# Perth weather watchers worry below-average winter rainfall leaving landscape vulnerable Source URL: https://www.abc.net.au/news/2020-08-31/wa-below-average-winter-rainfall-leaves-industries-exposed/12611216 Date: 20200830T2123 Eugenio Valenti has spent almost 70 years growing some of the most coveted grapes in the Swan Valley and turning them into his rustic, Italian-style wine. ## Key points: * Perth has had another winter of well-below-average rainfall * Industries including winemaking are at risk if the drying trend continues * Climate change lobbyists say investing in clean energy will boost jobs But a lot has changed since the 89-year-old started in 1952, most notably the climate. "It's changed a lot — before in the winter, there was lots and lots of rain, the drainage and the creeks were full," he recalled. "Close to the Swan River they were pruning with a little boat between the vines because the water was very deep. Now you never see that. Mr Valenti said while his vineyard had withstood the drier winters with few disruptions so far, hotter summers had caused the grapes to ripen earlier. Eugenio Valenti says the drier, warmer winters are a threat to winemaking in the Swan Valley.(ABC News: Irena Ceranic) He warned that if current trends continued, the region's winemaking industry would suffer. "But I won't have to worry anymore because I won't be here," he laughed. ## Kings Park looks to future-proof plants Perth's largest park has also had to adapt to ensure it thrives well into the future. Kings Park's seed collector travels throughout Western Australia sourcing species of plants that are not reliant on regular rainfall. Arid species, such as this Eucalyptus rhodantha — commonly known as a Rose Mallee — are being planted in Kings Park.(ABC News: Irena Ceranic) "There's been a real focus on the desert, on the Pilbara and the Gascoyne — those arid regions of Western Australia — in picking plants that we believe are future plants for the Perth region," senior curator Grady Brand said. "As water reduces there will be a range of plants that just won't make sense to grow here on the Swan Coastal Plain, [including] a lot of the exotic flora and even those from the far south-west where they have high water demands." Mr Brand said in the 42 years he had worked at Kings Park, the cold fronts that typically brought winter rainfall had lost their lustre. Grady Brand says Kings Park is focusing on sourcing plants that don't need regular rainfall to survive.(ABC News: Irena Ceranic) "I do remember you would see the front coming and it would be black and solid and you would know if … we're getting 25 millimetres, 50 or 75, it was just what happened in the 70s and 80s. "Whereas now they're broken, fragmented and unreliable." ## Rainfall dwindles as cold fronts fade Perth has recorded well below-average rainfall this winter, like most in recent years. The south-west of WA, which includes Perth, has experienced a significant decline in rainfall during the cooler months. According to the Bureau of Meteorology (BOM), the drop in the May-to- July period has been particularly steep, amounting to 20 per cent since 1970 and 26 per cent since 1999. Rainfall has been declining in the south-west of WA, including Perth, since the 1970s.(Supplied: Bureau of Meteorology) "What we are seeing is a lack of systems that deliver that rainfall — the cold fronts are becoming less frequent," BOM spokesman Neil Bennett said. During the cooler months, highs generally sit over central parts of the state, allowing cold fronts to reach southern WA. In the warmer months, the highs drop to the south, blocking the fronts from reaching the state. But Mr Bennett said there had been a shift in this seasonal pattern. "They are moving to the north much later, and they're moving to the south much earlier, so the season when that high pressure system is north of Perth is much shorter. And that's the reason we're seeing the drop-off in the rainfall." ## 'A signature of climate change' The south-west of WA has long been referred to as the "canary in the coal mine" for climate change. It was observed here much earlier than in the south-east of Australia. Consequently, the Water Corporation had to come up with methods to produce drinking water that were resilient to changes in the climate. About half of Perth's drinking water is desalinated Indian Ocean water.(ABC News: Ian Cutmore) Up to 50 per cent of Perth's drinking water now comes from the Indian Ocean and is processed in desalination plants. Streamflow into dams — traditionally one of Perth's primary sources of water — has reduced at such a rapid rate, it now makes up just 10 per cent of the city's supply. "The drying trend in the south-west is a signature of climate change," Mr Bennett said. "It doesn't mean that every single winter is going to get drier and drier, but what we are seeing is a decrease in the number of years where the rainfall is above-average." ## Industries to be 'wiped out': think tank Climate change think tank, Clean State, has warned that if WA continues on its current trajectory, industries such as winemaking would no longer be viable. Warm, dry winter days are threatening the future of winemaking in the Swan Valley.(ABC News: Irena Ceranic) "If we go to 2 degrees of warming (from pre-industrial levels) we'll have temperatures in Perth that are like Geraldton's and Perth's temperatures down in Margaret River," director of research and policy Chantal Caruso said. "That would wipe out all those industries down there that are depending on that beautiful Margaret River climate, like our wineries." Clean State has called on the WA Government to invest in clean energy and, in turn, create more jobs to reboot the economy. "Our wine and crayfish industries, agriculture and tourism, they're depending on the State Government to take strong action," Ms Caruso said. "We're really excited about the opportunities that action brings to local economies and to jobs in Western Australia." The State Government is expected to release its climate policy before the end of the year.