State of the Environment Report 2009
Indicators
Water Abstraction and Consumption


Indicator description

The amount of water abstracted or developed by purpose and drainage division.

Why is it indicative?

This indicator provides a measure of the pressure of water extraction. Demand for water supply is growing across many sectors in the Tasmanian economy. There are challenges in meeting increasing demands to ensure that water is available to satisfy human uses while maintaining environmental flows to meet the needs of water dependent ecosystems. These challenges were exacerbated during the extreme rainfall deficits in the reporting period (2003–08) and subsequent reduced streamflow (see Internal linkstreamflow). By monitoring water use, the community will be in a better position to respond to supply limitations and pressure on aquatic ecosystems.

Devonport agricultural landscape, Google Earthinternal SOE link to larger image

Data availability and limitations

There are a number of agencies involved in the administration and allocation of water in Tasmania. The key agencies and authorities are:

  • The DPIPWE which has the statutory regulatory role in the allocation, assessment, planning and management of water resources;
  • The Rivers and Water Supply Commission which owns and/or manages four regulated irrigation schemes;
  • Hobart Water, Cradle-Coast and Esk Water who are bulk water providers to the majority of local Government water supplies.

Most of these agencies generate data on water use as part of their administration of water resources. No single data source presents a comprehensive picture of water use in Tasmania. Information on changes to domestic consumption of water is not generally available in Tasmania because of limited adoption of water metering in the State. Data availability on water consumption at the farm level will be improved through the requirement for all licensed water use to be metered by the end of 2008. Improved water meter data collection has also been foreshadowed with the announcement that the Australian Government will spend $8 million on an automated data collection and management system through the use of telemetry on about 3,000 irrigation properties.

Four data sources have been used to report on this indicator, namely:

Tasmanian data from the Water Account for Australia

The Australian Bureau of Statistics accesses readily available data on water resources from various government and non-government organisations. Data are also collected directly through surveys conducted by the ABS. The ABS notes that while every care has been taken to ensure consistency between 2000–01 and 2004–05, the changes between the reference periods need to be interpreted cautiously owing to differences in climate, data sources, data availability and data quality. A further caution noted by the ABS is that calculating water use by industries is not straightforward as it can include self-extracted water, distributed water, or reuse water, and sometimes a combination of all three sources are used. The Water Account is valuable in integrating multiple sources and allowing state comparisons of water availability and use. However, it has limited value such as at more detailed catchment-scale assessment.

Water Information Management System of Tasmania

The Water Information Management System (WIMS) External linkdatabase is a register of the State's water licences, water allocations and dam permits. It provides details of clients, purpose and amount of water allocated and the size and capacity of dams. An important caveat for this source is that it provides details of the maximum licenced water allocation for any year, not the amount actually used. Also, the data presented only includes the irrigation allocations for direct extraction from rivers during the summer period (November–April), and does not include water extracted during winter and stored in dams.

Rivers and Water Supply Commission data on water delivered

The Rivers and Water Supply Commission owns and operates the South-East Irrigation Scheme suppling irrigation water to farmers along the Coal River from Craigbourne Dam to Richmond and via pipeline supply through to Cambridge. In 2003, the Commission was also appointed as the responsible water entity for the River Clyde Irrigation Scheme. The Commission also owns the scheme infrastructure of the Cressy-Longford Irrigation and Winnaleah Irrigation Schemes which are both now under agreement for management by the Cressy-Longford Irrigation Scheme Limited and Winnaleah Irrigation Scheme Limited respectively. Through the ownership of scheme infrastructure, the Rivers and Water Supply Commission continues to have access to information on water delivered by these schemes.

Conservation of Freshwater Ecosystem Values, abstraction index data layer

The CFEV upstream accumulated abstraction index for the river section includes both diversion and abstraction. The abstraction index values (excluding diversion) were selected to present a generalised view of abstraction pressure on Tasmanian rivers. The information is taken from water licensing datasets obtained from various sources such as WIMS and data supplied by Hydro Tasmania. As such it is subject to varying reliability and is considered as a relative measure only. The categories used for this assessment are detailed in the attached Internal linktable.

Bulk water suppliers

The three bulk water providers supply bulk water to their member councils, who in turn supply the consumers. Ten local councils manage their own drinking water supply schemes, and eighteen councils purchase water supplies from the three bulk water authorities.

Data

Tasmanian Data from the Water Account for Australia (Internal linkABS 2006)

  • As shown in the Internal linktable, water consumption was 434 GL in Tasmania in 2004–05 compared with 408 GL in 2000–01. This is an increase of 26 GL or 6% (Internal linkABS 2006).
  • In 2004–05, the agriculture industry was the largest consumer accounting for 258 GL or 59% of water consumption in the State. Agricultural use increased by 14% since 2000-01 when water consumption for the agriculture industry was 226 GL. In 2004–05, dairy farming consumed 85 GL, followed by pastures (other than for dairy) (63 GL), and vegetables (52 GL).
  • The next major consumer was households with 69 GL or 16%. Between 2000-01 and 2004–05, households overtook manufacturing in terms of their overall share of water consumption in Tasmania. Household consumption of water in Tasmania increased from 59 GL in 2000–01 to 69 GL in 2004–05 (an increase of 17%). On a per capita basis, household water consumption was 143 kL, an increase from 126 kL per capita in 2000-01, and above the Australia average of 103 kL per capita. Consumption per household also increased to 372 kL.
  • The manufacturing industry was a significant user of water in Tasmania, consuming 49 GL in 2004-05. The ABS Water Account notes that most of the water consumed by manufacturing in Tasmania was by the wood and paper products industry (35 GL or 71%). Manufacturing consumption decreased by 24% from 64 GL in 2000–01 to 49 GL in 2004–05.
  • Tasmania has the highest proportion of is agricultural land area under irrigation (Internal linktable 1 and (Internal linktable 2). Pasture, dairy farming and vegetables account for the largest areas of irrigated land in Tasmania.The area of land irrigated in Tasmania (with south-eastern Australia for context) is also shown in the following map from the ABS Water Account.

Area irrigated, south-east Australia, by drainage division, 2004–05

Area irrigated, south-east Australia, by drainage division, 2004–05internal SOE link to larger image

Source: Internal linkABS 2006

Water Information Management System of Tasmania

The Internal linktable shows that the highest percentage of licences allocated for irrigation (as a percentage of all licences issued) occurs in the Meander region and Mersey-Forth region. The Inglis-Cam water region (Internal linktable) contains the highest percentage of licences allocated for industrial purposes. Arthur-Pieman has the highest percentage of licences allocated for mining purposes.

The water licence data were analysed for Tasmania's planning and management catchments. This information is shown in the linked Internal linktable. The table gives a measure of the average amount of water allocated per licensed user. The Emu catchment has a higher proportion of industrial users so a relatively small number of users have a large demand for water (4,254 ML/year/client). Other catchments having comparatively higher intensity of water use include: Upper Derwent, North Esk, Musselroe-Ansons, Brumbys-Lake and Clyde.

Rivers and Water Supply Commission Data on Water Delivered

The Clyde River, Cressy-Longford, Winnaleah and South-East irrigation schemes are the main State irrigation schemes in Tasmania. The Meander Dam, which will also be owned and managed by the RWSC, will make another 24,000 ML of irrigation water available from November 2007. These schemes are operated by the Rivers and Water Supply Commission. Water use figures are collected and reported for each financial year. Water use is affected by the wetness or dryness of the irrigation season and also by the economic conditions at the time.

The data on water delivered shows that the Clyde River Irrigation Scheme had the highest variability of water delivered over the 10 year period. Over the 10 year period, the ratio of the most water delivered (16,660 ML in 1996/97) to the least (4,367 ML in 1999/00) is 3.8 to 1.0. The data on water delivered shows that the Winnaleah River Irrigation Scheme had the least variability of water delivered over the 10 year period. Over the 10 year period, the ratio of the most water delivered (4,844 ML in 1997/98) to the least (3,485 ML in 1998/99) is 1.4 to 1.0. The highest and lowest volumes of water delivered occurred in consecutive years (Internal linkRivers and Water Supply Commission 2007).

Water delivery to Tasmanian Irrigation Schemes, 10 years to 2005/06 (ML)

Year Clyde River Cressy-Longford South-East Winnaleah
1996/97 16,660 5,369 1,750 4,382
1997/98 8,220 6,182 3,275 4,844
1998/99 13,787 3,821 2,280 3,485
1999/00 4,367 7,505 3,536 3,546
2000/01 4,784 7,090 2,995 4,392
2001/02 4,670 6,171 1,831 3,523
2002/03 6,839 6,044 3,822 4,777
2003/04 5,188 8,898 3,211 4,836
2004/05 6,070 9,886 3,020 4,750
2005/06 7,105 4,907 2,628 3,744

Source: Internal linkRivers and Water Supply Commission 2007


Irrigation scheme, 10 year data on water delivered

Irrigation scheme, 10 year data on water deliveredinternal SOE link to larger image

Water use and crops irrigated, 2005/06

South-East Clyde River
Crop ML HA ML HA
Apricots 106 133 0 0
Barley 167 237 55 91
Beans 17 18 30 12
Cherries 135 0 0 0
Dam Filling 210 26 30 0
Grass 36 19 1,649 1,299
Golf course 153 115 0 0
Herbs 542 321 64 110
Lucerne 70 51 201 51
Market garden 14 29 60 15
Oats 51 50 322 532
Olives 89 239 0 0
Orchards 242 192 0 0
Pasture 71 89 1,438 878
Peas 41 37 360 233
Poppies 16 17 1,170 509
Potatoes 10 6 45 40
Rape 168 68 530 112
Seed 120 84 699 190
Vegetables, lettuce and herbs 297 157 60 20
Vineyard 11 8 0 0
Walnuts 25 49 90 20
Wheat 44 35 113 198
Other 0 0 190 185
TOTAL 2,635 1,980 7,106 4,495

View Interactive Excel Table Version

Source: Internal linkRivers and Water Supply Commission 2006


Conservation of Freshwater Ecosystem Values Project abstraction index data layer

The CFEV abstraction index data layer (Internal linkCFEV database, v1.0 2005) shows the relative pressure of abstraction (long-term decreases in mean annual flow volume and decreases in summer baseflows due to abstraction). This layer includes both changes to flow from abstraction of water and diverting of streams. The classes showing abstraction and the class showing no change were selected and mapped and tabular outputs were prepared. The Internal linktable details the CFEV abstraction index categories and the changes made to show only abstraction. The abstraction index values by river length and catchment can be viewed through the linked Internal linktable or downloaded from the following link.

CFEV Abstraction Index 

This information is also shown in the following maps. The thematic map on the left shows CFEV abstraction categories for the whole of the State. The interactive map on the right (requires External linkAdobe SVG Viewer) shows the length and percentage length of river segments in each abstraction class for the 48 planning and management catchments.

Water abstraction index from Conservation of Freshwater Ecosystem Valuesinternal SOE link to larger image

Water abstraction index by catchment from Conservation of Freshwater Ecosystem Valuesinternal SOE link to larger image

Bulk Water Suppliers Data on Water Delivered

Hobart Water sales and supply of bulk water

megalitres

2005-06 2004-05 2003-04
Sales (bulk and off peak) megalitres 38,150 41,394 40,679
Source of Supply
Derwent Water Supply 24,157 26,152 25,092
Hobart Mountain 7,756 7,342 8,468
Glenorchy Mountain 516 484 425
Lake Fenton 5,910 6,435 6,084

Source: Internal linkHobart Water 2007


Related Issues

An indicator can show trends or changes that apply to one or more environmental issues. The data within an indicator is used to inform an issue report and any related recommendations. A summary of the indicator's relevance to a particular issue can be found within the 'Indicator' section of each of the linked issue reports below.

Water Extraction and StorageInternal link
Water Quantity and UseInternal link

  External linkTasmanian Planning Commissioninternal SOE link to larger image

  Contact the Commission on:

email: External linksoe@justice.tas.gov.au
Phone: (03) 6233 2795 (within Australia)
Fax: (03) 6233 5400 (within Australia)
Or mail to: Tasmanian Planning Commission, GPO Box 1691, Hobart, TAS, 7001, Australia

 


Last Modified: 1 Mar 2010
URL: http://soer.justice.tas.gov.au/2009/indicator/76/index.php
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