TAAP-Transboundary Aquifer Assessment Program

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Collaboration in Binational Research and Engagement on Shared Aquifers

Photo: Santa Cruz River


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TAAP-A/S (Transboundary Aquifer Assessment Program-Arizona/Sonora) is a federally funded program co-hosted by the USGS Arizona Water Science Center in Tucson, Arizona, and the Water Resources Research Center (WRRC) at the University of Arizona. The program originates from U.S. Public Law 109-448, signed by the President on December 22, 2006 as the Transboundary Aquifer Assessment Act.

The Act applies to the states of Texas, New Mexico, and Arizona, where four transboundary aquifers have been designated for priority assessment; those being the Hueco Bolson and Mesilla Basin aquifers in the greater El Paso / Ciudad Juárez region, and the Santa Cruz and San Pedro aquifers across the Arizona – Sonora border (see map). TAAP-A/S is designated to operate for 10 years, with $50 million authorized for appropriation over that time period.

Mexican participation started in 2009, after the signing of the Joint Report of the Principal Engineers Regarding Joint Cooperative Process  United States-Mexico for the Transboundary Aquifer Assessment Program (Joint Report).

 WRRC-TAAP Highlights

Stakeholder engagement activity in Sierra Vista, AZ

Transboundary aquifer reconnaissance work, characterization of selected border communities, stakeholder engagement, collaborative efforts identified through the TAAP Cooperative Framework.

2) Water Balance Modeling Presentation in El Paso, TX

Development of water balance modeling tools to characterize the effects of system changes, particularly related climate uncertainties and changes in groundwater demand.

3) Binational Technical Working Meeting in Nogales, AZ

Participation in binational technical working meetings, publication of journal articles and reports, presentations at regional, national, and international conferences, organization of forums and seminars for improving knowledge on transboundary aquifers.

Arizona-Sonora TAAP Partners



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TAAP News and Events

TAAP Publications

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TAAP-Official Binational Report

The International Boundary and Water Commission, United States and Mexico (IBWC) have completed the Binational Study of the Transboundary San Pedro Aquifer. 


Other Relevant Topics

Additional Information

The views and conclusions contained on this page are those of the authors and should not be interpreted as representing the opinions or policies of the U.S. Geological Survey. Mention of trade names or commercial products does not constitute their endorsement by the U.S. Geological Survey.