Tropical glaciers across Peru and Bolivia have been retreating for decades, and the communities downstream are watching their water supply shrink with them.
Andean glaciers act as a natural reservoir, releasing meltwater gradually through the dry season when rainfall alone can't sustain agriculture, drinking water, or hydropower. As glaciers shrink, that seasonal buffer weakens — some basins see a short-term surge in meltwater before the long-term supply drops off sharply.
Downstream cities and farming communities are adapting through a mix of old and new water management: restoring pre-Incan water channeling systems that slow runoff and recharge groundwater, alongside new reservoirs and more efficient irrigation to stretch a shrinking supply further.
The deeper challenge is timing — glacial loss unfolds over decades, but the infrastructure and water-rights agreements needed to manage it take just as long to build. Communities that started planning water security around melt projections, rather than historical averages, are in a measurably better position for the water year ahead.