Overflow taken with grain of salt

Joshua Zimmerman and Rebecca TriggerThe West Australian

The South West's biggest dam is overflowing for the first time in four years but local farmers aren't singing in the rain just yet.

Collie's wettest September in 17 years has pushed the Wellington Dam, about 25km west of town, over its capacity after cold fronts dumped more than 210mm of rain on the area this month.

On average, dams in the South West are 80 per cent full, about 40 per cent higher than the same time last year. Perth dam levels are averaging 37.9 per cent, up from 32.4 per cent last year.

The Wellington Dam overflow attracted tourists and the community as water cascaded over the 367m concrete wall. An estimated 6 billion litres had overflowed by yesterday.

But farmers feared salinity levels remained less than ideal.

"It's good they get the water for irrigation and it keeps the paddocks green but nothing grows in it," Collie Shire president Wayne Sanford said. "There is too much salt in the water for it to be of any agricultural benefit."

Since 1990 Wellington Dam has supplied irrigation water to farmers between Benger and Dardanup and is regularly scoured to dispose of salty water.

Water Corporation South West regional manager Scott Moorhead said the overflow helped reduce salinity but opening the valve at the bottom of the dam wall was most beneficial.

"We would like to reduce overall salinity levels to improve the water for irrigators, but there are no plans to return it to a potable water source," Mr Moorhead said.

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