Juan Manuel Núñez, academic of the University Transdisciplinary Center for Sustainability (Centrus) of the Universidad Iberoamericana, sets as an example that it is unknown how much water the aquifer still has and how much it is extracted.
Nor do we have much knowledge of what happens from the level of the ground down of this city. That is, we know that there is the aquifer from which we extract water (…) but we do not know how much water remains, what we know is that we extract more water than we recharge.
Juan Manuel Núñez, academic of Centrus.
Every year it is estimated that the Aquifer of the Valley of Mexico is recharged with around 700 million cubic meters, but an estimated of 1.3 billion cubic meters of water is extracted, according to the article ‘Water in Mexico City’ published in the journal Sciences of UNAM .
The capital absorption plan
This 2025 will be rehabilitation of 93 absorption wells and sinks already existing in the Iztapalapa mayories, Tlalpan, Álvaro Obregón, as well as the construction of six new absorption wells in Tlalpan, Xochimilco and Iztapalapa, in addition to an infiltration dam in Cuajimalpa.
“It is thinking that the city’s body has imbalances and then we will intervene in many parts of the city, where we can infiltrate millions of liters of rainwater,” said the capital’s president when presenting the program on June 30.
Brugada assured that the construction of new infiltration wells will continue in the coming years and that each new work carried out by the Government of Mexico City must have one of these wells, including the 100 utopias it projects to build in its six -year period.
In order for infiltration wells to contribute to recharge to the aquifer a vital factor is its location, says Jesús Campos, vice president of the College of Civil Engineers of Mexico (CICM).
“We would have to study very well where to build those absorption wells because if we do them in areas where they are of clays, the absorption wells will be successful. I think that these absorption wells would have to be in volcanic areas, where water infiltration is facilitated,” explains the specialist.
For this first stage of ‘water acupuncture’ it will allocate around 30 million pesos and when the 100 wells and absorption points are ready.
Each well will have an ability to infiltrate around 25 liters per second, so as all the finished works will be the potential to infiltrate 2,500 liters per second in the city, although the water that is infiltrated will depend mainly on the quantity and frequency of the rains as Mario Esparza, Secretary of Integral Water Management, explained.
The risk in strategy
The aquifer is the source from which it is provided through extraction wells around 70% of the water consumed in the city, while the rest comes from the Cutzamala system.
Absorption wells have the objective of allowing or accelerating water infiltration to the aquifer, especially in areas mostly covered by waterproof surfaces, such as asphalt and cement of roads, sidewalks, houses and buildings.
However, absorption wells can mean a more risk than a solution if the quality of the water infiltrates, warns Luis Zambrano, researcher at the UNAM Institute of Biology.
The researcher explains that “they are like a direct syringe to the aquifer” to reduce the time that the water passes infiltrating to those areas of the aquifer, which can be 200, 300, 600 meters, which can take a long time.
“The absorption wells increase the speed at which the aquifer is recharged, but if that water is contaminated, it is like we are putting our water veins of Chapultepec: the aquifer will be contaminated. Then yes, they have to do very carefully,” says the doctor in basic biology by UNAM.
Therefore, it is necessary to implement continuous standards and evaluations of the quality of the water to be infiltrated during its collection, storage and treatment, says Zambrano.
