West Barwon Reservoir

Share on Facebook Share on Twitter Share on Linkedin Email this link


Water is essential for life. Its journey from the environment to our homes involves long distances and often begins at the West Barwon Reservoir.


Located in the Otway Ranges National Park, the West Barwon Reservoir supplies drinking water to the greater Geelong, Bellarine Peninsula and Surf Coast areas. It is the largest reservoir in the Barwon Water region and largest water supply source for the greater Geelong region, supplying more than 80% of the region’s drinking water demand.

At capacity the reservoir holds almost 21,500 million litres of water, enough for approximately six months’ supply of drinking water.

West Barwon Reservoir Masterplan

We are excited to be working to develop a future vision for the West Barwon Reservoir with our Traditional Owners and community. A series of community workshops will commence in 2023.

Want to be involved? Register your interest via email at projects@barwonwater.vic.gov.au


Explore the work we're doing in the region by clicking one of the tiles below.

Learn more about West Barwon Reservoir
Understand the history of West Barwon
Find out about how it works and how we operate it
Come on a journey to see how it looks when it spills (is full)
Look to the future with our five-year action plan
Read more about what's happening in Forrest






Water is essential for life. Its journey from the environment to our homes involves long distances and often begins at the West Barwon Reservoir.


Located in the Otway Ranges National Park, the West Barwon Reservoir supplies drinking water to the greater Geelong, Bellarine Peninsula and Surf Coast areas. It is the largest reservoir in the Barwon Water region and largest water supply source for the greater Geelong region, supplying more than 80% of the region’s drinking water demand.

At capacity the reservoir holds almost 21,500 million litres of water, enough for approximately six months’ supply of drinking water.

West Barwon Reservoir Masterplan

We are excited to be working to develop a future vision for the West Barwon Reservoir with our Traditional Owners and community. A series of community workshops will commence in 2023.

Want to be involved? Register your interest via email at projects@barwonwater.vic.gov.au


Explore the work we're doing in the region by clicking one of the tiles below.

Learn more about West Barwon Reservoir
Understand the history of West Barwon
Find out about how it works and how we operate it
Come on a journey to see how it looks when it spills (is full)
Look to the future with our five-year action plan
Read more about what's happening in Forrest





  • West Barwon Dam Safety – Routine Investigations (Feb 2023)

    Share on Facebook Share on Twitter Share on Linkedin Email this link

    We are conducting routine maintenance works throughout summer along the West Barwon Reservoir crest. There will be two stages of geotechnical assessments required as part of our ongoing safety reviews of the dam.

    The first stage will be between Monday 6 and Tuesday 7 February 2023.

    The second stage will be after the summer school holidays in late February 2023 and last approximately one – two weeks.

    While we are on site conducting these investigations:

    • Please use alternative walking tracks during this time.
    • All public amenities including toilets, picnic area and BBQ facilities will remain open via the Barlidjaru Trail.
    • There may be increased noise in the area as we conduct these important investigations. We apologise for any disruption.

    There are no planned disruptions to your water services as part of these investigations.

    Map of West Barwon Reservoir with icons to highlight where access will be closed across the dam wall.


  • Understanding the West Barwon Reservoir

    Share on Facebook Share on Twitter Share on Linkedin Email this link

    Background

    The West Barwon Reservoir supplies drinking water to Forrest, the greater Geelong, Bellarine Peninsula and Surf Coast areas. At capacity the reservoir holds almost 21,500 million litres of water, enough for approximately six months’ supply of drinking water. It is one of the most important water sources in our region.

    The West Barwon Reservoir also captures water for environmental flow releases in accordance with the environmental entitlement which is managed by the Corangamite Catchment Management Authority on behalf of the Victorian Environmental Water Holder.

    Geelong storages are now at 99.1%, approximately 1.6 percentage points higher than the same time last year and the highest storages have been in the last 10 years.

    Understanding the reservoir

    Did you know our reservoirs are not designed for flood mitigation? They are designed to fill and spill during wet periods. The water that is captured is primarily used for drinking water purposes and passing flow releases in accordance with our operating licence (Bulk Entitlement). This means we try to capture and retain as much water as possible to ensure we can provide drinking water for everyone after our required passing and environmental flows.

    Our operations teams work hard to manage our water network every day, including over night and on weekends.

    Maintaining high water storage levels at West Barwon Reservoir is a priority in the face of a changing climate. We are experiencing more extreme weather events which has a direct impact on our region’s water supplies. Our operations teams do a lot of planning and adaption to move water around our network in all conditions.

    Water movement helps reduce excess spills in wet weather, however weather conditions and maintenance requirements can limit how much we transfer.

    Managing wet conditions

    With the possibility of another wet summer on the way our operations teams are considering continuing to transfer water from the West Barwon Reservoir to Wurdee Boluc throughout January. We don't normally transfer during the dry summer, however this will reduce the likelihood of further spill this summer.

    This management of transfers is carefully considered every year and is dependent on storage levels, evaporation over warmer months, and the need for critical maintenance on the channel. We know as our climate becomes hotter and drier, our weather patterns are becoming more unpredictable which is why we must adapt our operations to suit conditions.

  • Our water transfers around Forrest

    Share on Facebook Share on Twitter Share on Linkedin Email this link

    We regularly move water across our water supply network. Water from West Barwon Reservoir supplies the township of Forrest and also gets transferred via the 57-kilometre Wurdee Boluc Inlet Channel. It is then treated at the Wurdee Boluc Water Treatment Plant then distributed throughout our water network for customers across the greater Geelong, Bellarine and Surf Coast region.

    The Wurdee Boluc Inlet Channel relies completely on gravity so it can take up to five days for the water to travel the 57-kilometers, and can only be transferred one way.

    Our operations teams carefully plan how much water is to be transferred each day to ensure we continue to maintain water security across our region. This planning also takes into account the minimum flows that need to be maintained in the rivers as required by our operating licence (Bulk Entitlement).

    The Wurdee Boluc Inlet Channel also receives water from creek and river diversions to supplement supplies from West Barwon Reservoir. There are five diversions that supply the Wurdee Boluc Inlet Channel:

    1. East Barwon River
    2. Callahans Creek
    3. Dewing Creek
    4. Matthews Creek
    5. Pennyroyal Creek

    What is a diversion?

    A water diversion is where water is moved from its natural flow path to a new flow path. Barwon Water harvests water from the Barwon River Catchment via the West Barwon Reservoir and a series of small diversion weirs on some of the creeks that flow into the Barwon River. Water from the reservoir and the creeks are diverted into the Wurdee Boluc Inlet Channel which transfers the water to the Wurdee Boluc Reservoir.

    Our operations teams are responsible for managing the diversion of water in our network in accordance with our operating licence (Bulk Entitlement) issued by the State Government. There are a number of factors that are taken into account when diverting water including rainfall, stream flows, storage levels, water quality, gate operations, safety and regulatory requirements such as passing flows and maximum diversion limits.

    In addition to providing a high quality and affordable source of critical drinking water, our diversions can also be used to help transfer environmental flows from West Barwon Reservoir to the East Barwon River in accordance with the seasonal watering proposals for the Upper Barwon Environmental Entitlement that is managed by the Corangamite Catchment Management Authority.

    Managing our diversions map of the network from West Barwon River to the Wurdee Boluc Reservoir


  • Finding out what’s going on with our river | Forrest Post extract

    Share on Facebook Share on Twitter Share on Linkedin Email this link

    Extract from the November 2022 issue of The Forrest Post


    About 75 people gathered at the Forrest Hall in late October for a deep dive into the many factors impacting the health of our Upper Barwon River, and a lively discussion about what needed to be done to restore it. Forrest Gerangamete Landcare Group hosted the event in collaboration with Barwon Water, Corangamite Catchment Authority (CCMA) and the Upper Barwon Landcare Network.

    Starting with a Welcome to Country from Gulidjan Elder Ebony Hickey, science and engineering experts from Barwon Water, CCMA and Alluvium Consulting presented detailed information on the complexities of managing the river to supply water to Geelong while at the same time maintaining sufficient flow to keep the river ecosystem healthy.

    Barwon Water chief scientist Will Buchanan said even though storage levels were healthy today, Geelong’s population was growing rapidly at the same time as the climate was becoming hotter and drier. In response, Barwon Water was planning to take pressure off the region’s rivers by transitioning to ‘manufactured’ (recycled or desalinated) water and facilitating smarter water use.

    Difficult questions include how best to bring ‘manufactured’ water into the downstream supply (for non-drinking purposes in the case of recycled water) to take pressure off rivers. Another is how to increase use of the West Barwon reservoir’s guaranteed ‘environmental entitlement’ of 1 gigalitre (1000 megalitres) per

    year to 5 gigalitres over the next decade, when the river constrictions and health make it challenging for the river to handle even the current entitlement. A key discussion point was the flow study finding that the river needs 29 gigalitres annually to support healthy ecosystems along its length.

    Jayden Woolley from CCMA reported on the Barwon Flagship Waterway project, a 30-year, large-scale project to rehabilitate the river. This project is prioritising the Upper Barwon due to the significant impact of willows and reed sweet grass (Glyceria maxima) in the area. It aims to work with landholders, key agencies and the community to trial strategies that can be applied to ‘choke points’, where willows and glyceria are constricting precious water flow. A common objection from landowners to becoming involved is the fear of losing too much river frontage and the unknown cost. Masters student James Malcher presented his program that can address this by modelling the trade-off between productivity and better water quality, erosion prevention and carbon capture for each farmer.

    PhD student Mariah Sampson also presented her study that is evaluating environmental benefits of restored riverbanks in several places in the Upper Barwon over time. These projects, along with scientists’ constant collection of data on water quality, flora and fauna, are helping inform water authorities’ decisions—though we heard that perfect solutions may not exist to some of today’s problems!

    Just as we in the audience were reaching information saturation point, the format shifted to a question and answer panel. Audience members through their questions to Eastern Maar representative Brodey Hamilton, Land and Water Resources Otway Catchment representative Neil Longmore, Friends of the Barwon representative Lach Gordon and Environmental Justice Australia representative Juliet LeFeuvre then sharpened the focus on more fundamental concerns.

    The question was raised whether the river should continue to be considered as a resource, or whether it needed to be respected as a living entity in itself. The panellists were more or less aligned in the view that the river needed to ‘be allowed to be a river’, whether this perspective sprang from a spiritual need to care for Country, or a justice approach in which the needs of urban users and rural catchments should have more equal weight. Panellists acknowledged Barwon Water’s significant strategic work in this direction, guided by meaningful public consultation and partnership with Traditional Owners.

    The fitness-for-purpose of the very legislation governing water management was thrown into question during the discussion. With a State election in a few weeks, Juliet LeFeuvre said she hoped that whoever won the election ‘just gets on with’ the urgent work of protecting river health.

    After a break and barbecue lunch, we boarded a bus to the channel diversion point on the East Barwon River, to see for ourselves how Barwon Water physically manages the river flow to divert water to Geelong from the combination of natural flows and flows it diverts into the East Barwon from the West Barwon Reservoir. We also saw how an infestation of willows just downstream quickly turned the remnant passing flow into a braided expanse of channels, swamps and billabongs. Looking upstream we could see the dramatic 3.5km section of the river where Barwon Water had removed willows last summer and nearly 40,000 plants had been planted to revegetate the riverbanks.

    Deidre Murphy from CCMA took this opportunity to explain citizen science projects that collected vital data on river waterbugs, and called for volunteers to help survey rivers to establish baseline information. She invited us all to join in these surveys, which will be at Barwon St, Birregurra, on Wednesday 16 November at 9:30 am; and at the Lake Elizabeth campsite on Thursday 17 November, also at 9:30 am.

  • West Barwon expected to intermittingly spill over coming months

    Share on Facebook Share on Twitter Share on Linkedin Email this link

    Latest news - September 2022

    Ongoing rainfall in the West Barwon catchment combined with a wet winter has led to ongoing high levels at the West Barwon Reservoir.

    In mid to late September, the reservoir started spilling again, the third time for 2022. Reservoirs are designed to spill when full, with water passing into natural waterways and supplementing flows, helping to support the ecological health of waterways.

    Given the high winter rainfall and high storage levels and likelihood of wet weather over spring, it is anticipated that further spill events will occur at the West Barwon Reservoir for the rest of 2022.

    Barwon Water will continue to monitor the reservoir levels and weather closely, and work with local agencies to share information and plan for any possible impacts with this current forecasted spilling and any future spill events for the rest of the year.

    Under Barwon Water’s bulk entitlement to use water from the Upper Barwon catchment for drinking supplies, transfers from the West Barwon Reservoir to the Wurdee Boluc Reservoir will be carefully managed depending on rainfall, flows in the East Barwon River and the capacity of the Wurdee Boluc Reservoir.

    Visitors are welcome at West Barwon Reservoir, Barwon Water encourages all visitors to take care and observe all safety advice and signage. This includes sticking to designated walking paths and tracks, observing permitted reservoir recreation activities including bird watching, fishing from the bank, bike riding and bushwalking. Swimming or any on water activities are not permitted at the reservoir.

Page last updated: 20 Jan 2023, 02:32 PM