Glossary

acid sulfate soils. Soils formed naturally when sulfate-rich water (e.g. saline groundwater or sea water) mixes with sediments containing iron oxides and organic matter. Under waterlogged, anaerobic (oxygen-free) conditions, bacteria convert sulfates to sulphides, which can form sulfidic sediments. When these sediments are exposed to oxygen, such as under drought conditions, chemical reactions may lead to the generation of sulfuric acid.

allocation. An allocation is the specific volume of water allocated to the holders of water entitlements in a given season. The allocation is often quoted as a percentage of the volume of each entitlement. For instance, a 20% allocation in a particular season allows a water user with a 100 ML entitlement to take 20 ML of water.

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

ANCOLD. The Australian National Committee on Large Dams Incorporated (ANCOLD Inc.) is an incorporated voluntary association of organisations and individual professionals with an interest in dams in Australia. It is the Australian national committee of the International Commission on Large Dams (ICOLD). A variety of ANCOLD technical working groups produce, for example, guidelines on design, management and risk assessment of dams.

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

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

Barmah Choke. A narrow section of the River Murray constraining the volume of water that can pass during major floods. During floods, large volumes of water are temporarily banked up behind the Barmah Choke, flooding the wetland system known as the Barmah-Millewa Forest.

baseline conditions. Conditions regarded as a reference point for the purpose of comparison.

Basin Plan. The Water Act 2007 (Cwlth) requires that the Murray-Darling Basin Authority (MDBA) develops and oversees the Basin Plan for the integrated management of Basin water resources. The Basin Plan will provide for limits on the quantity of water that may be taken from the Basin water resources.

Basin Salinity Management Strategy (BSMS). This strategy guides communities and governments in working together to control salinity in the Murray-Darling Basin. It establishes targets for the river salinity of each major tributary valley and the Murray-Darling system.

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

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.

Commonwealth Environmental Water Holder. Environmental water entitlements held by the Australian Government are managed by the Commonwealth Environmental Water Holder, a person who, under the Water Act 2007 (Cwlth), is given the function of using these entitlements to protect and restore the environmental assets of the Murray-Darling Basin, or assets outside the Basin where water is held for that area.

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

consumptive use. The use of water for private benefit consumptive purposes, including irrigation, industry, urban, and stock and domestic use.

critical human water needs. The needs for a minimum amount of water to meet core human consumption requirements in urban and rural areas that are dependent on Basin water resources. They also include non-human consumption requirements that, if not met, would cause prohibitively high social, economic or national security costs.

drawdown. Lowering the water level in a weir pool.

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

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. 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.

entitlement. Water users in the Basin hold a legal entitlement, or licence, to a share of the available water. An allocation is the specific volume of water allocated to the holder of an entitlement in a given season.

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 water. Water used to achieve environmental outcomes, including ecosystem function, biodiversity, water quality, and water resource health.

Environmental Works and Measures Program (EWMP). A major program to deliver works and measures to improve the health of the River Murray 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.

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.

GL. Gigalitre, i.e. 1 billion litres (1,000,000,000 litres).

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

icon sites. These six locations were chosen for The Living Murray program 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 and Lindsay-Wallpolla Islands, Murray Mouth, Coorong and Lower Lakes, and the River Murray Channel.

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

long-term Cap equivalent. A type of average which takes into account the different characteristics of water entitlements in New South Wales, Victoria and South Australia, and their reliability. This measure of water recovery creates a common unit of measure, thus allowing equitable comparison of a broad range of water recovery measures.

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

ML. Megalitre, i.e. 1 million litres.

Murray-Darling Basin. 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.

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

Ramsar/Ramsar listing. A Ramsar listing denotes the inclusion of a wetland area on the List of Wetlands of International Importance - an inventory prescribed by the Convention on Wetlands (more commonly known as the Ramsar Convention, which was signed in Ramsar, Iran, in 1971). As one of the original contracting parties to the Convention, Australia has designated 65 sites for this list.

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 or floodplain of a river.

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

River Murray Increased Flows (RMIF). Water recovered under investment in the Snowy Joint Government Enterprise and managed under The Living Murray framework.

salinity. The concentration of dissolved salts in groundwater or river water, usually expressed in electrical conductivity units (EC, see above) or milligrams of dissolved solids per litre.

salinity registers. A salinity-based accounting system underpinning the Basin Salinity Management Strategy. The system provides an accounting record of states' actions that affect river salinity.

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

southern connected Basin. The upper River Murray and the River Murray in South Australia, and regulated reaches of the Goulburn, Campaspe, Loddon and Murrumbidgee river systems.

sustainable diversion limits. A central element of the Basin Plan is to set environmentally sustainable limits on the amount of water that can be taken from the Basin's water resources. These are known as sustainable diversion limits (SDLs). The SDLs will limit the quantity of surface water and groundwater that can be taken from the Basin.

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 Basin; to give a better insight into the variability of river health indicators over time; and to trigger changes to natural resource management.

The Living Murray. One of Australia's most significant river restoration programs, with funding of almost $1 billion over the period 2004 to 2012. The program is a partnership of the Australian Government and the New South Wales, Victorian, South Australian and Australian Capital Territory governments.

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

water recovery registers. Water recovery measures have been approved and monitored using a system of three registers. The first stage of approval for a water recovery measure is the Developmental Register; the second is the Eligible Measures Register; and the third and final stage is the Environmental Water Register.

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.