NIK MOIR / SMH
Sheep on a dried out lake floor. Burrendong Dam has fallen to 1.6 percent.
The water levels at the Burrendong Dam of NSW, which is three times as large as those of Sydney Harbor, have fallen to a critical low of 1.6 percent, and rain is unlikely to help this weekend.
When the dam is full, it contains more than a trillion liters of water and supplies local irrigators and Australian cities such as Dubbo and Cobar in the central west of the state.
Only three years ago, the dam had a flood level of 120 percent, before devastating drought conditions occurred.
Now there are fears that the dam, which spans the Macquarie River, will run dry and leave cities without a water source. In some areas that can happen quickly: according to modeling programs, Dubbo can run dry by the middle of the year, while for Cobar regular water sources can fail by September.
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“It should be scary for many people,” said Cobar Chairman Peter Vlatko.
“The government’s commitment is that we will not run out of water. But the problem is that the Burrendong is 1.6 percent.”
The state government has promised that Cobar will receive 80 percent of its allocated water by 2020, Vlatko said.
But old and defective infrastructure has exacerbated problems, with a major pump failure in Hermidale at the end of last year. Residents of Dubbo and Cobar are reliant on ruthless water restrictions and miners have been told to save water.
An AGL hydroelectric station that is normally removed from the dam has also been shut down.
NIK MOIR / SMH
Burrendong Dam in drought seen from a drone.
In the meantime, local officials are trying to install additional pumps to extract water from the dam’s usual outlets.
There are also plans to divert water from the Windamere Dam, almost 200 kilometers away. WaterNSW meets landowners and can release up to 25 gigaliter in early February, according to a WaterNSW official.
According to the plan, water would flow into the Burrendong dam via the Cudgegong River.
WaterNSW will assess whether the emergency aid is needed after the predicted rain this weekend.
But it is unlikely that the rain will raise the water level in Burrendong significantly.
“The soil is currently so dry that it works like a sponge,” said NSW University water scientist Stuart Khan. “When that happens, a significant amount of rainfall is needed to generate runoff.
BURRENDONG SPORT AND RECREATION
Conservationists rescue kangaroos from a flooded Burrendong dam in December 2010.
“If we have 40 or 50 mm [rain], we might expect a good run-off. But 50 mm doesn’t fill it anymore. I think you need something like 50 mm to even generate run-off.”
WaterNSW agreed that “significant” rainfall would be needed to make a difference to the levels of the dam.
In its current state, Burrendong Dam looks unrecognizable compared to during flood years. In 1990 and again in 2010, deluges filled the dam until floods, with a catchment area of more than 150 percent.
Wildlife, including kangaroos, stranded, requiring a rescue operation by boat.
The last year of flooding was 2016, after which the levels started to fall.
Now, with so low dam levels, tourism and recreation have fallen off in the area.
Codey Swadling, from outside Orange, grew water skiing on the dam.
“It’s a significant loss for the people who regularly use the water for water sports,” he said. “[But there is] a much heavier impact on the communities and businesses that depend on … these hobbyists.”
WaterNSW said that “historic” dry conditions were responsible for the almost empty dam levels.
Swadling agreed that he had never seen the dam in this condition.
“The landscape has been destroyed. I cannot remember such a long period of emptiness.”