How parts of the state’s central west turned into a sea

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Large parts of inland NSW have been transformed into a freshwater ocean in just over a month. Where riverbeds were cracked and dry three years ago, they are now flowing with brown floodwater after weeks of heavy rainfall.

Major flooding has left millions of crops and livestock washed away, hundreds of homes damaged and thousands of miles of roads destroyed across the state. For almost a month, the central west has been subject to severe flooding.

Satellite images from NASA show the dramatic shift from drought to flooding in the Midwest. In 2019, major waterways including the Darling, Lachlan and Murrumbidgee rivers were bare. Three years later, they overflow.

In just over 24 hours on November 14, almost 120mm of rain fell on Forbes to an already saturated landscape, prompting fears it could experience its highest level of flooding for 70 years. The city held its breath as floodwaters rose and flooded main streets. The Lachlan River at Forbes peaked at 10.6m, just above the major floods but below the 1952 level of 10.8m.

The nearby town of Eugowra recorded a similar amount of rainfall between 12 and 13 November. One of the two gauges upstream of the town showed Mandagery Creek rising by up to 88 centimeters per hour on November 12 as rain poured across the northeast. of the Lachlan Basin. The river peaked at 9.8 m two days later, surpassing the previous record of 9.6 m in 1950.

The NSW SES has only just begun to assess the devastation in the city and records 216 damaged homes.

In satellite images taken of the region last week, it is almost impossible to distinguish where the Lachlan River begins and ends, compared to a photo of the same area in July.

Weather zone forecaster Felix Levesque said a widespread deep low pressure system was behind the latest rainfall that lashed the Central West region from November 12. The weather system also affected parts of Victoria, Queensland and South Australia. But it was NSW’s Central West that was worst hit.

Within days the system had moved across eastern parts of NSW, but the damage had already been done.

La Nina and the Indian Ocean Negative Dipole (IOD) exacerbated the wet weather, Levesque said. But these weather patterns look set to weaken in the coming months; IOD is already showing signs of relief. If it remains weak for the next fortnight, it will This is reported by the Bureau of Meteorology it would be able to classify it as finished. La Nina is set to weaken in the new year.

It will take weeks for the floodwaters to work their way to the sea; flooding in the central west will first flow through various rivers and streams before emptying into either the Darling or Murrumbidgee Rivers and then into the Murray River before moving through South Australia and out to sea.

The delay adds to the thousands of gallons of floodwaters that have washed through the state since earlier this year.

The flooded landscape across the central west paints a very different picture to three years ago, when Australia suffered a record drought.

Between January 2017 and December 2019, NSW temperatures were the hottest and rainfall was the lowest on record.

The satellite images show the Lachlan River during November 2019 and 2022. Where once dry folds of orange, clumped dirt lay, brown floodwaters now flow across the landscape.

Driven by the wet weather we have witnessed over the past three years, there has been a huge increase in moisture across the landscape. Sentinel Hub’s “normalized difference moisture” index data – which measures the water content of the vegetation – illustrates this increase compared to Forbes.

However, large floods can benefit ecosystems. Some animal and plant populations are now undergoing a massive boon. Professor Richard Kingsford, director of the Center for Ecosystem Sciences at the University of NSW, said the droughts of 2017 and 2019 caused rivers to dry up that many never expected, including the Macquarie Marshes and parts of the Darling River. The drought also resulted in the death of thousands of animal species.

But typically after heavy rains and floods, there is a period of blessing that Kingsford has already observed occur. The question for scientists will be how much these populations bounce back and whether they will be able to establish themselves before the next drought.

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“We’re likely to see a long-term shift in ecosystems,” he said.

“There’s a combination of the way we’ve managed rivers and climate change that may mean some of them may no longer be adapted to get through [those droughts]. While other plants and animals from more extreme systems may move into better water bodies where they survive and deal with the truly extreme droughts.

“This is a very big event. It has all the really damaging effects on us, the infrastructure – and it’s going to have huge economic consequences.

“But there will also be long-term economic and environmental consequences in terms of what this water has done to these ecosystems.”

Forbes Shire Council mayor Phyllis Miller said the region has seen back-to-back flooding since August, while Forbes has been hit three times since October.

“Of the three floods, this one was the biggest I’ve ever seen,” she said. “You go to bed and think about it, make sure everyone’s fed, stock up, and make sure everyone’s OK. We’re resilient, we’ll come back from it, but we just need a break.”

Farmer Gerard Glover has been in isolation on his property in the Central West – about 30 kilometers south-west of Brewarrina – for about four weeks. He said November’s flooding was one of the biggest the area has experienced, and even if they were prepared – by providing plenty of food, among other preparations – it will take weeks before they can get out.

“Santa won’t drive in,” he said. “If we don’t get any more rain, I think we might get out somewhere around Christmas or New Years.”

In the meantime, Glover will use helicopters and four-wheel drive vehicles to assess the damage to his property and do what he can, including mustering sheep and cattle. “Just because [flood] the peak has passed, it does not mean the flood is over for us,” he said.

NSW Farmers Business, Economics and Trade Committee chairman John Lowe said the floods had damaged thousands of kilometers of roads, adding stress to an already difficult time for farmers.

He said after years of drought, floods, fires and rising costs of living, many hoped this year’s crop would bring in a handy income stream. Lowe’s own property in the central west has been isolated by flooding since last November, and the family will have to place this year’s harvest in a silo until the roads reopen.

“We were looking at a record harvest [across the state] until the recent floods,” he said. “I don’t think there’s a road in NSW that doesn’t suffer significant damage.”

“This will keep state engineers awake at night, they will be busy figuring out how to allocate resources and how to keep the roads functional.”

Lowe said that while there are short-term solutions, such as putting gravel in holes, they were only temporary measures. Instead, he said more durable roads and drier weather are needed.

A Transport for NSW spokesman said the heavy rain this year had damaged more than 2100km of roads since February.

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The spokesman said Transport for NSW teams were working with emergency services to repair the road network as quickly as possible. While the damage from this latest round of flooding is still being assessed, more than 10,000 km of roads are expected to have been damaged. Earlier this year, more than 100 bridges were damaged during the floods in February and March. They are expected to cost about $150 million to repair.

For now it looks like there will be a break in the wet weather as a high pressure system moves through southern Australia.

“When it reaches NSW, it will ease the strong winds that have affected the south-east,” Levesque said. Another trough is expected to move across Victoria and NSW later this week, which could bring some more rain. But models show that the northern part of the country will be hardest hit.

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