The council commitment to reclaimed water to progressively replace that emanating from wells and galleries as the basis of consumption on the Island. Underground lighting today accounts for 78.2% of the volume and the goal is to reduce it to 65% in 2027. The reasons are mainly economic.among other things because each time you have to drill further down to reach the water table where the liquid element appears.
Tenerife is a peculiar space in terms of the water source. Thinking of supply infrastructures is equivalent to imagining rivers and dams, the surface flow. But On an island with a steep slope, there are only ravines that do not exceed, the longest, 20 kilometers.
It is not visible, but 78.2% of the resources consumed on the Island are of underground origin. Of the water that flows, 64% comes from galleries and 36% from wells.
The rest is obtained from the desalination of seawater and the reuse of residuals for agricultural use. In the whole of Spain, the average water of underground origin is 23%, according to data from the National Institute of Statistics (INE), from the year 2016.
Javier Rodríguez Medina is the island councilor for Sustainable Development and the Fight against Climate Change. He explains that “our Island maintains a peculiar situation due to the specific weight of groundwater as it is a pioneer territory in taking advantage of underground resources.” In fact, they exist in the 31 municipalities of the Island. The latest census, released last April, reflects a similar scenario to the previous ones: atomization and an already “perforated” island with few options to increase surface area.
Rodríguez Medina recalls that «There are 1,200 galleries in our subsoil but only 478 illuminate water; the rest are dry». In addition, those that illuminate an outstanding flow, more than five liters per second add up to just 149, 29% of the total ». The counselor adds that “that 29% represents 79% of the total waters.” Demonstration that it is a scarce good. Only 21 galleries flow more than 25 liters per second, 39% of the total flow. A reference is that of Vergara, in the municipality of La Guancha, where “unlike in others, it has not had to be re-drilled over the years,” details the counselor.
Of the total of 1,200 that perforate practically the entire subsoil of the Island, only 478 springs water. Of these, only 149, 29% of the total, with a powerful usable flow.
The analysis of the wells shows similar results. They only light water, 145 of the 400 total. And more than 25 liters per second, only 8. Rodríguez Medina explains: «The wells are located on coastal strips, below the 500 level, with exceptions such as the Rodeo de la Paja, in La Laguna».
The counselor emphasizes: «The period of massive drilling was the 60s and 70s of the last century. It must be borne in mind that the water table, the point where the water is, has been gradually declining. The trend is downward.”
The council’s roadmap, says Rodríguez Medina, “goes through reclaimed water for the agricultural sector with the idea of giving residual water a second life.” He considers that “in this way we achieve a double objective by uniting having quality water with stopping dumping waste into the sea.” He gives the example of the Güímar Valley Water Treatment Plant, included in a plan that should cover a good part of the island. Right now two are being worked on, the one in La Laguna and the other in Güímar.
Rodríguez Medina concludes with the mention of the objective: «In 2027 the current almost 80% of groundwater will drop to only 65%».