Transboundary Aquifer Assessment Program

The Texas Water Resources Institute is the responsible institution for implementing the 109th Congress of the United States “United States-Mexico Transboundary Aquifer Assessment Act” signed in 2006 as Public Law 109-448 along with its partners of the States of Arizona and New Mexico. In 2009, this law led to the 2009 signing of the “Joint Report of the Principal Engineers Regarding the Joint Cooperative Process United States-Mexico for the Transboundary Aquifer Assessment Program,“ under the umbrella of the International Boundary and Water Commission (IBWC), and the authority and framework under which personnel in the United States and Mexico could jointly study shared aquifers. 


U.S. Geological Survey

James Callegary, Ph.D.
Arizona Water Science Center
(520) 670-6671 ext 294

Anne-Marie Matherne, Ph.D.
New Mexico Water Science Center
(505) 830-7971 

Andrew Robertson
New Mexico Water Science Center
(505) 830-7975

Andrew Teeple
Texas Water Science Center
(512) 927-3560

International Boundary and Water Commission

Gilbert Anaya
United States Section
(915) 832-4702

New Mexico Water Resources Research Institute

Sam Fernald, Ph.D.
(575) 646-4337

University of Arizona Water Resources Research Center

Sharon B. Megdal, Ph.D.
(520) 621-9591

Texas Water Resources Institute, Texas A&M University

Rosario Sanchez, Ph.D.
(979) 862-6996


For additional information about the TAAP program, go to https://webapps.usgs.gov/taap/