in the document, as it concludes the next cycle of the Island Hydrological Plan—the island’s population will have surpassed one million (it’s currently 955,000), meaning it’s growing at an annual rate of 6,624 people. This is in addition to hosting over seven million tourists annually.
Consequently, the island’s total water demand—for consumption, irrigation, tourism, and industrial activities—will rise from 186 cubic hectometers in 2010 (186 billion liters) to 203.2 within eight years. This is a quantity that cannot be met by the current availability from both the deep aquifer and the water generated by purification and desalination plants. Herein lies the major problem if the current system is maintained and the measures initiated with the water emergency are not reinforced: soon, there won’t be enough water to meet the demand.
Where the water comes from and goes
The CIATF breaks down how this demand is distributed across sectors. In 2033, the population and tourists will consume 48.2% (98 billion liters), agriculture and livestock will use 45.3% (92 billion liters), industry will require 2.4% (5.4 billion liters), and golf courses will account for 2% (4 billion liters), with percentages very similar to today’s.
The report also details the unique source of this supply, a system unparalleled in the world, born from the ingenuity of farmers who over 175 years ago invested their own money to begin drilling into the mountains in search of the elusive ‘gold’ of hydrogen and oxygen. To this day, those privately initiated and still privately owned galleries and wells contribute 70% of the water, while seawater desalination has grown to surpass 40%, with the remainder coming from springs and regeneration systems.
A looming legal and investment challenge
The problem could be exacerbated if the water communities that own these cavities—an estimated 20,000 Tenerife residents hold shares in some 200 communities—withdraw their investments in maintenance as the deadline stipulated by the Canary Islands Water Law for maintaining concessions approaches. This deadline ends in 2040—just 15 years from now—after which these galleries and wells will pass into public hands.
Fearing that this uncertainty, coupled with the aquifer’s depletion from drought, will further reduce their water contribution, the Tenerife Island Council has begun the process to request a change to this 1990 law. The goal is to maintain the private model and extend the authorization period. The Island Corporation has initiated talks with parliamentary groups to push forward a request it considers “vital” for guaranteeing medium and long-term supply.
The heart of the problem: overexploitation
Blanca Pérez, the Island Council’s Minister of Natural Environment, has indicated that some communities have already begun reducing their investments, which could lead to “drops in flow rates that would cause a serious problem, adding to others already affecting this basic resource.” Engineer Juan José Braojos predicts the continuous decline in groundwater flow will persist in the coming years “as it has been since 1965.” He attributes this to “overexploitation” and “a succession of years with rainfall levels below usual.”
Based on the data he compiled for his book on the 175-year history of Tenerife’s galleries, the hydrologist sees clearly that “the aquifer is not recharging at the same rate it is being exploited.” The researcher, who previously worked at the CIATF, clarifies that the water pockets contained within the island’s volcanic ‘intestines’ will only begin to recover when the percentage contributed by water mines to the entire Tenerife supply system drops from the current 70% to 45-50%.
The urgent need for expanded desalination
Even in the hypothetical case that underground extractions maintain such a high contribution in the coming years—with the consequent risk of accelerated depletion—the impending water crisis will force authorities to significantly increase seawater desalination. In the CIATF’s 2033 projection, the island will need 203 cubic hectometers of water that year (remember, each cubic hectometer is one billion liters), while galleries and wells will have reduced their contribution to just 127.
To meet the total demand of the population and productive sectors, desalination plants—Tenerife has five major facilities—will have to double their output, rising from the current roughly 40 cubic hectometers to at least 76, an increase of 36. If this doesn’t happen, the numbers won’t add up, and saving measures and regeneration levels would need to be increased, though the latter solution is limited as regenerated water is only suitable for field irrigation and urban gardens.
Current measures are not enough
The measures implemented since the declaration of the water emergency in May 2024 are insufficient. These include installing portable desalination plants across the island (with limited production), island-wide and municipal efforts to fix leaks in often obsolete and degraded distribution networks (losses reach 60% in Icod de los Vinos alone), and mayoral decrees—especially in summer when consumption spikes—pleading with the population for maximum conservation efforts and imposing restrictions like banning pool filling and avoiding garden watering or car washing.
The Island Water Council’s report reminds us that a water emergency declaration “implies the implementation of efficiency measures by authorities to guarantee drinking water supply and preserve water resources, including, if necessary, declaring public utility or social interest should the adoption of measures require the expropriation of assets or rights.” However, based on the report’s own projections, these actions must be strengthened to be curative, not just palliative. The timeframe for reaction is minimal—eight years—especially considering that the estimated time to build a large desalination plant is five years.
