Toowoomba Tap Water Quality 2026: Free Chlorine (Not Chloramine), 47 Bores, and the Cressbrook Dam Project

7 min read

Toowoomba has one of the most unusual water supply profiles of any Queensland city. It is the only major QLD city not on the SEQ Water Grid, manages its own dams independently, draws 20-30% of its supply from 47 groundwater bores, and uses free chlorine rather than chloramine for disinfection. It is also the city that staged Australia’s most famous water referendum — the 2006 vote that rejected adding treated recycled sewage water to Cooby Dam by a decisive margin. Understanding Toowoomba’s supply means understanding why its water is fundamentally different to any coastal Queensland city.

Where Toowoomba’s water comes from

Toowoomba Regional Council manages the Bulk Water Supply Scheme, which serves the city of Toowoomba and surrounding towns across the Darling Downs. The primary surface water sources are three dams in the ranges northeast of the city: Cressbrook Dam (81,800 ML, the largest), Perseverance Dam (26,800 ML), and Cooby Dam (23,100 ML). These are supplemented by 47 groundwater bore stations that access subsurface aquifers and contribute approximately 20-30% of total supply — a groundwater reliance significantly higher than Brisbane, Sydney, or any coastal Australian capital.

Treatment occurs primarily at the Mt Kynoch Water Treatment Plant, with additional treatment at smaller plants at Pechey, Cressbrook, and Perseverance. A 38-kilometre pipeline from Wivenhoe Dam (operational since 2010) provides a backup source for the Cressbrook system, providing drought security when local dam levels fall critically low. Water is delivered via more than 370 km of pipelines, 18 reservoirs, and 17 pump stations.

The groundwater contribution is significant for water quality. Bore water typically has higher mineral content than surface water from dam catchments — the minerals accumulate as water moves through soil and rock. This means Toowoomba’s water hardness is typically higher and more variable than coastal QLD cities, with the specific characteristics depending on seasonal mix of dam water versus bore water in the distribution system.

The Cressbrook Dam safety project — 2024-2026

Since July 2024, Toowoomba Regional Council has been deliberately drawing primarily from Cressbrook Dam to lower its water level to approximately 70% before commencing a $270 million safety improvement project — Queensland’s largest local government-led dam safety project. The works involve widening the spillway and raising the dam crest to handle larger flood flows, as required by the Water Supply (Safety and Reliability) Act 2008. The project does not affect water supply to Toowoomba residents — treatment continues at Mt Kynoch WTP — but Perseverance Dam has been pumped to supplement supply during the Cressbrook drawdown period. Water quality is not impacted by the construction work, as the treatment plant sits downstream of the construction zone.

The 2006 recycled water referendum

Toowoomba holds a unique place in Australian water history. During the severe drought of the mid-2000s, Cooby Dam reached 8% capacity. Facing critical water shortage, the council proposed the “Toowoomba Water Futures” project: piping treated recycled wastewater (processed to drinking water standards) into Cooby Dam as a drought-resilient supply. On 29 July 2006, residents voted 62% to 38% against the proposal in a referendum that drew national attention.

The “no” vote became influential in Australian water policy debates. The technology proposed was not fundamentally different from what is now used in Singapore, parts of the US, and in Queensland’s Western Corridor Recycled Water Scheme (which indirectly supplements SEQ supplies during drought). Toowoomba’s water security instead came via the Wivenhoe pipeline, completed in 2010. The recycled water debate is historically relevant and recurs periodically in discussions about Queensland’s long-term water security.

Toowoomba water quality and what it means for filtration

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Frequently asked questions

Safe to drink?

Yes — Toowoomba Regional Council manages supply to ADWG standards.

Chloramine?

No — free chlorine. Unlike Brisbane/Gold Coast/Ipswich. Standard carbon filters work.

Recycled water referendum?

2006 — 62% voted against adding recycled wastewater to Cooby Dam. Famous nationally. Water security came via Wivenhoe pipeline instead.