Eight years after it was built, the $140 million Murrumbidgee to Googong Pipeline was finally used for its intended purpose on Thursday, for the first time transferring water to offset dry conditions as recent rain boosted local dams by just 2 per cent.
It's a bittersweet milestone for Icon Water - its investment finally put to use but only because the region is so dry. And, again, ironically, the pipeline is only being used because of recent rain improving flows in the Murrumbidgee River.
The pipeline was completed in 2012 to pump up to 100 million litres of water a day from the Murrumbidgee River to Googong Dam in drought conditions to ease the likelihood or length of water restrictions in Canberra.
But Thursday was the first time the pumps were turned on for water transfer.
Icon Water general manager Gerard Brierley said the pumps were being turned on gradually over three days this week, starting by extracting 20 megalitres a day and slowly building.
"It's terrific that the rainfall we've seen in recent weeks has boosted flows in the Murrumbidgee to the point we can begin pumping," Mr Brierley said.
"While Canberra's dams did not receive a huge boost, with overall storage increasing by around 2 per cent, being able to operate M2G means we have a second chance to lift our storages".
Mr Brierley said the pipeline would keep pumping as long as there was adequate flow in the Murrumbidgee and environmental guidelines were met.
The pipeline is meant to be triggered when Canberra's total water supply falls below 62 per cent but "low inflows and unprecedented climate conditions across the ACT" had meant the pipeline could not be used until now.
Mr Brierley said he expected somewhere between 50 and 100 megalitres of water to be transferred per day. The water transfer was likely to keep storage levels steady - "inflows matching outflows" - rather than lift Googong Dam to any degree.
Googong Dam is one of four dams that supply Canberra's water supply. Canberra's overall storage level was at 46.86 per cent on Thursday.
"While the ACT has had some good rainfall over the last few weeks, due to the dryness of the catchment landscape, the dams did not receive a lot of inflows, however across our four dams, storage did increase by around 2 per cent," Mr Brierley said.
The rain had helped to reduce water usage by Canberrans by 36 per cent.
"Any rain is good rain, as we have seen over the last few weeks, there has been a significant reduction in consumption of close to 36 per cent, which makes sense because around 40 per cent of water is used in the garden," Mr Brierley said.
"Canberra and Queanbeyan residents have done a great job at turning off their automatic watering systems and stepping away from the hose and we thank the community for that."
Water restrictions were still possible.
"It is still as important as ever though, that the community continue to be conscious of our water usage and take action to conserve water wherever we can," Mr Brierley said.
"At this stage, we are closely monitoring factors such as weather, dam levels and consumption.
"We are also mindful of the need to be flexible to unprecedented climate conditions and the sentiment of our community, and while we don't need to impose temporary water restrictions just yet, we are continuously evaluating all of these factors to determine if and when that decision may change.
"We can assure the community that we won't hesitate to act, if any when this is needed."
Icon Water had also been undertaking testing to ensure water quality meets both environmental and source water criteria, due to the impacts of the recent bushfires in NSW and the ACT.
"There is some discolouration to the water, which may show up in Burra Creek, however the water from Canberra and Queanbeyan's taps will be the same high quality the community have come to expect," Mr Brierley said.
Meanwhile, Mr Brierley said the pipeline was always meant to be a long-term investment.
"Source water infrastructure is designed to help us withstand droughts, and is not necessarily used during normal conditions," he said
"It is too soon to evaluate the benefits of the infrastructure in the current drought, but modelling for the business case to build the pipeline identified that it can significantly improve Canberra's water storage during drought conditions. This reduces the likelihood of Canberra experiencing water restrictions and can also reduce the length and severity of water restrictions if they are required."
