The concession was taken over by Altos Hornos de Vizcaya in 1945 and by its subsidiary Saltos y Aguas del Zadorra in 1947.

Ullíbarri-Gamboa and Nanclares de Gamboa were partially submerged but still exist, while Landa was reduced to the station neighborhood.

Garaio [es] wasn't flooded either but the lack of arable land resulted in the remaining inhabitants leaving by the early 1960s.

The inhabitants of the flooded settlements received eviction letters in the summer of 1957, giving them ten days to leave their homes.

[citation needed] There are three islands in the reservoir: Zuhatza [eu], isla de los Caballos and Orenin [es].

'rabbit island'), is the site of a youth hostel; [13] isla de los Caballos is a small islet located next to it.

[17][18] The Mendijur Ornithological Park, located in the eastern end of the reservoir, is a birdwatching site with adapted paths and two observatories.