The pipeline from Wivenhoe Dam (operated by SEQwater) provides security of supply when the rainfall in our dam catchments is insufficient to maintain supply to meet the region's growing needs. Once the capacity of Cressbrook dam falls below 40% we can start using water from Wivenhoe Dam. 

The following answers may answer questions you have regarding the Wivenhoe pipeline.

The pipeline was commissioned in December 2009 and first used in 2010 in the last year of the drought that broke in January 2011.

Pumping is only performed when additional water is required to supplement the Toowoomba Bulk Water System. For example; Pumping commenced again in April 2019 after several years of drought and ceased in February 2022 with the rainfall event that filled Cooby, Cressbrook and Perseverance dams. With full dams and careful water use by the community, we don't expect to have to restart pumping from Wivenhoe for some time - perhaps even a number of years.

There are many factors that contribute to when and how we use the Wivenhoe pipeline. This includes:

  • Contract arrangements
  • Weather
  • Engineering constraints on the pumps and pipeline
  • The existing water level in Cressbrook Dam
  • Electricity prices and other operating costs. 

The pump and pipeline cost $187 million in 2010. This asset is owned and maintained by us as part of our water network. The Queensland Government provided a subsidy of $112.2 million and a loan of $60.856 million over 20 years.

Operational costs include:

  • Usage charge (litres pumped from Wivenhoe dam).
  • Electricity to run the pumps.
  • Maintaining the pumps, pipes and related infrastructure.

Ongoing costs for access to Wivenhoe water exist in addition to operational costs. We pay SEQWater an access charge that applies whether the pipeline is being used or not.

Yes.

There are many water systems throughout the Region and the Wivenhoe pipeline supplements the Toowoomba Bulk Water Supply system. This includes the city of Toowoomba and the surrounding localities of Oakey, Jondaryan, Haden, Crows Nest, Highfields, Kingsthorpe, Gowrie Junction, Meringandan, Westbrook, Goombungee, Wyreema, Hodgson Vale, Top Camp, Mount Rascal and Preston.

Other town schemes are predominantly reliant on groundwater supplies. In the event of an emergency water situation in these towns, water is resourced from nearby locations, which may include the Toowoomba Bulk Water Supply. 

No, only water users connected to the Toowoomba Bulk Water Supply system contribute to the cost of water from Wivenhoe.

We set water pricing each year as a part of our budget. Current pricing is set in place until the end of June 2022.

Council water pricing is not directly influenced by pumping from Wivenhoe. It is a cost to Council that is incorporated in the comprehensive financial modelling completed to determine water pricing each financial year. Water prices are calculated to cover the cost of Council's water infrastructure and to continue the supply of water to the required quality for use by the community.

The loan is calculated into the costs of operating the overall system to avoid large variations in year-to-year water costs.

The payment of the Wivenhoe pipeline loan is supported by the income of water access and usage charges over the long term. As a part of our whole water network (worth over $900 million), this particular asset is managed in the same way as our other assets – with a long-term financial sustainability approach.

There isn't a direct relationship between a resident’s water access charge and the payment of the Wivenhoe loan, so it's unlikely that this charge will vary greatly when the Wivenhoe loan is paid off.

Contractual arrangements were originally set in place with SEQWater in 2010 for an initial 10-year term. This contract was renewed for a further 30-year term in January 2022, with options to extend this to a 50-year term. 

This contract sets out the usual issues of responsibility, maintenance requirements, risk management and details such as:

  • Maximum water take in any financial year of 10,000ML, with options to seek additional allocations each financial year.
  • Costs based on an access charge along with additional usage charges (litres pumped from the dam).

This contract is reviewed regularly.

The pipeline is the biggest water infrastructure project in the Region since the construction of Cressbrook Dam.

The pipeline helps secure water supplies for residents using the Toowoomba Bulk Water Supply. The water obtained from Wivenhoe may also be used to provide emergency supplies for towns not using the Toowoomba Bulk Water Supply.

On average 40ML/day is used. High usage days can increase to over 60ML/day.

This is currently limited by contractual arrangements with SEQWater (who own Wivenhoe Dam). This is 10,000ML/year. Assuming an equal amount pumped each day of the year, this would equate to 27ML/day. The existing pipeline and pump station has a capacity of around 42ML/day.  

Pumping rates will not be equal each day but rather will be designed based on a variety of factors including:

  • Water levels in Cressbrook Dam
  • Water demand in the network
  • Weather
  • Maintenance schedules on the pumps and pipes
  • Electricity prices.

Pipe details:

  • 38km long pipe
  • 762mm in diameter
  • Laid underground.

Pump details:

Two pumps lift the water 240m to Lake Cressbrook. There is an additional lift required to move the water from Lake Cressbrook to the Mt Kynoch Water Treatment Plant.

We work cooperatively with SEQWater to ensure the best possible outcomes.

Since the creation of our agreement with SEQWater, we haven't had a situation where SEQWater restrictions have been stricter than our own. If this occurs in the future, these details will be agreed depending on the circumstances at the time.

Water from Cooby, Perseverance and Cressbrook Dam is treated at Mt Kynoch (or at the point where it is drawn from the water main for localities such as Highfields).

Water taken from Wivenhoe is pumped into Cressbrook Dam. From Cressbrook Dam to our taps, the same network and award-winning treatment regime is used to treat water originally sourced from the Cressbrook catchment as from the Wivenhoe catchment.

SEQWater operates Wivenhoe Dam. SEQWater has its own high-quality water management systems that are independent of ours. This system includes trigger points based on the level of Wivenhoe Dam where they may introduce manufactured water from the Western Corridor Recycled Water Scheme when necessary. Under the drought response approach created by SEQWater, the Western Corridor Recycled Water Scheme is utilised when the combined grid-level falls to 40% capacity.

Yes. Over recent years a number of investigations have been made into additional water sources such as Water Vision 2050, the Interim Report on the Toowoomba Water Supply Task Force and Water and Wastewater Strategy Study for Toowoomba and the Surrounding Areas.

Options typically raised during water future investigations include building a new dam. Cooby, Perseverance and Cressbrook dams are rated as ‘B Grade’ water sources. Other possible sites for water supply dams within the Region are considered ‘C Grade’ sites at best. This combined with the expected 25-year approval and construction timeframe are significant considerations in the use of this option. Additionally, we continue to advocate for our Region in discussions with the Federal Government for solutions for our Region and a number of our neighbouring Councils.

Depending on the catchment properties, some dams may suffer from reduced capacity from the build-up of silt. Periodic tests have proven this not to be a significant concern for existing water supply dams. Routine monitoring programs keep an eye on this.

These investigations will continue as new technologies become available and other influencing factors may change.

The largest water user in our organisation is our Parks & Recreation Branch. This water is used on our Region’s parks, gardens and street trees. Much of this water is not taken from town water supplies but drawn from alternative water sources. The majority of parkland areas across the Region are not irrigated. Nevertheless, where we do use water in our parks, we do our best to conserve water in many ways. For example:

  • Use plants that have drought hardy characteristics.
  • Plant street trees that don't require watering beyond their initial establishment period.
  • Suspend the street tree planting program when the weather is not supportive.
  • Mulch around plants.
  • Adjust planting programs according to the weather.
  • Maintain efficient irrigation systems.
  • Design ponds and fountains to look attractive when empty or switched off.
  • Use water-efficient techniques to maximise a limited amount of water.
  • Design garden display beds that use a combination of annual flowers, xeriscapes and artworks depending on conditions and restrictions.
  • Focus irrigation on limited sports fields, high profile lawn areas and shrub beds, tree establishment and annual plantings.
  • Adhere to a water restrictions policy and water conservation plan.

Additionally, wherever possible in our offices and other facilities we use water-saving devices. For example, bathrooms for most of our major buildings are connected to rainwater tanks. Saving water is always a consideration when renovating our buildings.

 

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