Lamiako: vegetation and shores of the Nervión estuary

Environmental conditions

The environmental assessment of August 2026 describes ground composed mainly of estuarine mud with very low permeability, alongside more permeable human-made deposits. The Gobela is subject to tidal influence as it passes through this area, but its final stretch is heavily channelised. Existing vegetation is described as abandoned meadows with ruderal plants and isolated remnants of the original marsh vegetation. The surroundings therefore retain wetland elements within a heavily modified landscape, rather than an intact marsh.

Distribution and scope

The Lamiako basin is in Leioa, Bizkaia. Its surroundings lie between the metropolitan railway, the Udondo estuary, the Nervión-Ibaizabal estuary and Lamiako’s industrial area. The Udondo joins the Gobela before reaching the estuary. This is not a profile of every shore along the Nervión.

Structure

A botanical record published in Munibe in 2018 places Juncus acutus at Lamiako, on former marsh fill and beside the Gobela. It describes two separate patches: one by the river and another on fill, accompanied by other marsh plants. These groups of rushes add a specific biological dimension to the landscape, distinct from bare ground or vegetation of disturbed land. The record is historical: it is not a current count and does not imply that rush vegetation covers the entire basin.

Threats

The 2026 assessment identifies invasive plants including Cortaderia selloana, Spartina patens, Baccharis halimifolia and Paspalum vaginatum. Their presence must be distinguished from remnants of original vegetation: a surface with plants does not, by itself, amount to a preserved marsh community. The landscape combines disturbed land, ruderal vegetation and wetland elements; describing it as a homogeneous unit would conceal those differences.

Conservation

The August 2026 resolution assesses a project intended to restore part of the basin as marshland. It proposes removing fill, improving connections with the estuary and modifying the final stretch of the Gobela; it also includes an urban space in the part not intended as marshland. These are planned actions, not a completed restoration. Measures include protecting flora of interest, including the reported presence of Juncus acutus, and controlling invasive plants. The outcomes of restoration will need to be checked after implementation.