The repowering of the Artxanda-Mazarredo line is not required to undergo a general impact assessment

The Director of the Environmental Administration of the Basque Government, Nicolás García-Borreguero Uribe, specified in the resolution of September 4 that the repowering project of the Artxanda-Mazarredo 132 kV line, promoted by the company i-DE, Redes Eléctricas Inteligentes, S.A.U., does not require a general impact assessment, provided that the protection and corrective measures and monitoring controls established in the resolution are incorporated into the project. The resolution was published in issue number 183 of the Official Gazette of the Basque Country on September 24, 2026, with official reference 2026/4002.

The procedure was initiated on June 25, 2026, by the Territorial Delegation of Bizkaia, under the Department of Industry, Energy Transition and Sustainability, requesting the start of a simplified impact assessment. The Directorate of the Environmental Administration began the process of consulting public administrations and interested parties on July 6, in accordance with Article 79 of Law 10/2021 of December 9 on the Environmental Administration of the Basque Country.

The resolution is based on section 4.b) of Annex II of Law 21/2013 of December 9, in the case of lines with a voltage higher than 15 kV and a length greater than 3 km, and follows the organizational structure established by Decree 410/2024 of December 3.

Technical characteristics of the project

• The activity takes place over a length of 795 meters, between the municipalities of Sondika (38 m) and Bilbao (757 m), from existing support 30002 to support 30006.
• The current LA-380 GULL overhead conductor will be replaced by a new one of type LARL-380 GULL, also changing the insulation, clamps, and hardware; the supports will be maintained.
• In the 30002-30003 section, two FOADK cables will be replaced by one OPGW-16-80 cable and a new ARLE-53.
• The works require a temporary occupation of 4,988.36 m², and two temporary accesses of 168.91 meters must be opened for supports 30004, 30005, and 30006.
• The total duration of the project is 6 months, and the material execution of the work is 4 months.

Environmental impacts and compensation

According to the resolution, the main impacts will occur during the construction phase: on flora, habitats of community interest, soil, water quality, and the quality of life of the landscape or the population. The total area to be cut and cleared is 6,788.2 m²: 137.15 m² of oak, 105.83 m² of oak and acacia mixture, and 6,196 m² of clearing.

The affected habitats of community interest are: 4030 (European dry oak forests), 6510 (poor lowland hay meadows), and 6210* (mesophilic grasslands of Brachypodium pinnatum). As compensation, the promoter has proposed the reforestation of autochthonous forest in a 1:2 proportion, with 434 m² dried, in the Public Benefit Mountain No. 35 in the municipality of Garai, in agreement with the Provincial Council of Bizkaia.

Conditions and corrective measures

• It operates within the scope of the management plan for the European mink (Mustela lutreola), according to Provincial Decree 118/2006 of June 19; previously, Law 9/2021 of November 25 and Decree 167/1996 of July 9 must be complied with.
• During the bird breeding season (from March 1 to August 15), experts must carry out surveys to ensure that there are no nests or habitats within 250 meters of the work area.
• The Natural Heritage Service of the Provincial Council of Bizkaia recommends that all neutral and fiber optic cables be marked with bird diverters (salvapájaros).
• Prior authorization from the Basque Water Agency will be required for activities affecting unnamed streams 5002 and 6097.
• A protocol against invasive species will be written, with particular control of Cortaderia selloana, and environmental monitoring will be carried out for 2 years following the works.
• The Iron Belt and the Defenses of Bilbao, protected by Decree 195/2018 of December 26, must be respected, specifically the Artxanda Line, the San Roque mine gallery (SONF01), and the Pikotamendi machine-gun emplacement (SONF02).

Conclusions and validity

The third point of the resolution specifies that, taking these measures into account, it is not anticipated that the project requires a general impact assessment. The fourth and fifth points order that the content be notified to the Territorial Delegation of Bizkaia and published in the official gazette.

According to the sixth point, the environmental impact report will become invalid if the project is not executed within a period of four years from publication; in that case, the promoter must restart the simplified impact assessment procedure.

Although the resolution regulates a small section of 795 meters, it has a direct effect on the strengthening of the electrical supply between Bilbao and Sondika, and simultaneously establishes specific protection measures for the European mink and bird habitats, habitats of community interest, and the cultural heritage elements of the Iron Belt.

Fuente: Boletín Oficial del País Vasco, n.º 183 de 24 de septiembre de 2026, Otras Disposiciones, pp. 1-12 (official reference: 2026/4002).