A focus on a binational watershed with a view toward fostering a cross-border dialogue

Two border communities-Columbus, New Mexico, and Palomas, Chihuahua, bound by historical, familial, and economic ties-depend solely on groundwater ext racted from the Mimbres aquifer, a "closed basin located in arid southweste rn New Mexico and northwestern Chihuahua. During the last twenty years, the region's population has substantially increased. Agriculture contributes s ignificantly to the social and economic makeup of the area but also account s for 95 percent of the withdrawal and the depletion rates from the aquifer . Projected increases in population together with agriculture and industria l development will intensify pressure on the already declining water table. Contamination and alkalization are also concerns, and recurring drought ha s emphasized the need for water conservation. The international border has made it nearly impossible for the two communit ies to jointly manege the aquifer upon which they both depend. Adequate mec hanisms to deal with the dilemma are lacking. While both the New Mexico Sta te Engineer and the Comision Nacional de Agua (Mexico's National Water Comm ission) develop plans for their users, each formulates its own rate of with drawal without considering usage on the other side of the border Furthermor e, there has been little systematic gathering of data on wafer characterist ics or behavior, and no formal sharing of existing data, much less joint pl anning for future usage and conservation. The lack of information about the aquifer makes it difficult for residents to make rational choices between proposed uses of water. It also presents problems for government agencies t rying to predict the aquifer's carrying capacity. To date, this has resulte d in inappropriate policies, rendered current unilateral plans useless, hin dered impact analysis, and impeded the consideration of options. Efforts to address the situation are underway. If Columbus and Palomas can apply the lessons of other regions, the border between them would no longer be an imp ediment to conserving the lifeblood oft he region.