The Alqueva Dam has been releasing water in a controlled manner since 4:00 PM, by opening its mid-depth spillways, in response to the reservoir nearing its Full Storage Level.
In a statement, the Alqueva Development and Infrastructure Company (EDIA) revealed that, at 4:00 PM, it would open the dam’s mid-depth spillways to carry out “controlled discharges.”
This operation aims to respond to “the persistence of high inflows in the Alqueva-Pedrógão System, which raised the reservoir levels to values close to the Full Storage Level,” the company explained.
“It is expected an initial discharge flow of 600 cubic meters per second (m3/s) that, added to the turbine flow, results in a total discharge of 1,200 m3/s,” EDIA announced.
The water from Alqueva’s discharges will proceed to the Pedrógão Dam, which is also part of this multi-purpose undertaking and has been releasing since the 21st of this month into the Guadiana River.
“The discharge flow from Pedrógão Dam will be of the order of 1,500 m3/s,” revealed the management company of the Alqueva Multi-Purpose Project (EFMA).
According to the company, “storage at Alqueva has been managed, primarily, through the turbine operation of the hydroelectric plants, allowing the regulation of volumes and ensuring energy production.”
In parallel, it explained, “the Pedrógão Dam, located 23 kilometres downstream, was discharging flows that contributed to the management of inflowing waters.”
“However, in light of the persistent high inflows, it became necessary to supplement this operation with controlled discharges also at Alqueva, ensuring the maintenance of the reservoir’s operational safety margins,” it justified.
The discharges started today at Alqueva will “cause a rise in the levels and flows of the Guadiana River downstream of the Alqueva and Pedrógão dams, a situation that is being continuously monitored by EDIA in coordination with the competent authorities,” the statement reads.
The company, which guaranteed it is actively guiding the hydrological evolution, asked for collaboration from local authorities, civil protection agents and the public to safeguard people and property, recommending special attention to riverside areas and potentially flood-prone zones, as well as adopting preventive measures.
The maximum level of the Alqueva reservoir is 152, corresponding to a total storage capacity of 4,150 cubic hectometers of water (hm³).
The last operation of controlled discharges at the Alqueva Dam was carried out in 2013, also to manage the reservoir’s water volume, which approached the maximum storage capacity, EDIA recalled.
Alqueva first reached the Full Storage Level in 2010, eight years after the gates were closed, which motivated the first discharge operation, repeated again in 2011.
Also in 2014, 2024 and 2025 the reservoir reached its maximum storage capacity, but there was no need to discharge water, because the levels were controlled through the turbine operation of the hydroelectric plant.
