Sydney’s Warragamba Dam started spilling on Wednesday morning and is now combining with heavy rain to cause flooding on the Nepean and Hawkesbury Rivers.

An atmospheric river has been dumping heavy rain over central NSW during the last two days. The animation below shows this steady stream of rain falling over Western Sydney and the nearby ranges on Wednesday.

Video: Radar animation showing observed rainfall on Wednesday, March 2.

A rain gauge at Warragamba Dam received 155 mm of rain during the 31 hours ending at 4pm AEDT on Wednesday, including 48 mm between 11am and 1pm.

This rain caused Warragamba Dam, which was almost full prior to this wet weather, to start spilling on early on Wednesday morning.

River level gauges on the Nepean and Hawkesbury River have been responding to the heavy rain and inflows from Warragamba Dam.

Moderate flooding was being observed on the Hawkesbury River at North Richmond by 5pm, with major flooding likely from Wednesday night into Thursday.

Image: Flooding on the Hawkesbury River at Wisemans Ferry on Wednesday. Source: @hawkesburyriverescapes / Instagram.

The Nepean River at Menangle Bridge had exceeded the site’s moderate flood level of 9.2 metres by 1:45pm on Wednesday, which was an increase of an increase of nearly 9 metres in 24 hours. The river kept rising and shortly after 4pm it has exceed the major flood level of 12.2 metres.

Image: Observed river level heights from the Nepean River at Menangle Bridge on Wednesday, March 2. Source: Bureau of Meteorology.

More heavy rain will fall over a broad area of eastern NSW on Wednesday night and Thursday as moisture-laden onshore winds continue to feed in from the east. Within this river of atmospheric moisture will be an East Coast Low that is expected to cause more focused area of very heavy rain, thunderstorms and potentially damaging winds over the state’s central coast and ranges on Wednesday night and Thursday.

Severe weather warnings, flood warnings, evacuation warnings and evacuation orders are currently in place across large areas of eastern NSW, including parts of Sydney. Be sure to check the latest warnings and evacuation advisories in your area during the next 24 to 48 hours.