Event Recording
The second Coffee Break organized by the Permanent Forum of Binational Waters focused on the urgent and often overlooked issue of transboundary groundwater withdrawals between Mexico and the United States. Moderated by Rosario Sanchez and Gabriel Eckstein, the panel featured Sharon Megdal, Mario López Pérez, Carlos Rubinstein, and Rubén Chávez, all recognized experts on water governance.
Dr. Sharon Megdal opened with a clear assessment: “Groundwater is highly localized and invisible, so what we know varies greatly from place to place along the border.” She highlighted a persistent challenge in binational cooperation: “Mexico often reports water concessions, but not actual groundwater withdrawals, making data analysis very difficult.”
Mario López Pérez added that out of Mexico’s 36 officially recognized aquifers along the border, six are severely overexploited. “We know that in areas like Chihuahua and Sonora, groundwater flow is from the U.S. to Mexico,” he said, noting that while surface water treaties exist, there’s a gap when it comes to underground flows.
Carlos Rubinstein emphasized the ecological consequences: “As we overdraw aquifers hydraulically connected to rivers, we cause base flows to decline. In time, the hydraulic gradient may even reverse.” He stressed that transboundary groundwater withdrawals not only affect binational relationships but also compromise the sustainability of local water systems.
The conversation also addressed legal asymmetries. In the U.S., groundwater rights vary by state, with Texas treating it as private property. “In Texas, if someone told a landowner that the federal government would regulate groundwater pumping, they’d meet him with a well-armed group of friends,” Rubinstein said wryly.
Despite differing views on the necessity of a formal groundwater treaty, there was consensus on one key point: the current framework, including Minute 242 of the 1944 Treaty, is insufficient without cooperation and updated data sharing.
“Transboundary groundwater withdrawals are not just a technical issue; they’re political, social, and institutional,” concluded Sharon Megdal. With over 70 participants engaged throughout, the session made clear that the path forward requires trust, transparency, and local-to-federal coordination.