Extreme summer heat has increased water demand across central and northern Victoria during recent heatwaves, with daily water-use records broken multiple times in January as temperatures hovered near or above 40 degrees.
Coliban Water said the combination of sustained heat and bushfire activity placed unprecedented pressure on the region’s water network, requiring around-the-clock operational response to maintain supply.
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How heatwaves are reshaping demand patterns
Coliban Water Managing Director Damian Wells said it is normal to see water use rise during hot weather as people try to stay cool and hydrated, with demand peaking in the afternoon and evening when gardens are watered.
During January, however, the scale and persistence of demand increases exceeded typical patterns. Bendigo set new daily records on several occasions, with water use jumping from around 51 megalitres on milder days to more than 80 megalitres during extreme heat.
On January 8 and 9 alone, daily use reached 81 and 84 megalitres, respectively, an increase of 33 megalitres in a single day. That increase alone is enough to fill thirteen Olympic-sized swimming pools.
A second heatwave later in the month pushed demand even higher, with daily use exceeding 85 megalitres as temperatures climbed beyond 43 degrees.
Impacts across the wider network
The surge in demand was not confined to Bendigo. Castlemaine recorded a sharp increase in daily water use, rising from 8.8 megalitres to 14.9 megalitres in early January, before climbing again to 15.9 megalitres later in the month.
Kyneton also set a new daily record, reaching 6.3 megalitres on January 27.
Wells said some residents, particularly in holiday towns such as Echuca and Cohuna, may have experienced drops in water pressure during peak-demand periods because the system was stretched.
At the same time, Coliban Water crews were supporting the bushfire response in Harcourt, working with the CFA to identify emergency water sources and assess damage to water and sewer infrastructure.
Power outages, telecommunications failures and safety risks from falling trees made restoration efforts more complex during the emergency.
Keeping treatment plants running
To meet demand, Coliban Water operated its treatment plants at increased capacity, processing raw water into drinking water at higher rates throughout the heatwaves.
While urban water restrictions are considered unlikely this summer, Wells said restrictions may be necessary in some parts of the region next summer if storage levels do not recover.
“Looking at the data, the drying trend is a reality for our region and one we must prepare for,” he said.
Storage levels tell a longer-term story
Coliban Water’s three reservoirs near Kyneton have a combined capacity of 69,390 megalitres and are currently at 59 per cent, compared with 65 per cent at the same time last year.
The utility’s share of Lake Eppalock has fallen more sharply, sitting at 36 per cent compared with 85 per cent a year ago. Water from Lake Eppalock has been supplied to Bendigo via the Goldfields Superpipe since late 2024 to help preserve Kyneton’s local storages.
Both storage systems are currently below seasonal averages, reinforcing concerns about long-term supply resilience as climate variability intensifies.
The role of everyday water efficiency
Permanent Water Saving Rules apply year-round in Victoria, including restrictions on sprinkler use during the day and requirements to use trigger nozzles on hoses.
Wells said small, everyday actions still make a meaningful difference during extreme heat.
“Simple things like shorter showers, running appliances outside peak times, using the half-flush button and mulching gardens all help preserve our water supply,” he said.
As heatwaves become more frequent and intense, utilities across Victoria are increasingly focused on managing peak demand and working with customers to stretch existing supplies further.