Portugal loses enough drinking water to supply 30 million people – DECO

Portugal has lost enough treated drinking water over the past decade to supply around 30 million people for a year, according to consumer organisation DECO PROteste, which says the recent water supply crisis in Almada has exposed the urgent need to modernise the country’s ageing distribution network.

The warning comes after days of severe water shortages in the Lisbon district municipality (and year’s in which summertime water cuts have become commonplace).

As a result of the latest focus on the situation, authorities have introduced overnight supply cuts, and water-use restrictions. They hope these will be enough to save losses, while repairs are finally effected. In the meantime, the message to households (and businesses) is ‘conserve water’.

DECO stresses: consumer efforts alone will not resolve this drama.

According to the organisation, Portugal lost around 2 billion cubic metres of water through its supply networks between 2013 and 2024—equivalent to roughly half the storage capacity of the Alqueva reservoir, or enough water to meet the annual needs of around 30 million people (in other words, almost three times the number living in Portugal).

Losses equate to about 166 million cubic metres of treated water disappearing every year after it has already been captured, purified and pumped into the distribution system.

DECO PROteste say the disruptions in Almada should serve as a warning that water supply interruptions could become increasingly common as climate change, growing pressure on water resources and ageing infrastructure combine to strain existing networks.

Although the organisation notes that Almada’s current crisis stems from a specific operational problem, it said the episode underlines the need to make Portugal’s water systems more resilient.

Almada itself remains one of the country’s areas facing high to severe water scarcity.

The municipality reduced water losses from 402 litres per connection per day in 2023 to 284 litres in 2024, but DECO PROteste said leakage levels remain high enough to justify further investment in replacing ageing pipelines.

The organisation estimates that an average person could cut daily household water consumption from around 280 litres to approximately 100 litres by installing simple water-saving devices such as low-flow fittings, efficient shower heads and dual-flush toilets.

That would save up to 180 litres a day—the equivalent of 36 five-litre bottles.

Other recommendations include taking shorter showers instead of baths, turning off taps while brushing teeth and/ or washing hands, repairing leaking taps and toilets promptly, collecting cold water while waiting for showers to warm up, running washing machines and dishwashers only with full loads, and watering gardens during cooler parts of the day using drip irrigation where possible.

DECO PROteste also reminds consumers that water supply is an essential public service, meaning utility operators have legal obligations to provide clear and timely information whenever planned interruptions or major disruptions occur.

Following supply failures, customers should carefully check their water bills and challenge any charges that do not reflect actual consumption or where service quality standards have not been met, DECO adds. Complaints can be made directly to the utility provider and, if necessary, to Portugal’s water regulator.

Ultimately, however, DECO PROteste argues that household conservation measures must form only one part of a broader national strategy.

The organisation is calling for increased investment in renewing water networks, stronger monitoring of leakage, greater reuse of treated wastewater and targeted spending in the regions facing the greatest water stress.

“It is not enough to ask families to reduce consumption while millions of cubic metres of treated water continue to be lost through deteriorating infrastructure,” the organisation said, adding that protecting Portugal’s water resources will require shared responsibility between consumers, utilities and public authorities to ensure a more secure and resilient supply in the years ahead.

Source material: Executive Digest