FREE ESSAY ON BRISBANE RIVER

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 river's 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 river's 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
1970's 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 Jindalee
to the Botanical Gardens human occupation and urban development is obvious has high rise
building line the banks of St Lucia and Toowong. Strong urban development is particularly
evident throught the city and south bank reach. As the the river continues towards
Pinkenba industrial and commercial areas dominate. (fig1). From the Murarrie to the mouth
the river bocomes a mangrove lined estuary dominated by commercial shipping activity. A
distinct industrial character dominates the area with the huscle and bussle of a major
port. 
The speed of the river is generally determined by season. The river exhibiting maximum
flow in summer with its characteristic high rainfall levels, and minimum flow in Winter
where rainfall is generally minimal. Due to the slow water flow accumulation of
pollutants and general dterioration of waterquality can occur. However, the release of
water from storage dams upstream can eliminate this accumulation. Somerset and Wivenhoe
dams release set amounts of water to satify Brisbane's water needs. Wivenhoe allows for a
more even flow of water throughout the year, improving the general water quality of the
River. Wivenhoe is also used as a flood prevention mechanism to reduce water flow from
the Range. 
Concentrated large-scale drainage points where discharge from operations such as waste
water, treatment plants and industry comprise major sources of pollutants in the river.
At the present time sewage discharge is mainly treated to a secondary standard with a
small proportion only to a primary standard. The sewage discharges not only contribute
substantially to the nutrient load and demand for oxygen in the water but also to the
toxicant load. This leads to the contamination of fish and other marine oraganisms by
such substances. Sewage discharges in the Brisbane area are commonly chlorinated imposing
a negative impact on the river. The most apparent discharges are those situated around
the highly industrialised portion of the river. Brisbane City has two major waste water
treatment plants, including: Luggage Point on the northside and Gibson Island on the
southside, both of which situated in this heavily industrialized section. Additionally,
two oil refineries- BP at Bulwer Island and Caltex at Lytton discharge streams from
potentially contaminated sites into the river. Discharges into the river such as run-off
from urban and industrial land and from upstream parts of the catchment can distcharge
significant quantities of toxic pollutants (eg pesticides) into the river. Accidents
occur relatively infrequently but can have a major impact when they do occur. Spills of
insecticides, petroleum and other substances occur periodically in the city, often
resulting in serve contamination of the river, leading to extensive fish kills. On the
27th of April, 1998 a 230m tanker Barringon that was docked at the AMPOL Refined Products
berth at White Island, near Fisherman's Islands in Brisbane was hit by a local Tugboat
named "Austral Salvor". The accident caused 8 tonnes of heavy fuel oil to be spilled into
the Brisbane River (fig2).
3.0 TEST RESULTS
To recommend possible improvements towards the safe management of the Brisbane River one
must aquire a degree of knowledge concerning the current quality of the water. The
following tests were conducted on water samples at each of the four sample locations.
Tests conducted on site:
1. surface temperature 
2. pH level
3. dissolved oxygen
4. turbidity
Tested conducted in school laboratory:
1. suspended solids
2. dissolved solids
3. sulphates
4. chlorides
5. nitrates
6. phosphates
7. aluminium ions
8. zinc ions
9. manganese ions
10. detergents
3.2 SPECIFIC SAMPLE SITE LOCATIONS
3.2.1 Pinkenba
(figure 3 Specific site location for Pinkenba)
As figure 3 represents, the location of the Pinkenba site is in close proximity with the
mouth of the river and entrance to Moreton bay. The site is engulfed in the typical
characteristics of a jubilant industrial trade ground. From the Pinkenba site the Caltex
and BP oil refineries are visible, the Incitec fertiliser plant is also in close
proximity. Inustrial locations line the banks of this particular site. Evidence of flora
or fauna were minimal. (figure 4. Diagram of land use surrounding the Pinkenba site)
3.2.2 Story Bridge
(figure 5 Specific sample site location Story Bridge)
As figure five represents, the location of the Story Bridge site is situated in the
Central Business District of Brisbane and 23 kilometres from the mouth of the Brisbane
River and entrance to Moreton Bay. The featured site displays the typical characteristics
of that of a CBD district. The site is located directly under the Story Bridge on the
southern side of the river. The land use is predominantly residential development both
houses and high rises in nature. Across the river from the testing site is the CBD were
building sites and storm water drains predominate. Ferries and Citycats often passed the
site while testing was performed. The parkland surrounding the site provided a backdrop
of lush, green vegetation, lined with numerous trees and shrubs. This parkland provided a
habitat for bird and animal life. Pollution output around the site appeared to be limited
to the carelessly strewn litter from other students, however, the presence of sewage
outlets under the bank could not be indentified. 
(figure 6 Photo of land use around the Story Bridge site)
3.2.3 Fig Tree Pocket
(figure 7 Specific sample site location for Fig Tree Pocket)
As figure 7 suggests Fig Tree Pocket is located on the western side of the city and
measured approximately 45 km from the mouth of the river and entrance to Moreton Bay. The
site is in a predominantely semi residential semi rural location. The site of testing was
situated in Mandalay Park, were residential land use predominated. On the other side of
the river a more semi rural impression was given with the occasional house amoungst dense
green foliage. The site appeared reasonably clean with no apparent signs of waste
products entering the river. The site was aesthetically pleasing with a variety of trees
and lush grass. 
(figure 8 Photo of site and surrounding land at Fig Tree Pocket)
3.2.4 Mt Crosby Weir 
(figure 8 Specific sample site location for Mt Crosby Weir)
As figure 8 suggest Mt Crosby Weir is located on the western side of the city measuring
approximately 80 km from the mouth of the river and entrance to Moreton Bay. The site is
surrounded by all the characteristics classical of a rural environment. The site is based
directly below the Mt Crosby Weir. The site is completely surrounded by lush vegetation
with the only exception that of the council pumping station. The site is dominated by
native trees and shrubs, wildlife is prolific. No signs of waste production was observed
as the site receives minimal human interference. 
(figure 9 Photo of land use surrounding the Mt Crosby Weir)
3.3 TABLE OF TESTING RESULTS
Graph 1.0 
Temperature Vs. Time 
Time Pinkenba Story Bridge Fig Tree Pocket Mt. Crosby Weir
9.30 19.8 20.3 21.75 19.55
11.05 20.9 20.75 21.4 20
12.40 20.1 21.85 21.1 19.55
14.15 20.75 21.75 21.15 19.4
Graph 2.0 
pH Vs. Time 
Time Pinkenba Story Bridge Fig Tree Pocket Mt. Crosby Weir
9.30 8.45 7.75 7.55 8.15
11.05 8 7.8 7.4 8.45
12.40 8.1 7.7 7.75 8.6
14.15 8.75 7.75 7.55 8.5
Graph 3.0 
Dissolved Oxygen (ppm) Vs. Time 
Time Pinkenba Story Bridge Fig Tree Pocket Mt. Crosby Weir
9.30 5.25 4.5 4.4 8.5
11.05 4.3 1.5 6 7.2
12.40 5 4.55 4.65 7.85
14.15 5.05 1 5.5 7.2
Graph 4.0 
Turbidity Vs. Time 
Time Pinkenba Story Bridge Fig Tree Pocket Mt. Crosby Weir
9.30 10 150 101.5 0
11.05 12 137.5 80 0
12.40 13.5 144 180 0
14.15 37 75 137.5 0
Graph 5.0 
Suspended Solids Vs. Time 
Time Pinkenba Story Bridge Fig Tree Pocket Mt. Crosby Weir
9.30 1.16 0.24 0 0.01
11.05 4.62 2 0.89 0.025
12.40 0.79 0.81 0.27 0
14.15 0.12 1.33 0.09 0
Graph 6.0 
Dissolved Solids Vs. Time 
Time Pinkenba Story Bridge Fig Tree Pocket Mt. Crosby Weir
9.30 5.15 3.2 0.99 0.022
11.05 3.38 4 1.05 0.025
12.40 2.75 3.09 0.84 0.02
14.15 4.3 2.83 0.87 0.21
Graph 7.0 
Sulphates Vs. Time 
Time Pinkenba Story Bridge Fig Tree Pocket Mt. Crosby Weir
9.30 4000 630 950 1000
11.05 640 4000 1100 0
12.40 700 2580 500 30
14.15 2500 0 3600 0
Graph 8.0 
Chlorides Vs. Time 
Time Pinkenba Story Bridge Fig Tree Pocket Mt. Crosby Weir
9.30 37.0 29.4 8.2 0
11.05 36.8 28 14 1.6
12.40 18 30 26.4 1.2
14.15 44.8 20 64 18
Graph 9.0 
Nitrates Vs. Time 
Time Pinkenba Story Bridge Fig Tree Pocket Mt. Crosby Weir
9.30 0 12 5.5 11
11.05 1 12 13 2
12.40 19 5.5 12.7 1.6
14.15 2.8 39 13 2.7
Graph 10.0 
Phosphates Vs. Time 
Time Pinkenba Story Bridge Fig Tree Pocket Mt. Crosby Weir
9.30 1 1 3.5 0
11.05 1 1.25 2.5 0
12.40 0 1 3.5 0
14.15 1 0 2.75 1
Graph 11.0 
Detergent Vs Time 
Time Pinkenba Story Bridge Fig Tree Pocket Mt. Crosby Weir
9.30 Yes Yes None None
11.05 Yes Yes Yes None
12.40 Yes None Yes None
14.15 None Yes None None
4.0 DISCUSSION OF RESULTS