, John Shomaker & Associates Inc.
New Mexico’s surface water is shared with Texas, along with several underground water basins. Accounting of surface water is much easier than ground water, because of the ability to directly measure flows across political boundaries, although it can be complicated by effects of stream-flow depletion caused by ground-water pumping. The political boundaries for managing water between Texas and New Mexico have become complicated because water-planning regions follow national, state, and county boundaries, which overlie three interstate river compacts between New Mexico and Texas (Rio Grande, Pecos, Canadian), and at least five aquifers (High Plains, Capitan, Salt Basin, Hueco Basin, and Mesilla Basin).
The Salt Basin, located in south-central New Mexico and Far West Texas, is looming as a major state boundary issue for ground-water management. The Salt Basin in New Mexico has been relatively unexploited for many decades and currently faces a new era of resource management, with the potential for ground-water exportation and changes in uses of the region’s water resources. On the Texas side of the Salt Basin, ground-water development has been concentrated in agricultural areas of Dell City and Van Horn, with recent pressure to export ground water to the El Paso urban area.
Shared resources cannot be managed independently for sustainable supply by two or more parties, particularly when each party has a different quantification of available supply. Political entities with a shared water resource need to have the same definition of sustainability, and they must set the same limits on ground-water mining to have sustainable supply.
