The Rialb reservoir (Lleida) is, after the Canelles reservoir (with 679 cubic hectometres), the largest reservoir in Catalonia. It is one of the last Spanish marshes in which there was no hesitation in flooding a municipality, Tiurana, in favor of water supply.
The reservoir is located in the pre-Pyrenees, its dam has a height of 000 meters and was not finished filling until 99. On May 14 it only accumulated 26.7 cubic hectares of water, 6.60% of its capacity.