Overexploitation of water in San Miguel
By Jesús Ibarra
The main water source for the municipality of San Miguel de Allende is the Laja River Upper Basin, also known as the Basin of Independence, which supplies the municipalities of San Miguel de Allende, San Luis de la Paz, Doctor Mora, San Diego Union, San Felipe Torres Mochas and Dolores Hidalgo and is a tributary of the Lerma-Chapala Basin. The Laja River is the main waterway of the Basin of Independence, and its only egress is controlled by the Presa Allende, located in our town.
In a lecture offered at El Charco del Ingenio, Dr. Marcos Adrián Ortega, a researcher at the Mexican Institute of Geosciences, said that currently the Basin of Independence supplies 3,000 wells, of which 1,500 should not have been drilled because they are causing surface water depletion of the aquifer. Most of these wells are used for agriculture. Ortega showed through graphics that surface irrigation in the area increased from 10,000 hectares in 1960 to 60,000 hectares in 2000. In the 1980s, there were only 1,000 operating wells supplied by the aquifer, a figure that by the beginning of the twenty-first century had tripled. He also said that currently 1 billion cubic meters of water per year are extracted from the aquifer.
Dr. Ortega explained that while surface water is being depleted from overuse water from deep in the ground rises to the surface and is already being consumed in several communities of San Miguel, Dolores Hidalgo and San Diego de la Unión. This water is more than 10,000 years old and has reached great depths, so it has been in contact with subsurface volcanic rock, which has increased its concentration, above permissible levels for human consumption, of fluoride, arsenic and sodium.
Dr. Ortega says we cannot repeat past strategies to resolve this issue but must look to new solutions that incorporate knowledge and understanding of the theory of systems of groundwater flow, which Mexican authorities, at all levels, have not yet understood. “Groundwater is part of the hydrological cycle. This basin has been exploited for 60 years, and the water level of the aquifer is down by half, and it may continue to decline. Restoring the aquifer may be out of human reach. The water that filters into the aquifer during one year only raises the water level one meter, so we can see that the aquifer is no longer being recharged. Drinking water is not going to run out, but the problem will be costs and extraction techniques. Industries and agriculture will tend to disappear,” said Ortega.
The spring of La Cieneguita
The spring located in the community of La Cieneguita, known as “Los Lavaderos” (The Washing Places) is one of the most important sources of water that still exist in the municipality of San Miguel de Allende, both because of its perennial flow and thermal qualities and for the water it has supplied for centuries to the people of the community and surrounding areas. It is a place of recreation for families, where people go to swim or have picnics and women go to wash clothes. According to the opinion issued by the Geosciences Center of UNAM and conducted by Dr. Ortega, the spring of La Cieneguita represents “an ecosystem that has been part of the Otomí culture for hundreds of years and has gradually been disappearing by the overharvesting of the Laja River Upper Basin,” which requires immediate protection.”
Currently, the residents of La Cieneguita are waging a battle to defend their natural heritage, represented by its spring. On December 18, 2012, a deep well was drilled on a tract of land located on Prolongación Lázaro Cárdenas 5, in the same community, just 40 meters from the spring. Some residents said the well is 200 meters deep. According to the Geosciences Center, the well could significantly reduce the discharge of water to the springs, reducing its flow and causing their gradual disappearance. According to this opinion, this well, like two others operating in the area, was drilled too close to the spring. The neighbors say that the well is being used for domestic purposes, but with the water that runs off two fields of alfalfa are being irrigated, and since it has been operating there has been a reduction in the rate of flow.
The inhabitants of La Cieneguita, supported by the Observatory Group on Water and Sanitation in San Miguel de Allende (GOTAS), have gone to the authorities, in this case the National Water Commission, delegation Guanajuato (CONAGUA), requesting an order to stop the operation of the well. The response they received was that the owner of the well, a foreigner, has a drilling permit issued by CONAGUA itself, dated June 14, 2012. According to GOTAS, the well concession, by which the owner requested the drilling permit, belongs to a well in Acámbaro, Guanajuato, located in a basin and aquifer “completely outside the Laja River Basin, in which La Cieneguita is located.”
Despite the responses by the authorities, the residents of La Cieneguita do not intend to give up and will continue fighting to preserve their natural heritage. According to one of the residents, the new authorities of CONAGUA are reconsidering the previous response because they found irregularities in the well permits.