Removing a dam located at the headwaters of the River Ega (Navarra, Spain), in a Nature Reserve and Natura 2000 site.
The Molino de Zúñiga dam is located in a natural environment of great ecological significance, designated as a Nature Reserve and a Natura 2000 site by the Government of Navarre, on the Ega River in the Ebro basin. This is the most important area for the spawning of endemic fish species such as Parachondrostoma miegii and Achondrostoma arcasii, which are considered Key Elements in the Natura 2000 management plan and both included in the Habitat Directive. Other species associated with the aquatic environment, such as the European mink and the otter, are also found in the area.
| Project status | Completed |
|---|---|
| Project type | Dam removal: demolition |
| Country | Spain |
| River | Ega |
| Removal date | Autumn 2024 |
| Km to be opened | 5 km |
| Focal species | Parachondrostoma miegii, Achondrostoma arcasii, Mustela vison, Mustela lutreola |
| Organisation | CIREF |
| Website | cirefluvial.com |
The project is a great opportunity to restore the Ega River to its natural free flow, particularly in an area as important as its headwaters. In 2023, CIREF developed the dam demolition plan with the support of the Programme and discovered that, because this is an area in very good ecological condition, the river’s recovery following the removal of the barrier would be rapid and natural. Furthermore, the local community has been involved in the demolition project. Additionally, the water authority, local authorities, and the dam’s owner are also in favour of the demolition.
The project’s primary objective is to demolish the Molino de Zúñiga dam following the technical project and prior programme-supported studies conducted in 2023. This demolition will enable the free movement of fish species and the release of sediments that have been trapped by the dam for years. The project will employ minimally invasive bioengineering techniques to minimise environmental impact. Waste generated by the demolition, primarily local stones, will be treated on-site to reduce the use of heavy machinery. Plant material removed to facilitate machinery access will be restored to the site by constructing plant lattices and biodiversity refuges.
The civil engineering work to demolish the barrier was carried out between October and December 2024 in an inclusive and collaborative process that involved regional and local authorities from the outset, making the project a win-win-win situation. The river gained freedom and space for the movement of sediments and nutrients, as well as for the migration of native species. The community benefited from a better-preserved and more beautiful environment. The regional authority advanced in its nature restoration objectives and successfully completed one more removal – adding to the 15 demolitions achieved in 2024 in the region.
On 13 May 2025, once the work had been completed, a ceremony was held, attended by regional and local authorities, as well as residents of Zúñiga. The event consisted of a visit to the site where the dam was removed, followed by a meeting at the Town Hall, during which a video of the demolition was shown, featuring testimonials from residents about the process.
An interactive story map was also produced.
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