Heavily-populated regions of New South Wales (NSW), Australia’s most populous state, including its capital Sydney, are continuing to be hit by rapidly-rising floodwaters after several days of heavy rainfall. With the downpour not predicted to ease until Wednesday or Thursday, tens of thousands of people face the prospect of having to evacuate their homes.

Over the past 24 hours, the flooding has spread widely, with southeastern areas in the neighbouring state of Queensland also impacted. The rainfall has broken longstanding records in numerous locations.

Late yesterday, the NSW Liberal-National government declared a natural disaster in parts of the state. As of this morning, almost 3,000 people had been forced to evacuate in greater Sydney, along with 15,000 elsewhere in the state. The authorities are warning that as many as 54,000 could be compelled to do the same before the crisis is over.

As the intensity of the flooding has increased, fears over safety and the possibility of lives being lost have been added to concerns of the financial hardship that the disaster will create for working people, especially those living in low-lying areas.

Overnight, the NSW State Emergency Service conducted 150 rescues, and attended almost 2,000 other callouts, taking the total to nearly 10,000 since last Thursday. In one incident, an 80-year-old woman was rescued from her car, trapped in floodwaters on the NSW Central Coast. In others, entire families, including infant children, have been rushed from properties after they were surrounded by water.

Already, experts have said the impact of the deluge has been exacerbated by governments encouraging housing construction in flood-prone areas. Questions have also arisen over dam management, and broader disaster planning as the number of serious weather-related events has continued to increase this century.

Among the hardest-hit areas of Sydney are its working-class western suburbs. Evacuation orders were hastily imposed for some Penrith residents yesterday, as the Nepean River registered its highest water levels in some 60 years. Some received a text message late in the afternoon, instructing them to leave within half an hour and warning that they would be left without power and water if they failed to do so.

Parts of neighbouring suburbs, including Mulgoa, Windsor, Jamisontown and North Richmond, were also covered by the orders. Early this afternoon, the authorities registered a slight fall in the level of the Nepean, meaning a possible reprieve.

The northwest reaches of greater Sydney are under threat, as the Hawkesbury River also has risen to levels not seen since 1961. Evacuation orders are in place for Agnes Banks, Freemans Reach, Cornwallis, Pitt Town North, Gronos Point and Pitt Town Bottoms.

Sections of the Central Coast, north of Sydney, are experiencing rising waters.

So far, the largest number of evacuations have been further north, with many towns on the state’s mid-north coast inundated. Flooding in the region is tipped to be the worst in the past hundred years.

Residents in Kempsey were contacted just before midnight yesterday and told to leave their homes immediately, with many fleeing to an evacuation centre in the town’s showgrounds. Other low-lying areas in the region, such as central Wingham, Taree Estate, Dumaresq Island, Cundletown, Laurieton, North Haven, Dunbogan, Bulahdelah, Kings Point, Macksville and parts of Port Macquarie are also being cleared.

Andrew Mitchell, a local resident, gave the Sydney Morning Herald a sense of the speed of the flooding. He said that when he reached Telegraph, a town 50 kilometres from Kempsey, where his older parents live, the water was already up to their necks. He rescued them with his own boat, but that also rapidly took on water before they were able to reach safety.

The flooding destroyed Mitchell’s family home, which his parents had occupied for 40 years, and swept away their two cars. “The water was higher than the top of their door frame and washed away their personal documents, belongings, computers, fridges… everything,” Mitchell said. “They have nothing. Everything is destroyed.” With both having retired, they face the prospect of effective homelessness and poverty.

With the crisis still unfolding, the number of people suffering a similar fate is unknown, but is likely to be in the thousands, if not the tens of thousands. Floodwaters are continuing to rise in southeastern Queensland and northern NSW, including the regional city of Lismore.

In explaining the severity of the flooding, meteorologists have pointed to the convergence of three weather systems. A tropical low has hit a coastal trough, while a band of high pressure has prevented them moving away from the coastal regions.

In November, the Bureau of Meteorology (BOM) warned that Sydney faced a heightened risk of flooding over the following months as a result of a La Niña weather phenomenon and high dam levels. BOM’s Agata Imielska stated: “Our dam levels in the Greater Sydney area are at just over 95 percent capacity, with Warragamba Dam sitting at just over 97 percent. If we get any heavy rainfall in that area it’s more likely to produce flooding because of the limited capacity for our soils to absorb that moisture.”

As predicted, Warragamba began to spill over, after reaching capacity on Saturday, which apparently contributed to the speed of flooding in Penrith and surrounding areas. On Sunday, controlled releases of the water began, with some 450 gigalitres, or the equivalent of the entire Sydney Harbour, pumped out per day.

Dam management is apparently the subject of a conflict within the NSW government, with Emergency Services Minister David Elliott reportedly “furious” at Water Minister Melinda Pavey for failing to have ordered a reduction in the level of the dam before the forecast rains.

Publicly, however, government representatives, including Premier Gladys Berejiklian have claimed that the downpour was so great that the dam level would need to have been lowered dramatically to have any impact, potentially affecting its role as a main water supply for Sydney.

A government proposal to raise the level of the dam wall has been criticised by some experts. Professor Jamie Pittock, from the Fenner School of Environment and Society at the Australian National University, told the media that the flooding was more the result of “poor governance” than an “act of God.”

Pittock said: “Successive state governments have failed to address the 5,000 homes built below the 1:100 year flood line. The NSW government’s proposed ‘silver bullet’ solution of raising the Warragamba Dam to control floods is dangerous.

“The NSW government should stop plans for 134,000 people to move onto the floodplain by 2050. It should begin long-term programs to help the most flood-prone residents relocate to safe sites. Restoring the floodplain to give the river room to flood more safely can boost opportunities for agriculture, recreation and nature conservation.”

The growing population on flood plains is one aspect of a property and construction boom encouraged by one government after another, both Liberal-National and Labor. With tax incentives, cheap credit and little regulation, this has created a bonanza for property developers, real estate companies and wealthy investors.

The soaring property prices, moreover, have forced working-class households into cheaper far-flung areas, including those that are prone to flooding, and where housing flood insurance is prohibitively expensive.

In a sign of nervousness that the floods will compound growing social anger, Prime Minister Scott Morrison issued a video message of support yesterday. His government announced miserly, one-off disaster relief payments of $1,000 for adults and $400 for children, including for those who have lost their homes. Today, Morrison signaled that the military would be mobilised to assist recovery efforts, as in last year’s bushfire disaster, underscoring the inadequacy of civilian relief programs.