Gnangara Mound
Encyclopedia
The Gnangara Mound is an area north of Perth, Western Australia
where a large mound of sandy soil reaches an elevation of about 60 metres. It stores about 20 cubic kilometres of fresh water, about one hundred times Perth's current annual water usage. It is currently the single most important source of potable water for the city. Together with the Jandakot Mound
south of Perth it supplies about 35%-50% of the city's drinking water. However, studies have shown that water levels in the Gnangara Mound have fallen substantially in recent times and this has had a significant impact on nearby groundwater-dependent ecosystems such as wetlands and the Yanchep
Caves, and causing acidification of the nearby Lakes Gnangara
, Jandabup, Wilgarup and Mariginiup. The remaining mound springs of the Swan Coastal Plain depend on the aquifer and are susceptible to any dramatic change in hydrology
. It is widely recognised that sustainability of the Mound as a water resource is under threat. Depletion has been blamed on a combination of climate change
and excessive drawing of water.
The Liberal state government is currently considering building an industrial estate on top of Gnangara Mound (near the suburb of Banksia Grove) which will risk the permanent contamination of the city of Perth's main fresh water supply.
Perth, Western Australia
Perth is the capital and largest city of the Australian state of Western Australia and the fourth most populous city in Australia. The Perth metropolitan area has an estimated population of almost 1,700,000....
where a large mound of sandy soil reaches an elevation of about 60 metres. It stores about 20 cubic kilometres of fresh water, about one hundred times Perth's current annual water usage. It is currently the single most important source of potable water for the city. Together with the Jandakot Mound
Jandakot Mound
The Jandakot Mound, or Jandakot Groundwater Mound, is an unconfined aquifer in south-western Western Australia. It is the smaller of the two main shallow aquifers near Perth that together supply about 40% of Perth's drinking water. Its highest point lies about 18 km south of Perth’s central...
south of Perth it supplies about 35%-50% of the city's drinking water. However, studies have shown that water levels in the Gnangara Mound have fallen substantially in recent times and this has had a significant impact on nearby groundwater-dependent ecosystems such as wetlands and the Yanchep
Yanchep, Western Australia
Yanchep is an outer coastal suburb of Perth, Western Australia, located 56 kilometres north of Perth's central business district. It is part of the City of Wanneroo local government area. It was built by entrepreneur Alan Bond in the 1970s for the 1977 America's Cup...
Caves, and causing acidification of the nearby Lakes Gnangara
Lake Gnangara
Lake Gnangara is the most southerly of the Wanneroo wetlands in metropolitan Perth, Western Australia. The state government's Wetland Atlas defines the body of water as a lake. The surrounding terrain is low dunes and undulating sand plains...
, Jandabup, Wilgarup and Mariginiup. The remaining mound springs of the Swan Coastal Plain depend on the aquifer and are susceptible to any dramatic change in hydrology
Hydrology
Hydrology is the study of the movement, distribution, and quality of water on Earth and other planets, including the hydrologic cycle, water resources and environmental watershed sustainability...
. It is widely recognised that sustainability of the Mound as a water resource is under threat. Depletion has been blamed on a combination of climate change
Climate change
Climate change is a significant and lasting change in the statistical distribution of weather patterns over periods ranging from decades to millions of years. It may be a change in average weather conditions or the distribution of events around that average...
and excessive drawing of water.
The Liberal state government is currently considering building an industrial estate on top of Gnangara Mound (near the suburb of Banksia Grove) which will risk the permanent contamination of the city of Perth's main fresh water supply.