Abstract

Dispute settlement over groundwater issues is hampered by the fact that groundwater is not discussed in existing bilateral treaties between Mexico and the United States, whereas aquifers frequently span the border zone. Accurate, international data on groundwater resources and dynamics are therefore needed to assist formulation of binational groundwater policy, particularly in the Colorado River delta region. We present InSAR measurements of vertical surface displacements above the Mexicali Valley aquifer, using these as a proxy for aquifer depletion and recharge events. We anticipate the use of archived ERS SAR data will allow characterization of aquifer behavior across the border zone over the past decade, whilst recent ENVISAT ASAR acquisitions will reveal changes due to both the the proposed lining of the All-American canal and the federal reductions in Colorado River surface water allocations to urban and agricultural California consumers.