In the last fifty years, Tenerife It has been enduring an increase in the average temperature throughout its surface, as well as a progressive decrease in rainfall. The Third Cycle of Hydrological Planning 2021-2027 of Tenerife confirms the overexploitation of aquifers and the decline in the quality of the groundwater masses on the island.
Between 1985 and 2016 the joint flow of the island’s tributaries fell by 30 percent, going from 212 to 150 cubic hectometres per year. Faced with this water uncertainty, the Cabildo de Tenerife, through the public company Balsas de Tenerife (Balten), It has promoted the use of reclaimed and desalinated water to guarantee the supply of agricultural irrigation on the island in quantity, quality and price.
“Since 2019, the year in which we began the current mandate, we have carried out a total of 32 actions in different parts of the island, with an investment that exceeds 8.3 million euros, to bring quality water to the entire primary sector of Tenerife”, explains the Island Councilor for Agriculture, Livestock and Fisheries, Javier Parrilla. Reclaimed water actually exceeds 55 percent of the supply for agriculture on the island, “which demonstrates the wisdom and importance of continuing to invest in purification and desalination to give greater stability and quality to the supply.”
In this sense, Javier Parrilla points out that it has managed to triple the irrigation water supply capacity in the municipalities of Vilaflor de Chasna and San Miguel de Abona, and double it in other points, such as Valle de Guerra, Tejina or Tegueste, thanks to the release of white water in the upper area of the island due to the introduction of reclaimed and desalinated water in the lower areas.
“We have improved transportation or brought new pipelines to points in need, such as pumping reclaimed water from the Board, in Santa Cruz, to the Valle Molina raft, in Tegueste; pumping reclaimed water from the Pedro Ayerra WWTP (Valle de Guerra) to the Valle Molina pond; the installation of support pumping for the supply of water from Cruz Santa to the Benijos pond or the commissioning of the Tamaimo canal to provide water in Lomo del Balo”, Javier Parrilla abounds.
It should also be noted the conversion of the Valle Molina pond, the first in the north of Tenerife that offers reclaimed water to farmers throughout the Northeast region at a lower price than before; the re-impermeabilization of large ponds, such as the one in Benijos (La Orotava) and the one in Llanos de Mesa (San Juan de la Rambla); or the repair of the Santa Cruz Arona reclaimed water pipe, an essential infrastructure to guarantee the supply of irrigation water to the south of the island.
Looking to the future The Balten infrastructure is made up of 21 irrigation ponds (with a total storage capacity of more than 5 cubic hectometres), three desalination plants with EDR (reversible electrodialysis) technology, plus 1,500 kilometers of pipes, three wells and a gallery of underground water. In 2022, almost 20 million cubic meters of water were supplied to more than 11,500 paying customers, of which 11 million were reclaimed water.
Currently, the Cabildo is working on the expansion and improvement project of the Isla Baja desalination plant, which has a budget of 2.6 million euros; in the re-waterproofing of the Montaña de Taco reservoir, in Buenavista del Norte (1.7 million euros), in the extension of the desalination plant for treated water in Adeje-Arona, and in the commissioning of the desalination plant for brackish water from El Reventón, after signing the agreement with the Insular Water Council.
Therefore, Tenerife is immersed in a change of model. The use of reclaimed water not only responds to the growing water demand of the agricultural sector, “with sanitary and agronomic quality criteria that meet the most demanding standards”but also brings environmental benefits, helping to promote the circular economy “and freeing up quality water for the most demanding uses, such as the production of drinking water”.
Javier Parrilla also emphasizes that it is a transversal model change, which has been accompanied by the modernization of remote control and surveillance systems, digitalization in water management, and energy efficiency, through the implementation of renewable energies at the Balten facilities. “The increase in energy costs in recent years has forced us to adopt urgent measures to avoid jeopardizing the production and supply of water,” says Javier Parrilla.
In this sense, remember that this year a game of 3.5 million euros is planned to balance the cost of irrigation water and not raise the price of water for farmers. With regard to renewable energies, the Cabildo has launched the Balten Energy Rebalancing Plan, endowed with 1.5 million euros, making Balten the first company in Tenerife to decarbonise water.
