The water cycle has undergone great changes in Tenerife in recent years. Of the traditional wells and galleries –without this private system, unique in the world, disappearing– there has been a planned development of desalination plants, to convert salt water into fresh water, and treatment plants, to take advantage of wastewater. They are cheaper than underground processes, although 84% of drinking water continues to come out of the bowels of the earth. The regenerated for irrigation will go from 40% in 2019 to 100% in 2024, a large increase in five years thanks to the construction of 12 treatment and desalination plants throughout the island. But it has a cost. Energy costs have risen 40% in the last year. To deal with it, council promotes a shock plan endowed with five million euros.
This new economic injection was announced yesterday by the island councilor for Sustainable Development and the Fight against Climate Change, Javier Rodríguez Medina, in the presentation of the area’s balance on the occasion of the world water day, which is celebrated today. “Of course the increase affects us,” he explains, “because of its significant impact on the electrical consumption of sanitation or treatment infrastructures.” He encrypts the increase “around 40%” in the last year. Thus, he assures that “it has gone from 11 million euros in the initial forecast to 18.9.” For this reason, he advances, “we will inject an extraordinary five million euros to mitigate the increase in the rise in electricity rates in the infrastructures integrated into the integral water cycle.”
Treatment and desalination plants.
Rodríguez Medina, together with the manager of the Insular Water Council (CIATF), Javier Davara, announced that until 2024 they will invest in water treatment infrastructures. sewage water more than 250 million euros. The counselor points out – “and it is not a commitment but a reality” – that in that horizon of 2024 the Island will have 12 treatment and desalination plants completed and in operation. Five are already built, as many others are under construction and two are in the pipeline. “That compared to the only four that existed in 2019,” says Rodríguez Medina. The Insular Water Council will then have the capacity to treat 100% of the wastewater generated on the Island (63 cubic hectometres per year) compared to 40% in 2019 (25). They will be both urban and industrial purification and regeneration systems throughout the Island.
“This government team of the Cabildo understands that the unfavorable situation of discharges along the coast could not be maintained,” explains the counselor. It has been the cause of numerous sanctions from the European Union for not complying with the regulations. “Hence the firm commitment to regeneration to transform this residual water into regenerated and usable water, for example, in the primary sector.”
The manager of the Insular Water Council, Javier Davara, points out, for his part, that “the island’s treatment capacity will increase by 150% in five years and there will be a large amount of reclaimed water which will come to cover the deficit of the coming years due to the decrease in the production of the galleries». Among these systems, the extensions of the Urban Wastewater Treatment and Regeneration Stations of the Northeast, Valle de Güímar and Adeje-Arona and the industrial ones of La Campana and Valle de Güímar have already been completed. These works have involved an investment of more than 66 million euros.
Under construction are the Santa Cruz Treatment Plant (32 million), the Arona-Este San Miguel (79, including collectors), Granadilla (36.9) and the Oeste station and collectors (31.7 million), in addition to the industrial wastewater treatment plant in the Polígono de Granadilla (2 million euros). They will be able to treat a total of more than 110,000 cubic meters of wastewater per day. The project includes the station and collectors of Valle de La Orotava and the collectors and installation of Acentejo; Both projects will exceed 60 million euros On the other hand, the Insular Water Council will include twenty audiovisual pieces on its website on water management on the Island from a historical and technical point of view starting tomorrow for World Water Day. These videos can be seen at www.aguastenerife.or.
The 21 rafts of Tenerife, the second of the three legs of the water cycle –along with the purification and the wells and galleries– are in good health. As of yesterday they were at 67% capacity. Of a total of 5,006,131 cubic meters, the occupied volume was 3,350,426, an amount comparable to the water in 1,340 Olympic swimming pools. The excellent data from the North stands out, 59%, with 2,032,705 cubic meters of 3,434,541 capacity. This despite the fact that right now there is a pond in the process of being emptied, the one in Benijos, and another that is being filled with reclaimed water, the one in Valle Molina in Tegueste. The balance of the south, with less capacity, also shows a positive balance, with 84% filling. It accumulates 1,317,720 cubic meters for the 1,571,590 capacity.
Wells and galleries.
The vast majority of the water from treatment plants and ponds is intended for irrigation and, therefore, for agriculture. Drinking water continues to be extracted as is traditional from galleries and wells, a private market with a unique system in the world. Specifically, 84% compared to 16% that comes from desalination plants. Remember the porosity and permeability of the soils of the Island due to its volcanic nature. Hence, much of the rainwater filters into the subsoil, where the ingenuity and effort of the people of Tenerife have managed to access to capture these underground flows. Rainwater and moisture that condenses percolate through the soil and reach aquifers in the basal complex. These large underground pockets of water are the key to survival as they guarantee the water supply to the population. Of the total precipitation, 54% returns to the atmosphere in the form of evapotranspiration and 2% goes to the sea as surface runoff; 44% infiltrates, a fairly considerable amount and much higher than that of other islands, such as, for example, Gran Canaria, where only 19% infiltrates. With data from the Insular Water Council of 2020, 84% of the water consumed in Tenerife comes from the more than 2,200 kilometers drilled between galleries and wells. There are about eleven dams throughout the island territory, although with a residual capacity. Most of the drinking water comes from the 1,527 excavations in the subsoil to obtain it (1,126 galleries and 401 wells), of which 40% (478 galleries and 145 wells) supply water. They provide the aforementioned 84% of the resource and contribute an average of 141.34 cubic hectometres per year. 65% of the illuminated water comes from the galleries and 35% from the wells. The rest of the potable water, 16%, comes from the desalination plants. Four are the largest on the island: those of Santa Cruz and Adeje-Arona each produce 30,000 cubic meters a day, an amount comparable to the water in 12 Olympic swimming pools, as well as those of Granadilla and Fonsalía, 14,000 cubic meters. There are some 180 water communities in 27 of the 31 municipalities of the Island.
Counselor Rodríguez Medina explains that “in the galleries the energy cost is not excessive because the rise in water from the water table (the point of contact with the aquifer) is basically due to the effect of gravity.” However, in the wells there is an increasingly higher cost. Rodríguez sentences: «Historically it represents up to 60% of the global electricity bill. Now even more.”
The first Tenerife Island Hydrological Plan It dates from 1997. Currently, the so-called Second Cycle Plan 2014-2021 is in force and the third cycle Plan, corresponding to the 2021-2027 period, is on public display. The Insular Hydrological Plan analyzes consumption and studies ways to increase water production. The main sector of this consumption is agriculture, followed by the supply needs of the population. The first desalination station began operating in the south of the island in 1998. Tenerife also has plants to improve the quality of groundwater.
The Cabildo, through the public company Balsas de Tenerife (Balten), is organizing today, on the occasion of World Water Day, a conference on energy efficiency and digitization in water management. Eight professionals from the sector will discuss and present strategies for the optimization and improvement of hydraulic efficiency, as well as the existing link between water and energy. The island councilor for Agriculture, Livestock and Fisheries, Javier Parrilla, highlights the importance of this initiative, which aims to raise awareness of the importance of water and its responsible management. The head of the primary sector recalls that Balten’s energy costs have multiplied in recent years. From 2.5 million euros in 2020 to 5.5 in 2021. This year, in addition, the forecast is to exceed 6.8 million, so “we have decided to assume the extra costs, estimated at 1.3, with our own resources ». Parrilla also values the investment of 1.5 million for renewable energy projects in Balten’s own facilities.