Dry winter causes dams to plummet

Callum HunterSouth Western Times

A dry winter has caused the levels of some South West dams to plummet by more than 20 per cent in comparison with last year.

Three of the five major dams are more than 12 per cent lower than they were at the same time last year, decreases experts have attributed to the much drier than usual winter.

“As a result of climate change, there has simply been less inflow from rainfall into the dams across the South West,” Water Corporation South West regional manager John Janssen said.

“It is projected that winter rainfall will decrease by up to 15 per cent by 2030.

“Harris Dam is currently at 30.29 per cent capacity.”

As of September 12, Harvey Dam’s capacity was down 23.2 per cent, Wellington Dam was down 21.2 per cent and Waroona Dam was down 12.8 per cent compared to on the same day in 2018.

While not one of the major dams, Glen Mervyn Dam’s capacity was down almost 37 per cent compared to last year which had resulted in a prolonged closure of the water body’s water skiing season.

Logue Brook Dam was the only one in the South West to sit higher on September 12 this year than it did last year, up just 0.1 per cent while Drakesbrook and Harris Dams were down 3.5 and 5.6 respectively.

“Drinking water for Collie and the 44 towns in the Great Southern Towns Water Supply Scheme is sourced from Harris Dam in Collie, and supplemented from Stirling Dam when required,” Mr Janssen said.

“On average, the above irrigation dams are 17.94 per cent lower than the same time last year.

“We encourage householders and businesses continue to save water.”

Harvey Water is responsible for delivering non-potable water to the Harvey, Waroona and Collie River districts, drawing from Drakesbrook, Waroona, Harvey, Logue Brook and Wellington Dams via gravity flow channels and pipes.

General manager Bradd Hammersley said there was no need for alarm as data was still flowing in with contingency plans in place.

“The season hasn’t finished yet in terms of inflow,” he said.

“Particularly with those more northern dams, we typically see that those catchments just don’t yield as much water.

“As a result of that we do hold a bit of water back between years so that we can smooth out any peaks and troughs when it comes to seasonal allocations.”

Mr Hammersley said that in his experience, every five years or so there was often a dry year and without being a weather man, 2019 could well be that year.

Mr Janssen said the Water Corporation was continuing to plan for climatic changes and water demands.

“Small changes can make a big difference and save considerable amounts of precious water,” he said.

Get the latest news from thewest.com.au in your inbox.

Sign up for our emails