Water is an increasingly scarce and valuable resource. The gap between increasing water demand and a decline in water availability is perhaps the most critical resource problem Australia faces. Thus, the sources and uses of water are under closer scrutiny by all levels of government and private sector users in order to ensure higher levels of conservation, monitoring and appropriate usage.
A number of factors continue to overwhelm our major water sources, including growing rural and urban demand, changing awareness of the value in preserving the health of our rivers and wetlands and environmental flows as well as legacy decisions, systems and attitudes based 'in the past' when we had a lesser understanding of the importance of managing water in a wholistic and Australian context.
As an added pressure, Australia is experiencing the impacts of climate change — with changes in rainfall patterns, water distribution, atmospheric humidity and soil water retention characteristics. It is anticipated that climate change effects will become even more severe over the whole continent in the next few decades. Changes in water supply and catchment are likely to have a significant impact throughout all rural and urban landscapes, affecting the environment, agricultural productivity, infrastructure and communities.
> Can Australia Overcome Its Water Scarcity Problems?
> Water Scarcity & Demand — Connected Water
> Water Governance in Context: Case Study of Australia
> Water Scarcity & the Implication for Land Management
> Managing Australia's Water Resources: A New Approach
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Irrigation and the environment
Water and irrigation
Irrigation is defined as the processes through which water is distributed from a source (e.g. dam, tank, bore, river) to an end application point. Modern irrigation processes involve not only traditional practices such as channeling water onto land but also include more recent developments in the areas of Micro and Sprayed Irrigation, Laser Graded Flood Irrigation and Waste Water Irrigation.
The growth of crops for food and pasture — for domestic consumption or export — uses water which is channelled by a variety of forms of irrigation. Other users of irrigation include mining, recycling of all types, provision of domestic water supplies, sewerage, parks, gardens, waste water and so on. It is estimated that, of all the water consumption in Australia, about half is for end user, with the remainder used for these other purposes.
The water that is used for irrigation is estimated to produce $9.076b (AUD) per annum worth of agricultural production (2004-05; down from $9.618b in 2000-01). Farm GDP is expected to be approximately $20.5b (AUD) in 2006-07. Though this represents a significant decline, the sector nonetheless remains a major contributor to the overall Australian economy — particularly in the value of export earnings.
Irrigation water comes from a number of sources, including dams, rivers and bores, and is the chief process by which water is delivered to grow food crops.
Some of our best estimates of water usage put the total Australian water consumption (water extracted from the environment) at 79,784 GL (ABS: Water Account, Australia 2005-05, 4610.0). This excludes usage of direct rainfall by users and water recovered and reused by the consumer.
Of this amount, 11,337 GL was extracted by water providers, while water users directly extracted 68,447 GL. The bulk of water extracted from the environment (79,784 GL) was returned to the environment as regulated discharge – this totalled 62,445 GL, most of which was put to in-stream use by the electricity and gas supply industry for hydro-electric power generation.
The agriculture industry consumed the largest volume of water, 12,191 GL, representing 65% of water consumption in Australia (2004-05). In line with general per capita decreases in water usage, agricultural usage was down from 2000-01 figures (14,989 GL; 69% of water consumption).
Making more (food) with less water
Without irrigation, it would simply not be possible to provide the level of food production that Australia currently enjoys, let alone the increasing demands of crop production in the future. Irrigation is a key productivity improvement tool for the Australian agriculture sector.
However, conscious of the value of conserving water and the environment, irrigators use increasingly sophisticated methods of irrigation such as pressurised reticulation, surface and subsurface drip, and micro drip systems.
A number of challenges face the industry. As the demand for water increases, less will be available for irrigation. Irrigators are working to use water more efficiently through reducing storage, distribution and application losses. These methods will assist in addressing other environmental issues such as salinity and turbidity, as well as minimising wastage.
The continued support and development of 'smart' irrigation practicies remain the most efficient way to ensure that Australia is able to maintain an abundant food and pasture supply for domestic consumption and export.
> Agriculture, Water & Environment: Improving Rural Land & Water Systems
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Water and technology
Learning to be smarter
Irrigation technology is critical to the future of our national water security. Irrigated agriculture is critical to Australian and global food production; irrigation technology also supports many other important sectors of our economy — including mining, manufacturing, industrial processes, electricity and gas generation and domestic water re-use.
Major focus is now being directed at critical areas of water management, and significant resources are being allocated in areas such as —
• accurate collection and measurement of water data at national, basin, urban and individual levels — for availability and usage levels
• development of practical technologies and methodologies for forecasting
• development of common systems and standards.
Given that the agricultural irrigation sector is the largest (by volume) user of 'regulated' water in Australia, it will no doubt be in the 'front line' of change.
Modern irrigation practices increase the efficiency of water logistics (storage, transport and delivery). The industry is constantly working to find new sources of water, and improve irrigation methods and management through efficiency, technology and engineering solutions.
For example, irrigators are increasingly sourcing recycled or re-used water in recognition of the importance and growing scarcity of this resource. It is estimated that use of recycled water has increased 49% over the last few years. Additionally, advances in micro and sprayed irrigation, laser graded flood irrigation, waste water irrigation, pump and solar technologies, management controllers and distribution systems — all are contributing to a water-saving future.
The industry fully supports practical strategies to invest in new technology and techniques to ensure that our precious water resources remain economically and environmentally sustainable.
> Increasing Water Productivity Through Modernising Irrigation Systems
> Science to Improve Australia's Irrigation Systems
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