is a massive concrete gravity dam
on the Noguera Pallaresa
River, a tributary of the Ebro River
, north of Tremp
. The dam is 206 meters long and 82 meters high and supplies a hydro-electric
station with an output of 300,000 kW.
Construction of the dam began in 1913, a huge undertaking needing ten million cubic feet of concrete. It was part of a larger project to build dams to store water in reservoirs to feed powerplants and to provide irrigation for farming.