Porto, Portugal, Dec. 22, 2025 (Lusa) - The Portuguese Environment Agency noted "significant changes" to the high-speed rail project in Gaia and Porto proposed by the AVAN Norte consortium, particularly in the tunnels and crossings over the Douro River, and has rejected them.
In the Decision on the Environmental Compliance of the Implementation Project (DCAPE) on the first section of the high-speed line (Porto - Oiã), to which Lusa had access on Monday, the Environment Agency states that "one of the most significant changes to the Preliminary Study was the general increase in the elevation at which the project is being developed" between Espinho and Gaia.
The AVAN Norte consortium claimed that "the new location of the Gaia station, now above ground, led to an increase in the gradient of the route upstream (i.e. to the south) and thus to the elimination of some tunnel sections planned in the Preliminary Study".
However, in the Preliminary Study, "one of the main concerns was the extensive crossing of dense and consolidated urban areas, an aspect that was directly related to the need to develop the route, whenever possible, by mining tunnels, a solution that would not only minimise direct and irreversible impacts during the construction phase, but also minimise the impacts of the operation, particularly in terms of noise and vibrations, thereby reducing the inconvenience to the population".
The preliminary study envisaged an 11-kilometre (km) tunnel under Gaia, but the consortium proposed "a reduction in the length of the tunnels by about half, now to only six km, with most of them developed using a “cut & cover” solution, since, with the rise in gradient, the shallower depth at which the route is developed prevents the adoption of mining tunnel solutions".
"Consequently, there is a significant increase in the total number of demolitions planned for sub-sections STA4 and STA5, both for residential buildings and for commercial buildings, from 44 to 121 and from three to 36, respectively, for a total increase from 94 to 175," says the Environment Agency.
In the public consultation, which received 259 responses, "the reduction in the length of the tunnels is also one of the most evident concerns in the submissions presented," with "it being pointed out that this option in the Implementation Project accentuates the significance of the negative impacts, particularly in terms of territorial fragmentation, devaluation of heritage and landscape, as well as increased noise and vibration levels."
As for the construction of two bridges over the Douro instead of one road-rail bridge, as had always been planned, the Environment Agency also points out that this was "another structural element of the project that underwent significant changes in the Implementation Project compared to what was recommended in the Preliminary Study".
"The road-rail bridge solution in a single crossing would allow for the optimisation of infrastructure, avoiding its duplication in the area, with the consequent minimisation of the resulting impacts. It should also be remembered that this solution was recognised in the Environmental Impact Study itself as a way of minimising a significant cumulative impact that would occur with two bridges in a very close space and with non-concordant layouts," recalls the Environment Agency.
However, the consortium submitted a proposal for two separate bridges, stating that it had "decided to change the assumptions for approval of the Preliminary Study, calling it into question and contradicting the grounds and assumptions of the environmental impact decision issued".
"It should also be noted that, with regard to the road crossing, it is not presented with a level of development equivalent to an Implementation Project, and its potential impacts have not been studied or assessed, with the exception of the visual simulations presented to understand its impact on the landscape," the Environment Agency also points out.
The two-bridge solution was also criticised in the public consultation "for increasing the visual and landscape impact in an area already saturated with bridges, for doubling the environmental impact and for the lack of robust technical or financial justifications".
"The option presented goes beyond the current procedure for verifying the environmental compliance of the Implementation Project, as it corresponds to a solution that is totally different from the one evaluated and calls into question the added value identified during the evaluation of the Preliminary Study, resulting from the optimisation of infrastructure. In addition, the positions expressed by the local authorities highlight the need for further coordination at the local level," notes the Environment Agency.
JE/AYLS // AYLS
Lusa
