Ballarat City Council has resorted to pumping in about 60 megalitres over the rest of the summer to help fill the lake, which is suffering from the lack of rainfall since mid-December.

Only 1.2 millimetres of rain has been recorded in Ballarat since Christmas Day, and last year’s rainfall of 633 millimetres was well below 2010 and 2011 levels.

The lake is now about 275 millimetres below full, compared to about 190 millimetres below capacity at the same time last year.

Although the council initially reported it was filling the lake with recycled water from the Ballarat North treatment plant, The Courier has since learnt that bore water is being used instead, due to reduced recycled supplies because of closures over Christmas.

A Ballarat City Council spokesperson said low water levels were normal at this time of year, and enabled run-off from summer storms to be properly managed.

“Water supply for the lake includes recycled water and stormwater and stormwater inflows, with additional groundwater used when required,” the spokesperson said.

“The cost of additional water falls under a commercial-in-confidence agreement between council and Central Highlands Water.”

The spokesperson said pumps and pipes had been installed during the drought to restore the lake to capacity and make sure it could be maintained.

“The economic benefit of restoring the lake has been estimated at $5.4 million.

“This is reflected in increased attendances at events such as the Ballarat Begonia Festival. The lake’s restoration has also enabled Ballarat to successfully bid for the 2014 World Rowing Masters, which expected to attract up to 10,000 competitors and spectators.”

The spokesperson said the lake was  monitored daily, and evaporation caused by recent hot weather had affected its water level.

“Fluctuating water levels are normal and provide a healthier environment for fish, birdlife and aquatic plants in the lake.

“The lake is managed in summer to capture stormwater inflows from Paul’s Wetland, Redan Wetland and Brown Hill during rainstorms.

“While current levels are within expected variations, the water supply project completed in recent years enables the lake to be refilled at a faster rate when required.”

The lake is now at its lowest level since last February. After winter last year, the lake was full, before falling rapidly again in November and December.

fiona.henderson@fairfaxmedia.com.au