The City of Wanneroo is one of the oldest regions in Western Australia and one of the fastest growing local governments in Australia, with population forecast to increase by more than 100,000 residents by 2021. The City's diversity encompasses a wide array of environmental landscapes and multi-cultural communities.
Natural areas in the City include our coasts, wetlands, bushland and cave/karst systems. Included within these landscapes is our biodiversity which contributes to a number of ecological functions and human health. The value of this biodiversity is recognised by its inclusion within the Southwest Australia Ecoregion which is recognised as one of the world's 34 biodiversity hotspots currently under threat from development.
In recognition of its unique and diverse landscape the City has planned for the retention of the natural environment by including it as a key theme within the Strategic Plan and Smart Growth Strategy. The Local Environment Plan brings together the environmental objectives, strategies and actions from the Strategic Plan and Smart Growth Strategy to provide the overarching basis for a range of environmental action plans. In this way the City hopes to ensure that natural areas can be enjoyed long into the future.
Coastline
The City’s coastline stretches for 32 kilometres from Tamala Park (just south of Mindarie) in the south, to Two Rocks in the north. Wanneroo’s coast represents important regional conservation value, providing an extensive ecological linkage characterized by coastal limestone cliffs and coastal heathland vegetation. The coast line also represents relict sand dune formations (the Quindalup dune system) occurring as beach ridges and a variety of dune types.
It is important to effectively manage the coastline to protect the environmental features whilst balancing the recreational needs of the community which will become more apparent as the City becomes more urbanised. In order to manage the coast effectively, the City is involved in the development of foreshore management plans.
Wetlands
Throughout the City, wetlands have developed where the surface of low lying land crosses seasonal groundwater tables (Balla, 1994). The City has a chain of linear lakes, including Lakes Joondalup, Goolellal, Nowergup, Neerabup and Carabooda, and a chain of circular lakes, including Lakes Gnangara, Pinjar, Mariginiup and Jandabup.
The City has a range of wetland ecosystems including permanently inundated lakes, seasonally inundated swamps and seasonally waterlogged damplands. These wetlands provide important habitat for a diversity of fauna, the most visible being water birds, and have a valuable recreational function. It is therefore important to manage these wetlands to maintain their ecological function whilst also allowing for community enjoyment. The City is therefore updating the Gnangara Lake Management Plan, is developing an integrated catchment management plan for the Yellagonga Regional Park (in collaboration with the City of Joondalup and the Department of Environment and Conservation) and is developing a Management Plan for Lake Adams.
Bushland
The City contains a vast area of important vegetation that has local, regional, national and even international importance. The vegetation within the City includes species and communities that are found only in a restricted part of the south-west of Western Australia. Some vegetation, for example, areas of change between different vegetation types or complexes, are only found within the City otherwise the City provides the best remaining examples in Western Australia (Trudgen, 1996)
Of the 68,750ha of land that the City of Wanneroo encompasses, 31,612ha contain remnant vegetation, although two-thirds of this is under State Government Control, for example in State Forest or Regional Park (WALGA, 2008). The City considers that it can influence the future of 10,025ha of remnant vegetation which is in private ownership or in local government reserves. Much of this is however likely to be cleared and the City will need to plan carefully in order to retain some of the remnant vegetation during future development.
Currently the City manages over 2,000ha of bushland in local reserves. This is enjoyed by many local residents who enjoy bushwalking, bird watching and photography. In order to guide management of local bushland areas, the City undertook an assessment of all bushland reserves in 2003. Further to this, the City produces individual reserve management plans such as the Koondoola Regional Bushland Management Plan. The City will also plan for the protection, retention and management of remnant bushland as the urbanisation takes place, through the development of its Local Biodiversity Strategy.
Karst features are a key environmental characteristic in the City due to the distribution of Tamala limestone. Tamala Limestone is a porous rock that can be slowly dissolved by weakly acidic waters, such as groundwater or rainfall, which circulate through cracks and pores in the rock. This process is known as karst weathering, and results in a number of landform features including sinkholes, caves, dry valleys, tube structures and vaults (Geoscience Australia, 2003).
The distribution of Tamala Limestone in Western Australia shows a karst belt, crossing the City’s area, lying five kilometres inland from the coast. The karst belt is represented in the City by numerous lakes, and caves, some of which are a popular recreation destination, for example those at Yanchep. Caves themselves are scientifically and culturally identified as important components of natural landscapes.
Some of the caves in Wanneroo contain fauna that are specially adapted to living in the cave environment, called Troglobitic fauna. Troglobitic fauna are restricted to living in caves, with the most sensitive of these being stygofauna, which live in groundwater. Stygofauna mainly include different types of crustaceans, but also include worms, snails, insects, other invertebrate groups, and, in Australia, two species of blind fish. Most species spend their entire lives in groundwater and are not found in any other location (Jasinska, 1997).
Known populations of stygofauna and troglobitic species within the City are located in Yanchep National Park. These caves support critically endangered aquatic root mat communities, which are protected under the Federal Government’s Environmental Protection and Biodiversity Conservation Act 1999. These caves are managed by the Department of Environment and Conservation.
Karst features, however, also present hazards, including holes developing on private property, rock falls, exposed caves with inappropriate coverings and roads and houses built over caves and pinnacles. Such hazards present risk to pubic safety, built structures and the environment. It is therefore important to investigate this risk to protect the environment and minimise risk to property.
