Aguas Andinas' turbidity compliance in drinking water was 92.67% in 2025, down from 100% in each of 2022, 2023 and 2024, according to the data tables published with its 2025 integrated report. In 2021 the figure was 84.9%.
Sediment is the weak point
Other quality measures held up. Bacteriology compliance was 100% in 2025, and the company's summary drinking water quality compliance was 98.53%, against 99.93% in 2024. The integrated report lists 19 non-compliance incidents against drinking water standards in 2025.
The pattern matches the river. More than 80% of Metropolitan Region drinking water demand is met from the Maipo, where extreme turbidity events have risen from about 5 a year in 1990–2010 to 27 a year after 2011, according to CR2.
Customers notice
Complaints to Aguas Andinas reached 211,113 in 2025, up from 143,701 in 2021, and 65% of 2025 complaints concerned network problems. Unplanned supply interruptions numbered 1,293 in 2025, with an average duration of 5.46 hours.
The backup system held in 2026
Two flow and turbidity spikes in July and August 2026 were handled without material effect on operations, the company reported. It drew on the Cerro Negro wells and the link between the El Yeso reservoir and the Laguna Negra aqueduct, and used the Pirque reservoirs on a targeted basis, with stored volume never below 95%.
How Santiago's water resources, regulators and infrastructure fit together, where service quality is slipping, and which projects will reduce the city's dependence on a sediment-laden river are covered in the full report. The full report, Water Systems Overview: Aguas Andinas, is available for USD 499. For a free overview, read the Aguas Andinas Utility Snapshot.