Water scarcity in North and Centre threatens energy balance and river ecosystems
Portugal’s national water reserves sit at 75% of capacity, but this masks a critical divide: the Lima, Vouga and Mondego river basins in the North and Centre are at their lowest levels since 2022, falling below historical September averages. The Ministry of Environment and Energy confirms that reservoirs in these regions are now critically stressed—a situation that risks disrupting the country’s energy grid and ecosystems.
Hydro-electric power under pressure
With rainfall absent until the end of September, Portugal’s reliance on hydropower—a key buffer against volatile gas prices—is being strained. Minister Maria da Graça Carvalho, speaking from Soure, warned that continued dry conditions could force a sharp increase in gas-fired electricity generation. "If we have less water, we will have to exercise caution in relation to the use of hydroelectric power, which will force us to use more gas, which is very expensive," she said. While no final figures are yet available for September 2026, early indicators suggest hydropower output is significantly below seasonal norms, raising concerns that gas consumption could rise sharply if dry weather persists into autumn.
Invasive plant risk grows as funding stalls
While water levels fall, another ecological threat looms in the Mondego basin. The contract between the Coimbra Intermunicipal Community (CIMRC) and the Portuguese Environment Agency (APA) to control water hyacinth (jacinto-de-água) expires at year’s end—with no renewal confirmed. Since 2018, CIMRC has invested €5 million to manually remove and monitor the invasive species in municipalities including Soure, Montemor-o-Velho, and Figueira da Foz.
Jorge Brito, CIMRC’s executive secretary, warned that without immediate action, the plant could return with "proliferation levels unseen in decades." The floating weed forms dense surface mats that smother native aquatic life, reduce oxygen, and impede river flow. The lack of a coordinated response risks undoing six years of ecological recovery efforts.
CIMRC has formally demanded an "objective response" from both the APA and the Ministry, urging emergency intervention before the December cutoff.
Tejo river plan sparks environmental alarm
Meanwhile, the Ministry and AdP AQUA are preparing a comprehensive strategy for the Tejo River, aiming to evaluate the basin from its estuary to the Spanish border. The plan will examine solutions for salinity intrusion near Conchoso, supply for the South Bank, flood control, and agricultural water needs.
But environmental groups are raising red flags. Sara Correia of ZERO criticized the investment split: 65% allocated to dams and interconnections, just 31% to water efficiency, and 4% to monitoring. "The priorities have been inverted," she said. The original national strategy placed efficiency and reuse before new infrastructure—but that order appears lost.
Paulo Constantino of proTEJO fears the plan is a "phased reinvention" of the abandoned private Projeto Tejo, which proposed four weirs and two dams for €1.35 billion. He pointed to the Constância-Praia do Ribatejo weir and the proposed Conchoso structure as potential first and last links in a chain of new hydraulic works. "If you build the first and the last, you’ll inevitably build the ones in between," he said.
AdP AQUA president Macário Correia insisted dams are the lowest formal priority within the 294-measure "Água Que Une" plan, with only 14 involving new infrastructure. Yet critics remain unconvinced by assurances without public impact assessments or binding ecological safeguards.
What this means for residents
• Energy costs may increase if dry conditions continue into winter, pushing reliance onto imported gas.
• Water restrictions in northern towns are possible if August-to-October rainfall remains below 30% of normal.
• River ecosystems in Coimbra’s region risk irreversible damage if plant control is suspended.
• New infrastructure debates will now dominate public consultation cycles—especially around the Tejo’s estuary.
The government is monitoring reservoirs hourly, but the lack of precipitation forecasts through October leaves little room for optimism. As one environmental scientist noted: "We managed droughts with reservoirs. Now, we’re running out of reservoirs to manage."
