01
About the Utility
Aguas Andinas is the water and sanitation company for Greater Santiago, consolidating the concessions of Aguas Cordillera and Aguas Manquehue alongside non-sanitary subsidiaries. It reports full drinking water coverage, 98.9% sewerage coverage and full wastewater treatment coverage in the Santiago basin, so its responsibilities run from raw water capture and treatment through distribution to sewage collection and treatment. The parent concession alone served 2,177,084 drinking water customers in 2025. Tariffs are set in five-year processes overseen by the Superintendencia de Servicios Sanitarios, using a model company with a minimum return on assets of 7% after taxes; the current tariff period was approved by ministerial decree.
02
Water System
The Maipo River supplies over 80% of the Metropolitan Region’s demand, making the basin’s hydrology the company’s central supply risk. Central Chile endured a megadrought from 2010, Maipo flows are already nearly a quarter below their two-decade average, and groundwater’s share of production rose to 21% by 2020. Glacier melt has also made extreme turbidity events far more frequent, and very high sediment loads force treatment plants to stop. Storage is the main defence: the Pirque reservoirs raised supply autonomy to 34 hours. Network efficiency is the weaker flank, with total water losses of 28.3% in 2025.
Groundwater in drinking water production
Potable water produced from groundwater, 2016–2020
Reported actuals from a single table on one basis (Aguas Andinas, Aguas Cordillera and Aguas Manquehue); groundwater’s share rose from 14% to 21% as surface water fell from 86% to 79%.
Sources: Aguas Andinas Integrated Report 2020, potable water production by type of source, 2016–2020.03
Wastewater System
Wastewater is a core responsibility. The group’s 11,045 km collection network serves treatment plants that handled 498.9 million m³ in 2025, with full compliance reported for wastewater treatment. The turning point was the Mapocho Urbano Limpio programme, completed in 2010, which brought treatment to all of Santiago’s sewage and removed the discharge points into the Mapocho. La Farfana, among Latin America’s largest treatment plants, returns treated water to the Maipo and Mapocho systems, while the biofactories recover biogas, electricity and biosolids for reuse.
04
Investment & Priorities
Investment is set through the tariff process. The 2025–2030 agreement raised base drinking water and wastewater tariffs in three steps and added a further 7.4% tied to approved works against drought and other climate effects, including base drought works, an alternative Maipo catchment for turbidity and an emergency supply plan. The company later reported the investment plan optimised to CLP 365 billion. Execution is under way, with CLP 91,614 million invested in the first half of 2026, and a growing share of debt is green and social.
05
Sustainability & Resilience
Resilience planning centres on a basin under long-term climate stress. Glacier contributions to December–March flows are projected to fall by about three-quarters by the end of the century, and drought is expected to become more frequent in central Chile. Basin governance is changing too: the Water Code reform embedded the human right to water, and strategic tables for the Maipo are preparing basin plans. A wetter 2023 brought relief, with El Yeso reservoir at 94% at the end of March 2025, but the megadrought cannot yet be declared over.
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Key Challenges
- Securing supply from a Maipo basin facing lower flows, glacier retreat and recurring drought.
- Protecting treatment from extreme turbidity events driven by glacier melt and intense rainfall.
- Reducing network water losses that still exceed a quarter of the water supplied.
- Delivering the drought and turbidity works funded through the 2025–2030 tariff.
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Major Projects
Pirque mega reservoirs
Six treated water tanks at Pirque that raised Greater Santiago’s supply autonomy to 34 hours at inauguration.
- Status / period
- Inaugurated November 2020
- Investment / capacity
- 1,500,000 m³ · approximately USD $100 million
Cerro Negro–Lo Mena wells
Deep extraction wells in southern Santiago adding groundwater supply to extend autonomy during river turbidity events.
- Status / period
- Operation scheduled for March 2022 (as reported June 2021)
- Investment / capacity
- CLP $31 billion · over 400,000 residents
Maipo alternative catchment
Tariff-linked work in the 2025–2030 programme providing an alternative Maipo catchment against extreme turbidity.
- Status / period
- Approved plan, tariff period 2025–2030
- Investment / capacity
- 1.17% of tariff-linked works