West Barwon Reservoir spills
22 Jul 2021
West Barwon Reservoir in the Otways near Forrest is spilling for the first time in nearly 10 years.
A wet finish to 2020 and a wet start to 2021 has significantly boosted inflows to the 21.5-billion-litre storage, which is a welcome change for Barwon Water’s Geelong, Bellarine Peninsula and Surf Coast customers, whose main rainfall catchment storage has experienced an average drop in inflows of 32% on long-term averages since 1997.
Significant rainfall in January this year added approximately 3.6 billion litres of water to the storage when it would normally be declining or stable, which was a major contributor to the reservoir spilling for the first time since August 2014.
Above-average rainfall in May and June (132 mm and 138 mm respectively) saw the highest increase in storage for May in the past 10 years, while June had its second highest increase for that same period. July rainfall is tracking above average for the month to date.
At the same time last year, West Barwon reservoir was only 23.5% full (and held about five billion litres of water).
Barwon Water managing director Tracey Slatter said the reservoir spilling was a spectacular site that the community could enjoy from the comfort and safety of their homes thanks to drone footage taken by Barwon Water’s experienced network operators.
While most people are unable to visit West Barwon Reservoir at present due to the state’s lockdown, anyone thinking of visiting after restrictions have eased is urged to observe safety signage and barricades at the site, she said.
Ms Slatter said the reservoir spilling would contribute to already high river levels caused by the naturally wet conditions, which may mean, as it does during periods of significant rainfall, minor flooding on land immediately downstream of the dam on the West Barwon River.
She said Barwon Water had been in contact with landowners, Colac Otway Shire, VicRoads and other stakeholders to ensure everyone’s safety, and while some properties may experience some flooding no houses were expected to be impacted.
Ms Slatter said while the reservoir spilling was a welcome sign of storage health, Barwon Water’s water security focus extended into the future with the long-term trend to a hotter drier climate, more extreme weather events and a growing population meaning Barwon Water and its customers needed to continue to think differently about water and where it comes from.
This has been the focus of Barwon Water’s Water for our Future program in which the water corporation has engaged with over 5000 people across the region, including a community panel, to help develop its next 50-year Urban Water Strategy, a draft of which will be available later this year.