Water Resources

Water resources refers to all aquatic systems and water resources found in the South West NRM region, whether natural or recycled, whose use may require enforcement of user-rights or ownership, economic control and market valuation.

It refers to all inland waters, and includes all waterways (flowing surface waters including estuaries, rivers, streams, creeks, drains and floodplains), wetlands (permanent, seasonal or intermittent standing surface water including lakes, swamps, damplands, sumplands, springs, soaks, estuaries, karst caves and waterholes) aquifers and other underground water found in the region. The term “estuaries” refers to those assets requiring management actions to deal with threats that originate upstream from the assets, as distinct from “estuaries” in the theme area Coastal environments (see below). There will on occasion be some overlap with the theme area “Aquatic biodiversity”.

The South West Region is the fastest growing region in the State and there is increasing demand for ground and surface water and increasing issues with and threats to these resources. This is further compounded by the effects of climate change.
We need to collectively work together to improve the way we manage our water resources and aquatic systems. As we prepare for a future with less water it is important that we improve water use and infrastructure, and restore the health of our rivers.

Banner Photo: Wellington dam overflowing.  Source: Scott Kenny, DWER

Water is imperative to our way of life

Surface and groundwater drinking water catchments collect and hold raw water before consumption. It is important to protect and maximise water quality for safe consumption but also to support environmental services.

The Collie-Wellington catchment supplies water for surface irrigation to the South West Irrigation Area, while groundwater and some waterways such as the Preston and Capel Rivers provide local sources of water for agricultural production within the Region.

In addition to this, the Region is the source of significant proportion of the State’s water supplied through the Integrated Water Supply Scheme (IWSS), which services people in Perth, Pinjarra and towns and properties along the Goldfields pipeline to Kalgoolie-Boulder.

Industry in the Region is very dependent on water. This water is abstracted from both surface and groundwater systems and quality varies depending on industry requirements.

For example many crops require water with the same salinity levels as for human consumption (500mg/l Total Dissolved Solids). These activities become less economically viable as salinity levels increase.

Surface water

The 20 major river systems in the Region and numerous minor creeks and streams associated with them are surface water resources, but not all of them are proclaimed. All these systems suffer degrees of modification and degradation as a consequence of drainage and urban and agricultural activities.

Clearing and development within all the catchments in the South West has resulted in changes to the water balance, usually relating to flow and condition. There are two main symptoms expressed in the South West- Eutrophication and Salinisation. It is important that in our region, there are some naturally saline systems.

Streamflow needs to be monitored extensively because of the variability of responses to factors such as decrease rainfall. Small decreases in rainfall patterns have occurred since 1975 resulting in proportionally larger decreases in streamflow.

Groundwater

The groundwater resources of the Region are important as public drinking water sources, self supply for agriculture industry, horticulture , dairying and viticulture.

There are many ecosystems and wetlands systems dependent on groundwater in the South West. A number of rivers, creeks and wetlands in the Regional are hydrologically linked to groundwater systems. For example, the Yarragadee Aquifer in the Blackwood Groundwater Area feeds into the Blackwood Rive. Groundwater from superficial aquifers feeds many rivers during summer, maintaining base flows.

It is imperative that groundwater levels are monitored extensively because of the variability of responses to factors such as decreased rainfall. Small decreases in rainfall patterns have occurred since 1975 potentially resulting in decreases in groundwater recharge. As Groundwater areas are recharged from rainfall there also is the need to protect recharge areas from contamination.

Recycling water

The South West Region recycles 2.9 billion litres, or about 40 per cent, of its wastewater every year, and we expect recycling volumes to increase in the future.

Calls for actions

The public can play a key role in drinking water conservation by taking responsibility for reducing drinking water use in and around their home and workplace. The biggest savings can be made in the garden, and can be achieved very simply.

Water Corporation has a number of tools and a suite of information on its website to support water savings. Find out more here.

Case Studies