Information Sheet (environmental issues)

E6 - Impacts of Urban Development

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1. Description

When the first land in the Hills district was granted by Governor Hunter in 1799 the biophysical environment was dominated by Eucalypt tree species which included Grey Box and Bloodwood and shrubs including Acacias, Banksias and Grevillias. These bushlands would have supported a rich variety of native fauna such as wallabies, kangaroos, wombats, reptiles and great variety of birds.

In the 1940’s what is now West Pennant Hills was mainly a patchwork of agricultural fields. Acres of land had been cleared for market gardening to supply the ever increasing need for food by the growing population of Sydney and surrounds.

Today the catchment is a thriving urban area close to the geographic centre of the greater Sydney region. However the natural environment is paying the price for humanity’s greed as social impacts adversely affect the natural environment. The state of the catchment is of great concern to the 230,000 residents and the tens of thousands more who work and visit here.

2.    The Problem

Land use in the catchment can be summarised as follows:- (extract from the Upper Parramatta River Catchment Stormwater Management Plan 1999)

Fig. E6.1 Landuse in the Upper Parramatta River Catchment

This table shows that a very small percentage of the catchment, in fact less than 4.9%, is in its natural state.  The 4.9% classified as Bushland and Open Space includes fourteen regionally significant parks and four golf courses.

Increasing residential development and associated industrial activity has lead to severe impacts on the natural environment. Loss of habitat and biodiversity, flooding due to increased run off, pollution of air, soil and waterways, introduction of weed species and feral animals, loss of public amenity and siltation of local creeks are some of the problems associated with unchecked urban development.

Major land use issues in the catchment are:

·           New and infill development

·           Sediment and erosion control – retention of soils

·           Flood risk in low lying areas

·           Contaminated industrial land and former waste disposal sites

·           Retention and management of remnant areas

·           Stormwater runoff

·           Salinity

·           Recreation planning and management

·           Cultural heritage protection

The large degree of urbanisation in the Upper Parramatta River catchment has resulted in increasing pollutant loads entering the creeks and rivers. The major source of pollution is stormwater and sewage overflows. This pollution consists of:

·         nutrients from fertilisers and detergents

·         faeces from animals

·         oils, grease and heavy metals from motor vehicles

·         pesticides and herbicides

·         litter.

Other sources of stormwater pollution include:

·         industrial areas (oils and grease, heavy metals, toxic chemicals)

·         construction sites (sediment causing high levels of turbidity and suspended solids, and smothering aquatic habitat)

·         leaks, cracks and breakages in the sewerage system

·         spills from mobile sources such as motor vehicles and recreational boats (oils and grease, heavy metals, toxic chemicals, etc).

Water quality studies, including macroinvertebrate studies indicate that there is significant variation of diversity and abundance of organisms across the catchment. The results also expose a significant difference in health between the two major sub-catchments in the Upper Parramatta River catchment, Toongabbie Creek and Darling Mills/Hunts Creek.

Macroinvertebrate studies can be compared through the number of taxa recorded. The mean of total taxa (8) was greater in the Darling Mills system (12.8) than in the Toongabbie system (8.7), demonstrating that the ecology of the Darling Mills sub-catchment is more productive and its ecology less affected by pollution than the Toongabbie Creek sub-catchment. The ‘healthiest‘ creeks in the catchment, according to Lee Lau & Associates (1997), are located in the Darling Mills Creek system:

·           Upper Rifle Range Creek at North Rocks,

·           Bellbird Creek at North Rocks,

·           Darling Mills Creek at North Rocks and Baulkham Hills.

The Toongabbie Creek sub-catchment does not support as rich a diversity of macroinvertebrates, and it is evident that ecosystem health is poor (Lee Lau and Associates, 1997). Examples of creeks with such poor health are:

·           Upper Toongabbie Creek at Crestwood Reserve,

·           Lower Toongabbie Creek at Westmead,

·           Blacktown Creek at Blacktown.

Such a contrast in the sub-catchments can be explained by the land use of each. Toongabbie Creek sub-catchment contains large areas of residential, industrial and commercial development with only small remnants of bushland. The creeks in many areas have been converted to concrete channels. Conversely, Darling Mills Creek sub-catchment contains relatively extensive tracts of bushland with mainly residential land use, and the majority of the sub-catchment has natural creeks. Quarry Branch Creek at Torry Burn Reserve, Baulkham Hills in the Toongabbie Creek sub-catchment demonstrates this point. It is surrounded by a large amount of bushland and residential premises, and was rated the ‘healthiest’ creek in the sub-catchment.

3.Management Solutions

The challenge to maintain the catchment in a sustainable manner will need to involve everyone if the objectives of a healthier catchment are to be met. Community awareness of environmental problems and active involvement in finding solutions is critical to managing the catchment environment.

Land use planning is ideally a proactive approach to dealing with environmental and social issues associated with development.

Land management is about mitigating any adverse environmental or social impacts of land based activities.

The land use planning and land management framework is outlined by council Local Environment Plans and Development Control Plans and at regional level by Regional Environmental Plans such as the Parramatta REP. A key concept in land use planning in NSW is that of Ecologically Sustainable Development (ESD). (see Ecologically Sustainable Development fact sheet).

Past developments in environmentally sensitive areas have contributed to many of our current environmental management problems. Conditions on approval of new developments or redevelopments are the major tools for limiting the environmental impact of land use.

4. What can you do?

Councils, State government agencies and the Upper Parramatta Catchment River Trust coordinate a variety of community based management programs, such as Bushcare, Landcare and Rivercare, with which you can become involved. Local catchment trusts educate and empower their local communities in many ways including :

·         Streamwatch – a community based water quality monitoring program which is a partnership between Sydney Water, the Department of Land and Water Conservation, the Hawkesbury Nepean, Hunter and Upper Parramatta River Catchment Management Trusts.

·         Targeted workshops

·         Catchment Open Days and tours

·         Community tree planting

·         Media  advertising and newsletters

·         Providing small grants for community activities

As an individual you can make life style changes in an attempt to life in a more sustainable manner. For example:

·         Use a compost bin or worm farm for food scraps

·         wash your car on the lawn

·         install a rainwater tank

·         install energy saving light bulbs

·         grow your own vegetables in the back garden

·         use calico shopping bags instead of plastic ones

·         walk or take public transport rather than drive

5. Further Information & Links

·           Streamwatch www.streamwatch.org.au

·           Parramatta City Council ph 9806 5000

·           Baulkham Hills Shire Council ph. 9843 0555

·           Holroyd City Council ph. 9840 9840

·           UPRCT ph. 9891 4633

·           Department of Urban Affairs and Planning www.duap.nsw.gov.au

·           SoE Human Settlements www.ea.gov.au/soe/settlements/index.htm