Desal plant costs more to build, 20% less to run

A Multiplex-Degremont joint Venture will build Perth's new seawater desalination plant at Kwinana.

The new plant will increase Perth's water supply by 45 gigalitres a year from October next year and would become the biggest single water source feeding into Perth's integrated water supply scheme (IWSS).

Under the deal, the cost of construction has increased from $346m (estimated last July) to $387m. But the plant's projected operating costs have decreased by more than 20% due to improved desalination technology. This means that the potential cost impact on each household remains under one dollar per week at $44 per year - as stated last July.

“The construction of this climate independent, new water factory, signals an exciting move forward in the development of new water sources for Western Australia,” said premier Dr Gallop in announcing the award of the building contract.

“It clearly establishes the state as an innovator in keeping water flowing as our climate, as predicted, becomes hotter and drier. By coming on-stream in time for the 2006-07 summer, it will rule out any possibility of job-destroying, total sprinkler bans that would also undermine the amenity of our beautiful city.”

The Premier announced the winning tender outside Rottnest Island's desalination plant, just off the coast near Perth, which provides more than 70% per cent of the island's drinking water. The new plant will be powered by renewable energy, probably wind power, with the Water Corporation, which would own the plant, well advanced in negotiations with a major supplier. A wind farm with as many as 50 wind turbines would be required to provide the 24MW of power required by the plant.

Work at Kwinana would begin immediately, with the workforce through the next 18 months likely to peak at about 200 people. Work on the pipelines and other components required to link the plant - approximately the size of a Bunnings warehouse - to the IWSS, would also begin shortly.

The new plant will be owned by the Water Corporation and will be operated in a 25-year contract by Degremont. It will be the biggest desalination plant in the southern hemisphere and will complement dams and groundwater schemes as a third water source for Perth, parts of the South-West and towns serviced through the Goldfields pipeline to Kalgoorlie Boulder. The Premier said the commitment to desalination as the next source, came after the expenditure of more than $130million in the past three years, through an accelerated source development program involving both dam and groundwater projects. This had resulted in 39 gigalitres of new water being added to the integrated scheme.

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