Waternet's footprint under the CO2 Performance Ladder fell from 67,153.1 tonnes of CO2 in 2019 to 4,045.1 tonnes in 2023, a drop of 94%. Almost all of that came from one decision: the Amsterdam water company stopped buying grey electricity.
One line item did the work
In 2019 grey electricity alone produced 62,834.7 tonnes, more than nine-tenths of the total. Waternet switched to 100% Dutch wind energy and green gas, and by 2023 grey electricity contributed nothing. Scope 2 emissions fell from 63,291.9 tonnes to 1,281.7 tonnes over the same four years.
Waternet had set itself a target of a 94% reduction by 2026 against 2019. Its 2024 progress report says that target was met in the past year. It certified at step 3 of the Ladder in 2022.
The harder part is what remains
Scope 1 emissions, from Waternet's own operations, moved far more slowly. They were 2,919.3 tonnes in 2019 and 2,094.0 tonnes in 2023, a fall of 28%. In 2023 they made up more than half of the remaining footprint, and buying green power does not reach them.
The figures also need care. Waternet's 2023 progress report put its 2022 footprint at 4,633 tonnes; the 2024 report restates the same year as 4,422.2 tonnes.
Heat from the sewers
Waternet's next energy step is in the sewer network. Construction started on October 15, 2025 on a system to heat 607 existing social rental homes in Buikslotermeer, Amsterdam-Noord, using a heat exchanger in a sewer pipe just over 2 m in diameter. Heat supply is due in 2026.
Whether sewer heat stays with Waternet after the second phase of its split, when Amsterdam's sewer tasks return to the city, and how the utility's carbon position compares with the water board's separate footprint of 68 kton in 2024, are among the questions the report answers. The full report, Water Utility of the Future: Waternet, is available for USD 499. For a free overview, read the Waternet Utility Snapshot.