#hydrography

For comparison, Catalonia's largest natural lake (Estany de Banyoles) is 1.18 km², and the largest reservoir is by far Rialb, which amounts to 15 km².

This new discovery reveals that the underground sea was created as a result of a large river that existed there in Prehistorical times, over 25 million years ago.

Map of the underground sea (blue), compared to the largest reservoirs (orange). By Joan Teixidó i Pau in Segre.

The sea is under the towns of Gimenells, el Pla de la Font, and Almacelles, and has significant parts under Alfarràs and Almenar, and to a lesser extent under Alguaire, Lleida, Alcarràs, Saidí, and Albelda.

Little is known so far about it so far, now more studies about it will begin. They will see if it can be used as a source of water, considering that it has been discovered in an area already gravely affected by droughts, which will get worse with climate change.