HR-5709-119
Referred to the House Committee on Natural Resources.
Sponsored by Juan Ciscomani (R-AZ)
What it does
This bill would reauthorize the Transboundary Aquifer Assessment Program, a joint U.S.-Mexico scientific effort to study shared underground water supplies along the border. It would expand the program's geographic scope to include Arizona (with one specific aquifer excluded), extend the program's authorization through fiscal year 2033, and set new annual funding at $1.5 million per year — replacing the original lump-sum authorization of $50 million for 2007–2016.
Who benefits
Residents of Arizona, New Mexico, and Texas who depend on shared groundwater for drinking water, agriculture, and municipal supply. Farmers and ranchers in border regions who rely on aquifer-fed irrigation. State and local water managers who use the program's scientific data for planning. Researchers and scientists at universities and federal agencies involved in the assessments. Communities in northern Mexico that share the same aquifers and benefit from cooperative data sharing.
Who is hurt
Taxpayers who fund the program, though the annual cost is modest. The Yuma groundwater basin in Arizona is explicitly excluded from the expanded coverage, meaning communities and water users in that area would not benefit from the program's expanded scope. Water users in areas not covered by the program who may have competing claims on the same aquifers could face indirect pressure if assessments lead to new management decisions.
Supporters argue
Supporters argue that transboundary aquifers are a shared, finite resource that cannot be managed effectively without coordinated scientific data, and that the original program produced critical baseline assessments used by border-state water managers. They contend that expanding coverage to Arizona addresses a gap in the program, since Arizona shares significant aquifer systems with Mexico, and that the $1.5 million annual authorization is a cost-effective investment in long-term water security for one of the most water-stressed regions in the country.
Opponents argue
Opponents argue that the bill's annual funding level of $1.5 million — a fraction of the original $50 million authorization — may be insufficient to conduct meaningful scientific assessments across three states and multiple aquifer systems, potentially producing data too limited to guide sound water policy. They contend that water management is primarily a state responsibility under the Tenth Amendment and longstanding western water law, and that federal involvement in aquifer assessment could be a precursor to federal regulation of groundwater resources traditionally governed by states.
Constitutional context
Congress's authority to fund this program rests on the Commerce Clause (Art. I, §8, cl. 3) and the Necessary and Proper Clause, as shared water resources cross state and international boundaries. No significant constitutional tension is present — this bill funds scientific assessment and data collection, not regulatory mandates, so it does not implicate the major questions doctrine from West Virginia v. EPA (2022) or the post-Loper Bright heightened scrutiny of agency rulemaking.
Checks and balances
Congress controls the program's funding and scope through authorization; the U.S. Geological Survey and partner agencies implement assessments; states retain authority over actual groundwater management decisions based on the data produced.
Historical precedent
The original United States-Mexico Transboundary Aquifer Assessment Act (P.L. 109-448, 2006) established this program and authorized $50 million for fiscal years 2007–2016; this bill directly reauthorizes and modifies that existing framework.