Mill Creek photos by Brendon Bell

Brendon Bell spoke to the Oatley Flora & Society on the activities of the Sutherland Astronomical Society.

The audience were also treated to a bonus slide show of Brendon’s slides of Mill Creek on the Georges River.

Click here to view Mill Creek slideshow

 

Introduction  to Mill Creek  by Lloyd Hedges

Mill Creek is a tributary of the Georges River bordered by the suburbs of Alfords Point, Menai, Bardens Ridge, Lucas Heights and the Holsworthy Army base.  It arises at the junction of New Illawarra and Heathcote Roads and these roads mark the edges of its 200 sq km catchment.

It starts inauspiciously at the base of the Lucas Heights Tip Site. A major tributary, Bardens Creek, commences beneath the nuclear reactor at ANSTO, and another Lucas Heights Number 1 at the old tip site. This problematic start is compounded by other factors such as illegal dumping, weed invasion, and erosion caused by stormwater and vehicles, particularly trail bikes and 4WDs.

In light of the problems on the perimeter a stroll in the bush can be a pleasant surprise: near pristine bush, waterfalls, Aboriginal engravings, valleys full of wildflowers: In Spring Waratahs and Gymea Lilies; in Autumn/Winter Banksias, Wattles and epacrids like Red Five Corners.

Geomorphology

The valley has been incised into the ramparts of the Woronora Plateau. The dominant geology is Hawkesbury sandstone with its infertile soils and poor water holding capacity but overlaying this on the ridges are clay and shale lenses of the Wianamatta formation, particularly around the Little Forest area.

The creek starts as a series of pool s in a shallow valley but as it gathers more water it incises deeper and the steepness of the valley walls increase making access to the middle reaches of the creek difficult. When the salt water, which re invaded the valley 7000 years ago following the thawing of the last ice age, is reached there is a build up of alluvial soils along the edges which in places form swamps and river flats.

 

Flora

Within the catchment are a number of Endangered Ecological Communities. The turpentine/ironbark forest that grows on the shale lens at Little Forest is an example; it was never common around Sydney but the fact that it inhabited the plateaus where Europeans liked to build their houses and that its fertile soils were highly sort after has meant that Little Forest is one of the few remnants. The associated Shale/Sandstone Transition Forest that inhabits the area around Little Forest and few other sites has suffered a similar fate.

Along the river flats of the lower creek are three more endangered communities: Coastal Saltmarsh, River Oak Floodplain Forest and River-flat Eucalypt Forest. Also there is a dry clay heath that contains a number of rare and unusual species that has been designated a conservation area by the Sutherland Shire Council.

There are a number of rare plant species in the Mill Creek catchment. These include Hibbertia Menai sp nova discovered by A. Fairley in 2004, Darwinia diminuta, Hibbertia nitida, Tetratheca negl ecta, Melaleuca deanei and Lomandra fluviatilis; also there is the major popu lation of a sub-species of A llocasuarina diminuta ssp mimica which may well become a species in its own right.

Land Use

The major land holders in the catchment are ANSTO, Lucas Heights Waste Management Centre controlled by SITA, residents of suburbs on the eastern edge, some crown land, the Barden Ridge sports complex on the former tip site, a pony club and a quarry at Sandy Point. The biggest land holder with ownership or claims for over 40% of the area and over 50% of the remnant bush is the Gandangarra Local Aboriginal Land Council.

 

Georges River National Park

The region around the confluence of Mill Creek and the Georges River is now part of the Georges River NP. The western side between Sandy Point and Mill Creek was only handed to the NP in 2007. For many years it had been a buffer zone for the Holsworthy army base.

Although the service roads for the electricity pylons and other tracks have degraded some areas there are also as previously mentioned 3 Endangerical Communities. There are several salt ed Ecologmarshes fringed by mangroves and Swamp Oaks and a paperbark swamp that covers many acres; this is a delight in mid summer when they are in flower. The park also contains many species typical of the Cumberland Plains.

The importance of Mill Creek

As well as being a home to rare ecological communities and species the Mill Creek catchment is a bushy finger connecting the vast natural bush of Sydney’s water catchment through the army lands to the close in suburbs. It serves as a corridor for all manner of plants and animals to refuel the small stressed areas of bush of inner Sydney, including migrating birds.

It is also a recreational area for bushwalkers and mountain bike riders that attracts participants from all over Sydney. It would not take an enormous amount of work to connect up the existing tracks to complete a trail that commences at Sandy Point, runs the length of Mill and Bardens Creek and connects up with the Heathcote NP.

 

The challenges ahead

The GLALC have submitted plans to subdivide their holdings into 5000 home sites and an industrial area; in effect another suburb the size of Menai in the catchment. It is hard to imagine that much of what you see in these photographs will still be there in years to come.

 

 

 

 

 

 

 

by Lloyd Hedges, 7 July 2011

 

 

 

 

 

1 comment to Mill Creek photos by Brendon Bell

  • Dear brendon,
    May I please use your photos in a book I am writing on my professional interests? I was the complainant in a case of illegal dumping of safflower oil waste mixed with cyanide illegally dumped at Menai in the 1970’s which completely destroyed Mill Creek! This was in the N.S.W Supreme Court. I was also the expert witness in an accidental leak of potassium copper cyanide int the Cooks River one Christmas day. You can get me on 07 54970045 with some luck!( poor service area), I now live in Caboolture, QLD. Regards.

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