IWRA Proceedings

Water management and water security

• Groundwater dependence in the border region known as Ambos Nogales
• Santa Cruz River flows depend on precipitation events and, in some portions, effluent flows
• Different water management regimes on the two sides of the border and lack of a binational water management framework, though good cooperation through the International Boundary and Water Commission.
• Within the region, there are shallow groundwater basins, where recharge and water in storage are highly dependent on changing precipitation patterns and pumping regimes
• Binational effluent collection, outflows, and recharge are of importance but beyond the scope of this presentation

Two projects in this US-MX border region

• Transboundary aquifer assessment study (TAAP)
  • Federal-university partnership
  • US State of Arizona and Mexican State of Sonora
  • Santa Cruz aquifer is one of the two aquifers for which binational reports are in final stages of preparation
• Project funded by U.S. National Oceanic and Atmospheric Administration (NOAA), Groundwater, Climate and Stakeholder Engagement (GCASE)

Concluding Remarks

• Additional work is being done on groundwater scenarios on the US side of the border in collaboration with the Arizona Department of Water Resources
• Groundwater management in the U.S. is under the jurisdiction of the U.S. states, so any approach to binational management requires federal and state cooperation
• Potential for the GCASE approach to be applied in Sonora, Mexico
• The transboundary aquifer assessment report will provide binationallyagreed upon baseline information
• In the US, there is increasing understanding of the role of groundwater in meeting water needs and that drought is a serious concern
• These concerns should be recognized for groundwater-dependent communities, both large and small