Water. Desalination + reuse
Issue link: https://fhpublishing.uberflip.com/i/1056083
December 2018 Water.desalination+reuse In Site 25 QUEENSLAND • Gold Coast Desalination Plant has capacity up to 126,040 m3/d • Has been in standby mode since October 2010 • Projections suggest that the plant will be needed to meet peak demand by 2024-25 • Seqwater investigating desalination for northern region South-east Queensland experi- enced the worst drought in the state's history in 2005. Water storage levels plummeted and, combined with fast population growth, resulted in a severe water crisis. The Queensland government opted to build a new desalination plant, the larg - est on Australia's east coast. This non-climate dependent water source has capacity to serve up to 650,000 people living in the Gold Coast, Logan and Brisbane. The $1.2 billion facility at Tugun was constructed by John Holland and Veolia Water Australia. It was supposed to provide 125 gigalitres a year (342,500 m3/d). But shortly aŽer it was commissioned by Seqwa - ter in October 2010, rainfall in- creased, and most regional dams became more than 90 per cent filled. The plant was put into standby mode as a cost saving measure, and has remained so ever since, apart from inter - mittent use for contingencies. These were during flooding aŽer Cyclone Oswald in 2013; amid the refurbishment of Mudgeera - ba water treatment plant in 2015; and from May to August 2018, when Brisbane's largest water treatment plant Mount Crosby was offline for upgrade works. Output is expected to pick up in the future however. "Based on population growth and demand, it's likely that by 2020, the plant will be required to manage peak demand on the Gold Coast and will increasingly be used to help supplement the South-east Queensland Water Grid by 2024-25," a spokesperson for Seqwater says. Water sources are under greater threat in the northern sub-re - gion of Queensland, particularly on the Sunshine Coast, which in 2017 experienced its second consecutive failed wet season (an uncommon occurrence). The largest dam, Baroon Pocket, experienced record low inflows. "Our assessment shows that the next new bulk water source will be needed on the Sunshine Coast. This is based on the smaller size of its dams, and an expected doubling in popula - tion to 500,000 by 2040," says Seqwater's spokesperson. A new desalination plant is one of sev- eral options being investigated as it shapes its long-term water plan, the next version of which is due to be completed by 2022. VICTORIA • Victorian Desalination Plant (VDP) capacity up to 411,000 m3/d • Melbourne Water has advised the government to increase VDP's future water orders • State population expected to double by 2051 Victoria is home to Australia's largest, and arguably most controversial desalination plant, in Dalyston, on the Bass Coast in southern Victoria. It was completed in 2012 but lay idle for more than four years. The then Labor Government's $3.5 billion capital investment in Victorian Desalination Plant (VDP) was announced in 2007, when Melbourne's water reserves were at 28.7 per cent capacity, their lowest level ever. When the facility completed in December 2012 high rainfall had filled reservoirs to 81 per cent, and the plant went into standby mode. The shut-down sparked fierce public criticism over a perceived panic to invest in a plant that many considered too big, too expensive, and not required. The plant's operator, AquaSure, is paid around $604 million year to cover the cost of construction and maintenance, irrespective of whether any water orders are placed. "The VDP was not built to be turned on only when water supply reached critical levels, but to make sure that our water supply doesn't fall to those levels in the first place," a spokesman for the state department of environment, land, water and planning told Water. desalination + reuse. "The VDP provides security against drought, or bushfire in Melbourne's water catchments, and it provides flexibility and security to towns like Geelong, Melton, Sunbury, Ballarat, and Bendigo." VDP's fortunes changed in April 2016 when, a er a prolonged period of below average rainfall, the government placed an order for 50 gigalitres (137,000 m3/d) of water for the 2016-17 financial year. Subsequent water orders include a contract in 2017-18 for 15 gigalitres, and another 15 gigalitres for 2018-19. Utility Melbourne Water has advised the state water minister to place orders for 100 gigalitres a year (274,000 m3/d) from April 2019, and 125 gigalitres (342,500 m3/d) the following year. "Climate change will mean more extreme climatic events, less rainfall, and potentially a 50 per cent reduction in streamflow by 2065. Victoria's population is expected almost to double by 2051, placing further demand on scarce water resources. Our challenge is to ensure that we manage water to support a healthy environment, a prosperous economy and thriving communities," the department spokesperson added. The reverse osmosis racks inside the Victorian Desalination Plant, which is operated by AquaSure