PROJECT BACKGROUND
Project History
Completed in 1976, Stage 1 of the Hinze Dam provided a storage capacity of 42,400 million litres, which was increased to 161,070 million litres with the completion of Stage 2 in 1989. The Stage 3 project will raise the Hinze Dam embankment wall from 93.5 metres to 108.5 metres, providing a total storage capacity of 309,700 million litres (that’s about 820,000 Olympic sized swimming pools).
In September 2006 Gold Coast City Council (GCCC) selected a consortium of private sector partners to join them in a working alliance to raise the height of the dam wall.
On November 8, 2006 Hinze Dam Stage 3 was declared a “Significant Project” under the State Development and Public Works Organisation Act (1971). The Significant Project designation reflects the fact that the project:
- has a strategic significance to the region
- is characterised by complex approval requirements; and
- meets one or more tests of environmental, economic and/or social significance
The project requires an Environmental Impact Statement (EIS) under Part 4 of the State Development and Public Works Organisation Act (1971).
Why Raise the Wall?
The dam wall will be raised by approximately 15 metres. With a rapidly growing population and widespread drought, the pressure on water supply continues to increase. The Stage 3 project has been identified as a priority to increase the dam’s water storage capacity and delay the release of floodwaters onto the floodplains. This will reduce downstream flood levels and decrease the number of properties vulnerable to flooding.
Additional Water Storage
Raising the Hinze Dam wall will increase its storage capacity providing an additional benefit of improved security and reliability for the region's water supply. The Gold Coast Waterfuture (GCWF) Strategy, documents an increased yield of between 10 megalitres and 24 megalitres per day, which is in addition to increased environmental flows.
Flood Mitigation
Mitigation against potential flooding in the Nerang River catchment is the key driver behind the decision to raise the Hinze Dam wall.
The Nerang River Valley is home to many iconic attractions, such as Surfers Paradise and over 4,100 downstream properties. A cost benefit analysis conducted by Gold Coast City Council revealed the need for flood mitigation to reduce potential flood damage to down-stream properties in a one in 100 year flood event (Q100). This risk minimisation project has significant direct and indirect economic benefits for the region. A recent study has revised the future of rainfall figures in the catchment area. Consequently, the predicted levels of a probable flood may also be much higher than previously anticipated.
