Beja, Portugal, June 18, 2026 (Lusa) - Plans for two new dams that the Alqueva Development and Infrastructure Company (EDIA) intends to build in the Beja and Mértola areas are taking their "first steps", the company’s chairman said on Thursday.
Speaking to the Lusa news agency, EDIA’s chair, José Pedro Salema, said that the company intended to build the dams “downstream of the Alqueva-Pedrógão system”, on tributaries of the River Guadiana.
The Alqueva reservoir is the largest artificial lake in Western Europe. Located on the Guadiana River in the Alentejo region of Portugal, it covers up to 250 square kilometres and was created in 2002 to supply water, generate hydroelectric power, and boost regional development.
The construction of these two dams aims to “increase the resilience of the Alqueva system”, with the projects forming part of the national “Água que Une” (Water that Unites) strategy, he said.
EDIA has launched a public tender for the detailed design and Environmental Impact Assessment (EIA) of the Terges and Cobres Dam, in the municipalities of Beja and Mértola, representing an investment of €990,000, plus VAT.
According to the procedure, the notice for which was published on Thursday in the Diário da República (DR), the deadline for submitting tenders is 20 July and the contract is to be carried out within 18 months.
As for the implementation project and EIA for the Carreiras Dam, in the municipality of Mértola, “it will probably be another month before that tender is published” in the DR, he added.
Referring to the Terges and Cobres Dam project, the company director noted that “the preliminary study was carried out in-house by EDIA” and that it is now necessary to select the best of the “three sites previously studied” for the construction of the infrastructure.
“We have to hand [this task] over to a team of designers, who will study in detail where it makes the most sense – economically, ecologically and hydraulically – to build the dam and create the new reservoir,” he noted.
Normally, he said, a detailed design and EIA for a dam takes “around two years’ work”, whilst the issuance of the Environmental Impact Statement (EIS) “takes a further six months”.
“I would say we are about two and a half to three years away from being able to start work on these dams,” he estimated.
When asked about the planned investment for each of the dams, he stressed that the designers would now “draw up the budget estimate”, but acknowledged that it would be “a figure in the tens of millions of euros”.
Speaking to Lusa, Jose Pedro Salema explained that the streams “have water at certain times in winter, but in summer they run dry”, so the construction of these dams will be important for ensuring the ecological flow of the River Guadiana.
“If we have these dams, which are located downstream of Pedrógão but upstream of Pomarão, we can use the water stored there during periods of high water to ensure ecological flows in summer or when water levels are low, thereby relieving the pressure on Alqueva”.
In other words, he added, retaining water in the dams allows for “a regulated flow over more months” in the Guadiana, and the water released is that which “is not drawn from Alqueva”, thereby providing “greater resilience to the system”.
SM/ADB // ADB.
Lusa
