Skip to content
An ACT Government Website
Accessibility
Contact us
Accessibility Contact us

Water resources

Water is essential for the liveability of the ACT and the surrounding catchment areas. Rivers and streams provide water for our homes and gardens. They also support the environment, recreation and cultural activities.

The Office of Water manages water policies and programs for the ACT Government. The Office works with the Australian Government, other states and territories, Icon Water, and nearby councils in New South Wales. Its goal is to improve how we manage water, maintain its quality, and keep it secure.

Where water in the ACT comes from

Murray-Darling Basin

The ACT sits entirely within the upper Murrumbidgee River Catchment in the Murray-Darling Basin. The Murrumbidgee River, Molonglo River and Cotter River are key waterways in the upper Murrumbidgee Catchment. The Murrumbidgee and Molonglo rivers begin in NSW before coming together and flowing through the ACT. The Cotter River starts in the ACT and flows into the Murrumbidgee River.

The ACT is the biggest city in the Murray-Darling Basin. It plays an important role in looking after the valuable and limited water resources in the area.

Surface water

Surface water is any water on land or flowing over land after:

  • falling as rain, snow, sleet, or hail
  • rising to the surface naturally from underground
  • being returned to the environment after treatment or use.

All surface water passing through the ACT goes into the Murrumbidgee River and then flows into NSW.

In the ACT, there are many natural freshwater wetlands. These wetlands are usually found close to big rivers and creeks.

The Assessment of the ACT Surface Water Resource Under Historical Climate Scenario technical report [PDF 3.6 MB] provides information on the long-term average surface water resources in the ACT.

Groundwater

Groundwater is water located below the Earth's surface. It filters down and is stored in layers of rock, gravel, or sand.

In the ACT groundwater resources are small and not very deep compared to other parts of Australia. In the ACT there are two types of aquifers, which are the geological formations that hold groundwater:

  1. Aquifers in fractured rock
  2. Aquifers in soils and sediments around rivers (alluvium aquifers)

Both types of aquifers are relatively shallow and can support special ecosystems that rely on groundwater. In the ACT the only recognised groundwater-dependent ecosystems are small, unregulated streams that mainly get their water from local groundwater discharge. Groundwater from both types of aquifers eventually flows into streams. Environmental flow guidelines limit how much groundwater can be taken out to make sure that it doesn't harm the plants and animals living in the streams.

Environmental flows

Environmental flows describe the timing and amount of water required to sustain freshwater ecosystems. These flows help support the plants and animals living in the water and benefit people too. They keep the waterways healthy and help lessen the effects of dams and water removal by copying how rivers naturally flow.

There is a connection between surface water and ground water. Taking water from the ground can affect the flow of water in streams above ground.

In the ACT environmental flows are provided in one of two ways:

  • releases or spills from dams
  • restricting water volumes removed from a water management area.

The Environmental Flow Guidelines (under the Water Resources Act 2007) set out the flow requirements in the ACT. These Guidelines include environmental flows for the Molonglo River downstream of Scrivener Dam and drawdown limits for Lake Burley Griffin.

How we use water in the ACT

Most of the water consumed in the ACT is for use in urban areas. Unlike many other areas of the Murray-Darling Basin, very little water is used for agriculture.

Potable water

Potable water is water that is safe for drinking or using in food preparation.

Icon Water owns, manages and operates potable water services for the ACT. This includes a network of dams, water treatment plants, reservoirs, pumping stations, mains and other related infrastructure. Potable water in Canberra is sourced from surface water sources. After treatment it is stored in water supply reservoirs, before being piped to customers.

Non-potable water

Non-potable water is not suitable for humans to drink or prepare food with, but it can be used for other things.

Licensed non-potable water in the ACT is sourced from rivers, lakes, groundwater, recycled water, and rainwater. This water can be used to water parks, sports fields, golf courses, and crops. It can also provide drinking water for animals and meet various industrial needs.

Wastewater

Wastewater is water that comes from activities like showers, flushing toilets, washing dishes, and industrial activities that drain to the sewer. It can contain substances that might pollute our rivers or harm our health if it is not treated.

The Lower Molonglo Water Quality Control Centre (LMWQCC) is the ACT’s main wastewater treatment plant. It is also the largest inland treatment facility in Australia. While some recycled water is used for running the LMWQCC plant and for irrigation, most of the treated wastewater goes back into the Molonglo River, where it meets the Murrumbidgee River.

Stormwater

Stormwater is water that runs off surfaces like roads, roofs, driveways, and sidewalks instead of soaking into the ground. As it moves, stormwater can collect harmful dirt and chemicals and carry them into our rivers and lakes.

To help with the impact of stormwater, the ACT has Lake Burley Griffin, Lake Tuggeranong, Lake Ginninderra, and 198 built wetlands and ponds. The ACT Healthy Waterways Program also helps homes, businesses, and schools find ways to cut down on harmful pollutants right where they start.

Community perspectives on waterways

Members of the ACT and Region Catchment Management Coordination Group, including the ACT Government, have supported several community surveys to help inform water resource management in the ACT and region.

More information