KARSTIC ground formations are not likely to be a problem in a new development in Alkimos according to a local structure plan on the proposal.
The Alkimos Coastal Node local structure plan says while karstic ground formations are known to occur in the limestone rock band running north-south along the eastern side of Wanneroo Rd, well clear of the Alkimos Coastal Node area so it was considered very unlikely the Alkimos Coastal Node area contained karstic ground formations.
“The Alkimos Water Alliance has excavated an area, east of the Alkimos Coastal Node area, for the Alkimos Wastewater Treatment Plan,’’ the local structure plan said.
“The excavation extends 3m AHD in some areas, in limestone rock, and there has been no evidence of karstic ground conditions. “Similarly, there has been no karstic evidence experienced in excavation at Peet’s Shorehaven (to the north), at Satterley’s Eden Beach (to the south) or Lend Lease-LandCorp’s Alkimos Beach (to the south east) to date.
“Based on this evidence it is considered very unlikely that the Alkimos Coastal Node area contains karstic ground formations.’’
Karst topography is a landscape formed from the dissolution of soluble rocks such as limestone and is characterised by underground drainage systems with sinkholes and caves.
The structure plan said a number of fauna surveys had been completed in the Alkimos region over the past 20 years.
“The habitats within the Alkimos Coastal Node area can be broadly separated into four major types, comprising of Quindalup heath, cleared pasture-grassland and tuart trees.
“Of the significant fauna species considered most likely to occur within the Alkimos Coastal Node area, the Carnaby’s black cockatoo is considered most relevant but Alkimos Coastal Node area contains limited foraging habitat for the Carnaby’s black cockatoo, which is protected under the Commonwealth Environmental Protection and Biodiversity Act.
“There is a small area of dryandra sessilis within the northern portion of the Alkimos Coastal Node area, which will be retained if possible and addressed in future landscaping design.
“The tuart trees present within the Alkimos Coastal Node area were identified to be of poor quality during a survey in 2008 and therefore unlikely to provide any breeding habitat, but may provide minimal foraging and roosting habitat.
“The canopy area of these trees is approximately 0.2ha and is therefore not considered significant.
“A search of the online Aboriginal Heritage Inquiry System indicates that there are no Aboriginal Sites or Other Heritage Places currently listed within the Alkimos Coastal Node area.’’
The Alkimos Coastal Node local structure plan dated March 2016 covers 86ha of land on Lots 9001, 9017, 9022 and 9501.
The structure plan said the development would create a framework to facilitate a vibrant and connected regional beach destination, and deliver unprecedented densities and mixed use development within the north-west corridor of the Perth metropolitan region.
The land is bordered by the Indian Ocean to the west, the Water Corporation’s Alkimos Waste Water Treatment Plant and associated buffer to the east, Parks and Recreation reserve to the north, and the future residential development of the South Alkimos local structure plan area to the south.