Towards co-produced water management pathways to counteract deteriorating mountain water quality in the deglaciating Peruvian Andes

Glacier retreat has led to widespread downstream impacts increasing water insecurity. A growing number of catchments in the deglaciating Peruvian Andes is currently exposed to natural acid rock drainage which severely affects human and ecosystem health, and therefore urgently requires sustainable solutions. Yet, this challenging endeavour has barely been addressed in science and policy. We showcase the deglaciating Negro river catchment (Cordillera Blanca, Peru), to disentangle the complex spatiotemporal interactions between specific catchment characteristics, glacier retreat, water quality and local water governance. Therefore, in-situ measurements of water quality in rivers and wetlands are analysed against multidecadal glacier retreat. Our results reveal high acidity in glaciated subcatchments while deglaciated subcatchments indicate improved drinking water conditions, with considerable seasonal variability in rivers and wetlands. The results are jointly analysed with local villagers and decision-makers under a co-produced framework that supports strategies for adaptive management and policy to increase long-term mountain water security.