There are three dams within the Toowoomba Region boundary.
Cooby Dam (Lake Cooby)
Cooby Dam is the oldest of the city's three water supply dams, constructed during the period 1938-41. This Dam is located about 17 km North of Toowoomba on Cooby Creek, a tributary of Condamine River.
The storage statistics of Cooby Dam are as follows:
- Total Catchment Area = 159 km2
- Storage Area = 306 ha (full supply)
- Maximum Available Storage = 21,166 ML
- Dead Storage = 1,462 ML
- Full Water Supply Useable Capacity = 19,703 ML
- Full Water Supply Level at Spillway = RL482.2 AHD
- Depth (overflow - dead water level) = 12.5 m
Perseverance Dam (Lake Perseverance)
Perseverance Dam is the second largest, in terms of storage capacity, and the second oldest storage dam of the city's three water supply dams. Construction of this dam commenced in 1962 and was completed in 1965. This dam is located approximately 35 km Northeast of Toowoomba on Perseverance Creek, which is a tributary of Cressbrook Creek.
The storage statistics of Perseverance Dam are as follows:
- Total catchment area = 110 km2
- Storage area = 250 ha (full supply)
- Maximum available storage = 30,140 ML
- Dead storage = 3,207 ML
- Full water supply useable capacity = 26,893 ML
- Full water supply level at spillway = RL 446.08 AHD
- Depth (overflow - dead water level) = 23.1 m
Perseverance Dam filled immediately on completion and has an average storage level of about 80%
Cresbrook Dam (Lake Cressbrook)
Cressbrook Dam is the largest and newest of the city's three water supply dams. The dam is located on Cressbrook Creek approximately 10 km downstream of Perseverance Dam. The construction of the dam was commenced in 1981 and was completed in 1983.
The storage statistics of Cressbrook Dam are as follows:
- Total Catchment Area = 320 km2 (including Perseverance)
- Storage Area = 517 ha (full supply)
- Maximum Available Storage = 81,842 ML
- Dead Storage = 2,995 ML
- Full Water Supply Useable Capacity = 78,847 ML
- Full Water Supply Level at Spillway = RL 280.00 AHD
- Depth (overflow - dead water level) = 34.0 m
Cressbrook Dam was first pumped in November 1988 when it reached 67% of its full capacity. Since 1988, it has had an average useable storage volume of 71.8% of its full capacity. The dam's lowest storage volume on record was 7.5% in February 2010.
