Seqwater

About the Utility

Seqwater is South East Queensland’s bulk water supply authority, formally the Queensland Bulk Water Supply Authority. In 2024-25 it reached more than 3.7 million residents through five retailers: Unitywater, Urban Utilities and the water businesses of Logan, Redland and Gold Coast city councils. It also supplies commercial and raw water customers, including around 1,200 irrigators across seven water supply schemes. Responsible Ministers approve its major investments, it borrows through Queensland Treasury Corporation, and the Queensland Government sets its prices on the Queensland Competition Authority’s recommendation. Since March 2025 Seqwater has acted as strategic decision maker, with a service delivery partner maintaining key assets.

Water System

Supply rests on a network of dams joined by the SEQ Water Grid, created in response to the Millennium Drought water supply crisis. Rainfall-dependent storage is backed by climate-independent sources: the Gold Coast Desalination Plant can provide up to 133 ML a day at short notice, and the Western Corridor Recycled Water assets were built with Commonwealth capital grants. Combined grid storage was 83.5% at the end of July 2026, and with El Niño strengthening Seqwater has warned it could fall toward 70% in a dry year; a Drought Response Plan links actions to dam levels. In 2025-26 Seqwater supplied approximately 343,554 ML of drinking water through its retailers.

Infrastructure & Performance

Seqwater’s performance is measured where bulk water passes to its retailers rather than at the customer tap. Its national performance report for 2024-25 records thirty-five full-treatment plants with a combined capacity of 1,806.56 ML a day. Reliability has been strong: in 2025-26 all bulk water delivered complied with Australian Drinking Water Guidelines values, and no unplanned disruption interrupted supply to customers. Operations are also being digitised, with a mobile system for bulk chemical receival deployed at an initial seventeen treatment plants and one network site.

Investment & Priorities

Capital spending has stepped up sharply. Seqwater spent $534.8 million in 2025-26, the largest annual capital programme in its history, yet $212.5 million below budget after delayed environmental approval and staging work on the Toowoomba to Warwick Pipeline. Dam safety anchors the programme: Seqwater’s August 2026 capital briefing reports the old Lake Macdonald wall demolished and a new wall under way, with North Pine strengthening progressing on site. In July the Queensland Government announced a $545 million six-year Dam Repair Plan, starting with North Pine and Lake Macdonald.

Sustainability & Resilience

Long-term security is governed by legislated service objectives that limit how often medium-level restrictions may occur, and Seqwater’s Water Security Program sets out a three-decade plan to meet them. Regional demand is expected to grow from about 300,000 to about 500,000 ML a year over that period, mainly with population, while modelling puts the existing system’s yield at 430,000 ML a year if future climate resembles the historical record. The programme includes a detailed business case for a new desalination plant, likely to be required by 2035.

Key Challenges

1. Delivering a record capital programme after approval delays held spending well below budget in consecutive years.
2. Upgrading Lake Macdonald, North Pine, Somerset and Wivenhoe dams through the Dam Improvement Program.
3. Securing climate-independent supply, including a possible desalination plant, as demand grows.
4. Reducing leverage, which remains above benchmark, while borrowing for investment.
5. Maintaining full bulk water quality compliance and uninterrupted supply to retailers.

Major Projects