Irrigation overhauled:  modernising a rural water network

The small rural town of Harcourt is located in the Central Highlands region of Victoria, located approximately 121km from Melbourne. It is the foremost apple growing region in the state and home to developing wine and cider industries.

For the last 100 years, the town and surrounding regions have been supplied with water for irrigation via a system of open concrete and earthen gravity channels. However, as a secure and reliable water supply is vital in order to underpin the agricultural growth in the region, the need to replace this ageing infrastructure with a more modern and efficient system was identified.

Replacing the channel system with a network of underground pipes will give irrigators access to a year-round pressurised water supply, and is expected to save around 3,000 megalitres of water per year. These savings include an estimated 950 megalitres of water loss and a further 2,000 megalitres from water licences that rural customers sold to Coliban Water in 2013.

Coliban Water formed the Harcourt Water Services Committee in November 2008, composed of Harcourt rural customers who provided advice and guidance on modernisation. In 2012 the business case to modernise the irrigation system was approved by the Victorian Government and works began at the site in March 2014.

Contractors and works

The project involves the supply and installation of approximately 65km of pressurised pipeline underground, as well as two pump stations and a balancing storage tank.

The contract for the supply of pipes and fittings was awarded to Pentair in 2013, including various fittings, valves and 19 kilometres of ductile iron pipes and fittings to be used to construct the backbone of the new modernised rural pipeline system. All pipes and fittings have been supplied to the site.

The tender for the supply of pumps was awarded in two parts; one for each new pump station site.

Xylem was contracted for the Faraday site and KSB for the Barkers Creek site. The total cost for both pump supply contracts was around $600,000.

These contracts involved the supply of the pumps and motor sets needed for the new pump stations.

The contract to construct the pipeline and pump stations was awarded to Redline Group.

Faraday pump station

For the Faraday pump station, Xylem was contracted to supply three Flygt CP3240 submersible pumps. These pumps have the motor and hydraulics integrated into one unit with cast iron casing and double sealing technology, effectively flood-proofing the pump station.

The size of each motor is 290kW and the capacity for one pump is 145L/s at 103m head. Overall pump efficiency is 72 per cent.

The water for the Faraday pump station is drawn from the Coliban Main Channel, which is a gravity-fed channel supplied from Malmsbury Reservoir and the new pump station will have the capacity to run two pumps at a time depending on customer demand.

Construction work on the wet well for the Faraday pump station.

Barkers Creek pump station

KSB was contracted to supply four Omega 200-670B pumps and four 355kW WEG motors for the Barkers Creek pump station.

These pumps have cast iron casings and bronze impellers. They have a capacity of 127L/s at 133m head. Overall pump efficiency is 77 per cent.

The water for the Barkers Creek pump station is drawn from Barkers Creek Reservoir. The pump station will have the capacity to run three pumps at a time depending on customer demand.

CW_Barkers-Creek-pump-station-construction-2

The concrete slab for the Barkers Creek pump station.

Current status

All pumps for the project have been supplied and both pump stations are currently under construction. Coliban Water aims to have both stations operational by the end of 2014.

Once the stations are ready, the ongoing operation and maintenance of the pumps will be handled by Coliban Water’s service delivery and infrastructure team.