Acidification
The process whereby soil becomes acidic and has a pH level of greater than 7.
Annual Allocation
The amount of water that an irrigator is licensed to divert from a river in a year. An announced allocation is the percentage of this licensed water than an irrigator will receive that year.
Aquifer
A underground layer of stone, earth or gravel which holds water.
Barrage
A barrier built across a river to increase the depth of water and/or to prevent the upstream movement of saltwater.
Basin
The entire area drained by a river and its tributaries, where all of the runoff is moved to a single outlet.
Billabong
A river branch that forms a backwater or stagnant pool, away from the main river channel.
Bioremediation
Planting selected crops and native grasses, and spreading limestone particles in salinity affected areas to neutralise the acid in the soil.
Brackish
Water that tastes salty.
Cadell Tilt Block
Formed as the result of an earth movement along the Cadell Fault, approximately 25 000 years ago, it changed the course of the Murray River for some 500 kilometres.
Confluence
The location where two or more streams meet.
Dam
A physical barrier built across a river to control the flow, or raise the level of water.
Discharge
The volume of water transported by a river past a given spot.
Distribution Channel (or irrigation channel)
An open drain or channel that carries water from storage in dams or weirs to irrigation districts and farms.
Diversion
The removal of water from the river for human use.
Dryland Farming
Agriculture that relies on rain for its water rather than artificial irrigation.
EC (Electrical-Conductivity) Unit
A unit of measure for dissolved salts in water.
Environmental flow
Water left in a river system to maintain downstream ecosystems.
Estuary
A body of water formed where fresh water from rivers and streams mixes with sea water.
Floodplain
Lang alongside a river which floods when the river's discharge exceeds the capacity of its channel.
Floodplain Harvesting
Collecting and storing floodwaters in farm dams.
Gigalitre (GL)
One gigalitre (10^9 litres) of water would fill 1000 Olympic-sized swimming pools (each with an average depth of one metre)
Ground water
The water under the Earth's surface located in the pore spaces and cracks between the particles of soil, sand, gravel and bedrock.
Infrastructure
The basic facilities, services and installations needed for the functioning of a system. In the Basin, this includes dams, irrigation channels, pipelines, pumps, locks and barrages.
Irrigation
The application of water to crops or pasture to supply water requirements not satisfied by rainfall.
Levee Bank
A raised embankment built along a river to prevent flooding.
Megalitre
One megalitre (10^6 litres) of water would fill one Olympic-sized swimming pool (with an average depth of one metre)
Mouth (of a river)
The location where a river discharges into another body of water.
On-Farm Storage
Privately owned water storages such as dams.
Orographic Rainfall
Precipitation that occurs when moist air is lifted over a topographic barrier, such as a mountain range.
Pasture
Grass or other vegetation eaten by grazing animals, such as cattle, sheep and horses.
Perched Water Table
A separate body of groundwater lying above (perched) the surrounding water table.
Ramsar Convention
A treaty that provides for international co-operation for the conservation and use of wetlands and their resources.
Recharge Rate
The process where water moves from the surface into the ground. Surface water becomes ground water.
Reservoir
A natural or artificial pond or lake used for the storage of water. Often used to refer to the water stored behind a dam.
River Channel
The area occupied by a river, consisting of a river bed and the banks on either side.
Runoff
Water from rain, snowmelt or irrigation that flows over the land surface and is not absorbed into the ground. Instead it flows into streams, other surface waters or land depressions.
Salinity
High levels of dissolved salts in the water. If these levels are too high, the water is unsuitable for human consumption or for use on crops.
Source
The location where a river or stream begins.
Sub-Catchment
A smaller division of a catchment: the catchment of a tributary of a larger river.
Unregulated RIver
A river that does not contain any built structures, such as dams or major diversion weirs, to control the flow of water.
Water Allocation
The annual amount of water available to irrigators; determined by the water authority.
Water Buy-Backs
A Federal Government policy to buy back permanent water licenses from irrigators, so that the water can be used as environmental flows in the Basin.
Water Table
The upper level of the ground water in a given area.
Water Trading
The buying and selling of water-access entitlements on either a permanent or temporary basis.
Weir
A small overflow-type dam, commonly used to raise the level of a river or stream.
Wetland
Land that is flooded with shallow, slow-moving or stationary water on a temporary or permanent basis.