01
About the Utility
Águas e Energia do Porto, EM is the municipal company that runs Porto’s urban water cycle. It is wholly owned by the Municipality of Porto, which sets its service targets through a delegated management contract for 2024–2038. The company supplies drinking water, collects and treats domestic wastewater, and manages the stormwater network, urban streams and beaches; it has also taken on municipal energy roles. It operates no water treatment plants and buys its treated water in bulk from the multimunicipal Águas do Douro e Paiva. Tariffs are approved by the municipal council after an opinion from the regulator, ERSAR, and the company served 170,276 clients in 2025.
02
Water System
Porto’s drinking water arrives already treated from Águas do Douro e Paiva, so source protection and treatment sit with the bulk supplier while the company concentrates on storage, distribution and loss control across a network that extended 824.4 km in 2024, with six reservoirs and one pumping station. Metering and control zones, telemetry and real-time analytics underpin a sustained fall in non-revenue water: the index reached 11.76% in 2025, beating the contract target of 12.75%, with real losses of 58 litres per connection per day. Supply security, tested by the severe drought of 2022, rests on the regional bulk system.
Non-revenue water index
Águas e Energia do Porto non-revenue water index, %, 2018–2025 (calendar years)
Reported actuals as published in each year's annual report (one decimal to 2021, two decimals from 2022); 2023 from the 2024 report's comparative.
Sources: Águas e Energia do Porto, Relatório & Contas 2018–2024 and Relatório Integrado de Gestão 2025.03
Wastewater System
The company also collects and treats the city’s domestic wastewater through 572.2 km of sewers and two treatment plants, and runs a separate stormwater network that ERSAR does not regulate. Against the municipal contract, network renewal is on track, with sewer rehabilitation, structural collapses and infiltration all beating their 2025 targets; effluent and flooding are weaker, as compliance with discharge requirements fell short at 98% and flooding occurrences were 0.79 per thousand connections against a target of 0.70, while reuse remains at pilot scale in a membrane unit at the Freixo plant built to produce class A water.
04
Investment & Priorities
Investment is steady but runs below plan. In 2025 the company executed 67.4% of its budgeted programme, after 70.4% the year before, with wastewater drainage and treatment taking the largest share ahead of water supply and stormwater drainage. At year-end it held 18 approved co-funded applications, most backed by EU funds. With EBITDA rising and bank borrowings down to zero, the recurring gap between budget and execution stands out more than financing.
05
Sustainability & Resilience
Climate exposure centres on surface water. Dense building and highly impermeable soils leave Porto prone to urban flooding whenever intense rainfall exceeds what the stormwater system was designed to carry, as flash floods showed in late 2022. The energy picture is stronger: renewable sources covered 94.8% of the company’s own energy use in 2025, as solar capacity across the municipal estate expanded. Direct emissions, mostly process emissions, rose in each year of the company’s latest inventory.
06
Key Challenges
- Delivering more of the budgeted investment after execution slipped to 67.4% in 2025.
- Protecting the city from urban flooding as intense rainfall tests a stormwater network outside ERSAR regulation.
- Maintaining the fall in non-revenue water while relying on bulk treated water from Águas do Douro e Paiva.
- Bringing discharge compliance up to the contract’s 100% target and moving reuse beyond pilot scale.
