Terminology

A range of terminology exists around the management of Environmental Water. Below is a list that aims to provide explanation of some of these.

A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R - S - T - U - V - W - XYZ


B

Bankfull -carrying capacity of the stream before spilling out onto adjacent land

Baseflow –low flows sufficient to maintain fish passage, water quality, and pool and riffle habitats

C

Catchment management authority (CMA) – statutory authorities established to manage regional and catchment planning, waterways, floodplains, salinity and water quality

Channel - that part of a river where water flows at some time and includes the bed and banks, taken to mean the whole of the depression in which the water flows before it rises sufficiently to spill over onto adjacent lands as flood water

Commonwealth Environmental Water Holder (CEWH) – (part of the Department of the Environment) holds and manages the water entitlements purchased through the Restoring the Balance water recovery program

CMA – catchment management authority

D

DO – dissolved oxygen level of creek water

E

Environmental flow regime – the timing, frequency, duration and magnitude of flows for the environment

Environmental flow study – a scientific study of the flow requirements of a particular basin’s river and wetlands systems used to inform decisions on the management and allocation of water resources

Environmental water entitlement – an entitlement to water to achieve environmental objectives in waterways (could be an environmental entitlement, environmental bulk entitlement, water share, Section 51 licence or supply agreement)

Ephemeral – a non-permanent water body lasting a short period of time.

F

Flow - movement downstream of water confined in the channel. The term lotic applies to flowing or moving water

Flow component – components of a river system’s flow regime that can be described by timing, seasonality, frequency and duration (for example, cease to flow and overbank flows)

Flow regime - pattern of seasonal flow variations in any one year, usually consisting of periods of low flow during summer-autumn then high flows during winter-spring

Freshes - flows that produce a substantial rise in river height for a short period, but do not overtop the river bank. Freshes help maintain water quality and serve as life cycle cues for fish

G

GB CMA -Goulburn Broken Catchment Management Authority

Geomorphology (fluvial) - the physical interaction of flowing water and the natural channels of rivers including erosion and sedimentation

Gigalitre (GL) – one billion (1,000,000,000) litres

GMW – Goulburn-Murray Rural Water Corporation, trading as Goulburn-Murray Water

H

High flows - high flow within channel capacity. High flows allow full connection between all habitats in the river, which is important to fish passage during migration

High reliability entitlement – legally recognised, secure entitlement to a defined share of water, as governed by the reserve policy (full allocations are expected in most years)

I

Instream - refers to that area of a waterway below the surface of the water

Inter-Valley Transfers (IVT) – means bulk transfers of water from the Goulburn water supply system to supply water users in the Murray water supply system

L

Low reliability entitlement – legally recognised, secure entitlement to a defined share of water, as governed by the reserve policy (full allocations are expected only in some years)

M

Macro invertebrates – aquatic invertebrates whose body length usually exceeds 1 mm (included insects, crustacean, aquatic worms and aquatic snails)

Macrophytes – an aquatic plant that grows in or near water and is emergent, submergent, or floating

Megalitre (ML) – one million (1,000,000) litres

MDBA – Murray-Darling Basin Authority

O

Overbank flow –flood flows that overtop the banks and spill onto the floodplain

P

Passing flow – water released out of storages to operate river and distribution systems (to deliver water to end users), provide for riparian rights and maintain environmental values and other community benefits

Planktonic algae – floating microscopic plants that are an important food source for aquatic fauna

Pool - a significantly deeper area in the bed of a river

R

Reach - a length of stream that is reasonably uniform with respect to geomorphology, flow and ecology

Return Flow – Drainage water from irrigated farmlands that re-enters the water system to be used further downstream.

Riffle – a stream section with fast and turbulent flow over a pebble bed with protruding rocks (characterised by a broken water surface).

Riparian vegetation - vegetation growing on the water line, up the bank or along the very top of the bank. It is the vegetation which has the most direct effect on instream biota.

S

Slack water, as applied to fluvial systems, is runoff or streamflow that is prevented in some manner from maintaining a normal velocity and thereby becomes ponded or nearly so.

Spring Soak - any small area of land, as near a spring or at the foot of a hill, that becomes swamp-like or holds water after a period of heavy rain.

Seasonal allocation – the volume of water allocated to a water share in a given season, expressed as a percentage of total entitlement volume

T

The Living Murray (TLM) – an intergovernmental program, which holds an average of 500,000 ML of environmental water per year, for use at six icon sites along the River Murray

U

Unregulated entitlement – an entitlement to water declared during periods of unregulated flow in a river system, that is, flows that are unable to be captured in storages

V

Victorian Environmental Water Holder (VEWH) – an independent statutory body responsible for holding and managing Victorian environmental water entitlements and allocations (Victorian Water Holdings)

W

Water entitlement – the right to a volume of water that can (usually) be stored in reservoirs and taken and used under specific conditions

Water Holdings – environmental water entitlements held by the Victorian Environmental Water Holder

Waterway manager – agency responsible for the environmental management of waterways (includes catchment management authorities and Melbourne Water)

Waterways – can include rivers, wetlands, creeks, floodplains and estuaries

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