Statement on the Gellibrand River and the security of Warrnambool’s water supply

Wannon Water recognises the Gellibrand River has high environmental values and is a regionally significant source of water for urban communities as well as for irrigation and stock supplies.

Our extractions from the river occur under a Bulk Entitlement issued by the Victorian Government.

We work with the Corangamite Catchment Management Authority (CMA) to support the artificial opening of the Gellibrand River when necessary.

To assist with river health and improve passing flow rates, we pre-emptively reduced extractions on Monday 20 January by six megalitres a day – from 15 megalitres down to nine megalitres. This resulted in passing flows increasing from 35 megalitres a day to 40 megalitres.

Due to the current water supply situation for towns supplied by our Otway system, as well as the hot weather conditions forecast during the week, we were unable to cease or further reduce water extraction from the river.

Warrnambool’s drinking water is supplied from a combination of sources comprising the Arkins Creek and Gellibrand River in the Otways, the Warrnambool Roof Water Harvesting System, and from existing bores at Carlisle River and in Warrnambool’s Albert Park.

Multiple balancing storages increase the security of supply. We have an emergency bore located near Curdievale which can be used under drought conditions when needed.

The Otway system has reliably supplied water to meet its required demands for more than 40 years with a consistent streamflow pattern, however we are aware there is room for circumstances to change over time. We use modelling software to project how much supply is available from our water sources into the future under a range of climate scenarios.

Climate change, bushfires, floods, droughts, a change in population or industry demands, water quality events, the failure of key infrastructure, and changes to water markets and licensing are some of the threats that we consider.

Our response and contingencies include long-term planning, drought and bushfire preparedness plans, emergency response plans, asset performance monitoring and investment, back-up equipment, by-pass systems, water demand modelling, and engagement with key industry and community groups.

We research and publish an Urban Water Strategy every five years. The strategy provides a 50-year forecast of water supply and demand, helping us ensure that our region’s water supplies remain sustainable. It also allows us to meet the needs of our customers and community now and well into the future.

We also prepare and publish an Annual Water Outlook each year. The most recent outlook, released in December, confirms there are no water restrictions on the horizon for our customers.

While Bureau of Meteorology climate data shows that some parts of South West Victoria have faced their driest 12 months on record, the outlook explains how we are well prepared to meet urban water demands from customers.