The Río Marañón is Moving: Dam Construction in a Volatile Landscape

Rafting down the Río Marañón.

By expedition member, Alice Hill

On a tight curve on a dirt road, rock fall spat off the top of the 30-foot bank, pelting the road. By the looks of the piles of debris in the carriageway, it had been doing this for hours. Rockslides seemed to be a normal occurrence along the road to the Río Marañón in Peru’s Andean Cordillera Blanca. This landscape is active!

The proposed 300 MW Rupac dam site lies at the site of an old bridge where the Río Marañón exits the inner gorge. The canyon walls can be used to buttress the impoundment while the relative openness of the valley downstream facilitates access to the site for construction. Photo: Christian Martin

We were a team of 15 – scientists, writers, a videographer, lawyer, doctor, river guides, entrepreneurs, environmental planner and energy expert – from five countries that set out to run 620 km of the Río Marañón, the headwater stem to the globally important Amazon River. Río Marañón is subject to 20 proposed dams, two of which are approved. Construction of these dams would dissect the free flowing Río Marañón into a series of pools and drops to produce energy to fuel the hungry and growing mining sector in Peru.

With the support of National Geographic’s Committee for Research and Exploration our team had two main objectives – first to document our expedition through film and photography, and second to leverage our scientific and river-running expertise to collect baseline data along the river corridor prior to dam construction. With little-to-no information currently available relating to the Río Marañón corridor, a baseline data set initiates a data record and allows for evaluating impacts after major land use or river change.

Graduate student and hydrologist Alice Hill samples water quality on a pristine tributary in —> Read More