The City of Kalamunda has a rich diversity of natural environments made up of streams, wetlands, forests and woodlands, with a unique display of endemic flora and fauna, all on the City’s doorstep. Nearly three quarters of the City still remains as natural bushland, which the City is committed to preserving and enhancing.The natural environment is comprised of following landform types:
The Darling Plateau covers the majority of the City and is dominated by lateritic uplands and duritic gravels and sands which form a gently undulating surface. The topography ranges from 50m AHD (Australian Height Datum) on the westerly fringe of the deeply dissected Darling Scarp, to 360m AHD on elevated ridges. From west to east, the soils include the Darling Scarp, Swan, Dwellingup, Yarragil, Helena, Murray and Cook associations.
The Darling Plateau is the dominant landform type, covering the majority of the total area of the City and contains the following soil associations:
DwellingupDwellingup covers almost half the total area of the City and contains the lateritic uplands of the Darling Plateau. The crests and upper slopes are a common features of this landform and are dominated by lateritic duricrust and shallow gravelly sands.
YarragilYarragil occurs on the minor upland valleys in the western part of the Darling Plateau and surrounds the valley side slopes, headwaters and floor. The soils range from yellow duplex soils to sands over mottled clay on side slopes and headwaters, to poorly drained uniform clays on valley floors. The Yarragil association is usually adjacent to the Dwellingup unit associated with the major valleys.
MurrayMurray has deeply incised valleys and features soils made up of yellow, red and brown gradational earths and yellow mottled duplex soils. The narrow alluvial terraces occur throughout the Upper Helena Catchment and in large pockets within the suburbs of Bickley, Carmel and Canning Mills.
HelenaHelena is characterised by deeply incised major valley systems associated with the Middle Helena and Bickley Brook Catchments. The steep valley side slopes give way to gently inclined valley floors lower in the landscape. Yellow duplex soils, gradational earths and granite rock outcropping are common features.
CookCook classification unit is made up of hills that rise above the general plateau of the lateritic uplands. The mantled laterite surface may also contain granite rock outcrops and shallow duplex soils.
The Darling Scarp classification unit is characterised by moderately steep to very steep scarp hill slopes with shallow, yellow-brownish earths and yellow duplex soils. Granite outcropping is common throughout this area, which is situated on the western portions of Gooseberry Hill, Kalamunda and Lesmurdie.
Ridge Hill Shelf is located to the east of the coastal plain and forms the foothills of the Darling Scarp. It is a series of narrow, laterite covered ridges, a remnant of a more continuous area that existed along the the Darling Scarp before it eroded towards the east. It is what remains of two very weathered, former shoreline deposits ⎯ the Ridge Hill Sandstone and the Yoganup Formation.
The soils of this landform are typically high in iron and alumina content and have good drainage capabilities. The slope and drainage of the shelf does not allow water to pond, so swamps are rare.
The Swan Coastal Plain extends westwards from the lower edge of the Darling Scarp. The terrain is generally low lying, made up of alluvial and aeolian deposits, including the Guildford, Forrestfield and Southern river soil areas.
In general, the soils become more fertile on the east of the plain, in the zone of transition between the Swan Coastal Plain and the Darling Scarp, locally identified as the ‘foothills’. Wetlands can be found in low lying areas, and water levels are often interlinked to those of the underlying groundwater.
Guildford Guildford is restricted to the south western coastal plain section of the City, a flat alluvial plain containing gravelly yellow and brown duplex soils, with sand and loam topsoils.
The Guildford complex is a mixture of open and tall open forest of Marri (Corymbia calophylla), Wandoo (Eucalyptus wandoo), Jarrah (Eucalyptus marginata) and Wandoo woodland, with rare occurrences of Salmon White Gum (Eucalyptus lane-poolei). There are also small amounts of Flooded Gum (Eucalyptus rudis) and Swamp Paperbark (Melaleuca rhaphiophylla).
Southern RiverSouthern River is characterised by a sandplain with low dunes and many intervening swamps, iron and humus podzols, peats and clays. It flows through High Wycombe and the western parts of Forrestfield and Wattle Grove. The vegetation is an open woodland of Marri (Corymbia calophylla), Jarrah (Eucalyptus marginata) and Banksia species with fringing woodland of Flooded Gum (Eucalyptus rudis) and Swamp Paperbark (Melaleuca rhaphiophylla) along creek beds.
ForrestfieldForrestfield is made up of the laterised foothills of the Darling Scarp and is dominated by gravelly and sandy soils. Imperfectly drained and duplex soil is common throughout this area, particularly in association with alluvial fans and drainage channels. This type of soil occurs throughout Maida Vale and the central parts of Forrestfield and Wattle Grove. Forrestfield’s vegetation is complex ranging from an open forest of Marri (Corymbia calophylla), Wandoo (Eucalyptus wandoo), Jarrah (Eucalyptus marginata) to an open forest of Marri, Jarrah, Sheoke (Allocasuarina fraseriana) and Banksia species. Fringing woodland of Flooded Gum also appear in the gullies that cut through this landform.
SwanSwan is located on the northern tip of Gooseberry Hill and occurs as alluvial terraces with red earths and duplex soils. The area is closely associated with the Helena River and is contained within the Kalamunda National Park.
Healthy waterways have a stable bank bordered by native vegetation of various layers which provide habitat, assist with the filtering of excess nutrients and slow down water flow preventing bank erosion. The layers of plants that tolerate water logging and moist soils provide food, breeding habitats, shelter and protection from predators for frogs, native fish and waterbirds.
Many waterways and wetlands become degraded as a result of activities such as landclearing, urban and industrial land use, and altered water flow such as damming. Along with recreation and tourism, they can cause poor water quality, sedimentation, erosion, and reduce the condition of fringing vegetation and habitat for the local fauna.
Permission is required before any works can be undertaken in or on the banks of a watercourse within the City. It is illegal to disturb watercourses without a permit. Please contact the City if any creekline disturbance or major works near a creekline are to be undertaken. The City may consult the Department of Water regarding your proposed works.
Waterways in the City include:
Wetlands are areas that are permanently, seasonally or intermittently waterlogged or inundated with water. They can be fresh or salty, flowing or still, natural or artificial. Common wetlands include lakes, floodplains, damplands and springs. Lesser known wetland types include sumplands, playas, palusplains, barlkarras, paluslopes and palusmonts.
Wetlands are important for biodiversity. They are often rich in species and provide habitat and food to many plant and animals such as birds, fish, frogs, tortoises and invertebrates, including endangered species and important migratory birds.
They also act as a wildlife corridor between areas of remnant bushland; improve water quality by filtering out pollutants such as sediments, nutrients and pathogens; reduce the severity of floods; and provide refuges for wildlife during drought. In addition to their environmental value, wetlands are of social, recreational, scientific, educational, cultural (including playing a significant role in Aboriginal culture) and economic value.
Wetlands are directly linked with their surrounding landscape. This landscape forms the catchment of the wetland, and activities that occur in the catchment can ultimately impact on the health and function of the wetland. The City is within the same catchment as the Forrestdale and Thompson Lakes, which together form a Ramsar wetland.
At a national level, RAMSAR (The Convention on Wetlands of International Importance) Wetlands are protected under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC).