The hydrology of groundwater and the flow of surface water do not recognize the international boundary between the United States and Mexico. The jurisdictions of different bodies of law-both among the border states in the United States and between the United States and Mexico-further complicate the problem. Agreements between the United States and Mexico have not kept pace with changes in demand for water both for municipal-industrial use and agricultural use in the border areas. An international conference in La Paz, Mexico, examined some of the most pressing points of friction over wafer in the border area.