In Mexico, there is no specific policy for the governance of transboundary groundwaters. In fact, these groundwaters have been governed almost entirely from a national-domestic perspective with disregard for transboundary groundwater flows. This article analyses the links between water and political power in the management, administration and allocation of groundwater rights; the State has developed different instruments to politically control water, imposing a clientelistic policy approach to its distribution. From 1948 to 2018, more than 100 legal decrees on groundwater management were passed. These decrees are marked by scientific limitations in relation to the management of groundwater, but have allowed the State to control these waters, and to implement a policy framework for the allocation of water rights. In this context, the article examines the links between “aquifers”, and the practice of “free pumping” to analyse Mexico’s groundwater rights policies. It concludes that the State enforces its control over the allocation of groundwater rights e through a rhetorical discourse that has scant consideration for the crucial challenge of ensuring groundwater preservation and has never given specific consideration to transboundary groundwaters.