Perth is set on the Swan River, so named because of the native black swans. A Dutch expedition in 1697 captained by Willem de Vlamingh led to Vlamingh naming the river after the black swans. It is a city that fills the sandplain that lies adjacent to the Darling Scarp known as the Bassendean Sand Dune Ecosystem. The metropolitan area extends to Yanchep in the north, Mandurah in the south, total distance of approximately 125km by road. From the Coast in the west to Mundaring in the east, a total distance of approximately 50 km by road.
The coastal suburbs take advantage of Perth’s oceanside location and clean beaches. To the east, the city is bordered by a low escarpment called the Darling Scarp. Perth is on generally flat, rolling land – largely due to the high amount of sandy soils and deep bedrock. Perth metropolitan area has two major river systems, the first being the Swan and Canning Rivers. The second is that of the Serpentine and Murray Rivers, which discharge into the Peel Estuary at Mandurah.
In recent years, climate change has resulted in reduced rainfall in the region, reducing inflow into dams by two thirds over the last 30 years. The lower runoff into Perth’s dams and groundwater supplies, coupled with Perth’s relatively high population growth, has caused concerns that Perth will be “out of water” within ten years.
The Western Australian State Government has responded by introducing mandatory household sprinkler restrictions in the city. The State Government has also begun the process of constructing a sea water desalination plant in Kwinana (expected to be finished in late 2006).
Due to the emission of large volumes of greenhouse gases involved in sea water desalination, this plan has been criticised by some as environmentally unfriendly. The state government considered piping water from the Kimberley region, however this proposal was rejected in May 2006 due mostly to the high cost. Other proposals under serious consideration are extracting 45 gigalitres per year from the Yarragadee aquifer in the south-west or constructing another desalination plant.