Protecting the catchments

Protecting the quality of our drinking water supply is one of our most important activities. We put a lot of effort into safeguarding Melbourne’s protected water catchments from bushfires, human and animal contamination and erosion.

Bushfires in catchments

Bushfires seriously threaten the quality and quantity of our drinking water supply.

Rain can wash ash and sediment into reservoirs, taking them offline for many months while the water quality gradually improves as the sediment naturally settles.

Forests recovering from fire use a lot of water, reducing the amount entering our reservoirs. It can take more than a century for catchments to return to normal after a bushfire, which is why we work hard to protect them.

How we protect against bushfires

We’ve managed bushfire risk in the catchments for over a century. Each year we commit significant resources to this, including:

  • closed catchments – most catchments are off-limits to the public, reducing the risk of fires starting
  • early warning and detection – we use a lightning tracker tool, fire towers and fire fighter patrols to spot fires as soon as they start
  • grass cutting – we cut grass along roadsides and on access trails more frequently during summer, especially in high-risk areas
  • fire breaks – we maintain a network of over 600km of strategic fire breaks up to 30m wide that provide safer working locations for fire fighters to conduct both planned and back burns
  • access roads – we maintain 1,860 kilometres of road providing critical access for fire crews
  • planned burns – we carefully carry out strategic burns to reduce the risk of intense bushfires, without reducing water yield or impacting quality

Our fire fighting role

We’re often the first to respond to fires in the catchments, and aim to put them out before they spread. In major fires we work with the Department of Environment, Land, Water and Planning and the Country Fire Authority.

We have more than 40 fire fighters based near water catchments all year round. During fire season, summer casuals increase that number to more than 60 trained fire fighters on standby.

Our fire equipment includes:

  • 1 fire-bombing helicopter
  • 5 bulldozers
  • 25 fire trucks
  • 40 water tanks holding 22,000 litres each, strategically placed to provide easily accessible water for fire fighting

In the event of fire...

Our 10 water storage reservoirs are connected, allowing us to transfer water between them and away from bushfire zones. We did this during the devastating 2009 bushfires, where billions of litres of water was moved from the O’Shannassy and Maroondah catchments to Cardinia Reservoir as a safeguard.

This means we can rely on water from unaffected reservoirs for weeks or months until water quality returns to normal.

Human and animal contamination

We restrict access to most of the protected catchments to reduce the risk of contamination entering our water supply. We work with Department of Environment, Land, Water and Planning and Parks Victoria to maintain a security and surveillance system across the catchments.

Security teams patrol the catchments regularly. Serious offences like camping, fishing, motorcycle riding or shooting may be dealt with in court.

Pest animals such as wild dogs, feral cats, deer and foxes also need to be controlled to minimise the threat of diseases. A trapping and baiting program, led by Parks Victoria, is carried out every year.   

Erosion

Roads provide vital access to enable fire fighters to get to damaging bushfires and put them out as quickly as possible. However, roads are also a source of sediment entering the waterways that feed our reservoirs. 

We pay particular attention to the maintenance of roads in the catchments to ensure appropriate drainage is in place. This minimises erosion and sediment flowing into the water.

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