Melbourne’s protected water catchments are a precious resource, and the reason much of our water needs very little treatment.
Learn about the differences between protected and open catchments, and find out who’s responsible for them.
Most of Melbourne’s drinking water comes from protected catchments – forested areas to the north and east of the city that stretch along the Great Divide, from Wallaby Creek in the west, to Thomson Reservoir in the east.
Many of these protected catchments are located in national parks and state forests where public access is limited. They were set aside exclusively for harvesting water more than 100 years ago, and have remained largely undisturbed since.
Deep soils in these forests act like sponges to hold rainwater, then filter and slowly release it into springs, streams, creeks and rivers. These in turn feed the reservoirs that store our drinking water. Long storage times in our reservoirs are an important part of the filtering process, as most impurities break down over time.
Because the source water from protected catchments is of a high quality and rests for long periods in the reservoirs, it requires very little treatment – a fantastic legacy of our city’s early planners. Melbourne is one of only a few cities in the world that harvests water from protected catchments.
While most of Melbourne’s catchments allow limited public access, a smaller proportion of our water comes from open catchments. These areas contain farmland, rural properties and state forests that are open to activities such as camping and four-wheel driving and small amounts of timber harvesting.
The water from open catchments is put through a filtration treatment process, so it meets the same drinking water quality requirements as water from protected catchments.
Location of the catchments
The catchments cover an area of 156,700 hectares, made up of:
- 56,300 hectares of state forest, managed by the Department of Environment, Land, Water and Planning (DELWP) – some have limited public access while others allow activities like camping, four wheel driving and logging
- 90,800 hectares of national park, managed by Melbourne Water and Parks Victoria under agreement – most are off-limits to the public and allow only limited activities such as bushwalking
- 7,500 hectares of Melbourne Water land
- 2,100 hectares of private land
A big part of our work involves protecting the catchments from bushfires, unauthorised public entry and erosion, which would otherwise affect the quality of our water supply. You can read more about our work:
Timber harvesting in the catchments
A very small proportion of the water catchments - about 310 hectares out of a total of 56,300 hectares of state forest - is open to timber harvesting from December to April each year. This corresponds to about 0.2% of Melbourne's total water supply catchment area (156,700 hectares), and research has found this has a minimal impact on overall water yield.
All timber harvesting follows the Victorian Code of Forest Practices for Timber Production, and companies are audited by the DELWP to make sure they comply.
We do not collect water from the Yarra tributaries catchment when timber harvesting occurs. Instead, water flows downstream to help the Yarra River maintain a healthy river flow.