Ancient Rock Structures Revitalize Biodiversity on US-Mexico Border
In Cananea, Sonora, rancher Eduardo Ríos Colores has implemented ancient rock structures known as trincheras to combat severe drought conditions and restore local biodiversity. Installed in 2021, these structures span over a mile, helping to slow water flow, raise the water table, and reduce erosion, according to a report by Mongabay.
The region has faced extreme drought, with spring 2024 marking the driest March-May period on record in Mexico. As a result, Ríos Colores was forced to sell more than three-quarters of his cattle in 2025. The trincheras have become crucial in managing water resources during these challenging times.
Scientific studies support the effectiveness of such structures. A 2016 study by the USGS found that similar rock-detention structures in Arizona increased overall water flow volumes by 28% during monsoon seasons compared to unrestored areas. These structures have proven durable, with many remaining functional after 30 years.
Further research by the University of Arizona highlights the long history and ecological benefits of rock-detention structures in the Madrean Archipelago. These benefits include improved flood regulation, enhanced water infiltration, and vegetation recovery, making them valuable tools for managing riparian zones along the US-Mexico borderlands.