Warragamba Dam could spill on Monday due to heavy rainfall predicted for Sunday evening.
Water levels at the south-west Sydney dam were at 98 per cent at 6pm, after parts of the city received more than 37mm of rainfall since 9am.
Warragamba Dam, Sydney’s main catchment, last spilled over in August 2015 – and may again on Monday. Photo: Edwina Pickles
Heavy rain in the afternoon saw Homebush in western Sydney drenched by 9mm in 10 minutes, while Badgerys Creek, near the dam, had almost 22mm since the morning.
A WaterNSW spokesman said the catchment had been „saturated” and the heavy falls made run off at the dam a possibility.
„The heaviest rainfall will be this evening,” the spokesman said on Sunday. „We are working with the Bureau of Meteorology and the SES to monitor the rainfall.”
Cars go over Sydney Harbour Bridge as wet weather soaks Sydney on Sunday. Photo: James Alcock
Emergency crews expect to be on standby until at least Monday when the weather is likely to clear.
A NSW State Emergency Service spokesperson said the Bureau of Meteorology anticipated 50 to 70 millimetres of rain would fall over Warragamba Dam on Sunday night.
She said minor flooding could occur around North Richmond but those areas potentially affected were mainly rural farmland.
„NSW SES is closely monitoring Warragamba Dam as well as the Illawarra and South Coast as the low moves south,” the spokesperson said.
Weatherzone meteorologist Brett Dutschke said it would probably be raining more often than not.
„During the day – between 10am and 8pm – it looks like it will be raining 90 per cent of the time,” he said.
Mr Dutschke predicted there would be 20 to 40 millimetres of rain falling across most of Sydney, with some areas in western Sydney expected to cop up to 50 millimetres.
But the downpour will be only a fraction of the 100-200mm recorded during the last east coast low to drench the city two weeks ago, the Bureau of Meteorology says.
Some parts of Sydney may receive more rainfall as heavier bands within the larger rain band make their way south along the coast and off to the east.
„There will be some dry patches throughout Sunday, but generally it’ll be a wet one,” said Bureau of Meteorology forecaster Gabrielle Woodhouse.
„The rain will start easing on Monday, with between two and three millimetres predicted before clearing on Tuesday,” Ms Woodhouse said.
Northerly winds will start intensifying, with the Bureau issuing a strong wind warning for the Sydney, Illawarra and Bateman coasts on Sunday.
A low is expected to form near the Illawarra coast on Sunday evening before deepening and moving south early on Monday. Heavy rain in excess of 100mm, possibly 150mm, may lead to flash flooding in the area.
Damaging winds averaging 60-65 km/h with peak gusts in excess of 90 km/h are possible along the coastal fringe from the early hours of Monday.
A gale warning is in place for the Byron, Coffs, Macquarie and Hunter coasts.
King tides no longer threaten the coast, lowering the prospects of coastal erosion, though some areas of the coastline are still open to further damage, Ms Woodhouse said.
The Bureau also issued a flood watch on Friday afternoon, identifying a greater than 70 per cent chance of flooding in nine river valleys in NSW from Sunday onwards.
Most of the nine are expected to have minor flooding, although the Nepean-Hawkesbury is among three catchments that may get moderate flooding.
– with Georgina Mitchell
http://www.smh.com.au/nsw/warragamba-dam-set-to-spill-on-monday-as-heavy-rain-falls-on-sydney-20160619-gpmomm.html
