There’s one thing that crosses the U.S.-Mexico border everyday, although you can’t always see it: water.  

The Mesilla Bolson is an aquifer that runs south of Las Cruces, New Mexico, to an area just northwest of Ciudad Juarez — the second largest city in Mexico. While there are laws regulating the appropriation of international river water, such as the Rio Grande, the same can’t be said  for groundwater. And when you factor in the populations of two of the largest cities in the region, along with the many farms and orchards, the question of who gets what and how much can get pretty complicated.

Laura Villagran is an investigative reporter for Searchlight, New Mexico. She reported on the Mesilla Bolson in a five-part series for the Albuquerque Journal. Villagran spoke to Marketplace Weekend host Lizzie O’Leary about her reporting. You can listen to their interview on the media player at the top of the page.