Questions answered at topical water meeting
Thursday, 19th February, 2015
By Craig Brealey
You can’t get water from a stone and there is not much left in the Menindee Lakes either but Broken Hill locals did extract a welcome admission from NSW water authorities at a public meeting last night.
And that was that the city uses but a fraction of the water in the lakes system and that enough could be held there at all times to guarantee our supply.
The big problem was getting the three states that are party to the Murray-Darling management plan to agree to it, the meeting was told.
It was “possible”, Paul Simpson from NSW Office of Water, told the 100-odd people at the Musicians’ Club, but to get NSW, South Australia and Victoria to agree to it would be a “big process”.
Mr Simpson, along with representatives of Water NSW and local water company Essential Energy, all addressed the “community consultative meeting” which was the first to be held in the city to explain what was being done to keep Broken Hill and the Darling River towns supplied with water during the drought.
The crisis here began when the lakes were emptied in December 2013 to send the water south. Broken Hill is now on water restrictions and the NSW Government is sinking bores by Lake Menindee to look for water underground. A reverse osmosis plant will have to be used to extract the salt to make it drinkable and the saline waste from that process will have to be put somewhere.
Also, the meeting was told last night that Water NSW was looking at whether it would be feasible to raise the crest of Weir 32 to hold more water upstream in the river.
Approval has also been given to drill for bore water under the dry bed of Lake Menindee because it might not be as salty, and approval was being sought to drill at the Talyawalka floodplain, 20km south of Menindee.
The meeting also heard that the heavy rain last month had put about 6000 megalitres into Broken Hill’s reservoirs and extended the city’s supply by four months.
But everyone last night wanted to know why the lakes were drained when the drought had already begun. Mr Simpson explained that records showed that flows in the Darling had always been variable and that after the exceptional “Millennium Drought” no-one expected another so soon.
This prompted a question from floor: If the flows are so unpredictable, why not raise the level at which NSW takes control of the lakes and stops any more water being released, so as to permanently ensure Broken Hill’s supply?
It was at this point that Mr Simpson said that it would be possible because only “a small fraction of the water is used by Broken Hill”.
Raising the so-called “trigger level” could be investigated, he said.
But the immediate problem was what to do now, Mr Simpson said. “The lakes are below 25 per cent capacity and we have had seven years of low or no inflow” and the forecast was not good: without any fresh intakes, the water would get saltier by the month and the lakes would be dry by April next year.
At that point, said Guy Chick, Essential Energy’s Water Manager, the city would switch to bore water.
“If it stays dry for 14 to 15 months, that’s when you get it,” Mr Chick said.
That water would be treated through the reverse osmosis plant that was commissioned for the last big drought and the State Government had promised subsidies to pay for it, Mr Chick said. He said the government had been told that the city could not afford it.
He said reverse osmosis would make the water clean and potable (“It takes everything out”), and John Coffey, Essential Energy’s Manager of Water Supply and Quality, assured the meeting that there would be no repeat of the disaster last time when the muddy, salty water wrecked people’s air conditioners and water systems.
The meeting was also told that bore water was an emergency solution and that once the lakes filled again, they would be closed down. There were also no plans to mine the lake beds for mineral sands or grow cotton on them, the authorities said.
Broken Hill also won another concession last night. Everyone jeered when the water people tried to sheet some of the blame for our predicament to the Menindee Lakes losing more water than any other body of water in the land to evaporation.
Tony Webster of Water NSW said they got the message.
“I won’t use the ‘e word’ in mixed company every again,” he told the meeting.