Old weir removed from Spain's Bullón river, reopening 24 km to salmon
Red Cambera, a rural development association in Cantabria, northern Spain, has taken down the Valverde weir, a 1.7-metre stone wall in Frama that fish could barely get past. Salmon and other species now have 24 km of the Bullón river open upstream. The works finished in late October; whether fish actually return to those stretches will be checked through scientific monitoring over the coming months.
A wall of stone and masonry 1.7 metres high used to cut across the Bullón river at Frama, in the Liébana valley of Cantabria. Water dropped almost a metre and a half in one go, which, according to Red Cambera, made it “practically impassable” for salmon and the other fish in that stretch. That wall, the Valverde weir, is gone.
The Cantabrian association Red Cambera removed it with a €83,228 grant from the Open Rivers Programme, a European fund that pays for taking out small dams and weirs so rivers are connected again. Noel Quevedo Aja, who leads the project at Red Cambera, says the works free 24 km of channel upstream and another 42 km downstream.
The drop at the Valverde weir as demolition began. Photo: Noel Quevedo Aja, Red Cambera technician (shared with Happy News of the Day).
A wall that no longer did anything
The weir was built to divert water to the Frama fish farm, which had been abandoned for years and has since been dismantled. It had a small fish pass in the middle, but it did not work. The structure was out of use and had no water-use licence, the association says.
Before the excavator came the paperwork: talks with national, regional and local authorities, feasibility studies, the technical design and the permits. Of the 24 metres of wall between the two banks, 14 were removed, following the guidance of the Cantabrian river basin authority so that the channel can settle properly.
Before, during and after the removal, seen from the left bank. Photo: Noel Quevedo Aja, Red Cambera technician (shared with Happy News of the Day).
The same sequence from the right bank. Photo: Noel Quevedo Aja, Red Cambera technician (shared with Happy News of the Day).
The fifth barrier gone from the Deva basin
The Bullón flows into the Deva, so opening it up improves the connections across that whole river network. It is the fifth barrier Red Cambera has removed in the Deva basin since 2021.
The next step is to check the result. Over the coming months the association will run a monitoring plan with scientific criteria to see how the river behaves without the obstacle and to measure, in the medium and long term, whether the work has paid off.
