Appendix Five - Sources and statistics on water use
Sources
A first comprehensive national survey of water in Australia
(quality, availability and use) was conducted as part of the National
Land and Water Resources Audit,
which took place between 1997 and 2002. The Audit derived its raw data from a
range of sources, primarily State and Commonwealth Departments and agencies.
At about the same time the Australian Bureau of Statistics
(ABS) conducted its first Water Account Australia 1993-94 to 1996-97 survey, which was
published in May 2000. The next survey in the series, covering the years 1997-8
to 2000-1, was published in May 2004.
While the general order of magnitude of the figures was
similar, there were differences between the Audit and ABS figures. For example,
the Audit's estimate of total water use in 1996/7 was 24,058 GL and the ABS
figure was 22,186 GL.
It is likely that the ABS figures will, over time, create
the most reliable series as their regular two-yearly and five-yearly surveys
take place in the future.
National Land
and Water Resources Audit (NLWRA)
The National Land
and Water Resources Audit (the Audit) was set up in 1997 as a partnership
between the States, Territories and Commonwealth and funded under the Natural
Heritage Trust. The aim of the Audit was to provide better information to
resource managers which in turn would improve land, water and vegetation
management. [98]
The NLWRA, also known as Audit 1, took place from 1997 to
2002 at a cost of about $34 million.
Audit 1 represented the most comprehensive review ever
undertaken of Australias
natural resources. A number of detailed reports were published setting out the
state of Australias
farming systems and natural environment. An online atlas and data library of
the nations resources were created.
The Australian Natural Resources Atlas provides an extensive
range of information across seven key areas: agriculture; coasts; land; people;
rangelands; vegetation and biodiversity; and water.[99]
Audit 1, in its report Australian
Water Resources Assessment 2000, made the following comment in relation to
the availability of data on Australias
water resources:
Overall, data completeness and quality remain issues for
comprehensive reporting of Australias
water resources. On average only 77% of the groundwater management units have
information on aquifer characteristics, allocation, use and extraction.
Similarly 78% of all surface water management areas have information on water
availability, allocation, use and water trading. However the reliability of
this data is extremely variablewater quality and trend information is even
further limited.[100]
In discussing data content, quality, and comparability, the
Audit noted:
Data are extremely variable.There is a mismatch between data
availability and quality, and the requirements of decision makers.[101]
The Audit found a great diversity of procedures,
methodologies, and definitions between the States and Territories in relation
to water issues, which had evolved over the last 150 years or so. This made it
very difficult to compare methods and processes in different States and the
results achieved.
The Audit recommended that:
Australia
requires a systematic, and Australia-wide approach for water resource data
collection to provide a foundation for improved water resources management.
Data analysis and access need to be compatible and comparable.[102]
Following a review of the results of Audit 1, the
Commonwealth decided to continue the project. Audit 2 is a five year program,
2003 2007, with a budget of up to $3 million per annum.
Audit 2 collects data and information to enable an
evaluation of natural resource management initiatives such as the National
Action Plan for Salinity and Water Quality, and the Natural Heritage Trust.
Australian Water Data Infrastructure Project
In response to the Audit recommendation, the Australian
Water Data Infrastructure Project (AWDIP) was established to develop a
comprehensive national water information framework.
This project is managed by the Executive Steering Committee
for Australian Water Resources Information. The Steering Committee
comprises representatives of: the
Commonwealth Departments of Agriculture, Fisheries and Forestry (Chair) and
Environment and Heritage; representatives from each State and Territory government;
and representatives from the Australian Bureau of Statistics, the National Land
and Water Resources Audit, the CSIRO, the Bureau of Meteorology, the Bureau of
Rural Sciences, and the Murray-Darling Basin Commission. This project is funded
under the National Heritage Trust.
The Steering Committee met
for the first time in May 2003, and meets two or there times a year. It reports
to the Audit Advisory Council of the National
Land and Water Resources Audit on
data coordination issues.
Australian Bureau of Statistics
The ABSs first Water
Account Australia 1993-94 to 1996-97, published in May
2000, contains detailed water supply and water use tables. This survey was
based primarily on data collected by State-based departments and agencies, such
as bulk water suppliers. The ABS published the next in the series, Water Account Australia 1997-98 to 2000-01, in May 2004.
In October 2003 the ABS distributed to a large sample of
irrigators (7,000 out of an estimated total population of about 38,000
irrigators) a Water Survey - Agriculture
(WSA) questionnaire to gather information on water availability and use in
irrigated agriculture in 2002-03. The information being collected on the WSA covers:
- Water
entitlements and allocations
- Trading
of water (buying and selling)
- Area
of pastures and crops irrigated
- Volumes
of water applied to pastures and crops
- Irrigation
methods
- Irrigation
scheduling tools
- Sources
of irrigation water
- On-farm
water storage
- On-farm
water recycling
- Areas
of laser levelling for irrigation
- Changes
to irrigation practices
- Irrigation
expenses
- Basic
farm financials - value of agricultural and irrigated production, and net
profit/loss from agricultural production
The Water Survey
Agriculture 2002-03 represents the first time that the ABS has collected
detailed information on water direct from farmers themselves. This report is
expected to be published in late 2004.
The ABS is planning to undertake a Water Survey Agriculture report every two years, and the more
extensive Water Account for Australia every four years. To complete the water picture, in 2005
the ABS is planning to also commence two yearly Water Surveys to cover urban and industrial water use, and stock
and domestic rural water use.
Statistical overview
Information is drawn from the National
Land and Water Resources Audit and
the State of the Environment Report 2001.[103]
Water Availability
Surface water
On average, only 12 % of Australia's
rainfall runs off to collect in rivers and streams. The remaining 88% of
rainfall is accounted for by evaporation, water used by vegetation, and water
held in storages including natural lakes, wetlands and groundwater aquifers.
Table 1 shows that most run-off occurs in the northern parts
of the continent, with three drainage divisions, North East Coast, Timor Sea
and Gulf of Carpentaria, representing about two-thirds of total mean annual
run-off.
Mean annual run-off totals 387 184 GL, of which 18 147 GL
(4%) is presently diverted for consumptive use.
|
Table 1. Run-off, outflows and diversion
from each drainage division
|
|
Drainage division
|
Mean annual run-off (GL)
|
Percent mean annual run-off (%)
|
Mean annual outflow (GL)
|
Volume diverted (GL)
|
|
North-East Coast
|
73 411
|
19.0
|
69 580
|
3 182
|
|
South-East Coast
|
42 390
|
10.9
|
40 366
|
1 825
|
|
Tasmania
|
45 582
|
11.8
|
45 336
|
451
|
|
MurrayDarling
|
23 850
|
6.2
|
5 750
|
12 051
|
|
South Aust.
Gulf
|
952
|
0.2
|
787
|
144
|
|
South-West Coast
|
6 785
|
1.8
|
5 925
|
373
|
|
Indian Ocean
|
4 609
|
1.2
|
3 481
|
12
|
|
Timor Sea
|
83 320
|
21.5
|
81 461
|
48
|
|
Gulf of Carpentaria
|
95 615
|
24.7
|
96 066
|
52
|
|
Lake Eyre
|
8 638
|
2.2
|
n/a
|
7
|
|
BullooBancannia
|
546
|
0.1
|
|
<>
|
|
Western Plateau
|
1 486
|
0.4
|
n/a
|
1
|
|
Total
|
387 184
|
100%
|
|
18 147
|
|
Source: National Land and Water
Resources Audit, Australian Water Resources Assessment 2000, p. 25.
|
Australia
has 447 large dams with a combined capacity of 79,000 GL, developed mainly for
urban, irrigation and hydroelectric power uses. Australias
several million farm dams account for an estimated 9% of the total water
stored.
Groundwater
Australia
has 25,789 GL of groundwater that can be extracted sustainably each year and is
suitable for potable, stock and domestic use, and irrigated agriculture. Ten
percent (2489 GL) is used. Australia
has one of the worlds largest aquifer systems: the Great
Artesian Basin
is an estimated 1.7 million km2 and stores 8.7 million
GL. Each year the Great Artesian
Basin supplies 570 GL of water for
a variety of usesmainly grazing and mining.
Water Use
There is a great variation in water use. Some areas of the
country such as the northern coastline make little use of divertible water
resources. Other areas make significant use, notably the MurrayDarling
Basin. Table 1 shows that 51% of
runoff in the Basin is diverted for use.
Approximately 73% of the water used in Australia
(~24,000 GL in total) is supplied by rivers, 21% by groundwater aquifers, and
the remaining 9% by harvest of overland flows. Surface water predominates in
all States and Territories except Western Australia
and the Northern Territory.
Surface water use
Table 2 shows that surface water use in Australia
increased by 59% between 1983/4 and 1996/7. An estimated 26% of Australias
325 surface water management areas are either close to or overused compared
with their sustainable flow regimes.
|
Table 2. Change in mean annual surface
water use (GL),1983/841996/97
|
|
|
Total use 1983/84 (GL)
|
Total use 1996/97 (GL)
|
Percent increase
|
|
NSW
|
5 932
|
9 000
|
52
|
|
Victoria
|
3 714
|
5 166
|
39
|
|
Queensland
|
1 209
|
2 969
|
145
|
|
WA
|
461
|
658
|
43
|
|
SA
|
498
|
746
|
50
|
|
Tasmania
|
165
|
451
|
173
|
|
NT
|
29
|
51
|
76
|
|
ACT
|
n/a
|
68
|
|
|
Total
|
12 008
|
19 109
|
59
|
|
Source: National Land and Water
Resources Audit
|
Groundwater use
Table 3 shows that groundwater use across Australia
increased 88% between 1983/4 and 1996/7. Overall, 32% of groundwater extracted
is for urban-industrial use, 51% for irrigation and 17% for stock watering and
rural use. It is estimated that 30% of Australias
groundwater management units are close to or overused compared with their
sustainable yield.
|
Table 3. Change in mean annual
groundwater use (GL), 1983/841996/97
|
|
|
1983/84 (GL)
|
1996/97 (GL)
|
Percent increase
|
|
NSW
|
318
|
1 008
|
217
|
|
Victoria
|
206
|
622
|
202
|
|
Queensland
|
1 121
|
1 622
|
45
|
|
WA
|
373
|
1 138
|
205
|
|
SA
|
542
|
419
|
-22
|
|
Tasmania
|
9
|
20
|
122
|
|
NT
|
65
|
128
|
97
|
|
ACT
|
n/a
|
5
|
|
|
Total
|
2 634
|
4 962
|
88
|
|
Source: National Land and Water
Resources Audit, Australian Water Resources Assessment 2000, p. 65
|
Uses of water
Approximately 75% of the water used in Australia
is for irrigated agriculture. NSW (48%), Victoria
(25%) and Queensland (16%)
account for 90% of Australian irrigation. Half of the profit in 1996/97 from
Australian agriculture, when measured as profit at full equity, was generated
from irrigated production systems. These occupy less than 0.5% of Australias
land area. About 20% of total water use is for urban and industrial purposes,
the rest for other rural uses such as stock and domestic needs.
|
Table 4. Australias mean annual water use (GL) by use
category (1996/97)
|
|
|
Irrigation
|
Urban/industrial
|
Rural
|
Total use
|
|
NSW
|
8 643
|
1 060
|
305
|
10 008
|
|
Victoria
|
4 451
|
987
|
339
|
5 777
|
|
Queensland
|
2 978
|
1 052
|
561
|
4 591
|
|
WA
|
710
|
1 027
|
59
|
1 796
|
|
SA
|
819
|
292
|
53
|
1 164
|
|
Tasmania
|
276
|
186
|
9
|
471
|
|
NT
|
53
|
87
|
39
|
179
|
|
ACT
|
5
|
63
|
4
|
72
|
|
Total
|
17 935
|
4 754
|
1 369
|
24 058
|
|
Source: National Land and Water
Resources Audit, Australian Water Resources Assessment 2000, p. 56
|
Australian water use increased by 65% between 1983/84 and
1996/97. This was mostly due to increases in irrigated agriculture. Urban
centres have shown either low increases or net decreases in water consumption
per person over the same period.
|
Table 5. Change in mean annual water use
(GL) in Australia between 1983/84 and 1996/97 by water use category
|
|
|
1983/84
|
1996/97
|
Percent change%
|
|
Irrigation
|
10 200
|
17 935
|
76
|
|
Urban/industrial
|
3 060
|
4 754
|
55
|
|
Rural
|
1 340
|
1 369
|
2
|
|
Total
|
14 600
|
24 058
|
65
|
|
Source: National Land and Water
Resources Audit, Australian Water Resources Assessment 2000, p. 57
|
There are great variations in the efficiency of delivery
systems used to supply irrigation water. On average, only 77% of water reaches
users properties, although supply efficiency can be as low as 45% in some
irrigation areas.
Financial return
Different irrigation enterprises and the intensity of water
use in those enterprises leads to a wide range in the economic benefits
achieved from irrigation. There is scope for further rationalisation of water
use and increases in returns as water use moves to higher value products. The
gross value from irrigated agriculture for 1996/97 was $7,254 million. The
highest financial return in agriculture per hectare of irrigation comes from
vegetables, closely followed by fruit. Financial return on net water use is
similarly highest for vegetables followed by fruit.
|
Table 6. Water use and gross value for
irrigated agriculture (1996/97)
|
|
|
Gross value ($m)
|
Net water use (GL)
|
Irrigated area (ha)
|
Value/ha
$/ha
|
Value/GL
$m/GL
|
|
Livestock, pasture, grains, etc.
|
2 540
|
8 795
|
1 174 687
|
2 162
|
0.3
|
|
Vegetables
|
1 119
|
635
|
88 782
|
12 604
|
1.8
|
|
Sugar
|
517
|
1 236
|
173
224
|
2 985
|
0.4
|
|
Fruit
|
1 027
|
704
|
82 316
|
12 476
|
1.5
|
|
Grapes
|
613
|
649
|
70 248
|
8 726
|
0.9
|
|
Cotton
|
1 128
|
1 841
|
314
957
|
3 581
|
0.6
|
|
Rice
|
310
|
1 643
|
152
367
|
2 035
|
0.2
|
|
Total
|
7 254
|
15 503
|
2 056 581
|
|
|
|
Source: National Land and Water
Resources Audit
|
International comparisons
Australia
has a variable climate with high levels of evapotranspiration, resulting in a
low proportion of rainfall converted to runoff. Table 7 shows that Australia
is relatively dry in terms of overall rainfall and runoff. Australia
has about 5% of the world's land and about 1% of its water resources.
|
Table 7. Continents by: land area; % of world
water resources;
rainfall; and runoff
|
|
Region
|
Land Area
Millions of sq. kms
|
Estimated % of
worlds total water resources (a)
%
|
Average annual
rainfall (b)
mm
|
Estimated runoff as
% of average annual rainfall (b)
%
|
|
Africa
|
30.3
|
9
|
690
|
38
|
|
America,
North
|
24.7
|
16
|
660
|
52
|
|
America,
South
|
17.8
|
27
|
1,630
|
57
|
|
Asia
|
44.9
|
33
|
600
|
48
|
|
Australia
|
7.7
|
1
|
465
|
12
|
|
Europe
|
9.9
|
14
|
640
|
39
|
|
Source(a) Food
& Agricultural Organisation, Water Report No. 23 Review of Water
Resources by Country 2003, p. 127
Source (b) Year
Book Australia 2003, p. 30.
Percentages have been rounded to nearest
whole number.
|
Australian rivers have comparatively low and variable flows.
Table 8 compares some of the major rivers around the world with three of Australias
major rivers.
|
Table 8. Ratio of
maximum to minimum annual flow for selected rivers
|
|
Country
|
River
|
Ratio of maximum to
minimum annual flows
|
|
Brazil
|
Amazon
|
1.3
|
|
Switzerland
|
Rhine
|
1.9
|
|
China
|
Yangtze
|
2.0
|
|
Sudan
|
White Nile
|
2.4
|
|
USA
|
Potomac
|
3.9
|
|
Australia
|
Murray
|
15.5
|
|
Australia
|
Hunter
|
54.3
|
|
Australia
|
Darling
|
4705.2
|
|
Source: Murray Darling Basin Commission presentation
|
A recent study estimated water availability and use in
fourteen selected countries (see Table 9). Australia
ranked fourth in Estimated Per Capita Water Withdrawal in 2000. The study noted
that the data should be viewed with caution, as it comes from different sources
and over different periods. As well, international comparisons of water
availability and water use must be highly qualified because circumstances vary
so greatly.
|
Table 9. Water
resources and withdrawals, selected countries
|
|
Country
|
Annual Renewable
Water Resource km3/yr
(year of estimate)
|
Total Freshwater
Withdrawal kms3/yr
(year of estimate)
|
Estimated per
capita withdrawal in 2000
m3/p/yr
|
Agriculture as % of
total water usage
%
|
|
Argentina
|
814 (2000)
|
28.6 (1995)
|
772
|
75
|
|
Australia
|
398 (1995)
|
17.8 (1995)
|
945
|
75
|
|
Canada
|
2901 (1980)
|
43.9 (1990)
|
1,431
|
8
|
|
Chile
|
922 (2000)
|
20.3 (1987)
|
1,334
|
84
|
|
Germany
|
182 (2001)
|
58.9 (1990)
|
712
|
18
|
|
Indonesia
|
2,838 (1999)
|
74.4 (1990)
|
350
|
93
|
|
Mexico
|
457 (2000)
|
77.8 (1998)
|
787
|
78
|
|
New Zealand
|
397 (1995)
|
2.0 (1991)
|
532
|
44
|
|
South Africa
|
50 (1990)
|
13.3 (1990)
|
288
|
72
|
|
Spain
|
111 (1985)
|
33.3 (1994)
|
837
|
62
|
|
Thailand
|
410 (1999)
|
33.1 (1990)
|
548
|
91
|
|
Turkey
|
201 (1997)
|
31.6 (1992)
|
481
|
72
|
|
United Kingdom
|
120 (1980)
|
11.8 (1994)
|
201
|
3
|
|
USA
|
2,478 (1985)
|
469 (1995)
|
1,688
|
42
|
|
Source: The Worlds
Water 2002-03 - The Biennial Report on
Freshwater Resources, p. 237 & 243. Pacific Institute for Studies in
Development, Environment, and Security, Oakland
California.
|
Australia
has about 1% percent of the worlds water resources, and about 0.3% of its
people. On this basis Australia
could be regarded as water rich per person. However, other considerations
need to be taken into account. For example, almost half of Australias
water resources are in the far north, remote from the major population and
agricultural centres. Australias
relatively high rate of per capita water usage reflects its large agricultural
production, much of which is exported, and the amount of water used in
irrigation.