Murray-Darling Cap
Encyclopedia
The Murray-Darling Cap is a policy limiting the water diversions in the Murray-Darling Basin
(Australia
) at 1993 levels. It seeks to strike a balance between the amount of water available to irrigators
and the security of their water supply. At the time of conception in 1997, the level of diversions from the Basin was clearly nearing unsustainable levels. The Cap was introduced by the Murray-Darling Basin Ministerial Council after the release of the report titled "An Audit of Water Use in the Murray-Darling Basin".
The Murray-Darling system is a highly variable system in terms of inflows, and can vary between discharges of 1,600 GL and 53,000 GL. The average flow is 21,200 GL per year. In the six years prior to 1994 an average of 10,800 GL had been diverted, mostly for agricultural purposes. The diversion were having a significant impact on the ecological health
of the Murray-Darling river system.
The Cap limits surface water diversions at 11,000 GL per year. Seasonal adjustments are made for wet and dry years. The introduction was seen as the first step in water management
methods that progressed towards sustainable development of the river system. The aim of the cap is: "To ensure the long-term health of the rivers by returning more water to the river for environmental purposes
". The Cap affects all rivers located within the Murray-Darling Basin. As it was implemented in 1997 but capped at 1993 levels, the irrigators lost an amount of water. The cap made water in the Basin a more valuable resource, which gave entitlements to its diversion more value and saw increased trade in these entitlements. While the Cap restrains further increases in water diversions, it does not constrain new developments, provided the water for them is obtained by using water more efficiently or by purchasing water from existing developments.
Murray-Darling Basin
The Murray-Darling basin is a large geographical area in the interior of southeastern Australia, whose name is derived from its two major rivers, the Murray River and the Darling River. It drains one-seventh of the Australian land mass, and is currently by far the most significant agricultural...
(Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
) at 1993 levels. It seeks to strike a balance between the amount of water available to irrigators
Irrigation in Australia
Irrigation in Australia is a widespread practice to supplement low rainfall levels in Australia with water from other sources to assist in the production of crops or pasture. As the driest inhabited continent, irrigation is required in many areas for production of crops for domestic and export use...
and the security of their water supply. At the time of conception in 1997, the level of diversions from the Basin was clearly nearing unsustainable levels. The Cap was introduced by the Murray-Darling Basin Ministerial Council after the release of the report titled "An Audit of Water Use in the Murray-Darling Basin".
The Murray-Darling system is a highly variable system in terms of inflows, and can vary between discharges of 1,600 GL and 53,000 GL. The average flow is 21,200 GL per year. In the six years prior to 1994 an average of 10,800 GL had been diverted, mostly for agricultural purposes. The diversion were having a significant impact on the ecological health
Ecological health
Ecological health or ecological integrity or ecological damage are the symptoms of an ecosystem's pending loss of carrying capacity, its ability to perform ecological services, or a pending ecocide, due to cumulative causes such as pollution. it can also be defined as farming so as to minimize the...
of the Murray-Darling river system.
The Cap limits surface water diversions at 11,000 GL per year. Seasonal adjustments are made for wet and dry years. The introduction was seen as the first step in water management
Water management
Water management is the activity of planning, developing, distributing and managing the optimum use of water resources. In an ideal world. water management planning has regard to all the competing demands for water and seeks to allocate water on an equitable basis to satisfy all uses and demands...
methods that progressed towards sustainable development of the river system. The aim of the cap is: "To ensure the long-term health of the rivers by returning more water to the river for environmental purposes
Environmental flow
‘’’Environmental flows’’’ describe the quantity, timing, and quality of water flows required to sustain freshwater and estuarine ecosystems and the human livelihoods and well being that depend on these ecosystems...
". The Cap affects all rivers located within the Murray-Darling Basin. As it was implemented in 1997 but capped at 1993 levels, the irrigators lost an amount of water. The cap made water in the Basin a more valuable resource, which gave entitlements to its diversion more value and saw increased trade in these entitlements. While the Cap restrains further increases in water diversions, it does not constrain new developments, provided the water for them is obtained by using water more efficiently or by purchasing water from existing developments.
See also
- Murray Darling Basin Authority
- Water security in AustraliaWater security in AustraliaWater security in Australia has become a major concern over the course of the late 20th and early 21st century as a result of population growth, severe drought, fears of the effects of global warming on Australia, environmental degradation from reduced environmental flows, competition between...
External links
- Murray-Darling Basin Cap on Diversion - Water Year 1997/98 - Striking the Balance Report. Murray Darling Basin Commission: December 1998.