Blue Mountains Catchment

My part of the catchment

The Blue Mountains catchment lies mostly within the World Heritage-listed Blue Mountains National Park. The park is remarkable for its rare and ancient plants, isolated animal populations tucked away in its deep gorges, and Aboriginal and European cultural history.

Many of the spectacular lookouts and walking tracks in the region were developed for Victorian era honeymooners and day-trippers, who arrived by steam train on the new western railway. Weirs and dams were built to supply the steam locomotives, and with the arrival of more tourists and residents, domestic water supply dams soon followed.

The Blue Mountains six water supply dams were built between 1907 and 1942 in a small group of bushland valleys covering only a combined 22 square kilometres. Two-thirds of the catchments are within the Blue Mountains National Park.

These catchments are also Special Areas, which means that public access is restricted. Special Areas protect water quality by providing buffer zones of pristine bushland around dams and immediate catchment areas.

There is no public access to the five water supply dams in the Blue Mountains. There is limited public access to some bush tracks near Woodford Creek Dam, which is no longer used for water supply.

Your water supply

Three catchments supply six dams in the Blue Mountains:

  • Katoomba catchment (5 square kilometres) feeds water to the Lower, Middle and Upper Cascade dams on Cascade Creek.

  • Blackheath catchment (7.2 square kilometres) feeds water to Greaves Creek Dam and Lake Medlow Dam on Adams Creek.

  • Woodford catchment (9.8 square kilometres) feeds water to Woodford Creek Dam at the junction of Bulls and Woodford creeks.

The catchments are small, narrow and steep. The dams are also small, and because rainfall is sometimes unreliable, storage levels can change rapidly.

For these reasons the Blue Mountains water supply can be supplemented by water from outside the mountains.

Residents in the lower mountains get their water from Warragamba Dam, treated at the Orchard Hills filtration plant. Residents in the middle and upper mountains are supplied from the Cascade filtration plant, which draws water from the three Cascade dams at Katoomba and the nearby Greaves Creek and Lake Medlow dams.

The water supply in the upper and middle mountains can be topped up when needed from Oberon Dam or Duckmaloi Weir in the Fish River Scheme, west of the Great Dividing Range at Oberon.

In the area

Cascades Dam

The Upper, Middle and Lower Cascade dams near Katoomba, built between 1908 and 1938, supply the nearby Cascade water filtration plant that supplies the middle and upper Blue Mountains

Greaves Creek Dam

Greaves Creek Dam near Blackheath was the last of the dams built as part of the development of the upper Blue Mountains

Lake Medlow Dam

Believed to be one of the thinnest dam walls in the world when completed in 1907, Lake Medlow Dam was the first of the dams built as part of the development of the upper Blue Mountains.

View of how the Blue Mountains water supply catchment fits in your local council area

Living in the area

Developers & Council

Learn about the best approaches for managing stormwater during and after construction - for a home site or large development.

Developers & Council

Find out how you can look after your property at the same time as caring for your local catchment and waterways.

Developers & Council

Get practical tips on onsite wastewater systems - whether you have just moved to a property or are installing a new system.


Monday 18 October
2,426,169 ML
2,581,850 ML
9,030 ML
1,290 ML
3,065 ML
Monday 18 October