Project members: Thomas R. Rüde, Lisa Krienen, Timm Reisinger

Groundwater is the only water resource on the Mexican Yucatán Peninsula. But it is endangered by different hazards: a rising need of water in tourist regions, the lack of possibilities to drain off waste water via rivers but instead injecting them into deeper, saltier parts of the groundwater zone and a high vulnerability of the aquifer because it is not covered by impermeable layers.
In cooperation with the Mexican universities of Yucatán and San Luis Potosí, the groundwater of Merida, the capital of the federal state of Yucatán, is probed and a groundwater surveillance system has been installed. Moreover, inner- city areas with a high danger of contamination for the groundwater were detected and can now be surveilled in a more efficient way.

By studying the groundwater situation of Merida, big changes with regard to sustainability were made. The rise of salty groundwater was stopped by relocating the water production areas. Now, more water is seeping into the aquifer than is pumped out. However, this seepage water is of bad quality and the underground is polluted by faecal bacteria from the household waste water. These are big challenges for the groundwater protection.

The groundwater flow direction under Merida is pointing north towards the coast and the coastal mangrove woods. Here, the groundwater is discharged via several springs. These spring waters contain a significant amount of nutrient, nitrogen and phosphor which is brought into the mangrove ecosystem. The results of the studies are provided to the local water authority to support their projects.