Information Sheet (sub-catchment)

S8 - Toongabbie Creek Sub-Catchment

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1. General Description Toongabbie Creek is one of the two main creeks, (the other being Darling Mills Creek) into which most of the creeks enter before they join the Parramatta River. Toongabbie Creek corridor begins at Crestwood Reserve, Baulkham Hills and continues south through a large industrial area where it is narrow and severely degraded until it is joined by Greystanes Creek in McCoy Park. From there it travels east in a bushland corridor until its confluence with the Parramatta River at Cumberland Hospital. The creek varies from a concrete lined weed infested and polluted drain in the industrial areas in the upper reaches to mostly natural condition on a natural sandstone bed at the lower end. The bushland corridor contains several large reserves and three large areas of private open space which support a diverse range of vegetation.

2. Map Title

Toongabbie Creek Sub-Catchment Map

3. Geology

Toongabbie Creek flows near the zone between the two geological domains in the Upper Parramatta River Catchment. It is difficult to delineate the boundary between the Hornsby Plateau and the Cumberland Plain but analysis of soil landscapes, topography and vegetation indicates that the Plateau occurs north of the Parramatta River, west of Windsor Road, then east of Old Northern Road to Castle Hill. In the upper and lower reaches Toongabbie Creek flows through sandstone terrain of the Hornsby Plateau and in the middle section, through the Seven Hills industrial areas it is in Wianamatta Shales of the Cumberland Plain.

The Cumberland Plain is a low, undulating plain underlain by horizontally bedded sediments of the Wianamatta Group, mainly Bringelly Shales. These shales are generally composed of claystones, siltstones and carbonaceous shales with sparse sandstone lenses. The sediments were laid down in a coastal alluvial plain during the middle Triassic, (200Ma). Toongabbie Creek and its tributaries, which drain the south-west area of the catchment, flow through Bringelly Shales.

The Hornsby Plateau, in the north of the catchment, is made up of Hawkesbury Sandstone. Darling Mills Creek and its tributaries form steep incised gullies in the sandstone. Toongabbie Creek emerges from the edge of the plateau, flows across the northern section of the Cumberland Plain, then in its lower reaches straddles the transition zone between the two geological domains. Some areas of steep slope being indicative of undercutting in sandstone. The ridge tops, such as at West Pennant Hills, are capped by Ashfield Shales belonging to the Wianamatta Group. In some isolated areas discontinuous beds of the Mittagong Formation, interbedded sandstones and shales, can be seen between the Ashfield shales and the Hawkesbury Sandstone.

4. Geomorphology

Toongabbie Creek varies between a concrete, weed infested polluted drain in the industrial areas to a natural, sandstone bedded, well vegetated creek in the lower reaches. Flooding caused by increased stormwater run off and residential development in the flood plains causes problems insome areas such as parts of Toongabbie and Wentworthville. The creek has incised steep slopes into the sandstone, creating gullies such as at Third Settlement Reserve and Quarry Branch Creek, these steeper slopes are generally more affected by erosion and undercutting

6. Vegetation communities

Due to the complexity of the geological formations (alluvial, sandstone and shale) and vegetation communities the biodiversity of the Toongabbie Creek corridor is remarkable in the context of an urbanised environment. Three distinct communities occur along the catchment, each of these is considered to be rare and endangered at national, state and regional level. The three communities are:

• Cumberland Plain Woodland. Including such species as Spotted Gums, Forest Red Gums and Grey Box. The Sydney Water Site contains regenerating woodland dominated by Grey Box, Forest Red Gum and Narrow-leafed Ironbark

• Shale/Sandstone Transition Forest This includes a mix of Blue Gum and Grey Box

• Blue Gum River-flat Forest including some impressive large Blue Gums on the creek flats and Blackbutts and Forest Red Gums on the lower slopes. Remnants of this forest remain in Third Settlement Reserve and Hammers Road Reserve with fifty species being noted including Sydney Green Wattle, Rough-barked Apple, Grey Myrtle and Swamp She-Oak.

Three large areas of private open space with significant vegetation remnants include Buckleys Road, the Grand United Centenary Centre, (GUCC) and Bundilla Scout Camp. The density and vigour of weed growth, in particular Balloon Vine and Wandering Jew, in the lower reaches of the creek, reduces the regeneration of younger plants and has caused some species to disappear altogether. The lower reaches of the creek are also degraded by litter.

Dry weather, (base) flows are generally greater in Darling Mills Creek, Hunts Creek and their tributaries which rise in the Hawkesbury Sandstone areas in the north east of the catchment. The creeks that originate in the Wianamatta Shale country, that is, in the Cumberland Plain to the west and south, have very little dry weather flow. Toongabbie Creek collects water from its tributaries - Blacktown, Pendle Hill, Grantham, Greystanes, Pendle Hill and Coopers Creeks - therefore in its lower reaches is often subject to severe flood regimes.

11. Social History and impacts on landuse and the environment (incl. Aboriginal history)

The Upper Parramatta River catchment was originally home to the Dharug Aboriginal people who had inhabited the area for more than forty thousand years before British settlement in 1788. The local clan in the catchment was the Burramatta, from which the name Parramatta came, (burra meaning place and matta meaning eels). Many significant items of Aboriginal cultural heritage can be seen in the catchment, specifically in Lake Parramatta and Parramatta Park, including such things as middens, tree scars, cave paintings and stone flakes.

The early settlement in Port Jackson faced many difficulties, not the least of which was the poor soil which would not support imported strains of wheat and other staple crops. Governor Phillip, who had explored the upper tidal reaches of the Parramatta River in 1788, encouraged establishment of new farms on the low lying river flats by giving land and convicts to the white settlers. This resulted in the development of the township of Rose Hill which later became known as Parramatta, the Aboriginal name meaning "the place where the eels lie down." Parramatta is Australia's second oldest settlement, having been established on November 2nd 1788. Lake Parramatta provided a clean and reliable water supply for the orchards and market gardens so the township flourished. With the introduction of rail transport in the 1850's Parramatta became the main metropolis of NSW.

Today Parramatta and Blacktown are thriving urban areas and make up a major regional centre. The catchment area of 107 km2, is 70% urbanised and contains approximately 80,000 properties and a population of 220,500 (Australian Bureau of Statistics, 1999). The cities of Parramatta and Blacktown are located at the perimeter of the catchment; Parramatta Central Business District being at the outlet, and Blacktown at the western extremity.

The long history of intensive use of the catchment has resulted in significant environmental management problems. Today factories, residences and commercial businesses cover the area, impervious surfaces such as roads, roofs and car parks result in more frequent flooding and all forms of land use, (residential, commercial, recreational and industrial), have caused severe deterioration in water quality.

12. Community Groups

Parramatta City Council is preparing a Toongabbie Creek Plan of Management that covers the creek and its reserves from McCoy Park flood Basin to Oakes Road, Old Toongabbie. The draft plan provides for a wetland in the McCoy Park flood basin and planting in Sue Savage Reserve and other reserves along the creek. If the Plan of Management is adopted it will greatly assist the regeneration and restoration of vegetation along this section of the creek. Local residents and schools should be encouraged to participate in the restoration work. Industries adjoining the creek should be asked to participate in a revegetation program in the industrial area.

13. Management Measures in Place

The following structures have been put in place to alleviate flood problems and improve water quality in Toongabbie Creek:

14. Management issues

Toongabbie Creek offers significant potential for a biodiversity corridor due to the diversity and conservation status of the vegetation communities and the amount and continuity of the open space available. Although the creek is seriously degraded in places, the opportunity exists to regenerate bushland at the lower reaches and revegetate areas further upstream for a high quality and ecologically complex environment. Weed control and prevention of eutrophication is essential to encourage natural regeneration. The following suggestions have been made for managing the creek corridor:-

• Remove exotic weeds from the creek bed and banks and replace with indigenous species in such places as Third Settlement Reserve and Palestine Park.
• Identify areas with endangered ecological communities as first priority and link these to overcome the negative effects of fragmentation
• Control stormwater to reduce erosion, litter and eutrophication
• Revegetate areas such as Sue Savage Reserve
• Restore indigenous understorey so as to provide nectar, seeds and shelter for small birds and ground dwelling animals.
• Rezone areas of endangered remnant vegetation, eg Transition Forest and Cumberland Plain Woodland in the GUCC, the Blacktown half of Sydney Water land and Buckleys Road, to "Bushland Conservation" or "Environmentally Sensitive" land to increase its protection.
• Create a continuous informal path from Blacktown Creek to Quarry Branch Creek to encourage nature based recreational use

15. Other Resources and Links

• Toongabbie Creek Sub-Catchment Map
• Upper Parramatta River Catchment Trust www.uprct.nsw.gov.au
• Nature Conservation Council www.nccnsw.org.au
• Department of Land & Water Conservation www.dlwc.nsw.gov.au
• National Parks & Wildlife Service www.npws.nsw.gov.au