Sydney's disastrous flood wasn't unprecedented: we're about to enter a 50-year period of frequent, major floods
Last month’s flood in the Hawkesbury-Nepean River region of western Sydney peaked at a staggering 12.9 metres, with water engulfing road signs and reaching the tops of many houses. There hasn’t been a major flood on the Hawkesbury-Nepean for more than 30 years, with the last comparable one occurring in 1990. Long-term Sydneysiders, however, will remember that 12 major floods occurred during the 40 years before 1990. Five of these were larger than last month’s flood. So what’s going on? The long-term rainfall pattern in the region and corresponding river flow is cyclic in nature. Thi...