Geography and hydrography

Gwelup is bounded by Lake Gwelup, the Mitchell Freeway to the east, Old Balcatta Road to the north (Reid Highway, accessible via Duffy Road, is located just a few hundred metres further north) and Karrinyup Road to the south. Due to Gwelup's swampy nature and the Lake Gwelup Reserve, considerable tracts of land remain undeveloped. Peaty soils around the lake region that have been reclaimed, now feature the highest concentrations of dissolved arsenic in the world - some 25000 ug/L (some 400 times higher than that identified as safe levels for drinking water). It is well known among scientific communities that disturbance of acid sulphate soils causes the release of As, iron sulfides and other chemicals.  In the previous 32 years prior to 2000, the lake was recorded to dry out twice, since that year the lake barely remained wet once over the summer in 2005/2006. The lowered water tables can be blamed on reduced rainfall and over consumption of regional scheme waters.

At the 2006 Australian census, Gwelup had a mostly white middle-income population of 3,239 people living in 1,102 dwellings. The type and style of residential dwellings contained within Gwelup varies considerably, ranging from early market garden cottages to recently designed two-storey developments. New subdivisions, including Karrinyup Waters, Settlers Green and The Willows, contain modern architecturally designed homes. Along North Beach Road, there are remnants of older, rural-style housing. These character homes are gradually being renovated or replaced by new developments.


SIGNIFICANT LANDMARKS

Careniup Swamp: Careniup Swamp was first recorded as part of a survey in 1844. The name "Karrinyup" appears to have derived from this swamp, which is located on the northern boundary of Gwelup.

Lake Gwelup: The position of Lake Gwelup was first recorded by the Land Department in 1878. On early surveys the lake was marked as a swamp.