The Toowoomba Regional Council area has a population of 151,000 with 125,000 of those residents relying on the surface water storages of Cressbrook, Cooby and Perseverance dams as the main sources of drinking water.
At the time of writing, the level of available drinking water in the three dams was just over 9 per cent and recent rains have not sufficiently replenished surface water supplies.
The pipe is made of mild steel, reinforced with a concrete lining. The pipeline will be comprised of more than 3,500 joins and lengths of pipe, the latter ranging in size from 6-13.5 m long.
LinkWater Projects is the Queensland Government body responsible for constructing and managing a network of South East Queensland water pipelines. Together with its construction alliance partner, the Toowoomba Pipeline Alliance, LinkWater Projects is on track for its deadline to have the pipeline operational by January 2010. Construction began in March 2009 and more than 10 km of pipe has been installed.
The 762 mm diameter pipeline is being constructed by an alliance of WDS, AECOM and Clough, and is being buried approximately 1 m below the surface. It will have the capacity to deliver water at 42 ML/d, enhancing the water supply for Toowoomba for many years.
Key features of the pipeline include two pump stations at Wivenhoe Dam and an advanced electronic system to ensure remote operation of water flow is safe, consistent and accurate.
The smaller of the two pumps is a low-lift pump, housed on a jetty suspended over Wivenhoe, which will extract water from the dam and pump it to a 1,600 kW high-lift pump located on the shore nearby. This large pump will deliver the water over the 38 km length of the pipeline, traversing challenging terrain including a hill that is 265 m above sea level.
The water will be discharged into Cressbrook Dam via the outlet pipe located at the bottom of the dam wall. Once the pipeline is operational, the water will be reticulated by the Toowoomba Regional Council according to its needs. The pipeline is designed to pump in one direction, east to west.
The pipeline route has been designed to use existing infrastructure corridors where possible. It begins at the Wivenhoe Dam pump station at the end of Paddy Gully Road, proceeds along Brisbane Valley Highway through Esk township and on to rural land west of the township, leading to Kipper and Cressbrook creeks.
Environmental studies have been carried out, with strict environmental management taking place during construction. LinkWater Projects has said that areas used for pipe storage will also undergo strict environmental management and rehabilitation processes.
As part of its “˜good neighbour’ policy, the Toowoomba Pipeline Alliance has also committed to investments to local suppliers of goods and services valued at more than $5.5 million, including the purchase of vehicles, pipeline bedding materials, electrical and plumbing services.
The Alliance has established a campsite with high quality accommodation for 112 workers on disused land in Esk township, and employs 60 local residents among the total workforce of more than 200.