Peña Nieto’s airport in Atenco and Texcoco poses Serious Threat of Flooding
By Sergio Grajales Ventura
Flooded communal land in the Ejido Nexquipayac, Atenco. Photo: Sergio Grajales Ventura
The construction of the New International Airport of Mexico City (or as known by its initials in Spanish – NAICM) in the towns of Atenco and Texcoco poses a great risk of flooding, not just for the communities in the area, but for all of the eastern part of the Valley of Mexico. Additionally, land subsidence will accelerate, surface run-off will increase and the region’s most important regulatory reservoir, the former Lake Texcoco, would be destroyed.
I. Over-exploitation of water and subsidence
In a previous issues of El Salinero, we reported that in 2001 the Autonomous National University of Mexico’s PUMA programme (the University Programme for the Environment or in Spanish, “Programa Universitario de Medio Ambiente”) predicts that as early as 2020 the new airport and the related urban development in the area will significantly increase the extraction of the groundwater to 50.5 million cubic metres a year (2001:1), which is 23 times more than the amount the Federal Government claims the airport will actually consume. All this despite the fact the Texcoco aquifer is located in an area with strict controls and is considered a priority source of water for the region.
The over-exploitation of the aquifer will not only worsen the shortage of potable water available for our communities, but it will also cause greater subsidence of the ground. The increasing extraction of water from the aquifer causes dehydration of the surface strip of soil (called the aquitard), which consists of a thick layer of clay. This causes a reduction of the volume of the aquitard, in other words, it causes it to compact and therefore the ground sinks.
It is calculated that in the whole of the Valley of Mexico the ground sinks approximately 10 cm each year. In the eastern area, where the former Lake Texcoco is located, the subsidence is even faster, running between 25 and 40 cm annually. This means that every ten years Mexico City sinks a metre and a half on average, and the regulatory reservoir of the former Lake Texcoco sinks between 2.5 and 4 metres (Luege, 2014: 2-3).
This accelerated subsidence causes the drains (which make up Mexico City’s system of surface drainage) to lose their slant, whereas ordinarily the drains’ slant or inclination along with gravity would move large volumes of water from one point to move to another.
This is what has happened to the Churubusco, La Piedad, and Los Remedios Rivers. Previously the rain runoff flowed from the western part of the Valley towards Lake Texcoco, and that flow now only carries a small volume of sewage. Other rivers, like the Río de la Compañía, show such pronounced subsidence that water can only be extracted through the use of an expensive pumping system (Luege, 2014: 5).
Besides these rivers in the West, 11 more rivers flow into the former Lake Texcoco from the East. But since with the over exploitation of the aquifer is causing the ground to sink, ground which is covered with asphalt, this further prevents the replenishment of the aquifer, leading to further sinking.
II. Growing urban sprawl and water runoff
The chaotic development of the Valley of Mexico’s metropolitan area has meant that large areas of agricultural land, forest and flood plains have been covered with an enormous layer of asphalt. What before were areas where rain water could penetrate the ground and recharge the aquifer, now are large expanses of urban areas, waterproofed with asphalt, and where an increasing volume of water flows.
In addition to this, due to the uneven ground, runoffs are directed towards the centre of Mexico City, which has meant that the drain is mainly dependent on costly deep drainage systems.
Considering how urban growth has tended to happen and all that is attributable to the construction of an airport, it is estimated that there will be a significant increase in the total ground area covered by asphalt. This will increase the average annual runoff between 15 and 25% due to the new urban areas (PUMA:1).
III. The importance of preserving the regulatory reservoir of the former Lake Texcoco
When prolonged and heavy storms hit, Mexico City’s pumping system and deep drainage collapse. It is unable to cope with the drainage flow, and various parts of the metropolitan area flood.
The long and heavy rain of tropical storm Arlene at the end of June 2011 exceeded the capacity of the drainage and pumping systems, and caused severe flooding in the eastern part of Mexico City. The only way to prevent catastrophic flooding for the residents of Ecatepec and Nezahualcoyotl was to flood the regulatory reservoir of former Lake Texcoco.
To avoid tragic flooding, the Constitution protects the floodplains of lakes and lagoons as "inalienable and imprescriptible" and the National Water Act declares "natural reservoir of national waters" and prohibits construction or any change to how the area is used.
Ponds, Ejido Nexquipayac, Atenco. Photo: Sergio Grajales Ventura
The federal government has turned a blind eye to all of this. The environmental impact report for the airport project completely omits consideration of environmental risks associated with the possibility of flooding due to wet weather.
And as if this were not enough, the “Unión de Científicos Comprometidos con la Sociedad” states that the report also lacks the technical know-how to demonstrate that the hydraulic works being done to divert the runoff will be enough to prevent the flooding in the area of the new airport and the surrounding communities (UCCS) (UCCS: 11).
In conclusion, building the New International Airport of Mexico City in Atenco and Texcoco will increase the area’s vulnerability to flooding. This will be caused by the rising volume of runoff water, as well as a quickening rate of subsidence, while the regulatory capacity of the reservoir will shrink.
- Córdova-Tapia F., Straffon-Díaz A., Ortiz-Haro G. A., Levy-Gálvez K., Arellano-Aguilar O., Ayala Azcárraga C., Zambrano L., Sánchez-Ochoa D. J. y Acosta-Sinencio S. D. 2015. Análisis del resolutivo SGPA/DGIRA/DG/09965 del proyecto “Nuevo Aeropuerto Internacional de la Ciudad de México, S. A. de C. V.” MIA-15EM2014V0044. Grupo de Análisis de Manifestaciones de Impacto Ambiental. Unión de Científicos Comprometidos con la Sociedad. México.
- Programa Universitario de Medio Ambiente (PUMA), UNAM, 2001. Estudios específicos: Descripciones y predicciones ambientales. Evaluación ambiental comparativa de dos sitios considerados para la ubicación del Nuevo Aeropuerto Internacional de la Ciudad de México (NAICM).
Translated by the UK Zapatista Translation Service