The Mayan Aquifer, an enigmatic underground world

The Mayan Aquifer, so named because it underlies a region in which the Mayan civilization developed for a long time and is still inhabited by its descendants, is one of the largest aquifers in the American continent. It is also one of the aquifers that contains the most enigmas, both due to its intricate underground configuration and the history of the peoples that inhabited the region where it is located.

This aquifer system covers some 400,000 km2 in southeastern Mexico, northern Guatemala, Belize and surrounding coastal strips.

It is a karstic aquifer, which means that it is contained in the fissures and hollows of limestone that were deposited in the Cenozoic (20 to 50 M years ago) in the Yucatan Peninsula and adjacent coastlines and that later underwent dissolution processes forming networks. of caves, caverns and open fissures that after being flooded by waters, both rainy and coastal, today constitute an aquifer system that presents hydrological continuity. These cave systems are especially developed under the Yucatan peninsula, in southeastern Mexico,

After the caves have been formed, processes of dissolution of carbonates can continue to be experienced, particularly in the ceilings of the caves with frequent collapse of the ceilings, forming uncovered cavities, which often contain water and which receive the generic name of sinkholes, but in Yucatan They are called “cenotes”.

In the Yucatan peninsula, in southeastern Mexico, there are about 6,000 cenotes formed in this way.

It was precisely in the subsoil of the Yucatan Peninsula that an important underwater exploration has actually been carried out in the caves and cenotes that I mentioned earlier.

The director of the Great Mayan Aquifer Project (GAM) Guillermo de Anda stated: "We knew that there was a natural aquifer under the Peninsula that includes the states of Yucatan, Campeche and Quintana Roo, but one of the missions was to first characterize it with a name and the discoveries we have made is that its extension is much greater than what we thought, are thousands of kilometers of caves flooded with fresh water.”

In this investigation, the connection of two large cave systems called Sac Aktún and Ox bel was found, giving rise to the longest flooded underground system in the world, 379 kilometers long,"

It should be noted that currently this aquifer and its cenotes constitute the only means of water supply for the entire Yucatan Peninsula, with a population of 5 million inhabitants.

The main field of wells for the supply of drinking water is located in the vicinity of the city of Mérida, which is the capital of the state of Yucatán, with 1.3 million inhabitants.

The supply is carried out through a plant called Mérida I, located south of the city with a total of 25 extraction wells with a depth of 40 meters.

  The karstic characteristics of the groundwater of the Maya aquifer make it very vulnerable. This occurs because the fractures, dissolution channels and the presence of caverns allow rapid infiltration of contaminating elements that infiltrate or percolate from the surface.

In the surroundings of the Mérida I plant, it is where the greatest consumption takes place, the use of land is mainly agricultural and livestock, so the uncontrolled use of agrochemicals and the inadequate disposal of livestock waste are the potential sources of contamination. of groundwater.

"Because there is human occupation in the Yucatan region more than 10,000 years ago and in particular because the Mayan culture developed for three thousand years, which was an organized society, relatively dense with urban centers of some importance. For this reason, there are abundant archaeological remains in the region, in many cases within the cenotes themselves, even underwater in flooded cenotes.

Currently most of the cenotes are unexplored.

Through the investigation that we mentioned before when exploring the cave systems, there is also the possibility of entering an unknown part of the history of what is also known as the Mayan "underworld".

In their tours of underground waters, the group of speleologists, archaeologists and hydrogeologists found places where no human being had been for thousands of years.

The members of the team dive through the underground currents and with special equipment take images of the remains that are found that will form part of a virtual museum of the aquifer.

However, as the Director of the Project, Guillermo d Anda pointed out, until now the explorations of the Aquifer "remain on the shore, there is still a world to explore.