Brisbane River Essays - Environmental Science, Water Pollution

Brisbane River 1.0 INTRODUCTION The Brisbane River has flowed for over 400 million years. The catchment of the Brisbane River has overcome phases of flood and drought while its origins altered as the surrounding land changed overtime. In 1823, John Oxley entered the river for the first time. At the time the river appeared clean and unpolluted. Oxley immediately recognised the rivers potential as a site for new settlement, through his recommendation the city of Brisbane was established in 1825. The Brisbane River extends inland for 300km reaching its source at the foothills of the Great Dividing Range. The rivers catchment occupies an area of approximately 30,000km2 and releases it waters into Moreton Bay. The once pristine waters were used as a source of drinking water and recreational purposes. Industries saw the river as a cheap and efficient source for waste discharge. Before road links were established with Sydney the river held the only form of transport including trade. The Brisbane River was and still is the cities most valuable asset for both recreational, relaxational and transportational purposes. Throughout the past century the Brisbane River has been over used and polluted. The river basin has provided fertile agricultural and grazing lands, and suitable catchment sites for damming purposes. The advantages the river presented were carelessly exploited, to an extent self reparation seemed impossible. Today, the Brisbane River has experience substancial modification to satisfy the requirements of the increasing population. Through extensive public awarness promotions the river gained political support in the form of anti-polution acts. The responsibility of water quality control in the Brisbane now rests in the hands of the Queensland Parliament which passed two acts designed to protect the river from pollutants. These include: the Pollution of Waters by Oil Act of 1973 and the Clean Waters Act of 1971. Through increasing public awarness and involvement the water quality the river is steadily improving, however, its pollution levels still exceed safe levels. One must remember that the river supports approximately 2 million people with industry and transport heavily relient on its waters, therefore, certain levels of pollution are understandable. The ultimate purpose of this report is to analyse the condition of Brisbane River water in 2001. Through testing of river water in different collection locations I statement can be made concerning the overall health of the river. From the results collected recommendations can be made to reduce pollution and erosion levels along the river. Throughout the collection period for different locations were visited where water samples were collected from each. The sites included: 1. Pinkenba 2. Story Bridge 3. Fig Tree Pocket 4. Mt Crosby Weir The water from the locations stated was tested for temperature, dissolved oxygen content, pH, turbidity, suspended and dissolved solids, sulphates, chlorides, nitrates, phosphates, aluminium ions, zinc ions, lead ions, manganese ions, detergents, colour, odour, conductivity, surrounding animal of plant life and land use. 2.0 CURRENT STATE OF THE BRISBANE RIVER The Brisbane River has seen substantial modification during the past 150 years of European occupation. The river has supported waves of exploration, grazing, land clearing, agriculture, settlement and current urbanisation which requires water storage for drinking purposes and flood mitigation; dredging construction materials, shipping channels and flood prevention. Sand extraction through dredging has dominated history along the river, proving extremely important to local construction industries. Between the years 1900 and 1970 an estimated 12 million cubic metres were removed. Extraction of sand reached its peak in the mid 1970s at around 1.45 million cubic metres of sand per year. Annual production was decreased to 1 million cubic metre and later ceased in 1996-7. Extraction primarily took place between Mt Crosby Weir and Milton with small operations between Milton and East Brisbane. The Port of Brisbane is now responsible for maintanance dredging of the lower reaches to maintain a deep channel for cargo vessels. The extensive dredging operations over the years has significantly deepened the river causing river bank instability. The banks of the river have serviced a foundation for city growth. The reaches of the river between Wivenhoe and Mt Crosby Weir are most aethetically pleasing with a rural atmosphere and green vegetation. Between Mt Crosby and Jindalee the river widens flowing through rural and rural residential areas, human interference is evident. From