La Mojana ancient hydraulic system built via local cooperation

A new study from the University of Cambridge, published in Communications Sustainability, reveals that an ancient hydraulic system in the La Mojana region of northern Colombia was built through horizontal cooperation rather than centralized authority. The pre-Hispanic network of canals and raised agricultural fields covers approximately 500,000 hectares—an area three times the size of modern-day London.

Used by Zenú populations from the early centuries BCE until the 11th century CE, the infrastructure functioned as a natural water regulator. During rainy seasons, the canals managed excess water to prevent flooding, while during droughts, the system redistributed moisture to maintain soil fertility and support fishing.

Researchers used satellite imagery and soil displacement analysis to estimate that a local workforce of approximately 800 people could have completed the project without metal tools. This discovery challenges previous assumptions that such massive infrastructure required powerful, hierarchical rulers, suggesting instead that local family groups could coordinate large-scale, sustainable water management projects.