Worsening problems with algal blooms in the Quipolly Dam has caused Liverpool Plains Shire Council to rethink its water treatment approach.
Water services manager Rodney Batterham said drought was a "main driver" behind the algal blooms showing up more often and for longer, especially the past two to three years.
It has set back Quipolly Water Project start date by two months and there are concerns it may cost more but Mr Batterham said "it was good it showed at this stage in the plan process so we could adapt to it".
The council had developed a concept design for the water treatment plant but the "ever-changing raw water quality in the dam" meant the design had to change "significantly".
It is in the process of acquiring pricing for a new system and plans to go to tender by mid-year.
Mr Batterham said work started on the project 10 years ago when the algal blooms were "sporadic" but now there was "a constant population in excess of the very high range for six months of the year".
"While in the past it was seen as 'a' thing to treat, it is now 'the' thing to treat [and] our water treatment procedure has skewed towards treating this as an ongoing issue," he said.
"We’ve been doing a lot more sampling than we did originally to confirm those issues."
We’re asking for innovation from these contractors and we’re involving them intimately now all the way.- Rod Batterham, water services manager
The new treatment plant is key to solving ongoing water quality issues in Werris Creek, which sources its water from the dam.
Mr Batterham said Werris Creek residents had been put on level 1 water restrictions because the treatment plant is struggling to keep up.
The council has selected three contractors to consider the Quipolly Water Project, including Gongues Constructions, which built Gunnedah's new water treatment plant.
"We’re developing the design we go along," Mr Batterham said.
"We’re asking for innovation from these contractors and we’re involving them intimately now all the way and when we get ready to set the trigger we’ll ask them to price it and that’ll be the tender."
Under the Quipolly Water Project, a new water reservoir will be built in Werris Creek and a new pipeline from Werris Creek to Quirindi for "water security".
"We can send the different water sources to different towns so if one’s struggling a bit, the other one can help," Mr Batterham said.
"It’s a diversity we’ve never had."
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