Cooby Dam

The Cooby Dam is a rockfill embankment dam with an ungated spillway across the Cooby Creek, a tributary of Condamine River, at Groomsville in the Toowoomba Region on the Darling Downs, Queensland, Australia. The main purpose of the dam is for potable water supply of the Toowoomba region. The impounded reservoir is called the Cooby Creek Reservoir.

Location and features
The dam is located approximately 17 km north of. The other two storages used for Toowoomba are Perseverance Dam and Cressbrook Dam. Completed in 1942, the rockfill dam structure is 32 m high and 207 m long. The 71 e3m3 dam wall holds back the 23100 ML reservoir when at full capacity. From a catchment area of 169 km2, the dam creates an unnamed reservoir, with a surface area of 301 ha at a maximum depth of 12.5 m when at full capacity. The uncontrolled un-gated spillway has a discharge capacity of 680 m3/s. The dam is managed by the Toowoomba Region Council.

Cooby Dam's lowest usable storage volume was recorded at 8% in January 2010.

In July 2006, public outcry and a referendum with winning "No" vote rejected plans to place recycled water into Cooby Dam. In 2007, the idea was again resurrected when plans for an advanced water treatment plant to be built near Cooby Dam by the Toowoomba City Council were suggested. The trial would test the re-use of recycled water into Toowoomba's drinking water supply. In 2008, an emergency bore was used to extract water from the Great Artesian Basin to supplement water supplies for the dam as drought conditions reduced supply to critical levels.

Recreational activities
A stocked impoundment permit is required to fish in the dam.

Darling Downs Sailing Club uses the dam.