Ananova:

Long distance swimmer Tammy van Wisse has been forced to postpone her 1,500 mile swim of one of Australia's most polluted rivers due to flooding.

Van Wisse was hoping to start her marathon swim at Corryong in Victoria on Sunday, but sections of the Murray River are in flood and conditions are dangerous.

The three-month swim to highlight environmental problems and the need for conservation has been put off for a week.

Supporter Alan Jameson said: "The water is flowing in excess of 15 kilometres an hour, there is white water and turbulence and conditions are treacherous."

The Murray River is plagued with toxic blue-green algae, which kills off water life, polluting the river and making it unsafe for swimming. Van Wisse plans to spend more than two months swimming the length of the river, for eight hours per day, stopping at towns and cities along the way.

She has previously set records swimming Loch Ness and the Bass Strait - the stretch of water which lies between the Australian mainland and Tasmania, the Sydney Morning Herald reports.

She will not be the first to swim the Murray River, but she plans to be the fastest - beating the record set by Graham Middleton, who stopped 40km short of the mouth of the river during his swim in 1991.

Van Wisse said she intended to use the trip to highlight the degradation of the river and the need for conservation.