Floods in Colombia Trigger “Toxic Water” Crisis on Ranches

Large swathes of “dead zones” have emerged on ranches in Colombia’s Lower Cauca region following receding floodwaters. These areas tested positive for E. coli, botulinum toxin, pesticide residues, and heavy metals like mercury and lead—representing a combined biological and chemical contamination. The pollution resulted from floodwaters carrying agricultural pollutants and industrial heavy metals, accelerated by oxygen-deprived conditions that hastened organic decay. Livestock have died after drinking the contaminated water, while local residents’ drinking water safety is threatened, severely damaging the regional ecosystem.