Putting an end to or minimizing the recurring water losses in municipal networks will involve developing a plan, following a report from the town councils. This is the main comprehensive measure, together with optimizing agricultural irrigation, as well as the desalination plants and treatment plants in progress to alleviate the drought affecting the countryside in Tenerife, which led to the declaration of a water emergency this month. Javier Davara, manager of the Insular Water Council, an entity under the Island Council, details the proposed initiatives. Among them, the most prominent are the 34 hydraulic projects to be promoted – with a total value of 420 million Euros – or the 14 actions to balance supply and demand. Davara predicts: “We do not foresee water cuts from the tap next summer.” He points out that “the particularities of an interconnected system for all uses, supply, and irrigation must be taken into account.”
The manager of the entity in charge of managing the water emergency declaration due to the drought on the island clarifies concerning possible restrictions on human consumption that “may occur at some point in high areas or with lower pressure, as happened last year in the La Laguna area during heatwaves, but without cuts in human supply.”
Valued by an expert in the comprehensive water cycle who says that “in an emergency situation like this, you can not only act from the supply side to generate more, but also from the demand side” because “the more in the market, the more will be consumed if you do not implement tariff measures or promote savings because no matter how much you produce, it will never be enough.” He notes that “the initiatives taken are aimed at this.” David points out that “it seems that there has been an improvement in irrigation efficiency in recent years, there is no longer blanket irrigation but only drip or sprinkler irrigation.” One key aspect would be to reduce demand, not for basic needs, but for optimization.
It is also essential, and another aspect of the problem in Tenerife, to alleviate water losses in municipal networks. “The councils know what they need to do, but they must roll up their sleeves or seek help to undertake the task,” emphasizes Davara. He appreciates that “major municipalities have minimized losses in recent years, but in small ones, they are high, and other mediums like Icod acknowledge that they reach 50%”. Therefore, he explains, “we have requested reports from the town councils.” Based on these reports, a plan will be designed that will allow, hand in hand with the local government and with private companies providing indirect management assistance, to mitigate or eliminate these losses.
Davara does not believe that the tourist sector’s consumption plays a key role in the drought. On the contrary, he believes that the 21 cubic hectometres out of the total demand of 197.2 are manageable. He concludes; “It is supported by desalination plants and regenerators, meaning that as long as there is energy, there will be water.” He adds that in many cases, “they are self-sufficient.” Ideally, they would be able to achieve this with renewables.” One worrying fact is the demographic growth in recent years. The consumption of white waters (groundwater) plus regenerated ones remains within the historical range of 2010-2020, “but everything may have changed in this last period.” Davara remembers engineer Juan José Braojos, “who was a colleague,” and “estimates that the aquifer will remain and stabilize around 100 cubic hectometres.” This “with normal rainfall levels that have not been present in recent years.”.
The declaration of a water emergency in Tenerife due to the lack of rain and the scarcity of water for farmers and breeders is currently highlighting the issues faced by the island, including the aforementioned losses in the public network and the failure to complete infrastructures. Javier Davara focuses on the solutions and details the main projects to be tackled to alleviate the island’s water needs among the 34 scheduled.
Desalination plants. In addition to portable modules to be distributed across the region, expanding three desalination plants will allow a leap forward in the short term. Desalinated water represents only 40 cubic hectometres out of the total production of 198. Groundwater (wells and galleries) still accounts for 140 – with the annual consumption in La Laguna being around 9. The key infrastructure includes the plants in Granadilla de Abona, Adeje-Arona, and Fonsalía (Guía de Isora). It is also noteworthy in this area the expansion of the Metropolitan Desalination Plant of Santa Cruz.
Regenerated water. Regenerated water is “the great white hope.” Primarily for irrigation in the countryside. Currently, it represents only 17 out of the 198 cubic hectometres of supply. Crucial in this regard is the completion of the expansion of the Santa Cruz Treatment Plant. It will double the current 20,000 cubic meters per day – with the same amount being lost in the sea – to carry water to the south. Two infrastructures have been completed and are starting to bear fruit. On the one hand, the one in Valle de Guerra, in La Laguna, completed in 2019, although in full operation since 2022 supplying the Northeast (Aguere Norte, Tegueste, and Tacoronte). On the other hand, the expansion of Adeje-Arona completed this year. Javier Davara hopes that three more will be delivered in 2024: those in Güímar (April-May); Los Letrados, in Granadilla, very important to end discharges in El Médano, and the Western one, from Los Gigantes to Playa San Juan. In these last two cases, delivery to the Council is expected in July.
Supply-demand balance. The design of actions to balance supply and demand outlines fourteen proposals, focusing on improving water use efficiency by agricultural operations. Firstly, incentivising the installation of irrigation systems adapted to the limiting conditions of the supply. Also, promoting audit campaigns on farms to identify possible leaks or ensuring the best management of irrigation facilities through training programs. Another measure is to adapt irrigation to the soil’s water retention capacity to avoid losses. The aim is to promote automation for this purpose.
Ensuring irrigation according to the specified doses in the weekly recommendations provided by the technicians is essential. Specific and personalised support and advice on irrigation and its efficient management by the Irrigators Office are crucial.
The declaration conditions the granting of public aid for irrigation to the compliance with commitments, control practices, and audits of the facilities, or providing agricultural aids for the automation, monitoring, sonorization, and techniques that reduce evaporation. Other objectives include controlling the appropriate use of irrigation water supplied by public networks, urging detailed study of mid-range agricultural consumption, training campaigns on the management of reclaimed water in anticipation of the imminent expansion of the island network, or providing aid for the conservation of mid-range cultivated biodiversity at high risk of erosion due to drought, mainly potatoes, temperate fruit, cereals, and native legumes.
It also proposes the analysis of public prices for irrigation water and the study of a tiered tariff structure based on irrigation efficiencies.
Finally, municipalities are urged to establish regulations aimed at the rational use of the population’s water, avoiding non-priority uses such as hosing down streets, facades or sidewalks, filling pools, washing vehicles on public roads, etc.
Foundations of the drought: On the 1st of this month, the plenary session of the Tenerife Island Council approved the declaration of a water emergency on the island due to drought. It was subsequently ratified by the Board of the Insular Water Council. The basis of the decree lies in several articles of the Water Law of Canary Islands and the Hydraulic Public Domain Regulation. Specifically, articles 107 of Law 12/1990 and 106 of Decree 86/2002 of the Regulation clarify that in the event of a severe decrease in available flow rates or water reserves, caused by foreseeable transitory circumstances endangering the production and water supply of an island or area, the Insular Council may declare a state of emergency for the entire area or a part of it for a specified period (six months), which may be periodically extended as required. Furthermore, article 197 of the Hydraulic Public Domain Regulation states that once the state of emergency is declared, the Insular Council may make water allocations to specific uses and areas; impose forced sales to certain recipients at the approved price; establish forced transfers; resort to the exploitation of unprofitable facilities; and order the use of stored water and other measures to ensure the necessary water availability. Any specific damages caused by its actions will be compensated according to the legislation on compulsory purchase.
If the emergency leads to water shortages or the drought is exceptional, the Council may impose restrictions on water consumption without prejudice to immediately implementing the extraordinary measures needed to ensure the minimum necessary for sanitary and domestic uses, which will be taken in coordination with Civil Protection.
The Insular Council may take the necessary measures to overcome this situation, regardless of the water rights title.
