Western Australia's Swan Valley area has been declared a disaster zone after some of the worst flooding for decades damaged urban areas and also vineyards.

Summer floods caused ‘extensive damage’ to several Swan Valley vineyards, as well as urban areas and city parks, according to officials.

Photos showed vines half under water.

The un-seasonal flooding is some of the worst in living memory and, to complicate matters, has arrived at harvest time.

City of Swan mayor Mick Wainwright declared a state of emergency this week as the area tries to deal with the consequences of floods that have left vines, public parks and streets under several feet of water.

Local media reported that the damage to wine grape growers in the area could be between $10 million and $15 million Australian dollars, citing estimates by Darryl Trease, the president of the Grape Growers Association of Western Australia.

However, precise damage reports to vineyards were not immediately available.

Swan Valley lies just outside of Perth. It is one of Australia’s oldest wine regions, and settlers first planted vines there more than 180 years ago.

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