Floods the price of bad planning

NSW and federal taxpayers are facing costs of billions of dollars to implement buybacks and land swaps to help thousands of Northern Rivers residents whose homes have been inundated during numerous floods. Premier Dominic Perrottet rightly has accepted every recommendation of the independent inquiry led by Mick Fuller and Mary O’Kane into the catastrophic Northern Rivers floods. Helping residents in “dire circumstances” is “the right thing to do”, as Mr Perrottet says. He has asked Anthony Albanese for a joint funding agreement to underwrite the cost of the recovery, as the federal government did for Queensland after the 2011 Grantham flood.

Government and local planning authorities must learn the lessons in the report. The effects of the floods, and the report, are a testament to years of bad planning and shortsighted approvals. “Many people live on flood plains in NSW, and many of these are in known high-risk areas,” the report notes. If a 19m flood (such as the 1867 record flood) happened in the Hawkesbury-Nepean Valley, more than 90,000 people would need to be evacuated and more than 15,500 homes would flood: “In all development considerations there is an overriding obligation to keep people safe. At minimum, development should only occur where it is possible to ensure residents’ lives are saved through safe and effective evacuation processes. Protecting property is a secondary but still important obligation.”

Like the surrounds of other capital cities, Sydney’s outskirts lack available land for another big dam. While not taking a view on a proposal to raise the wall of Warragamba Dam by 14m, being assessed by the NSW government, the report says the $2bn proposal to do so “has been assessed by Infrastructure NSW as the single most effective flood mitigation option available”. Modelling by Infrastructure NSW showed raising the wall had the potential to reduce flood impacts on homes and help with evacuation by delaying flood peaks and increasing the time before roads are closed.

However, the environmental impact statement for raising the wall, the report says, “identifies significant likely Aboriginal cultural heritage and biodiversity impacts from increased intermittent flooding of the World Heritage-listed upper catchment”. Indigenous sites and 88 threatened flora and fauna species would be at risk. The Insurance Council of Australia estimates that since 1970 the total incurred claims from flooding are more than $21.3bn, with floods in NSW and southeast Queensland in February-March this year costing more than $3.35bn. “These costs are likely to grow with climate change,” the report says. Governments can no longer postpone hard decisions on buybacks, planning and dams.