9 November 2020

Canberra dams near full capacity but we're still urged to be water-wise

| Michael Weaver
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Googong Dam

Googong Dam in full flow with water spilling on 4 November. Photo: Icon Water.

All four of Canberra’s dams are near full capacity for the first time since November 2016.

As of today (7 November), the combined capacity level of the four dams that supply water to Canberra and Queanbeyan was at 99.3 per cent. Only Corin Dam remained below 100 per cent capacity.

However, a spokesperson for Icon Water said inflows into Corin were dropping ever so slightly, and with no major rainfall forecast, the dams may not reach 100 per cent this weekend as predicted.

When the dams hit 100 per cent capacity, it will only be the second time the ACT’s total water storages have reached 100 per cent since the enlargement of the Cotter Dam. The first time was in November 2016.

Cotter Dam

A different view of Cotter Dam from above. Photo: Tim Burgess.

The smallest of the four dams, Bendora, was the first to reach capacity in late August after strong inflows from winter rainfalls. The water spilled into the Cotter River and made its way downstream to the Cotter Dam which reached 100 per cent capacity on 3 October.

It was the first time this had occurred since December 2016.

The water that spills from Cotter Dam eventually makes its way to the Murrumbidgee River which is particularly important for endangered Macquarie Perch to feed, breed, migrate and spawn.

Googong Dam, on the Queanbeyan River system, reached 100 per cent on 2 November. Water there flows into the Molonglo River upstream of Lake Burley Griffin. Once past Scrivener Dam, water then flows down the Molonglo, past Lower Molonglo Water Quality Treatment Plant and into the Murrumbidgee River. The water then makes its way through rural land and onto Burrinjuck Dam.

Corin Dam was at 97.3 per cent capacity on Saturday (7 November) and was filling after good rainfall again earlier this week, but the level remains just below tipping point.

Video below by Trevor Webb of Cotter Dam on 2 November

Icon Water’s general manager of infrastructure services Gerard Brierley said inflows have been high recently but not close to any record levels that were experienced in 2010 when inflows into Googong Dam were in excess of 90 gigalitres per day.

“Over the last week, inflows to Googong Dam have been on average 1.84GL/day,” Mr Brierley said.

He said hard work by the Canberra community to reduce water consumption and lots of rain put Canberra and Queanbeyan’s water supply in a very good place.

We are thrilled that due to recent rain and the work to reduce water consumption by our community that we will soon reach this milestone. We know that the dry conditions of last summer resulted in devastating bushfires that reached the Cotter catchment, and the landscape surrounding the Corin Dam was severely damaged.

“Just nine months ago, in February 2020, dam levels dropped below 45 per cent, following a very hot summer and two of the driest years on record.

“And now we are talking about 100 per cent storage and we are thrilled.

“It is a great sight now if you get out to visit any of the dams to watch the water flow over the side,” Mr Brierley told Region Media.

He also urged Canberrans to continue their water-wise habits.

“All community members should always think about not wasting water, no matter the dam levels. It is also important to teach our kids water-wise behaviour and to build positive habits. That way when conditions are dry again we are already doing the right things and not wasting water,” he said.

Cotter Dam

Cotter Dam spilling on 3 October. Photo: Michael Weaver.

Minister for Police and Emergency Services Mick Gentleman warned that above-average rainfall is increasing the risk of flash flooding in the ACT.

“The ACT has seen a large increase in dam and river water levels, as well as water pooling on land and roads due to significant ground saturation,” said Mr Gentleman.

ACT Emergency Services Agency Commissioner Georgeina Whelan says the La Niña weather pattern will also see a higher risk of storm and flood during the bushfire season.

READ ALSO Googong goes with the flow to prevent potential flood in Queanbeyan

“With a La Niña event well and truly in force, it is important residents take the time now to prepare their homes and properties for all types of hazards,” said Commissioner Whelan.

“The Bureau of Meteorology is forecasting drier days over the coming week before the return of wet weather once again. Use this time to repair existing damage and ensure you are storm and flood ready.”

You can visit the ACTMapi website to check if you live in a flood-prone area. There are also tips to be flood-ready on the ACT Emergency Services Agency website.

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