Water Corporation

About the Utility

Water Corporation is a Government Trading Enterprise under Western Australia’s Government Trading Enterprises Act 2023, providing water, wastewater and drainage services to households, businesses and rural communities across over 2.6 million square kilometres; its regional services also include irrigation. It operates under water services licence WL32, which the Economic Regulation Authority renewed for 25 years from March 2021. It manages $54.1 billion of assets at replacement value, spanning dams, borefields, seawater desalination, treatment plants, pumping stations, water resource recovery facilities and drains. Funding is mostly self-generated through regulated revenue, with minor borrowings through the Western Australian Treasury Corporation and public-private partnerships for some major projects, and Strategic Asset Plans go to Treasury each year.

Water System

Supply draws on a mixed portfolio of dams and weirs, borefields and two seawater desalination plants, supported by a statewide network of treatment plants. Surface storage is a pressure point: at 30 June 2026 the Perth hills dams held 40 per cent of their maximum storage. Water Corporation supplied 419,682 megalitres in the latest year. Drinking water quality is consistently strong, with every locality meeting microbiological and health-related chemical criteria in 2024-25. Network condition is a growing concern, however: leaks and bursts on water mains have risen steadily in recent years, and unplanned interruptions are trending upwards.

Wastewater System

Wastewater is a core responsibility. Water Corporation operates a statewide network of water resource recovery facilities and wastewater pumping stations, and its Perth system also supplies recycled water. In 2024-25 it treated more than 183 billion litres of wastewater and recorded 1,350 overflow events, although 99.92 per cent of properties were unaffected by an overflow. Ageing pumping assets are the main constraint: under the current constrained budget, only about a third of forecast pump station and pressure main renewals can be undertaken, and required refurbishment and replacement spending climbs year on year in that scenario.

Investment & Priorities

Capital spending has accelerated sharply, with new works investment, excluding developers’ take-over works, rising every year since 2021-22. The independent review of the asset management system nonetheless flagged the adequacy of the capital programme, finding that 10 per cent of assets are beyond their expected life while only 30 per cent of investment sustains existing infrastructure. It judged the system robust and mature, but found that a lack of resources held back implementation. In the latest year debt equalled 20.5 per cent of total assets, with interest cover of 7.6 times.

Sustainability & Resilience

Climate and energy pressures shape the outlook. Water Corporation is targeting net zero Scope 1 and 2 greenhouse gas emissions by 2035, while its own situational assessment identifies extreme weather testing asset resilience, energy cost increases of up to 30 per cent that particularly affect desalination, and continued population growth. Options short-listed to secure the city’s water supply pair new asset solutions with non-asset choices: stronger demand management, regulatory and pricing reform, and a revised groundwater management scheme.

Key Challenges

1. Securing future supply for a growing population as new source and demand options are weighed.
2. Delivering a sharply expanded capital programme while sustaining an ageing asset base.
3. Reversing rising leaks, bursts and unplanned interruptions across the water network.
4. Funding wastewater pump station renewals that current budgets cannot fully cover.