Australian Water Information Dictionary

Alphabetical list of items

A   B   C   D   E   F   G   H   I   K   L   M   N   O   P   Q   R   S   T   U   V   W   Y   Z   other  

E

/

EC

electrical conductivity

This definition applies to:

eco-hydrogeological zone

A region where similar processes determine the interaction between groundwater and ecosystems, due to similar ecology, geology, climate, and groundwater/surface water connections.

Related: EHZ

This definition applies to:

ecological water requirement

Description of the water regimes needed to sustain the ecological values of water-dependent ecosystems at a low level of risk.

Source: adapted from definition for Environmental Water Requirements in ARMCANZ & ANZECC 1996, National principles for the provision of water for ecosystems, Sustainable Land and Water Resources Management Committee Subcommittee on Water Resources Occasional Paper SWR No 3.

Related: EWR

This definition applies to:

ecosystem

A dynamic complex of plant, animal and micro-organism communities and their non-living environment interacting as a functional unit.

Source: Commonwealth Environmental Protection and Biodiversity Conservation Act 1999

This definition applies to:

EHZ

eco-hydrogeological zone

Related: eco-hydrogeological zone

This definition applies to:

El Niño

Refers to the extensive warming of the central and eastern Pacific Ocean that leads to a major shift in weather patterns across the Pacific. In Australia (particularly eastern Australia), El Niño events are associated with an increased probability of drier conditions. See the Climate Glossary webpage on El Niño for more information.

Related:

This definition applies to:

El Niño Southern Oscillation

The oscillation between the El Niño climate phase and the La Niña phase, usually over several years. See the Australian Climate Influence webpage on ENSO for more information.

Related:

This definition applies to:

electric tape

A water level measurement device comprising a graduated measurement tape with a moisture detector on one end and a signal device on the other.

The moisture detector is lowered into the bore and sends an electrical signal to the surface when it makes contact with the groundwater. This triggers the signal device, usually a light or sound, enabling the operator to measure the distance to water.

This definition applies to:

electrical conductivity

There are multiple contexts for this item

Context 1

In relation to water, the capacity of the water to transmit a flow of electricity and is a common measure of the salinity of the water.

Source: Water Regulations 2008 Schedule 3 Part 1. For the latest information on Australian Government law please go to Federal Register of Legislation

This definition applies to:

Context 2

Electrical conductivity (EC) measures dissolved salt in water. The standard EC unit is microSiemens per centimetre (µS/cm) at 25 °C.

This definition applies to:

electronic format

A format that is machine readable, but does not include scanned documents.

Source: Water Regulations 2008 Regulation 1.03. For the latest information on Australian Government law please go to Federal Register of Legislation

This definition applies to:

endorheic basin

A closed surface water drainage basin that retains water and has no outflow to the sea.

This definition applies to:

ensemble

A column of depth cells equivalent to a vertical in conventional current meter gauging. An ensemble or profile may refer to a single measurement of the water column or an average of pings or profile measurements.

This definition applies to:

ensemble forecast

A set of multiple forecasts for the same period and location. The spread of multiple forecasts provides information about forecast uncertainty.

This definition applies to:

ENSO

El Niño Southern Oscillation

The oscillation between the El Niño climate phase and the La Niña climate phase, or opposite phase, usually over several years. See the Weather and Climate page on ENSO for more information.

Related:

This definition applies to:

entitlement security

The frequency with which water allocated under a water access entitlement is able to be supplied in full.

Related: security licence

Synonym: reliability

This definition applies to:

entitlement system

A jurisdictional gazetted instrument (e.g. Water Sharing Plan), subordinate to the overarching State or Territory water rights legislation, intended to share the portion of the total water resource it covers.

This definition applies to:

entitlements held for the environment

Water Access Entitlements held for the benefit of the environment. They may include entitlements of a specific environmental class and non specific classes of entitlement.

Related: water access entitlement

This definition applies to:

environmental allocation

Allocations announced on entitlements held for the environment.

This definition applies to:

environmental flow

The streamflow required to maintain appropriate environmental conditions in a waterway or water body.

This definition applies to:

environmental water

Water that is available or preserved, to achieve environmental outcomes, including ecosystem function, biodiversity, water quality and water resource health.

Source: Water Act 2007 Part 1 Section 4, at 8 Febraury 2019. For the latest information on Australian Government law please go to Federal Register of Legislation

This definition applies to:

environmental water commitment

Instruments in place to achieve the environmental water determination, e.g. environmental water storage release rules, water access rules to limit abstractions, rules on diversion to wetlands and annual environmental watering plans.

This definition applies to:

environmental water determination

The environmental objectives or water regime that will be provided to meet the appropriate ecological values. The water regime is defined in terms of specific water level or flow criteria at key representative sites, which together form the Environmental Water Provisions (EWP).

This definition applies to:

environmental water outcome

Water level or water flow with its timing and location that has been determined or delivered for the benefit of the environment

This definition applies to:

environmental water provisions

The specific water level or flow criteria at key representative sites that the environmental water regime is set to achieve as part of the environmental water determination. They may meet in part or in full the environmenal water regimes requirements.

This definition applies to:

environmental water regime

Water regime for the benefit of the environment.

This definition applies to:

environmental water regime requirement

The water regime needed to maintain ecological values of water dependent ecosystems at a low level of risk.

This definition applies to:

environmental water release

Water released from infrastructure, such as a surface water storage, for the benefit of the environment.

This definition applies to:

ephemeral

Something which only lasts for a short time. Typically used to describe rivers, lakes and wetlands that are intermittantly dry.

This definition applies to:

ESRI

A software development company based in the United States that builds ArcGIS.

Related: ArcGIS

This definition applies to:

ESRI File Geodatabase

A format for storing GIS data within the ArcGIS software.

Related: Geographic Information System

This definition applies to:

ET

evapotranspiration

The sum of evaporation and plant transpiration from the earth’s land surface to the atmosphere.

This definition applies to:

evaporation

A process that occurs at a liquid surface, resulting in a change of state from liquid to vapour. In relation to water resource assessment and water accounting, evaporation refers to the movement of water from the land surface (predominantly liquid) to the atmosphere (water vapour). The liquid water at the land surface that may be available for evaporation includes surface water, soil water, water within vegetation, and water on vegetation and paved surfaces.

Related:

This definition applies to:

evapotranspiration

There are multiple contexts for this item

Context 1

The sum of evaporation and plant transpiration from the earth’s land surface to the atmosphere.

This definition applies to:

Context 2

The combined loss of water from a given area during a specified period of time by evaporation from the soil or water surface and by transpiration from plants.

Source: Australian and New Zealand Guidelines for Fresh and Marine Water Quality (2000)

Synonym: evapotranspiration

This definition applies to:

EWP

Environmental Water Provisions

This definition applies to:

EWR

ecological water requirement

Related: ecological water requirement

This definition applies to:

exceedance probability

The forecast probability that a particular variable such as streamflow volume will be exceeded.

This definition applies to:

exposure

The measure of the energy received per unit area.

Source: Water Regulations 2008 Schedule 3 Part 1. For the latest information on Australian Government law please go to Federal Register of Legislation

This definition applies to:

external trade

A transaction to transfer a water right from one legal entity to another out of a specified area. The area can be a water system, water management area or a trading zone as defined in respective State and Territory legislation.

This definition applies to:

extraction

Synonymous with abstraction in case the water is removed from the groundwater store.

Synonym: abstraction

This definition applies to: