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Glossary

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anabranch. A branch of a river that leaves the main stream and rejoins it further downstream.

aquifer. An underground layer of soil, rock or gravel able to hold and transmit water.

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barrages. Five low, wide weirs built at the Murray Mouth to reduce the amount of seawater moving in and out of the Mouth due to tidal movement. They also help control the water level in the Lower Lakes and Murray River below Lock 1.

baseline conditions. The current status of a system.

Basin Salinity Management Strategy (BSMS). This strategy guides communities and governments in working together to control salinity in the Murray-Darling Basin and their catchments. It establishes targets for the river salinity of each major tributary valley and the Murray-Darling system itself that reflect the shared responsibility for action both between valley communities and states.

biodiversity. The variety of life forms, plants, animals and micro-organisms; the genes they contain; the ecosystems they form; and ecosystem processes.

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Cap on water diversions. The limit imposed on the volume of surface water that can be diverted from rivers for consumptive uses. Started in 1995 as the Interim Cap.

catchment. The area of land drained by a river and its tributaries.

channel capacity. The volume of water that can pass along the river channel at a certain point without spilling over the tops of the banks.

connectivity. Related to maintaining connections between natural habitats, such as a river channel and adjacent wetland areas.

consumptive use. Water that is used by other than natural processes by human beings and not returned to streams or groundwater. This includes water used in farm irrigation and water use in residences and businesses.

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demonstration reach. A large-scale river reach in which multiple management interventions are applied in order to demonstrate to the community the cumulative benefits of integrated river rehabilitation.

drawdown. Occurs when the water level in a weir pool is lowered.

dredging. A process whereby machines equipped with scooping or suction devices remove mud etc., in order to deepen a waterway.

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easement. A grant of rights over land by a property owner in favour of another person to enter onto land for the purpose of installing and maintaining facilities such as cables, pipelines, etc. An easement may also grant the right to cross over land in order to gain access to other land.

EC (units). Electrical conductivity unit commonly used to indicate the salinity of water (1 EC = 1 microsiemen per centimetre, measured at 25°C).

end-of-valley targets. A water quality target for salinity, set for a point in the lower reach of each catchment.

environmental flows. Any river flow pattern provided with the intention of maintaining or improving river health.

environmental outcome. Project outcomes that benefit the ecological health of the river system.

Environmental Works and Measures Program (EWMP). An eight-year, $150 million program to deliver works and measures to improve the health of the Murray River system by making the best use of the water currently available, optimising the benefits of any water recovered in the future, and considering other policy interventions.

exchange rate trade. An arrangement under which a water entitlement within a state (origin) is cancelled, extinguished or suspended and an equivalent entitlement is created within another state (the destination). The exchange rates are based on a set of principles that are considered to be equitable with regard to all water users (that is, minimises third party impacts).

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First Step Decision. A decision announced in November 2003 by the Murray-Darling Basin Ministerial Council. The initial focus of the First Step Decision is on maximising environmental benefits for the six significant ecological assets.

fishway. A structure that provides fish with passage past an obstruction in a stream.

flow regime. The spatial and temporal pattern of flows in a river.

hydrology. The study of the distribution and movement of water.

icon sites. Now referred to as icon sites, these six locations were chosen because they are of regional, national and international importance for their ecological value, and there is concurrence that they are at risk and require improved water flow regimes. These sites are Barmah–Millewa Forest, Gunbower–Koondrook–Perricoota forest, Hattah Lakes, Chowilla Floodplain, Murray Mouth, Coorong and Lower Lakes, and the River Murray Channel.

integrated catchment management (ICM). A process through which people can develop a vision, agree on shared values and behaviours, make informal decisions and act together to manage the natural resources of their catchments. Their decisions on the use of land, water and other environmental resources are made by considering the effect of that use on all those resources and on all people within the catchment.

lock. Consists of a rectangular chamber of concrete with gates at each end. It allows vessels to move from one water level to another.

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macroinvertebrate. An invertebrate animal (animal without a backbone) large enough to be seen without magnification.

MSM_Bigmod. The Murray Simulation Model MSM-Bigmod is a suite of in-stream hydrologic models of flow and salinity for the Murray River used to establish Baseline Conditions and to assess the salinity impacts of Accountable Actions and Delayed Salinity Impacts.

Murray Darling Association. A non-government organisation that represents local governments within the Murray-Darling Basin.

Murray-Darling Basin (MDB). The entire tract of land drained by the Murray and Darling Rivers. The basin covers land in Queensland, New South Wales, the Australian Capital Territory, Victoria and South Australia.

Murray-Darling Basin Commission (MDBC). The executive arm of the Murray-Darling Basin Ministerial Council. MDBC is responsible for managing the Murray River and the Menindee Lakes system of the lower Darling River and advising the Ministerial Council on matters related to the use of water, land and other environmental resources of the Murray-Darling basin.

Murray-Darling Basin Initiative. A partnership of governments and communities formed to enhance the environmental resources of the Murray-Darling Basin.

Murray-Darling Basin Ministerial Council. A council of ministers of contracting governments who hold land, water and environment portfolios.

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National Water Initiative (NWI). In June 2004 the Council of Australian Governments reached agreement on a National Water Initiative to improve the security of water access entitlements, ensure ecosystem health, expand water trading, and encourage water conservation in our cities.

Native Fish Strategy (NFS). This strategy aims to ensure that the Murray-Darling Basin sustains viable fish populations and communities throughout its rivers. The goal of this strategy is to rehabilitate native fish communities to 60 per cent of their estimated pre-European settlement levels within 50 years of implementation.

Reference Group. A committee involving a range of expertise to inform and critique projects and project findings.

regulated flow. A controlled flow rate resulting from the influence of a regulating structure, such as a dam or weir.

riparian. Of, inhabiting, or situated on, the bank and floodplain of a river.

river health. Status of a river system based on water quality, ecology and biodiversity.

River Murray Water (RMW). An internal business unit of the MDBC responsible by specific delegation for exercising the MDBC’s function for water and asset management.

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salinity. The concentration of dissolved salts in groundwater or river water, usually expressed in EC units or milligrams of dissolved solids per litre.

salt interception scheme. Involves large-scale groundwater pumping and drainage projects that intercept saline water flows and dispose of them, generally by evaporation.

significant ecological asset (SEA). Now referred to as icon sites, these six locations were chosen because they are of regional, national and international importance for their ecological value, and there is concurrence that they are at risk and require improved water flow regimes. These sites are Barmah–Millewa Forest, Gunbower–Koondrook–Perricoota forest, Hattah Lakes, Chowilla Floodplain, Murray Mouth, Coorong and Lower Lakes, and the River Murray Channel.

stoplog. A beam (timber, concrete or steel) inserted into a slotted frame to retain water.

Sustainable Rivers Audit (SRA). A program designed to measure the health of the rivers within the Murray-Darling Basin. The Audit aims to determine the ecological condition and health of river valleys in the Murray-Darling Basin; to give us a better insight into the variability of river health indicators across the Basin over time; and to trigger changes to natural resource management by providing a more comprehensive picture of river health than is currently available.

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tagged trading. The method by which the water that becomes allocated to an entitlement issued within a State (the origin) is made available for use in another area of the State or another State altogether (the destination). Water transferred through this method always retains the characteristics of the entitlement to which it was originally allocated.

water market. The buying and selling of water entitlements, on either a temporary or permanent basis, in order to improve the efficiency of water use.

water recovery. Implementation of measures that result in water being made available under TLM environmental watering plan.

weir. A dam placed across a river or canal to raise or divert the water, or to regulate or measure the flow.

weir pool. The body of water stored behind a weir.