Glossary v3

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1st Order Kinetic Model k-C*

Model available in Source Catchments. The 1st Order Kinetic Model k-C* filter model describes the decay or reduction in inflow constituent concentration within a treatment facility such as a grass filter strip. The effectiveness of the treatment is a function of the inflow concentration, the âbackground concentrationâ of the treatment facility (i.e. some measure of the ability of the treatment to reduce concentration), the inflow, and the treatment area. The k-C* model is the fundamental model used in the Universal Stormwater Treatment Model (USTM) of MUSIC (eWater 2009). The model is a conceptualisation of the reduction in constituent concentration that can be provided by a range of different treatment facilities. The basic equation is a decay function.

Source: (eWater CRC 2010a)

2CSalt

(software plugin) Places a time series of salt concentration into a Source Catchments network, with the Source Catchments network being modified to fit with the 2C salt results by replacing and removing network sections.

Australian Environmental Council

Source: (NWC 2007)

AEP

Annual Exceedance Probability

The distance in kilometres, measured along the middle of a watercourse, from the mouth or junction.

Source: (Stanley, K. 2007)

Annual series

A means of analysing flood frequency that involves selecting the largest values in each year of the record often for the purposes of fitting a frequency distribution. Often the annual maxima are selected on the basis of water years rather than calendar years.

AsciiGrid Pre-processor

A software plugin. A mechanism for rapidly and easily importing daily rainfall or potential evapotranspiration data. It is particularly suitable for large and very large catchments (e.g. 50,000 to a million km2).

Source: (eWater CRC 2010a)

Attenuation

The gradual change in shape of a hydrograph as it passes downstream along a stream channel, with a reduction in the peak flow and the hydrograph shape becoming flatter.

Source: (Shaw 1994)

Australian Research Council

The ARC is a statutory authority within the Australian Government's Innovation, Industry, Science and Research (IISR) portfolio. Its mission is "to deliver policy and programs that advance Australian research and innovation globally and benefit the community." Refer: http://www.arc.gov.au/

Source: (NWC 2007)

Australian Water Balance Model

Australian Water Balance Model. Model available in Source Catchments. A conceptual rainfall runoff model that relates runoff to rainfall with daily data, and calculates losses from rainfall for flood hydrograph modelling. The model contains five stores; three surface stores to simulate partial areas of runoff, a base flow store and a surface runoff routing store.

Australian drinking water guidelines

Portion of the National Water Quality Management Strategy (1996) dealing with the physical, chemical and biological components of water for human consumption.

Source: (toolkit 20091023)

Authority

the Murray Darling Basin Authority.

Blue green algae

Source: (NWC 2007)

BMP

Best Management Practice best management practices

Use: best management practice

is the collective name given to approximately 70000 ha of wetland habitats located on the floodplain of the River Murray between Echuca, Deniliquin and Tocumwal.

Source: (toolkit 20091023)

Baseflow index

The ratio of mean annual baseflow to mean annual flow.

Baseflow separation

The process of dividing a hydrograph into baseflow and quick flow (or surface flow) components. Often this is achieved using a recursive digital filter algorithm.

Basin Plan

the Basin Plan adopted by the Minister under section 44 (as amended from time to time).

Source: (NWC 2007)

Source: Water Act 2007

Basin State

(a) New South Wales; (b) Victoria; (c) Queensland; (d) South Australia; (e) the Australian Capital Territory.

Source: (NWC 2007)

Source: Water Act 2007

Best Practice Modelling

eWater defines Best Practice Modelling as a series of quality assurance principles and actions to ensure that model development, implementation and application are the best achievable, commensurate with the intended purpose. In particular, the principles and actions ensure that: â¢ Models are developed according to a best practice framework, including stakeholder governance, formal capture of user requirements, technical specification and review, testing procedures as well as software quality assurance procedures and usability testing. Also, this is all undertaken through an industry standard project management framework. â¢ Models are based on the best appropriate science, and considering data and scale constraints. â¢ Model assumptions and science are transparent and defensible; articulated in clear user documentation and supporting reference material. â¢ Model set-up, calibration and application are robust, transparent, repeatable and defensible within the constraints of data availability, and based on a consistent approach that is the best available. â¢ Model implementation is assisted by clear, unambiguous guidelines. â¢ Modelling and predictive uncertainties are clearly articulated in the context of a risk framework that stakeholders and decision-makers can understand and confidently make use of: all are based on sound decision science. â¢ A mechanism exists that allows for continuous improvement in best practice modelling as the state of knowledge and technology improves.

Source: (eWater CRC 2010c)

Bird guard

A device often fitted to evaporation pans to prevent birds from using the pan to drink from. Comparative studies have shown that fitting of bird guards typically reduce recorded pan evaporation from Class A pans by 8%.

Bureau

The Commonwealth Bureau of Meterology established under section 5 of the Meterology Act 1955.

Source: (NWC 2007)

Catchment Water Management Plan

Source: (NWC 2007)

Calendar year

Year starting on 1 January and ending on 31 December.

Catchment Yield Estimation Tools

Computer software, formulas or heuristics that can be used to estimate the water yield from a catchment with a specified reliability

Celerity

The velocity of a very small wave along a body of water.

Channel roughness (Manningâs n)

Manningâs n is an estimate of channel roughness, used in the calculation of flow velocity and discharge. The value of n is typically between 0.01 and 0.1 and varies with channel slope, bed material composition (sand, gravel, cobble etc), in-stream vegetation and sinuosity.

Source: (Ward and Trimble 2004)

Channelisation

Process that occurs when defined streams start to form to capture water that had previously flowed from an upstream hillslope along undefined flow pathways.

Class A pan

Because evapotranspiration is difficult to measure directly, atmospheric evaporative demand is often estimated by observing the evaporation rate in an open water container. The Class A pan evaporimeter is the standard instrument used for such observations in Australia. This is a circular pan made of galvanized iron, 4 ft (121 cm) in diameter and 10 in (25 cm) deep, mounted on an open wooden platform. In Australia, the pans are protected with a wire âbird-guardâ to stop animals affecting the measurements.

Source: (Rayner 2005)

Coarse sediment

Sediment that is trapped principally by settling.

Source: (eWater CRC 2008)

Commonwealth Environmental Water Holder

The Commonwealth Environmental Holder established under section 104.

Source: (NWC 2007)

Source: Water Act 2007

Commonwealth environmental water holdings

has the meaning given by section 108.

Source: (NWC 2007)

Source: Water Act 2007

Constituent concentration

Ratio of the load of a constituent to the flow rate at a particular location at a particular point in time.

Constituent load

Mass of a particular constituent passing a particular point over a defined period of time.

Continuity equation

An equation that expresses equilibrium between the various flow components (e.g. inflow, outflow, and storage). Derived initially by Leonardo da Vinci as a statement of the law of conservation of mass.

Source: (Ward and Robinson 1990)

Contributor

A software plugin. A tool to determine the amounts of a constituent that travels to a point in a network.

Source: (eWater CRC 2010b)

Crop Water Economic Index

Gross Production ($) Ã· Evapotranspiration (mm)

Source: (NWC 2007)

Source: (ANCID 2001)

Crop Water Production Index

Total Product (kg) Ã· Evapotranspiration (mm)

Source: (NWC 2007)

Digital Elevation Model

Use: digital elevation model

Department of Primary Industries (NSW), (Vic) Department of Primary Industries

(software plugin) A plugin that allows the user to perform a range of simple transformation functions on single values, a time-series of values or rasters of spatial data.

Data modification Tool

(software plug-in) Provides a basic set of operations for modifying input data, such as a raster of land use, based upon an approach that builds rules from combination of various conditions.

Source: (eWater CRC 2010b)

Decay (nutrient)

Reduction in the concentration of a constituent with time.

Decay model

An in-stream processing link model available in Source Catchments. Constituent Decay is a simple exponential decay model which acts on the selected constituent load within each link to which the model has been applied. The model is primarily based on physical principles.

Source: (eWater CRC 2010a)

Department of Natural Resources, Environment and the Arts (NT)

A department of the Northern Territory government. Refer: http://www.nt.gov.au/nreta/

Source: (NWC 2007)

Differential attachment

Differential attachment of solutes, especially cations, onto the finer soil particles (silt and clay)Â occurs dueÂ to the larger surface area and surface charge that finer particles have. This results in aÂ increasedÂ mass of attached solute per unit mass of the soil particle as the size range of the particles decreases and results in enrichment of the solute concentration as the particle size decreases.

Dissolved oxygen

Use: Event mean concentration (mg/L)

EMC/DWC

Model available in Source Catchments. The Event Mean Concentration (EMC) / Dry Weather Concentration (DWC) model applies two fixed constituent concentrations (EMC & DWC) to a functional unit (FU) to calculate total constituent load. This model is based on physical principles.

Environment Protection Authority Environment Protection Authority

Enrichment of solute concentrations in runoff occurs due to differential attachment of solutes on to finer particles (silt and clay) and these finer particle being transported larger distances as they stay suspended for longer in the runoff.

Entitlements and Trade Terminology

(a logical grouping of terms in this glossary)

Environment Protection Agency

In Queensland, NSW & Victoria, a state regulatory, planning and research organisation responsible for development assessment, policy implementation and management of environmental issues.

Source: (toolkit 20091023)

Environmental Water Holdings Special Account

The account established by section 11 of the Water Act.

Source: (NWC 2007)

Source: Water Act 2007

Event Mean Concentration/Dry Weather Concentration

Model available in Source Catchments. The Event Mean Concentration (EMC) / Dry Weather Concentration (DWC) model applies two fixed constituent concentrations (EMC & DWC) to flow generated from a functional unit (FU) to calculate total constituent load. EMC is applied to quick flow and DWC to baseflow.

Source: (eWater CRC 2010a)

Source: (Merritt, Letcher, Jakeman 2003)

Event flow

Difference between the total flow and the baseflow for a flood event.

Event mean concentration (mg/L)

Mean concentration of a particular constituent over the quick flow component of an event hydrograph. EMC = Total constituent load during the event / Total quick flow during the event.

Exponential decay

A model of the reduction in the load of a constituent with time where the rate of reduction is proportional to the load of the constituent at that point in time.

Export Rate model

Model available in Source Catchments. The Export Rate model applies a fixed constituent rate to a functional unit (FU) to calculate total constituent load. It requires only single parameter so is quick to use and therefore useful for exploring sensitivity. This model is based on physical principles.

Source: (eWater CRC 2010a)

Export rate (kg/ha/a)

Average rate of generation and/or delivery to stream of a particular constituent per unit area and per unit time.

F

FARWH

Framework for Assessment of River and Wetland Health

Source: (NWC 2007)

FEBIGS

Floodplain Ecosystem Benefits of Interactions between Groundwater and Surfacewater.

Source: (Welsh, Podger 2008)

FMA

Forest Management Area

Source: (toolkit 20091023)

FOI

Freedom of Information

Source: (NWC 2007)

FU

pronounced "foos" Areas of a catchment (either contiguous or non-contiguous) that are assumed to have similar responses in terms of hydrology and/or generation and movement of constituents.

Use: functional unit

Falling limb

Part of a flood hydrograph where the stream level or flow is decreasing with time.

Farm Dam model

The Farm Dam model has been developed from the Tool for Estimating Dam Impacts (TEDI) which has been used effectively to estimate the impact of farm dams on stream flows in many catchments in Australia, particularly in Victoria and New South Wales. The Farm Dam model acts as a filter model by capturing a proportion of runoff within each functional unit (FU), according to the total storage density of dams. Overflow from dams in one FU will contribute to the total runoff of all FUs within a sub-catchment. This is a mass balance model based on conceptual relationships.

Source: (eWater CRC 2010a)

Financial year

Year that aligns with Government, company or tax reporting requirements. In Australia, taxation requirements and many companies and Governments use 1 July through 30 June as the financial year and this year is often adopted as the reporting year for water accounts.

Fine sediment

Sediment that is trapped principally by infiltration and adhesion.

Source: (eWater CRC 2008)

Fixed Concentration

Node model available in Source Catchments. The fixed concentration node model allows the user to specify the concentration of a constituent at a particular node. This is a conceptual model.

Source: (eWater CRC 2010a)

Flood Harvesting Diversion

A node model available as a plugin to Source Catchments. The Flood Harvesting Diversion model replicates a licensing procedure to grant a landholder (such as a farmer or irrigator) permission to divert an amount of water from the river system if the water level exceeds a height threshold, such as during a major flood.

Source: (eWater CRC 2010a)

Flood frequency curve

A curve that shows the mathematical relationship between flood peak flows, flood peak water levels or flood volumes at a particular location and the annual exceedance probability of that quantity.

Flood hydrograph

The trace which describes the change in stream flow (or water level) over time at a given location in a stream during a flood event.

Flood peak

The maximum value of flow or water level observed during a flood event.

Flow

Source: (NWC 2007)

Source: (toolkit 20091023)

GMA

Groundwater management area

Source: (NWC 2007)

GMP

Groundwater Management Plan

Source: (NWC 2007)

GMS

Groundwater Management System

Source: (NWC 2007)

GMW

Geomorphology

The science dealing with the form and surface configuration of the solid earth. It is primarily an attempt to reveal the complex interrelationships between the origin (and therefore material composition) of surface features on the one hand, and the causes of the surface alteration (erosion, weather, crustal upheaval, etc) on the other hand.

Source: (American Meteorology Society 2000)

Gnangara Mound (WA)

The Gnangara Mound is Perth's largest source of groundwater, stretching from Gingin in the north to the Swan River in the south. It is commonly referred to as the superficial shallow or unconfined aquifer overlaying deeper confined aquifers.

Source: (NWC 2007)

Great Anabranch

The Great Anabranch leaves the main channel of the Darling River below the Menindee Lakes and rejoins the main channel of the Murray River some 300 miles/480 km later below the Darling-Murray confluence. Refer 34Â° 5' 54" S, 141Â° 46' 20" E. Source: http://encyclopedia.farlex.com/anabranch.

Grid Based Input Assignment

A method commonly used in Source Catchments input screens that shows a table with model components (FU, sub-catchments, links or nodes) listed down the left columns and table cells in the remaining columns where the user can select model options or provide model parameter values.

Groundwater - Surface Water Interaction Tool

Groundwater - Surface Water Interaction Tool developed by eWaterCRC.

A spatial map or grid that defines the relative likelihood (or hazard) of sediment erosion from different parts of the catchment.

HoA

Heads of Agreement

Source: (NWC 2007)

Hydraulic Analysis Module

(software plugin) Allows users to construct a one-dimensional hydraulic model of a river reach and determine ecologically relevant flow thresholds based on hydraulic parameters such as water depth and velocity. Allows the creation of time series data.

Source: (eWater CRC 2010b)

Source: (Welsh, Podger 2008)

Maximum rate per unit time and area that water (usually from precipitation) can pass into an unsaturated soil. Usually this is the same as the hydraulic conductivity of the soil.

Infiltration excess runoff

Runoff that is generated due to the rate of water input (usually from precipitation) exceeding the infiltration capacity of the catchment.

Integrated Quantity and Quality Model

River system model that has been widely applied in Queensland and New South Wales over the 1990s and 2000s for the development of water sharing and water resources plans. River system model that has been widely applied in Queensland and New South Wales over the 1990âs and 2000âs for the development of water sharing and water resources plans.

Source: (Welsh, Podger 2008)

Interception

Precipitation that is caught by vegetation in the catchment and later evaporated without contributing to infiltration or runoff.

Irrigation Water Economic Index

Gross Production ($) Ã· Irrigation Water Applied (ML)

Source: (NWC 2007)

Source: (ANCID 2001)

Irrigation Water Production Index

Total Product (kg) Ã· Irrigation Water Applied (ML)

Source: (NWC 2007)

Source: (ANCID 2001)

Isohyetal map

Map showing contour lines of equal rainfall depth recorded over a particular period of time.

J

JCPAA

Joint Committee of Public Accounts and Audit

Source: (NWC 2007)

JRG

Jurisdictional Reference Group

Source: (NWC 2007)

Jandakot Mound (WA)

The Jandakot Mound, to the south of Perth, holds about 2700 million cubic metres.

Source: (NWC 2007)

K

KCB

Knowledge and Capacity Building

Source: (NWC 2007)

KPI

Key Performance Indicators

Source: (NWC 2007)

Kinematic wave

Kinematic wave occurs where the inertial terms (local inertia, convective inertia, pressure gradient and moment source terms) in the equation of motion are considered to be small. This implies that discharge is a function of depth alone and that the friction slope is equal to the bed slope.

Kriging

Kriging is a group of techniques used in the analysis of spatial data and involves the interpolation of a spatially varying quantity based on the observations of that quantity at a set of near-by locations.

Use: MSM-BigMod

Source: (Welsh, Podger 2008)

MSM-BigMod

The Murray-Darling Basin Authority's existing river simulation model. Murray Simulation Model - Big Model, a custom designed water resources planning model of the main stem of the Murray River system.

Source: MDBA

MSWQS

Major Storages Water Quality Study

Source: (toolkit 20091023)

MUSIC

The acronym used for the Model for Urban Stormwater Improvement Conceptualisation software developed by the CRC for Catchment Hydrology to model urban stormwater management schemes

Source: (toolkit 20091023)

A stochastic process with a finite number of states in which the probability of occurrence of a future state is conditional only upon the current state; past states are inconsequential.

Source: (American Meteorology Society 2000)

Mean Annual Diversion

The average volume of water taken by an allocation or group of allocations in a year. It is calculated by adding the total volume of water taken over a period of years and dividing by the number of years in that period. The calculation is performed on a water year basis.

Source: (Stanley, K. 2007)

Mean Annual Flow

The average volume of water in a year that would flow past a point and is calculated by adding the total volume of flow over a period of years and dividing by the number of years in that period. The calculation is performed on a water year basis.

Source: (Stanley, K. 2007)

Meander

One of a series of somewhat regular, sharp, freely developing and sinuous curves, bends, loops, turns or windings in the course of a stream. It is produced by a stream swinging from side to side as it flows across its flood plain or shifts its course laterally.

Source: (Eggleton 2001)

Meander wavelength

The distance of one meander along the down-valley axis.

Modelling Terms

(a logical grouping of terms in this glossary)

Morton equation

Equation for estimating the evaporation rate from shallow lakes.

Murray Darling Basin Authority

Murray-Darling Basin Authority

Source: Water Act 2007

Source: (NWC 2007)

Murray-Darling Water Basin

Murray-Darling Basin means the area falling within the boundary described in the dataset that: (a) is titled Murray-Darling Basin BoundaryâWater Act 2007; and (b) has a dataset scale of 1:250,000; and (c) specifies the boundary of the Murray-Darling drainage division derived from the dataset that is titled âAustraliaâs River Basins 1997â and is dated 30 June 1997; and (d) is held by the Commonwealth.

Source: Water Act 2007

Muskingum Flow

A link model available in Source Catchments. The Muskingum Flow routing model makes use of the storage-outflow relationship, based on the inflow, storage dimensions, discharge, the travel time through the reach, and a dimensionless value expressing the relative effect of inflow and outflow on the storage of the reach. This model is based on physical principles.

National Land and Water Resources Audit.

Department of Natural Resources, Environment and the Arts (NT)

Nutrient storage

Source: (NWC 2007)

PPET

"The ET that would take place, under the condition of unlimited water supply, from an area so small that the local ET effects do not alter local air mass properties. It is assumed that latent and sensible heat transfers within the height of measurement are through convection only. For example, this represents the evapotranspiration which would occur from small irrigated fields with a never-ending water inflow, surrounded by unirrigated land. Point potential ET may be taken as a rough preliminary estimate of evaporation from small water bodies such as farm dams and shallow water storages."

A means of analysing flood frequency that involves selecting all values above a particular threshold value. Normally the threshold value is chosen so that the number of peaks chosen is between two and three times the number of years of record.

Pass Through

Filter model available in Source Catchments. The Pass Through or null filter preserves the amount of constituent generated in a functional unit (FU) and passes this to the downstream sub-catchment node. This is a conceptual model.

Source: (eWater CRC 2010a)

Penman Equation

Uses wind, net solar radiation, humidity and temperature data to estimate evaporation (E) from an open water surface.

Source: (Borrelli 2003)

Penman Montheith Equation

The Penman-Monteith equation (FAO-56) estimates reference crop evapotranspiration in mm/day, with inputs including relative humidity and wind speed.

Source: (Allen et al 1998)

Power Function

The Power Function is a constituent generation model that fits a rating curve describing the relationship between constituent concentration or load and discharge in linear space. This model is an empirically derived statistical function.

Source: (eWater CRC 2010a)

Pride

A specific instance of a water user node where demands are estimated based on crop water requirements that take account of climatic factors.

Priestly Taylor Equation

The Priestley-Taylor method (Priestley and Taylor, 1972) for the calculation of daily potential evapotranspiration replaces the aerodynamic term of Penman-Monteith equation by a dimensionless empirical multiplier.

Probable Maximum Flood

The flood resulting from Probable Maximum Precipitation (PMP), and where applicable snow melt, coupled with the worst flood-producing catchment conditions that can be realistically expected in the prevailing meteorological conditions.

Source: (Welsh, Podger 2008)

Probable Maximum Precipitation

The theoretical greatest depth of precipitation for a given duration that is physically possible over a particular catchment area, based on generalised methods.

ROP

Regional Operations Plan (Qld)

Use: resource operations plan (Qld)

Source: (NWC 2007)

RPM

"Filter model available in Source Catchments. Conceptual model of particulate trapping in riparian buffers through the processes of settling, infiltration and adhesion. The model is primarily based on physical principles."

A graphical representation of a ranking of all the rainfall values over a fixed duration in a given period, from the lowest to the highest, where the rank is the percentage of time the rainfall value is equalled or exceeded.

Rainfall surface

Grid showing the spatial variation in rainfall depths for a given duration over an area.

Raster

A map image formed by a matrix of pixels arranged in rows columns, which can be displayed on a computer screen.

Rating curve

relationship between water level at a given location and flow rate.

Recursive digital filter

A mathematical algorithm for separating baseflow from the total runoff signal.

Resource Allocation Model

REsource ALlocation Model (Perera et al. 2005). A monthly river system simulation model used mainly for Water Resource Planning in Victoria. A tool that has been routinely used for water resources planning in Victoria, South Australia and Western Australia since the 1980's.

Source: (Welsh, Podger 2008)

Richardâs equation

Formulated by Lorenzo A. Richards in 1931, the equation represents the movement of water through saturated or unsaturated soils. Richardâs equation is the foundation of all mechanistic models used to simulate the dynamics of water (or other liquid) in permeable materials, including rocks, soil and aquifers.

Source: (Buchan 2003)

Riparian Particulate Model

Filter model available in Source Catchments. Conceptual model of particulate trapping in riparian buffers through the processes of settling, infiltration and adhesion. The model is primarily based on physical principles.

Source: (eWater CRC 2010a)

Rising limb

Part of a flood hydrograph where the stream level or flow is increasing with time.

River Analysis Package

Contains a suite of tools for analysing the hydrology and hydraulics of a river and their relationship to ecology.

Source: (Stewardson and Marsh 2004)

River Manager

River Manager is a personal-computer-based application for describing and modelling the behaviour of river systems. It is part of a family of eWaterCRC products including River Operator and Source Catchments. River Manager is designed to support the construction and operation of river models that mimic river behaviour over arbitrarily-long periods (weeks, months, years, centuries). This contrasts with River Operator which is intended to support day-to-day applications.

Use: Source IMS

Source: eWater CRC

River Operator

A tool for assisting water authorities to operate regulated and unregulated river systems on a daily or seasonal basis.

Use: Source IMS

Source: (Podger 2009)

River Systems Pre-processing Tools

(software plugin) Inserts extra methods for importing input time series data into Source Catchments.

Sewage Treatment Plant

Source: (NWC 2007)

SURM

"Model available in Source Catchments. Simple Urban Runoff Model is a conceptual rainfall runoff model that estimates daily stream flow from daily rainfall and areal potential evapotranspiration data. It is a simplified version of SIMHYD. The model contains three stores for interception loss, soil moisture and groundwater and model has seven parameters. This is a mass balance model based on conceptual relationships."

Runoff that is generated due to soils at the surface having all of their pore space full with water.

Sediment

Transported and deposited particles or aggregates derived from rocks, soil or biological material.

Source: (Soil Science Society of America 2008)

Sediment load rate at sill

Parameter of the load based sediment delivery ratio filter model that defines the rate of sediment input at which all of the sediment is then delivered to the stream (with no removal).

Sediment loading rate threshold

Parameter of the load based sediment delivery ratio filter model that defines the rate of sediment input at which all of the sediment is removed by the filter (with no delivery to the stream).

Sediment storage

Process for sediment to accumulate within one or more reaches of the model for a period of time, possibly to be released later. Sediment storage would most commonly occur in large reservoirs or in flatter lower lying reaches of large rivers.

Settling

Process by which particles suspended in water fall out of the water column over time and come to rest on the bottom.

Settling velocity

Rate at which particles suspended in water fall out of the water column over time and come to rest on the bottom.

Simple Urban Runoff Model

Model available in Source Catchments. Simple Urban Runoff Model is a conceptual rainfall runoff model that estimates daily stream flow from daily rainfall and areal potential evapotranspiration data. It is a simplified version of SIMHYD. The model contains three stores for interception loss, soil moisture and groundwater and model has seven parameters. This is a mass balance model based on conceptual relationships.

Source: (eWater CRC 2010a)

Soil water stores

Mathematical components of a conceptual water balance model that represent the ability of the soils of the catchment to store water.

Source Catchments

Catchment modelling tool developed from E2. Used for modelling, forecasting and managing the amounts of water and materials flowing across a catchment and into receiving waters.

Use: Source IMS

Source: (anonymous 2009)

Source IMS

Umbrella application environment, based on E2, which supports river management, operations and and catchments scenario types. Incorporates antecedent products such as WaterCAST, Source Catchments, River Manager, River Operator and Source Rivers. See http://www.ewater.com.au/products/ewater-source/

Source Rivers

Umbrella application environment supporting River Manager and River Operator scenarios.

Use: Source IMS

Spatial interpolation

Process of estimating values of a particular quantity at spatial locations where data has not been observed from point observations of that quantity. This is commonly undertaken with rainfall, where rainfall depths are required across a catchment but observations are only available at point rainfall gauges.

Spline interpolation

A form of interpolation where the interpolant is a special type of piecewise polynomial called a spline.

Source: (Rivlin 2003)

Split-sample test

(Also differential split-sample test). Common approach of separating the available data into a set used for model calibration and an independent set for validation of the performance of the model. A common approach used in hydrology is to use part of the record (say the first 2/3 of the available years of data) for calibration and the remaining part of the record to validate the performance of the model using the parameter values that had previously been calibrated on the first part of the record.

Staff gauge

Streamflow gauge that records water level heights using visual observations of water levels on vertical graduated measuring sticks known as staff boards. Before the installation of automated level recording equipment, water levels were often only recorded manually from the staff gauge once per day.

Stage height

Recorded water level at a streamflow gauge expressed in a distance above the defined datum for that gauge. It is common for the datum to be defined as the bed level of the stream channel at the gauge location and in that case the stage height is the depth of water in the channel. There are other situations where a different datum is used, such as Australian Height Datum or other local survey datums.

State Entitlements and Trade Terminology

(a logical grouping of terms in this glossary)

Device for measuring the level of water in a stream with time, which can then be used to estimate the flow rate of water.

Sunken pan

Used in the estimation of evaporation from lakes. It is a 920mm square and 460mm deep container made of unpainted galvanised iron that is buried and level with the ground surface. The sunken pan can have similar radiation and aerodynamic characteristics to a lake. On an annual basis, lake evaporation is approximately 80% of sunken pan evaporation (using a 0.80 pan coefficient conversion constant).

Source: (Subramanya 2008)

Supervisory Control And Data Acquisition

Supervisory, Control And Data Acquisition process using dedicated computer equipment and purpose written software. SCADA differs from âautomatic controlâ in that it provides the facility for remote surveillance and control of supply works.

Source: (NWC 2007)

Surface flow

The component of streamflow that has travelled through the catchment as interflow or across the surface as overland flow. Also sometimes referred to as "surface runoff" or "overland flow".

Surface runoff

The Choke

Refers to the reach of the River Murray, between the junction of the Edward River and the Barmah township, with the lowest channel capacity (10600 ML/day) between Lake Hume and South Australia. Refer 35Â°56'S 144Â°57'E.

Source: (toolkit 20091023)

The Invisible Modelling Environment

Software development architecture specifically written for developing eco-hydrological models based upon the Microsoft .NET framework.

Source: (Welsh, Podger 2008)

Thiessen interpolation

A method of spatially interpolating point rainfall to a surface that assumes that the rainfall depth for the period at any location is the same as that recorded at the nearest rainfall gauge. For this reason it is sometimes known as "nearest neighbour" interpolation.

Thiessen weightings

Thiessen weightings are derived from the proportion of a catchment that is nearest to a particular rainfall gauge.

Thin plate splines

A method of spline interpolation that fits a surface to point observations using a polynomial function.

Threshold

A value of an algorithm or mathematical function at which there is a defined change in the behaviour of the function.

Time Series Analysis

A graphical user interface that allows users to interactively investigate time series data. Designed as an interpretive tool.

Source: (eWater CRC 2010b)

Time Series Manager

(software plugin) A tool for manipulating, infilling, cleaning and transforming time series. It can also apply any rating curve to a time series to create new time series.

Source: (eWater CRC 2010b)

Total Water Economic Index

Gross Production ($) Ã· Total Water Applied (ML)

Source: (NWC 2007)

Source: (ANCID 2001)

Total Water Production Index

Total Product (kg) Ã· Total Water Applied (ML)

Source: (NWC 2007)

Source: (ANCID 2001)

U

UA

Unincorporated area (for groundwater management)

Source: (NWC 2007)

UC

University of Canberra http://www.canberra.edu.au/

UN

United Nations

Source: (NWC 2007)

USLE

Universal Soil Loss Equation

Source: (toolkit 20091023)

USTM

The 1st Order Kinetic Model k-C* model describes the decay or reduction in inflow concentration within a treatment facility such as a grass filter strip.

Use: Universal Stormwater Treatment Model

UV

Ultraviolet

Source: (NWC 2007)

UV disinfection

The use of ultraviolet light to irradiate drinking water to kill pathogens such as bacteria and viruses, and to inactivate cysts and oocysts of harmful protozoa.

Source: (toolkit 20091023)

Units of Measurement

Quantities chosen as a standard in terms of which other quantities may be expressed.

Universal Stormwater Treatment Model

The 1st Order Kinetic Model k-C* model describes the decay or reduction in inflow concentration within a treatment facility such as a grass filter strip.

V

VFF

Victorian Farmersâ Federation

Source: (NWC 2007)

VU

Victoria University. http://www.vu.edu.au

Source: (Welsh, Podger 2008)

VWQMN

Victorian Water Quality Monitoring Network

Source: (toolkit 20091023)

Vic

Victoria

Water supply protection areas

Source: (NWC 2007)

Water Management and Operation Terms

(a logical grouping of terms in this glossary)

Water Resource Terms

(a logical grouping of terms in this glossary)

Water Terms

(a logical grouping of terms in this glossary)

Water table

The water table, at atmospheric pressure, marks the variable upper limit of the unconfined aquifer. Locally a lens of clay, or other impermeable layer, can hold up the groundwater to form a perched water table.

Source: (Shaw 1994)

WaterCAST

WaterCAST is the original name given to Source Catchments.

Use: Source IMS

Watercress

Water resources planning model commonly used in South Australia.

Wave celerity

The velocity of a very small wave along a body of water.

Use: Celerity

Wetted perimeter

absorption trench

The disposal field of a conventional domestic on-site effluent disposal system; an excavated area, filled with gravel with a light cover of soil from which water from a perforated pipe from a septic tank can evaporate and percolate into the surrounding soil.

Source: (toolkit 20091023)

account

Entity to keep track of the status of a water userâs water usage. Note that a given water user can have more than one account, and these do not necessarily have to be of the same account type.

account balance (Qld)

The remaining volume or share of water available to an account holder. The sum of all the credits to an account minus the sum of all of the debits.

Source: River Systems specification

account sharing method

Demand is distributed between resource assessment system accounts. When the account sharing method is used, water supplied to the water user is limited by the balance of the accounts and accounts are updated for orders placed or water used.

accuracy

Closeness of a measured or computed value to its âtrueâ value, where the âtrueâ value is obtained with perfect information. Due to the natural heterogeneity and stochasticity of many environmental systems, this âtrueâ value exists as a distribution rather than a discrete value. In these cases, the âtrueâ value will be a function of spatial and temporal aggregation.

Source: (USEPA-CREM)

acid

A substance containing more H+ ions than OH- ions in solution; a condition where the pH is below 7, where the activity of the H+ ion exceeds that of hydroxyl OH- ions.

Source: (toolkit 20091023)

activated carbon

High porosity, high surface area carbon obtained by burning organic matter in the absence of air, which possess a high capacity to remove trace and soluble components from solution; used to remove impurities causing odour and undesirable taste from drinking water by absorbing gases and various organic and inorganic molecules. Also used for removing cyanobacterial toxins from drinking water.

Source: (toolkit 20091023)

activated sludge

A rich mixture of bacteria and mineral substances that has been through a reactor tank and which is to be reintroduced, aerated and mixed with the incoming sewage; a type of sewage treatment plant in which the above process is used to break down organic matter and nitrogen compounds.

Source: (toolkit 20091023)

active volume

The volume of water currently stored that may be released through outlet structures and is equal to the current volume less the inactive volume.

Source: (NWC 2007)

aquifer recharge

Build up of the water level in a natural underground storage

Source: (toolkit 20091023)

aquifer storage and recovery

The storage of water through wells installed into aquifers, with subsequent retrieval from the same wells during demand for the stored water

Source: (toolkit 20091023)

area

The extent or measurement of a surface (eg a piece of land or a body of water).

areal actual evapotranspiration

The ET that actually takes place, under the condition of existing water supply, from an area so large that the effects of any upwind boundary transitions are negligible and local variations are integrated to an areal average. For example, this represents the evapotranspiration which would occur over a large area of land under existing (mean) rainfall conditions.

Source: (Chiew 2002)

areal potential evapotranspiration

The ET that would take place, under the condition of unlimited water supply, from an area so large that the effects of any upwind boundary transitions are negligible and local variations are integrated to an areal average. For example, this represents the evapotranspiration which would occur over a very large wetland or large irrigated area, with a never-ending water inflow. A "large" area is defined as an area greater than one square kilometre.

Source: (Chiew 2002)

artesian basin

A geological structural feature or combination of such features in which water is confined under pressure.

Source: Macquarie Dictionary

Source: (NWC 2007)

artesian bore

A bore whose shaft penetrates an aquifer and in which the water level rises above ground by hydrostatic pressure.

Source: Macquarie Dictionary

Source: (NWC 2007)

artificial channel storage

Volume of water in artificial channels. Includes the instantaneous volume of moving water, and any water in structures which are not classed as off river storages, on-river reservoirs or farm dams.

Source: (Sinclair, Knight, Merz 2006)

Source: (NWC 2007)

artificial wetland

A constructed habitat with either static or running water and aquatic or terrestrial vegetation, with the objective of directly reducing contaminants in the water or creating conditions for this to occur.

Source: (toolkit 20091023)

asphalt

A hard surface lining formed by the spreading of asphalt on the subgrade of the channel to form a hard surface and seal the channel.

available water

Water potentially available for both extractive and non extractive use.

bentonite sediment sealant

Dry, high swell bentonite in granular form is spread over the channel water surface. This material sinks to form a seal at the base of the channel.

Source: (ANCID 2001)

Source: (NWC 2007)

bentonite soil blanket

A liner constructed by uniformly spreading powdered bentonite over the surface area of a dry channel. The powder is then mixed into the top layer of soil using a rotary type mixer and to 100 mm thick blanket over the channel section.

biofilm

Microbial populations that grow on the inside of pipes and other surfaces. A growth of microscopic organisms (ie bacteria and algae) living on any available surfaces (eg, plant, rock, sediment) in the water body

Source: (toolkit 20091023)

biological diversity

All the forms of landscape and its components

Source: (toolkit 20091023)

Influent to or effluent from a septic tank or sewage system; water containing human excrement.

Source: (toolkit 20091023)

blue-green algae

An archaic name for cyanobacteria

Use: cyanobacteria

Source: (toolkit 20091023)

bore

A deep hole of small diameter bored to the aquifer of an artesian basin, through which water rises under hydrostatic pressure.

buffer zone

The area between the basin and its interception works and the surrounding land. Often contains trees or other vegetation to improve the aesthetics of the basin.

Source: (toolkit 20091023)

buffering

Resisting a change in pH when acids or bases are added to a solution

Source: (toolkit 20091023)

calculated

An value or number determined mathematically or via measurement.

calibration

Process of adjusting the values of model parameters within physically defensible ranges until the model performance adequately matches observed historical data from one or more locations represented by the model (i.e. a match is obtained that is robust and fit for purpose).

Source: (USEPA-CREM)

calibration model

A calibration model involves the modelling of flows, extractions, operational rules, and infrastructure that occurred historically to produce a model that can be used to simulate âwhat if scenariosâ based on historical flow, rainfall and evaporation patterns and catchment conditions.

Source: (Stanley, K. 2007)

canal

The expression âCanalâ is also used for some main channels and usually forms part of the proper name in these cases, eg Cattanach Canal, Mulwala Canal.

Use: channel

Source: (ANCID 2001)

Source: (NWC 2007)

cap

An upper limit for the volume of water available for use from a waterway, catchment, basin or aquifer.

Source: (NWC 2007)

Source: Australian Water Resources 2005

cap development conditions

This is a scenario that represents water resource development infrastructure and management practices that existed in the 1993/94 water year (as defined in the MDBMC Cap). This term is relevant to hydrologic modelling for water management purposes, Water Sharing Plans and Cap accountability.

Source: (Welsh, Podger 2008)

capillary fringe

The zone immediately above the watertable, where water is drawn upwards by capillary tension.

Source: (ANCID 2001)

Source: (NWC 2007)

capillary tension

The forces acting on soil moisture in the unsaturated zone, attributable to surface tension effects and pore geometry.

Source: (ANCID 2001)

Source: (NWC 2007)

capital works grants

Capital works grants are funds received and receivable from governments for specific capital works.

Source: (NWC 2007)

Source: (National Performance Framework 2006)

carbon dioxide

A colourless, odourless gas, utilised by plants in photosynthesis and produced during respiration by plants and animals, used in water treatment to reduce corrosion potential.

Source: (toolkit 20091023)

carbonate

The CO32-ion; a salt of carbonic acid eg. calcium carbonate (limestone).

Source: (toolkit 20091023)

carryover

A portion of allocated water in regulated river systems that can be carried over from one water year to the next by water users.

Source: (Welsh, Podger 2008)

carryover reserve

Water in storage in a regulated river system in a given year that is kept in reserve to meet high security requirements in the subsequent year (sometimes referred to simply as a âreserveâ to avoid confusion with âcarryoverâ).

Source: (Welsh, Podger 2008)

cash flow budget

A cash flow budget is a technique used to show future costs and returns associated with a project over a period of time. These are the basis for deciding whether or not to undertake a project, for obtaining finance and for monitoring its performance once it commences. These are used primarily to evaluate an investment.

Source: (toolkit 20091023)

catchment

The area of land drained by a water course that could range from a small runnel to a creek or a river. In hydrologic terms every point in the landscape is the outlet of a catchment of some description. As the term has a wide range of applicability it gets used very broadly (and loosely). The equivalent term in the US is âwatershedâ.

Source: (Welsh, Podger 2008)

catchment area

A drainage area in a river system to a defined location.

Source: Macquarie Dictionary

Source: (NWC 2007)

caveat (WA)

(Buyer beware) - A warning to a person searching the original Water Access Entitlement that there is a claim lodged on that Water Access Entitlement, which may prohibit the Registrar of Titles from registering a dealing upon that Water Access Entitlement.

Source: (NWC 2007)

cease to pump indicator

The indicator measurement at which irrigators must stop pumping.

Source: (Welsh, Podger 2008)

ceding

Ceding occurs when there are multiple water owners with fixed storage shares and one water owner gives up water to another water owner using predefined percent distribution rules.

Source: (Gilmore et al 2008)

change (NSW)

Change to the location, category, water source of a licence.

Source: (NWC 2007)

Specific tests in a quality assurance plan that are used to evaluate whether the specifications (performance criteria) for the project developed at its onset have been met.

Source: (USEPA-CREM)

chemical coagulation

Formation of a floc using chemical additives to treat water-containing colloids in suspension.

Source: (toolkit 20091023)

chemical nutrient reduction

The use of a chemical eg. aluminium sulphate, ferrous chloride, to reduce the phosphorus content of effluent by chemical precipitation of phosphates and filtration.

Source: (toolkit 20091023)

chemical oxygen demand

The amount (mg/L) of oxygen required to react with chemicals present in effluents to convert them to their oxidised state.

Source: (toolkit 20091023)

Local-scale basins that are shared by a small group of properties and are either privately or authority owned.

Source: (toolkit 20091023)

community service obligation

The amount received or receivable from governments for specific agreed services to the community. A CSO must be: - a non-commercial product or service, that is, products and services whose provision is not in the commercial interests of a commercial business entity; - clearly purchased by the Government for delivery to the community on its behalf to achieve a specific social or economic objective that has been established by the Government; and - purchased by the government from an appropriate commercial business entity.

Source: (NWC 2007)

Source: (National Performance Framework 2006)

compacted clay

Compacted clay or a compacted earth lining consists of importing (and compacting) soils which have better soil characteristics than the in-situ soils (ie low permeability and high resistance to erosion).

Source: (ANCID 2001)

Source: (NWC 2007)

compaction of soils in-situ

This involves the enhancement of in-situ soil characteristics such as stability and permeability using standard compaction techniques.

Source: (ANCID 2001)

Source: (NWC 2007)

complexity

The opposite of simplicity. Complex systems tend to have a large number of variables, multiple parts, mathematical equations of a higher order, and are more difficult to solve. In relation to computer models, complexity generally refers to the level in difficulty in solving mathematically posed problems as measured by the time, number of steps or arithmetic operations, or memory space required (called time complexity, computational complexity, and space complexity, respectively).

Source: (USEPA-CREM)

component

A collective term for nodes, links, rainfall runoff models, filters and constituent generation models.

component model

A model associated with a particular component e.g. node models are associated with nodes; link models with links etc.

composting toilets

Devices though which excrement and domestic wastewaters are passed

Source: (toolkit 20091023)

computer software

Programs and other operating instructions and information used by a stored program digital computer.

concentration

The quantifiable amount of chemical in the surrounding water, food or sediment.

Source: (toolkit 20091023)

conceptual basis

This is the underlying scientific foundation of model algorithms or governing equations. The conceptual basis for a model is either empirical (based on statistical relationships between observations) or mechanistic (process-based) or a combination. See definitions for: empirical model and mechanistic model.

Source: (USEPA-CREM)

conceptual model

A hypothesis regarding the important factors that govern the behaviour of an object or process of interest. This can be an interpretation or working description of the characteristics and dynamics of a physical system.

Source: (USEPA-CREM)

conceptual rainfall runoff model

A model that represents the hydrological response as a series of mathematical relationships, often attempting to represent the storage and transport of water through conceptual soil water and groundwater storage buckets.

concrete

A hard surface lining formed by the construction of concrete channel sections either in-situ or elsewhere, which are placed onto tof the channel subgrade to form a hard surface and seal the channel.

Source: (ANCID 2001)

Source: (NWC 2007)

concrete cast in situ

Concrete that is cast into its final shape and position.

conductivity

The ability of a solution to convey an electrical current; concentration of major salts or major ions in solution.

Source: (toolkit 20091023)

confidence interval

The interval which includes the true value [of a data item, whether observed or estimated] with a prescribed probability and is estimated as a function of the statistics of the sample.

Source: (WMO 2008)

confidence level

The probability that the confidence interval includes the true value.

Source: (WMO 2008)

confined aquifer

An aquifer that is overlain by a confining bed. The confining bed has a significantly lower hydraulic conductivity than the aquifer.

Source: (ANCID 2001)

Source: (NWC 2007)

confluence

The point at which two watercourses join.

Source: (Stanley, K. 2007)

confluence node

A node model available in Source. The Confluence node represents the location where two streams are joined to become one. Flows from the two streams are added together. Orders must be passed upward at a confluence so rules must be specifed that allow the determination of the proportion of orders to be supplied by each stream flowing into the confluence.

Source: (eWater CRC 2010a)

confounding errors

Errors induced by unrecognised effects from variables that are not included in the model. The unrecognised, uncharacterised nature of these errors makes them more difficult to describe and account for in statistical analysis of uncertainty.

Source: (USEPA-CREM)

connected water/sewerage property

A connected water/sewerage property is: - connected to the licenseeâs water/sewerage system - the subject of billing for water supply/sewerage collectionâfixed and/or consumption - any property which, at the end of the reporting period, is connected to the water/sewerage system and is separately billed for water/sewerage servicesâfixed and/or consumption including a connected non-rateable property, and a connected but non-metered property, but does not include a body corporate, a rated but unconnected property, or a non-real property or strata garages, ie a master meter for a block of separately metered strata title flats.

Source: (NWC 2007)

Source: (National Performance Framework 2006)

consolidation (NSW)

Cancellation of two or more licences and issue of a single licence with the same total share.

Source: (NWC 2007)

consolidation (Vic)

Two or more water shares may be consolidated by cancelling all or all bar one, and issuing a new share or increasing the remaining share.

Source: (NWC 2007)

constant head permeameter

A device for measuring the saturated hydraulic conductivity of soils. A constant head of water is maintained in a shallow auger hole and the rate of leakage from the apparatus to maintain this constant head (once saturated conditions have been reached) is proportional to the saturated hydraulic conductivity (or permeability) of the soil.

Source: (ANCID 2001)

Source: (NWC 2007)

constants

Quantities with have fixed values (e.g., the speed of light and the gravitational force) representing known physical, biological, or ecological activities.

Source: (USEPA-CREM)

constituent

A material that is generated, transported and/or transformed within a catchment. Constituents commonly include sediments, nutrients, contaminants (eg pesticides, heavy metals), pathogens and other water quality properties.

constituent generation model

A model for deriving the load of constituents produced from a given functional unit at a model time step.

Source: (Merritt, Letcher, Jakeman 2003)

constituent phase

The ninth phase of execution within a time-step. In this phase the transport and transformation of water quality constituents is undertaken.

Source: (Podger 2011)

constraint phase

The second phase of execution within a time-step. In this phase relevant constraints are identified.

Source: (Podger 2011)

Biological or chemical substance or entity, not normally present in a system, capable of producing an adverse effect in a biological system, injuring structure or function.

Source: (toolkit 20091023)

continuous accounting

1. The sub-division of water resources in a dam (within a regulated river system) into user shares. The shares are updated on a frequent basis: eg currently monthly in the Gwydir and Namoi systems. Users manage their usage from their own account. 2. A resource assessment and allocation system with carryover only limited by available storage, user's balances limited to an upper bound, and the storage, transmission and operation losses funded from a communal account. 3. The accounting and sharing out of water resources in either a regulated or an unregulated river system based on an annual cycle, as for annual accounting, but with broader carryover provisions than under annual accounting. This provides water users with greater flexibility in managing their own accounts than under annual accounting, although account balances may not be permitted to become negative (ie no overdraw permitted; if a user needs more water they can enter into a temporary or permanent trade to buy the water needed). Carryover may be limited by annual and multi-year use limits. In a regulated river system the storage, transmission and operation losses are funded from a communal account.

Source: (Welsh, Podger 2008)

Source: River Systems specification

Source: (Ribbons, C 2011)

Covenants requiring that the Water Access Entitlement to be used or not used in specified ways.

Source: (NWC 2007)

covered flexible membrane

The construction of a lined channel using a geomembrane to reduce seepage where the geomembrane is covered with a nonerosivematerial that protects the geomembrane.

Source: (ANCID 2001)

Source: (NWC 2007)

credibility

The confidence that (potential) users have in a model and in the information derived from the model such that they are willing to use the model and the derived information. Specifically, credibility is a function of the performance record of a model and its conformance to best available, practicable science.

Source: (Morton 1993)

critical drought

The duration in time that resulted in the either the lowest dam levels, aquifer levels or pressures, or longest duration of restricted water access.

Source: (Welsh, Podger 2008)

crop efficiency factor

The dimensionless coefficient, crop factor, assumes 100% efficiency of evapotranspiration from the crop. In reality, there is not 100% efficiency so the crop efficiency factor adjusts for this. Sometimes, this is used as a calibration factor when calibrating a crop model to recorded water use.

crop factor

Dimensionless coefficient used to calculate evapotranspiration requirement for a particular crop from the potential evapotranspiration for a reference crop (ETo). Crop factors are determined experimentally and take into account leaf area development of the crop and the crop canopy physiology.

Source: (ANCID 2001)

Source: (NWC 2007)

crop water requirement

The total volume of water required to meet the plants requirements for evapotranspiration for a given planting area and period (excluding leaching fraction).

Source: (ANCID 2001)

Source: (NWC 2007)

cropping farming

Farm type for which main crops are winter and/or summer grain (wheat, barley, oat etc.).

Source: (toolkit 20091023)

cross banks

mounds of soil created by scraping of snig tracks

Source: (toolkit 20091023)

cryptosporidium

A genus of water polluting protozoa

Source: (toolkit 20091023)

culvert

An underground structure or pipe carrying water beneath a road, carriageway etc.

Source: (ANCID 2001)

Source: (NWC 2007)

current balance of committed water

Volume of water committed (set aside) in storages for environmental water rules at a point in time.

Source: (NWC 2007)

Source: (Sinclair, Knight, Merz 2006)

current development conditions

This is a scenario that represents water resource development infrastructure and management practices at the current point in time; this scenario requires regular updating. This term is in common use but can be misleading without a specific reference date. This term is relevant to hydrologic modelling for water management purposes and Water Sharing Plans.

Source: (Welsh, Podger 2008)

current volume

The volume of water currently stored.

Source: (NWC 2007)

Source: Water Resources Observation Network

customer (rural)

Any individual person or entity entitled to receive a rural water service from a rural water delivery agency.

Source: (NWC 2007)

Source: (National Performance Framework 2006-07)

customer collection point

A legitimate water service location that may or may not have a measurement device at which a customer is provided with a rural water service from a rural water delivery agency. This could be either a water supply or a drainage collection point.

Source: (NWC 2007)

Source: (National Performance Framework 2006-07)

customer service point

A legitimate water service location that may or may not have a measurement device at which a customer is provided with a rural water service from a rural water delivery agency. This could be either a water supply or a drainage collection point.

Source: (National Performance Framework 2006-07)

Source: (NWC 2007)

cyanobacteria

A diverse group of bacteria in which the photosynthetic pigments are not localised in definite chromatophores or the nuclear material localised in nuclei

Source: (toolkit 20091023)

cysts

Hard-coated dormant life forms of protozoa such as Giardia

Source: (toolkit 20091023)

D

dS

deciseimens

Source: (NWC 2007)

dairy farming

Farm type for which the main production is milk or milk related products. Milking cows are predominant animal category. Crops are perennial and annual pasture.

Source: (toolkit 20091023)

dam

A barrier to obstruct the flow of water, especially one of earth, masonry, etc., built across a stream.

Use: water storage

Source: Macquarie Dictionary

Source: (NWC 2007)

dam permit (Tas)

Approval under Part 8 of the Water Management Act 1999 to undertake dam works (NB: a dam permit does not take effect until a water licence to take water is obtained).

Source: (NWC 2007)

dam safety emergency plan

A continually updated set of instructions and maps that deal with possible emergency situations or unusual occurrences at a major dam.

Source: (Welsh, Podger 2008)

data assimilation

The combining of diverse data, possibly sampled at different times and intervals and different locations, into a unified and consistent description of a physical system, such as the state of the atmosphere.

Source: (AMS Glossary, 2010)

data fusion

The use of techniques that combine data from multiple sources and gather that information in order to achieve inferences, which will be more efficient and potentially more accurate than if they were achieved by means of a single source. (Source: Wikipedia, http://en.wikipedia.org/wiki/Data_fusion, accessed on 2 Nov. 2010.)

data uncertainty

Uncertainty (see definition) that is caused by measurement errors, analytical imprecision and limited sample sizes during the collection and treatment of data. Data uncertainty, in contrast to variability (see definition) is the component of total uncertainty that is âreducibleâ through further study.

Source: (USEPA-CREM)

dead storage

Reduction of layer formation in water storages by producing turbulence with aerators or mechanised mixers.

Source: (toolkit 20091023)

detention time

The time it takes for a âparcelâ of water to flow from the inlet of a wetland system to the outlet. Depending on the flow path taken by individual parcels of water, the time may vary significantly within the one system

Source: (toolkit 20091023)

deterministic model

Deterministic models contain no random component, and provide no measure of error or uncertainty. They are commonly used for descriptive, analytical and predictive purposes, for example comparison of discharge in paired catchments. Contrast with stochastic models. A model that provides a solution for the state variables rather than a set of probabilistic outcomes. Because this type of model does not explicitly simulate the effects of data uncertainty or variability, changes in model outputs are solely due to changes in model components or in the boundary conditions or initial conditions.

Source: (Black 1996)

Source: (USEPA-CREM)

dethridge meter outlet

Positive displacement flow measurement device used to determine water volumes supplied from the authority supply channel to an individual farm. The meter consists of a metal wheel fitted with 8 vanes around the circumference and mounted on a horizontal axis in a concrete flume emplacement. Water flowing along the flume causes the wheel to rotate and a counting device records the number of revolutions which provides a direct measure of the volume of water supplied over a given time. The counting mechanism records the volume in ML passing through the meter over a given time from which flow rate in ML/d may be derived. In field use the rate of rotation of the wheel in âRevolutions per minuteâ, (usually abbreviated to âRevsâ) is used to determine the approximate flow rate by application of a conversion factor determined by the size and geometry of the particular meter.

Source: (ANCID 2001)

Source: (NWC 2007)

dethridge-long meter

The Dethridge-Long (DL) Meter is an improved high capacity meter with 6 vanes and accurately measures flows up to 20 ML/d. The Dethridge Meter is intended primarily for measurement in open channel systems but can also be adapted for use in low pressure pipe systems, channel outfalls and drainage systems.

Source: (ANCID 2001)

Source: (NWC 2007)

developed area

The maximum land area that a farmer has the infrastructure in place to irrigate.

Source: (Welsh, Podger 2008)

developed yield

Developed yield should be reported as the total volume of water that could be diverted for use, on average, at existing infrastructure levels over the critical period of interest and at a set level of reliability. The developed yield does not include volumes released for the environment, that is, it is the yield capable of being supplied under current infrastructure development after provisions for environmental flows have been made. For some surface water management areas the developed yield may exceed the sustainable yield.

domain boundaries (spatial and temporal)

The limits of space and time that bound a modelâs domain and are specified within the boundary conditions (see boundary conditions).

Source: (USEPA-CREM)

downstream regulation

A method of channel regulation where the water level is controlled or maintained on the downstream side of the control structure. This control mode often operates automatically as demand signals are passed up the system.

Source: (NWC 2007)

Source: (ANCID 2001)

A rural water service that provides for the diversion of raw water by customers from a surface water source at a specified level of service and which confers common obligations on customers. Typically, service provision involves water access, works or site licence administration, metering or measurement and monitoring of diversions on a regular basis. Aspects of water planning and water resource management may also be involved.

Source: (NWC 2007)

Source: (National Performance Framework 2006-07)

drainage system

An engineered network of horizontal pipe drains (also referred to as tile drains), horizontal open drains, or groundwater pumping from bores (also called tubewells, spearpoints or wells) used to manage water tables and thereby control waterlogging and the build up of salt in the plant root zone.

Source: (toolkit 20091023)

drainage water

Water that passes beyond the root zone as a result of rainfall and irrigation.

Source: (toolkit 20091023)

drawdown

The lowering of a storage resulting from the loss of water from the storage.

Source: (Stanley, K. 2007)

drop structure

Concrete, timber or steel weir structure placed in supply channel or drain to dissipate energy (to minimise erosion) at a point of desired reduction in water level.

Source: (ANCID 2001)

Source: (NWC 2007)

dual reticulation

A system of piped water reticulation in which treated effluent is provided for industrial, household or garden use, via a separate delivery system to that for potable use.

Source: (toolkit 20091023)

dynamic model

A model providing the time-varying behaviour of the state variables.

en-route storage

A water storage (weir or lake) located either instream or off-stream in the middle or lower part of a river system (eg Hay Weir on the Murrumbidgee).

Source: (Welsh, Podger 2008)

A specific instance of a water user node where the water demands of an environmental asset are estimated based on previously agreed rules to protect environmental values.

The level of water extraction from a particular system which, if exceeded would compromise key environmental assets, or ecosystem functions and the productive base of the resource.

Source: (NWC 2007)

ephemeral

A short-lived, transitory event or occurrence often used to describe the life cycle of plants and animals. When used to describe wetlands, ephemeral refers to habitats that are either rarely inundated or only inundated for a very short period of time.

Source: (toolkit 20091023)

epiphytes

A plant which lives on the surface of another plant but does not derive water or nourishment from the host; in this document, epiphytes generally refer to algae growing on the surface of aquatic macrophytes

Source: (toolkit 20091023)

epistemic uncertainty

Uncertainty due to imperfect knowledge; this form of uncertainty can be reduced by further studies such as research and data collection.

Source: (Refsgaard et al, 2005b)

equifinality

The principle that in open systems a given end state can be reached by many potential means. In environmental modelling studies, and especially in hydrological modelling, two models are equifinal if they lead to an equally acceptable or behavioural representation of the observed natural processes. (Source: Wikipedia, http://en.wikipedia.org/wiki/Equifinality, accessed on 30 June 2010.)

equivalent persons

The total population computed in adult terms, making allowance for a different or lower demand for a resource or output of a waste product by younger persons.

Source: (toolkit 20091023)

estuarine

Relating to that part of an inlet or river mouth where there is a tidal influence on the fresh or brackish current, affecting water height, salinity and nutrient levels, erosion and drainage channels on a daily basis.

Source: (toolkit 20091023)

estuary

The part of the mouth or lower course of a river in which its current meets the seaâs tides, and is subject to their effects.

To turn to vapour; pass off in vapour, or to give off moisture.

The rate of conversion calculated and agreed to be applied to water to be traded from one trading zone and/or jurisdiction to another.

Source: National Water Initiative

Source: (NWC 2007)

extraction rate

The rate in terms of unit volume per unit time that water can be drawn from a surface or groundwater system. Used in the NWI in the context of a constraint that might exist due to the impact of exceeding a particular extraction rate at a particular point or within a specified system.

Source: (NWC 2007)

Source: National Water Initiative

extraction rate (WA)

The rate in terms of unit volume per unit time that water can be drawn from a surface or groundwater.

Source: (NWC 2007)

extrapolation

Extrapolation is a process that uses assumptions about fundamental causes underlying the observed phenomena in order to project beyond the range of the data. In general, extrapolation is not considered a reliable process for prediction; however, there are situations where it may be necessary and useful.

Source: (USEPA-CREM)

F

faecal streptococci

A group of bacteria whose presence in water indicates faecal pollution

Source: (toolkit 20091023)

false negatives

Also known as false acceptance decision errors. False negatives occur when the null hypothesis or baseline condition cannot be rejected based on the available sample data. The decision is made assuming the baseline condition is true when in reality it is false.

Source: (USEPA-CREM)

false positives

Also known as false rejection decision errors. False positives occur when the null-hypothesis or baseline condition is incorrectly rejected based on the sample data. The decision is made assuming the alternate condition or hypothesis to be true when in reality it is false.

Source: (USEPA-CREM)

field capacity approximation

The equilibrium water content of an undisturbed soil core at a soil suction of 0.01MPa. If only loose, or disturbed soil is available, the equilibrium water content at 0.033MPa suction should be used. In both cases the method used to determine the field capacity value should be clearly stated (Loveday, 1974).

Source: (ANCID 2001)

Source: (NWC 2007)

field water requirement

Total volume of water required to meet the combined water requirements for evapotranspiration, leaching and distribution for a given planting area and period.

Source: (ANCID 2001)

Source: (NWC 2007)

filter

A filter model represents any transformation or storage of constituents that takes place between when they are generated and when they reach a sub-catchment node. Filtering allows representation of physical processes that may occur due to riparian buffers, small dams or detention ponds or denitrification processes.

filter model

A model that represents the reduction in concentration of a particular constituent between where it is generated in a catchment and delivery of that constituent to the node-link network in a Source Catchments model.

filter-strips

intact belts of forest adjacent to streams to control water quality

Source: (toolkit 20091023)

filtration

The separation of suspended material from a liquid by passing the liquid through a porous substance, a filter or other membrane which will retain insoluble matter or particles large in size than the pores in the membrane.

Source: (toolkit 20091023)

first flush

The initial flow of stormwater runoff that often contains high concentrations of contaminants that have built up during intervening dry periods; a mechanical device used to reject and discard the initial runoff from a roof catchment, so as to reduce contaminant loading to a storage tank.

Source: (toolkit 20091023)

fish ladder

A structure on a dam or weir designed to allow fish to move upstream to fresh water or downstream to the estuary or sea

Source: (toolkit 20091023)

fixed charge

The fixed amount the business levies on a residential property per year. This is the component of each residential propertyâs bill that varies with the amount of water used or sewage produced.

Source: (NWC 2007)

Source: (National Performance Framework 2006)

fixed crest weir

Permanent weir structure across a channel waterway used to measure water flow and/or control upstream water level. This may include both sharp crested and broad crested weirs.

Source: (ANCID 2001)

Source: (NWC 2007)

flexible membrane

A geomembrane is a thin flexible impermeable liner, which combined with the strength of the base soil, can be used to reduce seepage. There are two distinct ways of constructing channels using geomembranes: Covered flexible membrane and exposed flexible membrane.

flood retarding basin

A temporary flood storage system used to reduce flood peaks.

Source: (toolkit 20091023)

flooding frequency

the percentage of days (during December-April) during which flooding occurred in the Barmah-Millewa Forest (also âunseasonal flooding frequencyâ).

Source: (toolkit 20091023)

floodplain

The low-lying land adjacent to the riparian zone.

Source: (toolkit 20091023)

floodplain harvesting

Includes water: Pumped from the floodplain to an on farm storage during large floods using secondary lift pumps. Entering an on farm storage from the floodplain because flood levels are high enough to allow it to flow in by gravity.

Source: (Welsh, Podger 2008)

flow distribution phase

The sixth phase of execution within a time-step. During the flow distribution phase, Source determines the physical constraints on releases, and if necessary adjusts the releases within the bounds of these constraints. The flow of water is then modelled from the most upstream node, down through the system. As the model passes demands, water is extracted to meet these demands if there is sufficient water available to meet the previous order and the current requirement. The order of execution is determined in the network phase.

Source: eWater CRC

Source: (Podger 2011)

Source: (Holz, 2010)

flow duration curve

A graphical representation of a ranking of all the flows in a given period, from the lowest to the highest, where the rank is the percentage of time the flow value is equalled or exceeded. These curves may be derived for flows in any time interval, such as daily flows, monthly flows or annual flows.

Source: (Welsh, Podger 2008)

flow percentile

The percentage of time for which a given flow is equalled or exceeded. The flow percentiles are used to define a flow duration curve.

Source: (Welsh, Podger 2008)

flow routing

The change in magnitude, speed and shape (height and duration) of a flow hydrograph as it moves downstream, due to channel and floodplain storage and frictional effects. Also known as flow attenuation and translation.

Source: (Welsh, Podger 2008)

flow routing model

A model for estimating the flow hydrograph at the downstream end of a model link (or stream reach) given the flow hydrograph at the upstream end of the model link or stream reach.

flume

Open conduit having concrete, metal or timber sides and floor used as a supply channel where topography is not suitable for a conventional earthen channel. Flumes are often raised above natural surface and supported by columns or piers.

Source: (ANCID 2001)

Source: (NWC 2007)

fluoride

A compound of fluorine with another element such as sodium or calcium

Source: (toolkit 20091023)

forcing/driving variables

External or exogenous (from outside the model framework) factors that influence the state variables calculated within the model. These may include, for example, climatic or environmental conditions (temperature, wind flow, oceanic circulation, etc.).

Source: (USEPA-CREM)

forms

Models can be represented and solved in different forms, including: analytic, stochastic, and simulation.

Source: (USEPA-CREM)

freeboard

Vertical distance between a channelâs maximum design operating level and the top of the channel bank.

Source: (ANCID 2001)

Source: (NWC 2007)

freehold land (WA)

The greatest estate that can be held by a person without being the absolute owner, which is the Crown.

Source: (NWC 2007)

full supply level

The maximum normal operating level of a reservoir behind a dam. The water level can go above this, such as during floods when the spillway is operating (referred to as flood surcharge), but if the water level rises above the crest of the dam then the dam will be overtopped, and it may fail. For example, Burrinjuck Dam was overtopped on one occasion, but did not fail. Sometimes the FSL may be set lower than the maximum capacity for dam safety reasons.

Source: (Welsh, Podger 2008)

Source: Australian Water Resources 2005

Source: (NWC 2007)

function

A mathematical relationship between variables.

Source: (USEPA-CREM)

functional unit

Source: (toolkit 20091023)

grey water

Effluent from kitchen, bathroom and laundry used earlier for washing household utensils and clothes, in cooking, showering and bathing.

Source: (toolkit 20091023)

gross pollutant trap

A structure used to trap large pieces of debris (> 5 mm) transported through the stormwater system.

Source: (toolkit 20091023)

groundwater

(a) water occurring naturally below ground level (whether in an aquifer or otherwise); or (b) water occurring at a place below ground that has been pumped, diverted or released to that place for the purpose of being stored there; but does not include water held in underground tanks, pipes or other works.

Source: Water Act 2007

Source: (NWC 2007)

groundwater dependent ecosystems

Ecosystems that are dependent on groundwater for their existence and health.

Source: Australian Water Resources 2005

Source: (NWC 2007)

groundwater discharge

Flow of groundwater from the saturated zone to the earth surface.

Source: Australian Water Resources 2005

Source: (NWC 2007)

groundwater diversion service

A rural water service which enables customers to divert or pump water from a groundwater source at a specified level of service and which confers common obligations on customers. Typically, service provision involves water access, works or site licence administration, metering or measurement and monitoring of diversions on a regular basis. Aspects of water planning and water resource management may also be involved.

Source: (NWC 2007)

Source: (National Performance Framework 2006-07)

groundwater drawdown

The lowering of the water table resulting from the loss of water from the aquifer.

Source: (Stanley, K. 2007)

groundwater flux

Water lost or gained from the interaction between the river and a groundwater acquifer. A loss is represented by a positive number, a gain by a negative number.

Source: River Systems specification

groundwater management unit

A hydraulically connected groundwater system that is defined and recognised by state and territory agencies. This definition allows for management of the groundwater resource at an appropriate scale at which resource issues and intensity of use can be incorporated into local groundwater management practices.

Source: (NWC 2007)

Source: Australian Water Resources 2005

groundwater recharge

Inflow of water to a groundwater reservoir from the surface. Infiltration of precipitation and its movement to the water table is one form of natural recharge.

Source: Australian Water Resources 2005

Source: (NWC 2007)

H

hard water

Water which, due to the presence of calcium and magnesium salts in solution, reduces lathering after soap or detergent addition, reduces the efficiency of water-clarifying agents and flocculants, shortens the life of water heaters and pipes due to scale formation and then effectiveness of some pesticides. Hardness may be temporary (reduced by boiling) or permanent.

Source: (toolkit 20091023)

harmony operation

The operation of reservoirs in parallel with the aim of minimising the amount of spill from both reservoirs, while ensuring user needs within the branch are also met.

headwater

The source and upper reaches of a natural waterway.

Source: (Stanley, K. 2007)

headwater storage

A water storage reservoir created by a dam in the upper (usually higher rainfall) part of a river valley.

Source: (Welsh, Podger 2008)

hectare

An area equal to the area of an equilateral rectangle where each side is one hundred metres in length.

Source: eWater CRC

heritage value

The heritage value of a place includes the placeâs natural and cultural environment having aesthetic, historic, scientific or social significance, or other significance, for current and future generations of Australians.

Source: (EPA 1999)

Source: (NWC 2007)

high flow loss

Water loss from a reach during periods of high flow.

Source: River Systems specification

high level of development

Sum of water access entitlements is between 70 per cent and 100 per cent of sustainable yield.

hydraulic roughness

Surface roughness of any medium that influences the velocity distribution of flow

Source: (toolkit 20091023)

hydraulics

The science that deals with the laws governing water or other liquids in motion and their applications in engineering. The science of the conveyance of water through a natural or artificial structure (eg wetland, pipe, channel).

Source: Macquarie Dictionary

Source: (NWC 2007)

Source: (toolkit 20091023)

hydro-electric

hydrology

The science dealing with water on the land, or under the earthâs surface, its properties, laws, geographical distribution, etc. The science of the natural occurrence, distribution and movement of water. The study of water occurrence.

Source: Macquarie Dictionary

Source: (NWC 2007)

Source: (toolkit 20091023)

hydrophyte

A plant growing in water or very moist ground.

Source: Macquarie Dictionary

Source: (NWC 2007)

hydroponics

The cultivation of plants by placing the roots in liquid nutrient solutions rather than in soil.

Source: Macquarie Dictionary

Source: (NWC 2007)

hydrotropic

Turning or tending towards moisture.

Source: Macquarie Dictionary

Source: (NWC 2007)

I

in situ field capacity

The percentage of water remaining in a soil two or three days after having been saturated, with the soil surface covered to prevent evapotranspiration and after free drainage has practically ceased.

Source: (ANCID 2001)

Source: (NWC 2007)

in-stream use

The use of freshwater in situ (for example, within a river or stream). Can include recreation, tourism, scientific and cultural uses, ecosystem maintenance, hydroelectricity and commercial activities, and dilution of waste. The volume of water required for most in-stream uses cannot be quantified, with the exception of hydro-electricity generation.

Source: (NWC 2007)

Source: Australian Water Resources 2005

indigenous heritage value

Indigenous heritage value of a place means a heritage value of the place that is of significance to indigenous persons in accordance with their practices, observances, customs, traditions, beliefs or history.

Source: (NWC 2007)

Source: (EPA 1999)

infiltration

The process by which water soaks into the soil from precipitation or irrigation. The movement of water through soil pores or other porous material

Source: (Welsh, Podger 2008)

Source: (toolkit 20091023)

infiltration limited

Describes basins where the rate of leakage is determined by factors that impact at the base of the basin. Leakage is therefore determined by the depth of water in the basin, and is moderated by the permeability of the basin floor.

Source: (toolkit 20091023)

inflow

The average flow rate into a link or river reach during a time-step.

Source: River Systems specification

inflow (stormwater)

Stormwater entering a sewage treatment plant, due to illegal connections. Movement of liquid into a storage.

Source: (toolkit 20091023)

inflow node

A node model available in Source. An Inflow node originates flows into a model. Inflows include runoff generated for defined headwater and residual catchment areas in the river system, point sources of water such as inter-basin transfers, and return flows from water users. Inflows are not used to account for rain falling directly on water bodies.

inflows

Surface water runoff and deep drainage to groundwater (groundwater recharge) and transfers into the water system (both sufrace and groundwater), for a defined area.

Source: Australian Water Resources 2005

Source: (NWC 2007)

influent stream

An influent stream is one which gains water from groundwater (also known as a âgaining streamâ).

Source: (Welsh, Podger 2008)

infrared

The reduction or increase in the water allocations in the account of a water licence associated with corresponding changes in interstate entitlements.

Source: (NWC 2007)

intrinsic variation

The variability (see definition) or inherent randomness in the real-world processes.

Source: (USEPA-CREM)

inverted siphon

Structure or section of pipeline that conveys channel flow under a natural depression, river or drain.

Source: (ANCID 2001)

Source: (NWC 2007)

irrigate

To supply land with water and thereby promote vegetation by means of canals, especially artificially made, passing through it.

Source: Macquarie Dictionary

Source: (NWC 2007)

irrigation area protected by drainage

The solution for a network linear program is reached by iteration. There may be one or more iterations per time-step.

K

kT

Kilotonnes

Source: (toolkit 20091023)

kilolitre

1,000 litres.

Source: (NWC 2007)

L

lag time

The time delay between inflow and outflow of a river reach assuming that all flows have the same travel time.

Source: River Systems specification

lake

A body of water (fresh or salt) of considerable size, surrounded by land.

Source: Macquarie Dictionary

Source: (NWC 2007)

large dam

The Australian National Committee of Large Dams (ANCOLD) has defined large dams as dams with a crest or wall height greater than 15 metres, or as dams with a dam wall height of greater than 10 metres but meeting other size criteria, including creating a reservoir capacity of no less than 1000 ML.

Use: major storage

Source: Australian Water Resources 2005

Source: (NWC 2007)

lateral flow

Radial leakage away from a basin that occurs at shallow depth, top 4-5 m of soil.

Source: (toolkit 20091023)

lateral throughflow

Relatively rapid subsurface flow through cracks, pipes, macropores in the soil. Also referred to as lateral subsurface flow and interflow. Water that infiltrates the soil surface and then moves laterally through the upper soil horizons towards the stream channels, either as unsaturated flow, or more usually, as shallow perched saturated flow above the main groundwater level.

Source: (Welsh, Podger 2008)

Source: (Ward and Robinson 1990)

leaching

The passage of water past the plant root zone causing the flushing of accumulated salts from the root zone. (Can be induced by application of more irrigation water than is needed to supply the plant evapotranspiration requirement).

Source: (ANCID 2001)

Source: (NWC 2007)

leaching fraction

The fraction of infiltrated irrigation water that percolates below the plant root zone. For this unit to be meaningful, it needs to specify the time over which the leaching fraction is measured and the depth interval over which it is calculated.

Source: (ANCID 2001)

Source: (NWC 2007)

leakage

The process by which water from the basin moves through the floor of the basin to the soil below

Source: (toolkit 20091023)

leakage rate

The amount of water that leaks from a basin in a given time. Leakage rate may be given in volumetric units (m3/day or ML/yr) or per unit area (mm/day or ML/ha/yr).

Source: (toolkit 20091023)

lease of a water allocation (Qld)

The passing of the benefits and responsibilities associated with ownership of the allocation to another person for a fixed period. The lease of a water allocation must be registered on the Water Allocations Register.

Source: (NWC 2007)

left bank

Left side bank of a channel or drain when looking in the direction of flow.

Source: (ANCID 2001)

Source: (NWC 2007)

level of development

Ranges of water access entitlements as a percentage of sustainable yield.

Source: (NWC 2007)

levels of evidence

A ranking system used [in evidence-based medicine] to describe the strength of the results measured in a [clinical trial or] research study. (Wikipedia, http://en.wikipedia.org/wiki/Levels_of_evidence, accessed on 3 Nov. 2010.)

life cycle cost

The total cost incurred to construct, operate, maintain and replace an asset over a given time frame.

Source: (toolkit 20091023)

limited period transfer (Tas)

Enables a licensee to transfer part or all of a licence or water allocation for a limited period of time (equivalent to a lease). The length of time for such a transfer is governed by the time remaining before the expiry of the seller's water licence or the allocation. The purchaser will require a new water licence or a variation to an existing licence before the transfer can proceed. At the end of the "lease", the control of the licence and/or water allocation automatically reverts to the transferor.

Source: (NWC 2007)

limited term transfer (Vic)

The transfer of the whole of the right to future water allocations under a share for a period of not more than 20 years to the owner or occupier of land specified in a water-use licence or water-use registration.

Source: (NWC 2007)

link

Links represent river reaches but there are some important differences. A reach refers to a physical section of a river, while a link is is a logical connection within a Source model. A link will sometimes be defined as having zero length (to conveniently represent certain processes), which is not possible for a reach. Links act to store water and to route or process water and constituents passing between nodes and may represent sub-catchment processes.

Source: River Systems specification

A node model available in Source. The Loss node model describes the amount of water that is lost from a point in the stream network. Losses may include physical processes such as transmission losses due to evaporation and seepage, or may be used to represent losses associated with measurement error in the data used to develop the model, such as flow-measurement uncertainty. The Loss model is a conceptual model.

Source: (eWater CRC 2010a)

low level of development

Sum of water access entitlements is less than 30 per cent of sustainable yield.

Source: (NWC 2007)

Source: Australian Water Resources 2005

lower bound pricing

The level at which to be viable, a water business should recover, at least, the operational, maintenance and administrative costs, externalities, taxes or tax equivalent regimes (not including income tax), the interest cost on debt, dividends (if any) and make provision for future asset refurbishment/replacement. Dividends should be set at a level that reflects commercial realities and stimulates a competitive market outcome.

Source: National Water Initiative

Source: (NWC 2007)

lower bound pricing (WA)

The level at which to be viable, a water business should recover, at least, the operational, maintenance and administrative costs, externalities, taxes or TERs (not including income tax), the interest cost on debt, dividends (if any) and make provision for future asset refurbishment/replacement. Dividends should be set at a level that reflects commercial realities and stimulates a competitive market outcome.

Source: (NWC 2007)

lumped routing

Models the movement of constituents based upon the kinematic wave velocity in a link division. Lumped routing is less computationally intensive and more applicable for determining constituent loads at a larger temporal resolution.

M

macrophyte

A large plant including macroscopic algae, mosses, ferns and flowering plants; a term commonly used to differentiate large plant from microscopic plants. Sometimes also used to describe aquatic macrophytes; see aquatic macrophytes, emergent aquatic macrophytes, submerged aquatic macrophytes.

Source: (toolkit 20091023)

main channel

A channel whose primary purpose is to convey bulk water from headworks storage or river diversion points into the distribution system.

Use: channel

Source: (ANCID 2001)

Source: (NWC 2007)

main pipelines

A supply pipeline whose primary purpose is to deliver water from storage or river into the distribution system.

Source: (ANCID 2001)

Source: (NWC 2007)

major extracted water storages

Major off-river storages that primarily store water extracted from rivers or aquifers, or from flood water emanating from rivers.

Source: Australian Water Resources 2005

Source: (NWC 2007)

major on-stream storages

Major storages on defined watercourses.

Source: Australian Water Resources 2005

Source: (NWC 2007)

major storage

Storages greater than 1000 megalitres in volume are considered to be major storages for the purposes of the water balance.

Source: Australian Water Resources 2005

Source: (NWC 2007)

manual calibration

The process of model calibration where parameter values are adjusted manually by trial and error within physically defensible ranges, based on the judgement of the modeller, to obtain a match between model results and observed data that is robust and fit for purpose. The resultant set of parameter values may or may not be unique (see âequifinalityâ) and may or may not represent a local or global optimum.

Source: (James & Burgess 1982)

marginal cost

Marginal cost is defined as the change in total cost per unit increase in output. It is the cost of producing an additional unit of output.

Source: (toolkit 20091023)

marginal revenue

Marginal revenue is the change in total revenue per unit increase in output

Source: (toolkit 20091023)

marker routing

Models the movement of constituents based upon the average water velocity in a link division. Marker routing provides greater resolution in modelling constituent concentration as it captures constituent âspikesâ, and is useful for forecasting impacts of management decisions on constituent concentrations

mass balance

Equation based on the principle that water mass is preserved in the river system. Used to determine whether a model has been calibrated properly. In simple terms: Change in Storage = Inflows - Outflows

Source: (anonymous 2009)

matric potential

A variable describing how strongly the water within a soil matrix is bound to the soil by capillary and other forces.

Source: (ANCID 2001)

Source: (NWC 2007)

maximum allowable depletion

The maximum level of depletion to which the soil can dry without causing water deficit stress in a crop that has a fully expanded root zone. Notionally, the sum of the readily available water in each soil horizon within the plant root zone with an allowance made for the soil water extraction pattern of the crop. Also called A depletion.

Source: (ANCID 2001)

Source: (NWC 2007)

maximum order constraint node

A node model available in Source. Maximum order constraint nodes adjust orders to ensure that flows do not exceed a contraint in a river system.

measurement

A value in a time-series file, typically in megalitres per day.

measurement errors

Errors in the observed data that are a function of human or instrumental error during collection. Such errors may be independent or random. When a persistent bias or mis-calibration is present in the measurement device, measurement errors may be correlated among observations. In some disciplines, measurement error may be referred to as observation error.

Source: (USEPA-CREM)

measurement flume

A section of concrete channel flume with specially shaped sidewalls and/or floor that forms a constriction in the waterway. Measurement of the difference in water surface levels through the constriction allows calculation of water flow rate by referral to rating tables calibrated for the site. Particular types of measurement flume include the Parshall and Venturi flumes.

Source: (ANCID 2001)

Source: (NWC 2007)

mechanistic model

A model that has a structure that explicitly represents an understanding of physical, chemical, and/or biological processes. Mechanistic models quantitatively describe the relationship between some phenomenon and underlying first principles of cause. Hence, in theory, they are useful for inferring solutions outside of the domain that the initial data was collected and used to parameterise the mechanisms.

Source: (USEPA-CREM)

megalitre

1,000,000 litres.

Source: (NWC 2007)

memorial (WA)

Information recorded on a Water Access Entitlement prohibiting dealings on that Water Access Entitlement.

Minor off-river storages (eg farm dams, turkeyâs nest dams) that primarily store water extracted from rivers or aquifers, or from flood water emanating from rivers.

Source: Australian Water Resources 2005

Source: (NWC 2007)

minor on-stream storages

Small storages (farm dams) on minor watercourses.

Source: Australian Water Resources 2005

Source: (NWC 2007)

minor storages

Storages less than 1000 megalitres in volume are considered to be minor storages for the purposes of the water balance.

Source: Australian Water Resources 2005

Source: (NWC 2007)

mitigation water requirements (WA)

Elements of the water regime that are identified to improve diminished water quality resulting from land use practices and developments in the catchment.

Source: (NWC 2007)

model

A simplification of reality that is constructed to gain insights into select attributes of a physical, biological, economic, or social system. A formal representation of the behaviour of system processes, often in mathematical or statistical terms. The basis can also be physical or conceptual.

Source: (USEPA-CREM)

model application

Application of a fit for purpose model to address a real world problem such as supporting natural resource management decision making.

Source: (CRCCH 2005)

model code

The mathematical representation of a conceptual model in the form of a functioning computer program.

Source: (Beven 2004)

model coding

The process of translating the mathematical equations that constitute the model framework into a functioning computer program.

Source: (USEPA-CREM)

model development

The conceptualisation, specification in mathematical terms, coding, testing and verification of a modelling tool, with the end product intended to be model code which is ready to be implemented and applied to addressing real world problems.

Source: (CRCCH 2005)

Uncertainty related to the hypotheses that underlie the model itself and the model structure.

Source: (Grayson and Bloschl, 2001)

moderate level of development

Sum of water access entitlements is between 30 per cent and 70 per cent of sustainable yield.

Source: (NWC 2007)

Source: Australian Water Resources 2005

modes

Manner in which a model operates. Models can be designed to represent phenomena in different modes. Prognostic (or predictive) models are designed to forecast outcomes and future events, while diagnostic models work âbackwardsâ to assess causes and precursor conditions.

Source: (USEPA-CREM)

modified soil mix

To improve the slope stability, erosion resistance and permeability of the soil being used in the channel construction (in-situ or imported), soil may be treated or mixed with relatively small quantities of substances such as lime, cement, gypsum, and certain chemicals to overcome their natural deficiencies.

A modelling approach used when there are multiple paths from storage to demand. This includes the situations where an order can be supplied from two or more water storages, or can be routed via alternate paths such as anabranches or channels. Rules for river operation also need to be satisfied when deciding which storage(s) an order should be met from and which path to utilise for delivery. A network linear program is used to select the optimal combination of storages and paths while meeting operations constraints.

multistage flash

A series of distillation processes used to remove salt from seawater to produce water of drinking quality.

Source: (toolkit 20091023)

N

natural channel storage

Volume of water in river channels. Includes the instantaneous volume of moving water, and any water in weirs which are not classed as major on-river storages or minor on-stream dams.

Source: (Bertsekas 1991)

network phase

The fifth phase of execution within a time-step. During the network phase, the order of execution through the node-link network is determined. The user can view and change this information if required.

Source: (Holz, 2010)

network supply service

An individual rural water supply service that is dependent on a supply network and is provided to customersâ properties at an agreed and specified level of service and common price, which may allow for differentiated service standards or prices, but which is commonly available to customers and which confers common obligations on customers with properties served by the supply network. In some circumstances, drainage (typically surface drainage) may be included as part of the supply service rather than being defined as a separate service.

Source: (NWC 2007)

Source: (National Performance Framework 2006-07)

node

Nodes represent a class of model within Source that modifies flows and/or constituent loads at a point on a river system where certain processes occur. For example water can beadded, extracted, stored, recorded, or have a change in ownership. The node type identifies the rules and parameters that are used by the model to simulate the relevant processes at a given location.

Source: (Stanley, K. 2007)

node-link network

A node-link network is a simplified representation of a river system for use in computer simulation modelling.

noise

Inherent variability that the model does not characterise.

Source: (USEPA-CREM)

O

oasis effect

on-farm storage

A large private water storage off the mainstream, eg on an irrigation property, such as a cotton farm. Some are formed by modifying billabongs but usually they are constructed at any convenient location on the property.

Source: (Welsh, Podger 2008)

on-site system

Sewage treatment equipment for converting household effluent to materials suitable for local disposal, eg septic systems, grease traps, composting toilets and household sewage treatment plants.

Source: (toolkit 20091023)

operation loss

The volume of water released from a dam to meet irrigator water orders that is subsequently not diverted by the irrigators. This occurs when irrigators reject their ordered water because local rainfall has met their water needs since a water order was placed. This âlossâ also includes an allowance for operator uncertainty in predicting how the river system as a whole will behave during the time the release water takes to travel from the dam to the users.

Source: (Welsh, Podger 2008)

options contract

A contract that gives the right, but not the obligation, to purchase or sell a good at a specified price within a specified period of time.

Source: (Productivity Commission 2006)

Source: (NWC 2007)

order time

The number of days in advance that an order has to be made to ensure that the ordered water arrives on time.

Source: (Stanley, K. 2007)

ordering phase

The fourth phase of execution within a time-step. In a regulated system, during the ordering phase Source begins at the most downstream end of the system and accumulates any orders as it passes back up the system. It takes into account any losses and forecast inflows, as well as making adjustments to orders if necessary at any minimum or maximum flow nodes. Orders are directed to specific storages where subsequent releases are made. Various ordering methods can be specified including: 1. Optimised multiple supply (NetLP); 2. Algorithm; 3. Network costs; and 4. Rules-based. In unregulated rivers, orders are compared with forecast inflows. If there is insufficient inflow to meet the orders then the available water is distributed between used according to specified rules.

Source: eWater CRC

Source: (Podger 2011)

Source: (Holz, 2010)

other supply

A type of network supply or regulated surface diversion service where customers are supplied on the basis of a roster determined by the rural water delivery agency, or the right to access water at any time subject to availability and threshold conditions. Roster periods may be varied according to different supply and demand circumstances or may be one off in nature, such as for an annual dam filling schedule for a gravity non-irrigation network supply service. Restrictions or rostering may apply in stages and in the most severe circumstances be a total ban on the taking of water.

Source: (NWC 2007)

Source: (National Performance Framework 2006-07)

outfall structure

Regulating structure located at the downstream end, or intermediate points, of a supply channel to allow safe discharge of surplus flows arising in the system due to the effects of rainfall inflow, planned channel shutdown or operational error. An outfall can also be used to drain water from the channel at the end of the irrigation season. Water released through the outfall is usually discharged to a drainage channel, natural waterway or regulating storage.

Source: (ANCID 2001)

Source: (NWC 2007)

outflow

The average flow rate out of a link or river reach during a time-step.

Source: River Systems specification

over order factor

The factor by which water orders in an IQQM model need to be increased to account for operational inefficiencies in a water supply scheme. This factor does not account for transmission losses.

Source: (Stanley, K. 2007)

over-fitting

Calibrating a model to the point where goodness of fit statistics for the calibration period are maximised/optimised but the calibrated model is not robust when used with input data for other periods.

Source: (Good & Hardin 2006)

Source: (CRCCH 2005)

overallocation

There is an overallocation for a water resource plan area if, with full development of water access right in relation to the water resources of the area, the total volume of water able to be extracted by the holders of water access rights at a given time exceeds the environmentally sustainable level of take for those water resources.

Source: (NWC 2007)

Source: Water Act 2007

overallocation (WA)

Refers to situations where with full development of water access entitlements in a particular system, the total volume of water able to be extracted by entitlement holders at a given time exceeds the environmentally sustainable level of extraction for that system.

Source: (NWC 2007)

overbank flow

Water which flows out of a river channel onto floodplains or into billabongs and wetlands during high flows. Some of this water will not return to the river when water levels subside as it goes into storage.

Source: (Welsh, Podger 2008)

overdraw

A portion of next water yearâs reserved water in a regulated system that can be used in the present water year.

Source: (Welsh, Podger 2008)

overfall weir

A channel regulator where water flows over a weir crest which can be varied in level for changing flow rates.

Source: (ANCID 2001)

Source: (NWC 2007)

overland flow

Surface runoff, which is caused when either, the ground surface is impervious, the underlying soil is saturated and cannot accommodate any more water, or because the intensity of rainfall is greater than the soilâs capacity to infiltrate it.

Source: (Welsh, Podger 2008)

overturn

An inversion process in water-bodies, where the cooler, deeper layers rise towards the surface.

Source: (toolkit 20091023)

overuse

There is an overuse for a water resource plan area if the total volume of water actually taken for consumptive use from the water resources of the area at a given time exceeds the environmentally sustainable level of take for those water resources. Note: An overuse may arise for a water resource plan area if the area is overallocated, or if the planned allocation for the area is exceeded due to inadequate monitoring or accounting.

Source: (NWC 2007)

Source: Water Act 2007

overused (WA)

Refers to situations where the total volume of water actually extracted for consumptive use in a particular system at a given time exceeds the environmentally sustainable level of extraction for that system. Overuse may arise in systems that are overallocated, or it may arise in systems where the planned allocation is exceeded due to inadequate monitoring and accounting.

Source: (NWC 2007)

owner

1. An entity that owns a share of water in a river system. 2. An entity (a state) that owns a parcel of water and has the location of that water tracked as it moves through a river system. An owner is associated with a resource assessment system.

Source: (anonymous 2009)

Source: River Systems specification

ownership phase

The seventh phase of execution within a time-step. In this phase any distribution between owners is calculated and owners' accounts are updated.

Source: (Podger 2011)

ozone

A blue gas with a pungent odour; a highly reactive oxidising agent, produced by passing an electric discharge through oxygen or air, used in the disinfection and purification of polluted water.

The surface in a perched aquifer at which the pore pressure is atmospheric.

Source: (ANCID 2001)

Source: (NWC 2007)

perfect information

The state of information where there is no uncertainty. The current and future values for all parameters are known with certainty. The state of perfect information includes knowledge about the values of parameters with natural variability.

Source: (USEPA-CREM)

permanent pool

The level of water retained within a basin below the invert of the lowest outlet structure

Source: (toolkit 20091023)

permanent transfer

Permanent transfer of a water entitlement (licence to take water) from one licensed user to another.

Source: (Welsh, Podger 2008)

permanent wilting point

The soil matric potential below which plants wilt and fail to recover, even when placed in a humid chamber. This soil matric potential is usually estimated to be - 1.5 MPa.

Source: (ANCID 2001)

Source: (NWC 2007)

permeability

The measure of the ability of a rock, soil or sediment to transmit a fluid. The magnitude of the permeability depends largely on the porosity and the connectedness of pores spaces.

Source: (ANCID 2001)

Source: (NWC 2007)

phenology

The study of periodic plant and animal life cycle events and how these are influenced by seasonal and interannual variations in climate. (Wikipedia, http://en.wikipedia.org/wiki/Phenology, accessed on 11 Jan. 2011.)

piezometer

A non-pumping well, generally of small diameter, that is used to measure the elevation of the watertable or potentiometric surface. A piezometer generally has a short well screen through which water can enter.

Source: (ANCID 2001)

Source: (NWC 2007)

pipe

A closed conveyance or carrier regardless of material, size or shape which conveys water typically for supply service. It is also a buried perforated carrier to collect subsurface drainage water.

Source: (National Performance Framework 2006-07)

Source: (NWC 2007)

piped sub-surface drainage service

A drainage service which collects and removes excess groundwater through a series of collector pipes.

Source: (NWC 2007)

Source: (National Performance Framework 2006-07)

piston-flow

The process by which leakage from the basin displaces all soil water and groundwater from areas into which it flows. No mixing or diffusion with existing water is considered to take place.

Source: (toolkit 20091023)

planted area

The area that an irrigation farmer plants in a season. The planted area may be reduced during the season if there is not enough water available to service the whole of the initially planted area.

Source: (Welsh, Podger 2008)

plug flow

Flow conditions where all âparcelsâ of inflow have the same detention time. In this document this term is also used to describe flow conditions where a constant detention time is achieved, but is less than maximum (Q/V) because of ineffective flow volume, ie âapparentâ plug flow.

Source: (toolkit 20091023)

plugin

A component model or tool that can be incorporated into Source Catchments. Usually in the form of .dll or .exe files.

point potential evapotranspiration

The ET that would take place, under the condition of unlimited water supply, from an area so small that the local ET effects do not alter local air mass properties. It is assumed that latent and sensible heat transfers within the height of measurement are through convection only. For example, this represents the evapotranspiration which would occur from small irrigated fields with a never-ending water inflow, surrounded by unirrigated land. Point potential ET may be taken as a rough preliminary estimate of evaporation from small water bodies such as farm dams and shallow water storages.

Source: (Chiew 2002)

pollute

To make foul or unclean; dirty.

Source: Macquarie Dictionary

Source: (NWC 2007)

pond

A small artificial body of open water (ie dam or small lake).

Source: (toolkit 20091023)

pondage test

A water balance approach to measuring channel seepage within an isolated reach of channel. A section of channel is blocked off with embankments and the section filled with water. The seepage rate is calculated from the rate of water drop after corrections are made for evaporation and rainfall.

power of attorney (WA)

Gives authority to another person to act on an individual's behalf. The document should state what powers this person has and for what time length. The Transfer of Land Act contains a schedule (19th) form, which must be used and closely followed, to deal in land it is anticipated that this will also apply to Water Access Entitlements.

Source: (NWC 2007)

pre-resource assessment phase

The third phase of execution within a time-step. In this phase account balances are adjusted prior to ordering to take account of any resource allocation rules, or accounting requirements.

Source: (Podger 2011)

precast concrete

Concrete that is cast into its final shape before positioning.

Source: (Moore 2004)

precautionary principle

The precautionary principle is that lack of full scientific certainty should not be used as a reason for postponing a measure to prevent degradation of the environment where there are threats of serious or irreversible environmental damage.

Source: (NWC 2007)

Source: (EPA 1999)

precipitation

Rain, snow, hail, sleet, dew.

Source: (Welsh, Podger 2008)

precision

The quality of being reproducible in amount or performance. With models and other forms of quantitative information, precision refers specifically to the number of decimal places to which a number is computed as a measure of the âprecisenessâ or âexactnessâ with which a number is computed.

Source: (USEPA-CREM)

predictive modelling

Applying a model to analyse scenarios representing the past, the present or possible future options.

Source: (CRCCH 2005)

predictive uncertainty

Uncertainty in prediction of hydrological responses associated with: uncertainty in the input data due to sampling or interpolation error; uncertainty in simulated responses due to errors in model parameter values; and uncertainty related to the hypotheses that underlie the model itself and the model structure.

Source: (Hill and Tiedeman, 2007)

preferential flow

The process by which leakage from the basin does not pass through the entire soil matrix. Sometimes referred to as bypass flow.

Source: (toolkit 20091023)

preliminary treatment

The first processes used in a sewage treatment plant, involving screening to remove gross solids, rags and plastic and the settling of sand and grit particles.

Source: (toolkit 20091023)

pressurised network supply service

Any raw water supply service from a supply network where the minimum design residual pressure head at more than 95% of customer service points is greater than or equal to 3 metres.

Source: (NWC 2007)

Source: (National Performance Framework 2006)

primary treatment

The first major treatment process in a sewage treatment facility, principally designed to remove a substantial amount of suspended matter, but little or no colloidal or dissolved matter. Typical primary sewage treatment processes may include clarification (with or without chemical treatment, to accomplish solid-liquid separation), grease removal and screens.

project management

Planning, monitoring and control of all aspects of a project and the motivation of all those involved in, the aim being to achieve the project objectives on time and to the specified cost, quality and performance.

Source: (PMI 2008)

property connection sewer

A short sewer, owned and operated by the sewerage agency, which connects the main sewer and the customer sanitary drain. It includes a junction on the main sewer, a property connection fitting, a vertical riser (in some cases) and sufficient straight pipes to ensure the property connection fitting is within the lot to be serviced.

Source: (National Performance Framework 2006)

Source: (NWC 2007)

property service

Includes any water infrastructure between the water main and the internal plumbing of the property. It may be owned by the water business, and is often referred to as the âmains to meterâ service or connection. All waterplumbing downstream of the meter is usually the property ownerâs asset.

Source: (National Performance Framework 2006)

Source: (NWC 2007)

protected catchment

An area upstream of a water storage in which human activity is not permitted or is restricted so as to protect water quality values

Source: (toolkit 20091023)

protozoa

Single-celled organisms including amoebae, ciliates and flagellates, free-living in aquatic habitats, sometimes pathogenic

Source: (toolkit 20091023)

provisional cap

A cap that recognises that the level of entitlement may be raised in the future.

Source: (NWC 2007)

Source: Australian Water Resources 2005

Flow of surface water from a given area resulting from the effects of rainwater and/or applied irrigation water in excess of crop water requirement and leaching.

Source: (ANCID 2001)

Source: (NWC 2007)

rainfall runoff harvesting

Water from a rainfall event that is harvested on irrigation farms via a water recirculation system.

Source: (Welsh, Podger 2008)

rainfall runoff model

A model that generates runoff from rainfall and other climatic inputs (often potential evaporation and sometimes temperature). In Source rainfall runoff models operate at the scale of the FU or sub-catchment.

rainfall volume on storage

The volume of rainfall over a period of time on the storage water surface.

Source: Water Resources Observation Network

Source: (NWC 2007)

raw sewage

Untreated liquid waste entering a sewage treatment plant through a system of pipes, collected from domestic and industrial sources.

Source: (toolkit 20091023)

raw water

Untreated water from a storage, stream or aquifer destined for treatment for domestic and industrial uses.

Source: (toolkit 20091023)

reach

A length of channel between two points.

Source: (ANCID 2001)

Source: (NWC 2007)

reach dead storage

The storage in a river reach that does not contribute to outflow from that reach.

Source: River Systems specification

reach length

The distance along the river reach.

Source: River Systems specification

reach storage

The volume of water stored in a river reach, which is a function of reach dead storage and flow in the reach.

Source: River Systems specification

reach width

The average river reach surface width at a specific flow or storage volume. This information is used to calculate the surface area of the reach by multiplying by the reach length.

Source: River Systems specification

reactor tank

A vessel of steel or concrete in which chemical and biological processes occur to remove biodegradable organic material by bacterial digestion and to reduce nutrient levels, during sewage treatment.

Source: (toolkit 20091023)

readily available water

Water that can be removed from a soil horizon by a crop without resulting in water deficit stress. This is often estimated to be half the âtotal available waterâ.

Source: (ANCID 2001)

Source: (NWC 2007)

receiving water

A river, estuary or ocean site into whose waters treated effluent is discharged

Source: (toolkit 20091023)

recession

The falling limb of a hydrograph.

Source: (Stanley, K. 2007)

reclaimed water

Wastewater that has been recently treated to a standard sufficient to enable it to be recycled for some specific use

Source: (toolkit 20091023)

recycled water

Treated effluent that is used by either the water utility itself, a business supplied by the water utility, or supplied through a third pipe system or urban reuse. Recycled water can be provided for onsite reuse, agriculture, irrigation,industry, potable or other use external to the treatment process.

Source: (National Performance Framework 2006)

Source: (NWC 2007)

reduced water level

Groundwater levels given with respect to height above sea-level (ie a given metres above Australian Height Datum, mAHD).

Source: Australian Water Resources 2005

Source: (NWC 2007)

reducible uncertainty

Uncertainty in models that can be minimised or even eliminated with further study and additional data. See data uncertainty.

Source: (USEPA-CREM)

reference crop evapotranspiration

The evapotranspiration rate from a reference surface, not short of water, is called the reference crop evapotranspiration or reference evapotranspiration and is denoted as ETo. The reference surface is a hypothetical grass reference crop with specific characteristics.

Source: (Allen et al 1998)

regional natural resource management plans

Plans that cover specific regions like those developed under the Natural Heritage Trust and the National Action Plan for Salinity and Water Quality.

Source: (NWC 2007)

Source: National Water Initiative

regional natural resource management plans (WA)

Plans that cover specific regions like those developed under the Natural Heritage Trust and the National Action Plan for Salinity and Water Quality.

Source: (NWC 2007)

regional-scale basins

Basins that accept drainage water from multiple farms and irrigation districts and/or sited outside the districts themselves.

Source: (toolkit 20091023)

regulated flow

Water that is released from storage to meet downstream requirements.

Source: (Welsh, Podger 2008)

regulated resource assessment system

A way of characterising a resource assessment system based on its resource type.

regulated river

The section of river that is downstream of a major storage from which supply of water to irrigators or other users can be regulated or controlled. In NSW these storages and rivers are operated by State Water and the regulated rivers are designated by legislation.

Source: (Welsh, Podger 2008)

regulated river network

A water supply network which at its simplest may comprise a single structure such as a dam, which provides storage and the ability to regulate or control river flows, but which may comprise many structures and multiple connected regulated rivers or streams. A regulated river network would typically provide a regulated river's commercial or urban supply customers.

Source: (NWC 2007)

Source: (National Performance Framework 2006-07)

regulated river section

A section of river that is operated to manage regulated water using a set of storages and expected inflows. Regulated users in a regulated system can order water from different storages. The water available to each regulated user is determined by rules on their licences and rules used to operate the system. There can be unregulated water and unregulated users in a regulated river section.

Source: eWater CRC

regulated river supply service

A rural raw water supply service that is dependent on assets such as dams, weirs and bulk carriers and is provided at customer service points at an agreed and specified level of service and common price, which may allow for differentiated service standards or prices, but which is commonly available to customers and confers common obligations on customers. This service excludes issuing and administration of licences and may or may not include activities related to water ordering, metering and measurement. This service does not apply to any agency in South Australia in relation to the River Murray in South Australia, where the storage releases occur in the upper states in accordance with the provisions of the Murray Darling Basin Agreement.

Source: (NWC 2007)

Source: (National Performance Framework 2006-07)

regulated surface diversion service

A drainage surface diversion service that enables customers to pump or divert from a surface water source, typically a river that is regulated or controlled by a structure or structures operated by a rural water delivery agency.

Source: (NWC 2007)

Source: (National Performance Framework 2006-07)

regulated system

River system where the flow of the river is regulated through the operation of large dams or weirs.

Source: Australian Water Resources 2005

Source: (NWC 2007)

remote sensing

Any kind of data recording by a sensor which measures energy emitted or reflected by objects located at some distance from the sensor (ie no direct ground contact).

Source: (ANCID 2001)

Source: (NWC 2007)

A geophysical technique used to measure the apparent resistivity of the sub-surface by applying a direct current to the ground and measuring the resultant ground potential and current in the vicinity of the applied current.

reuse water

Re-using water that would otherwise be wasted instead of using fresh water. Reuse water includes wastewater, stormwater, rainwater, and greywater.

Source: (National Performance Framework 2006)

Source: (NWC 2007)

reverse osmosis

A membrane filtration process that allows only the passage of water; can be used for desalination or where water of high purity is required.

Source: (toolkit 20091023)

rhizomateous

The pattern of plant growth originating from an underground stem-like root system

Source: (toolkit 20091023)

riffle

A fast flowing, turbulent portion of a stream or river, where the water is shallow, well-aerated and the surface broken by rocks, stones or gravel.

Source: (toolkit 20091023)

right bank

Right side bank of a channel or drain when looking in the direction of flow.

Source: (ANCID 2001)

Source: (NWC 2007)

ring tank

An off-stream storage, filled by pumping during periods of high flow in the stream.

Source: (toolkit 20091023)

riparian zone

The zone adjacent to streams and rivers; usually there is some exchange of water and nutrients between this zone and the stream. An area or zone within or along the banks of a stream or adjacent to a watercourse or wetland; relating to a riverbank and its environment, particularly to the vegetation.

Source: (Welsh, Podger 2008)

rising mains

are small excess flows (which are generated by local rainfall) in the unregulated tributaries of the Murray upstream of the forest.

Source: (toolkit 20091023)

sales water (Vic)

Lower-reliability water offered to irrigators on a seasonal basis, in proportion to their base rights, after provision has been made to meet the base rights in the following year.

Source: (Victorian Water Accounts 2008-2009)

saline disposal basins

Man-made or natural shallow depressions used for the disposal of saline water. Often referred to as evaporation basins.

Source: (toolkit 20091023)

saline groundwater

Groundwater that exceeds a salinity concentration of 3500 milligrams per litre.

Source: Australian Water Resources 2005

Source: (NWC 2007)

salinity

The concentration of soluble salts in a solution, soil or other medium

Source: (toolkit 20091023)

salt export

The process in which saline water is transported outside the irrigation area in which it originated

Source: (toolkit 20091023)

salts

Chemical compounds that dissolve in water to form a cation and an anion, eg sodium chloride

Source: (toolkit 20091023)

saturated zone

The zone in which the voids in the rocks or soil are filled with water at a pressure greater than atmospheric. The watertable is the top of the saturated zone in an unconfined aquifer.

Typically, a biological treatment process that is designed to remove approximately 85 per cent of the Biological Oxygen Demand (BOD) and influent suspended solids. Some nutrients may incidentally be removed, and ammonia may be converted to nitrate. Typical secondary sewage treatment processes may include sand filtration, disinfection, a polishing step (to lower suspended solids and bacterial levels), activated-sludge processes, anaerobic plus aerobic processes, biological filters and lagoons (aerated, facultative, maturation or polishing).

Source: (NWC 2007)

Source: (National Performance Framework 2006)

sediment delivery ratio

sediment delivery ratio - proportion of eroded sediment actually delivered to streams from sediment source

Source: (toolkit 20091023)

sedimentation

The process whereby suspended particles settle from a water column; the disposition of soil materials as the end-process of erosion.

Source: (toolkit 20091023)

seepage

The movement of water downwards or laterally through soils or permeable rock. This water can originate from a very wide range of sources, including all water bodies and most land surfaces. Seepage water may percolate far enough to reach groundwater.

Source: (Welsh, Podger 2008)

seepage meter

Covered cylindrical infiltrometers modified for use under water. Seepage meters are used for spot measurements of seepage in channels without artificial lining. The most well known seepage meter is the âIdaho Meterâ.

Source: (ANCID 2001)

Source: (NWC 2007)

seepage plume

The horizontal and vertical extent of groundwater which has been mixed with channel seepage water.

Source: (ANCID 2001)

Source: (NWC 2007)

self-extracted water

Water that is extracted by the user (generally in-situ) from either surface waters (streams or dams) or groundwater bores.

Source: (toolkit 20091023)

sequestration

The process of removing carbon from the atmosphere. Generally, sequestration is achieved through establishing tree plantations; however it can also be accomplished by other means, including chemical treatment and deep ocean air injection.

Source: (National Performance Framework 2006)

Source: (NWC 2007)

settling tank

A container of water or wastewater in which solid matter in suspension forms a sediment or sludge for later removal, while the liquid flows on to the next step of the treatment process.

Source: (toolkit 20091023)

sewage

The waste matter which passes through sewers. Wastewater of domestic or industrial origin to be treated at a sewage treatment plant.

Source: Macquarie Dictionary

Source: (NWC 2007)

Source: (toolkit 20091023)

sewer

An artifical conduit, usually underground, for carrying off waste water and refuse, as from a town or city.

Source: Macquarie Dictionary

Source: (NWC 2007)

sewer reticulation main

Sewer reticulation mains include all gravity sewer mains, all pressure mains (including common effluent pipelines, rising mains etc) and all vacuum system mains of any diameter. This excludes property connection sewers and pipelines carrying treated effluent.

Source: (National Performance Framework 2006)

Source: (NWC 2007)

sewerage

The system of pipes and pumps used to collect and transport sewage to, and the equipment used to treat and discharge effluent from, a sewage treatment plant.

Source: (toolkit 20091023)

sharing delivery capacity

An approach to sharing of an irrigation supply channel capacity (supplemented systems) or a water course capacity (unsupplemented) held by an entitlement holder and specified as a percentage share or volumetric supply rate at a particular time.

Source: (NWC 2007)

Source: National Water Initiative

Represent the development of a solution by incremental steps through the model domain. Simulations are often used to obtain solutions for models that are too complex to be solved analytically. For most situations, where a differential equation is being approximated, the simulation model will use finite time step (or spatial step) to âsimulateâ changes in state variables over time (or space).

Source: (USEPA-CREM)

siphon tube

Small flexible pipe used to discharge water from a farm channel on to land using siphonic action.

Volume of water held as snow.

Source: (Sinclair, Knight, Merz 2006)

Source: (NWC 2007)

social water requirements (WA)

Elements of the water regime that are identified to meet social (including cultural) values.

Source: (NWC 2007)

soft water

Water that contains less than 200 mg/L CaCO3, lathers readily with soap or detergents.

Source: (toolkit 20091023)

soil sealants

Soil sealants are either natural or artificially processed materials that can be either injected into water, mixed into the soil, sprayed onto the soil or injected into the subsoil to reduce the channel seepage losses and increase soil stability.

Source: (ANCID 2001)

Source: (NWC 2007)

soil water

Water in the unsaturated zone in the soil profile

Source: (Sinclair, Knight, Merz 2006)

Source: (NWC 2007)

soundness

One of EPAâs five Assessment Factors (see definition) that describes the extent to which the scientific and technical procedures, measures, methods or models employed to generate the information are reasonable for and consistent with, the intended application.

Source: (USEPA-CREM)

special levies

Special levies are any charges that are directly levied upon properties, and are neither a fixed or pay for use charge for water or sewage (eg environmental improvement levy).

Source: (NWC 2007)

Source: (National Performance Framework 2006)

specifications

Acceptance criteria set at the onset of a quality assurance plan that help to determine if the intended objectives of the project have been met. Specifications are evaluated using a series of associated checks (see definition for checks).

Source: (USEPA-CREM)

spillway

The construction beside or in the wall of a dam to allow overflow during periods when intake exceeds storage capacity.

Source: (toolkit 20091023)

spillway volume

Volume at the spillway crest level.

Source: Water Resources Observation Network

Source: (NWC 2007)

splitter node

A node model available in Source. A splitter divides water travelling down a single branch into two different branches. Splitters can be used to represent distributaries (a system with multiple end-points), effluents (a split in the river into the main channel and a smaller channel), anabranches (where a smaller section of river branches away from the main channel and then rejoins the main channel further downstream), or losses (where water is leaving the system). There are two kinds of splitter:â¢ a splitter node models the behaviour of a natural system;â¢ a controlled splitter node models the behaviour of a system where the flow down the effluent can be controlled by some kind of regulating structure.

spring

An issue of water from the earth, flowing away as a small stream or standing as a pool or small lake, or the place of such an issue.

Source: Macquarie Dictionary

Source: (NWC 2007)

square kilometre

An area equal to the area of an equilateral rectangle where each side is one kilometre in length.

Source: eWater CRC

stakeholder

An individual or organisation with a vested interest in the long-term success of a project.

Source: (toolkit 20091023)

standing water level

Depth to groundwater (m) below a datum point or reference point, usually from the top of casing or natural surface.

There may be steps in the pay for use charge as usage increases past certain levels, meaning the same charge may not apply to each unit used by the customer. The steps of the pricing structure, usually in kilolitres, are the points where the usage charge applied to each customer changes.

Source: (NWC 2007)

Source: (National Performance Framework 2006)

stochastic

The random variability in the occurrence and magnitude of a parameter (eg, rainfall, streamflow, etc.)

Source: (toolkit 20091023)

stochastic model

A model that includes variability (see definition) in model parameters. This variability is a function of: 1) changing environmental conditions, 2) spatial and temporal aggregation within the model framework, 3) random variability. The solutions obtained by the model or output is therefore a function of model components and random variability.

Source: (USEPA-CREM)

stochastic uncertainty

The random variability in the occurrence and magnitude of an environmental variable (eg, rainfall, streamflow, etc.). This variability may cause stochastic uncertainty.

Source: (Refsgaard et al, 2005b)

stochasticity

Fluctuations in ecological processes that are due to natural variability and inherent randomness.

Source: (USEPA-CREM)

storage behaviour

The time varying change in a water storage status, influenced by rainfall, inflows, outflows and evaporation.

Source: (Welsh, Podger 2008)

storage catchment runoff

The volume of water flowing into storage over a period of time from the catchment between the headwater tributaries and the dam wall and upstream of the storage water surface.

Source: Water Resources Observation Network

Source: (NWC 2007)

storage demand

The volume of water that has been requested to be released from the storage. Note this may be more than the storage release.

Source: Water Resources Observation Network

Source: (NWC 2007)

storage inflow

The volume of water flowing into storage over a period of time that includes upstream tributaries, storage catchment runoff and rainfall on the storage.

Source: Water Resources Observation Network

Source: (NWC 2007)

storage node

A node model available in Source. A storage represents a point in a river system where water is retained until released. A release may be controlled (eg through a valve) or uncontrolled (eg during a spill). Storages operate by maintaining water mass balance.

storage release

The volume of water released to meet downstream demands. Note this may be less than storage demand due to release or operational constraints.

Source: Water Resources Observation Network

Source: (NWC 2007)

storage spill

The volume of water discharged from the storage in excess of the storage demand.

Source: Water Resources Observation Network

Source: (NWC 2007)

stormwater

A sudden, excessive run-off of water following a storm. Surface runoff resulting from excess rainfall, usually passing quickly through a drainage area.

Source: Macquarie Dictionary

Source: (NWC 2007)

Source: (toolkit 20091023)

stormwater management scheme

A holistic approach to managing urban stormwater that incorporates some or all of the following considerations; stormwater drainage, water quality improvements, aquatic habitat protection, stormwater harvesting and use, and landscape amenity

Source: (toolkit 20091023)

stratification

The formation of layers in a water body, showing differences in temperature, turbidity, pH, nutrients, salinity and light penetration at various depths; lack of mixing within a water storage.

Source: (toolkit 20091023)

sub-catchment

Area of land within a catchment; used in specific contexts to distinguish components of a larger catchment.

Source: (Welsh, Podger 2008)

sub-division (Vic)

A water share may be divided by cancelling (or reducing) the share and issuing new water shares.

Source: (NWC 2007)

sub-division (allotment cluster)

A grouping of allotment clusters. For example, a sub-division could represent a new residential housing development consisting of 5 streets, with approximately 20 houses in each cluster â roughly 100 allotments in total.

Source: (Hardy 2009)

sub-reach

A sub-division of a reach for routing purposes.

Source: River Systems specification

sub-surface drainage system

System of drainage collector pipes, wells, ditches and/or pumps designed to intercept and remove excess groundwater so as to control the watertable level to be below the plant root zone. Often designed to exclude or restrict entry of surface drainage and rainfall.

Source: (ANCID 2001)

Source: (NWC 2007)

subartesian water

A confined aquifer containing groundwater that will, if tapped by a bore, not flow naturally to the surface.

A node model available in Source. A supply point node represents a point in a river system where water can be diverted to meet demands.

surety (Tas)

Actual or relative probability with which a water allocation is expected to be available in any year having regard to the natural variability of the supply of water.

Source: (NWC 2007)

surface drainage service

A drainage service which collects and removes irrigation induced excess surface water, generally through surface drains.

Source: (NWC 2007)

Source: (National Performance Framework 2006)

Source: (National Performance Framework 2006-07)

surface drainage system

System of open drainage channels, modified natural waterways and/or storages designed to collect drainage from rainfall and irrigation runoff on rural lands and convey it to disposal. A system may include private, community and public works.

Source: (ANCID 2001)

Source: (NWC 2007)

surface inflow

Water flowing on the surface into an entity from adjoining entities. Includes river flows and overbank flows.

Source: (Sinclair, Knight, Merz 2006)

Source: (NWC 2007)

surface outflow

Water flowing on the surface out of an entity from adjoining entities. Includes river flows and overbank flows.

Source: (Sinclair, Knight, Merz 2006)

Source: (NWC 2007)

surface water

Includes: (a) water in a watercourse, lake or wetland; and (b) any water flowing over or lying on land: (i) after having precipitated naturally; or (ii) after having risen to the surface naturally from underground

Source: Water Act 2007

Source: (NWC 2007)

surface water (WA)

Water flowing or held in streams, rivers and other wetlands on the surface of the landscape. Water courses or artificial channels that is able to be captured and stored and supplemented from dams and reservoirs.

Source: (NWC 2007)

sustainable yield (WA)

The amount of water that can be taken from a water resource system (expressed as an extraction regime) without causing unacceptable impacts.

Source: (NWC 2007)

system flexibility

the degree to which the regulated system can accommodate unseasonal surplus flows, either through airspace at Yarrawonga or flow of the River Murray below bankfull capacity.

Source: (toolkit 20091023)

T

take

To remove water from, or to reduce the flow of water in or into, the water resource including by any of the following means: (a) pumping or siphoning water from the water resource: (b) stopping, impeding or diverting the flow of water in or into the water resource; (c) releasing water from the water resource if the water resource is a wetland or lake; (d) permitting water to flow from the water resource if the water resource is a well or watercourse; and includes storing water as part of, or in a way that is ancillary to, any of the processes or activities referred to in paragraphs (a) to (d).

Source: Water Act 2007

Source: (NWC 2007)

temporary trade

Trade in seasonal water allocations that involves transferring some or all of the water allocated to the entitlement for the current irrigation season or for an agreed number of seasons.

Source: (Productivity Commission 2006)

Source: (NWC 2007)

temporary transfer

Transfer of a volume of water, during a water year, from one licensed user to another.

Source: (Welsh, Podger 2008)

temporary transfer (Tas)

The short term movement (max 21 days) of the right to take water from an allocation to a person who does not hold a licence. In this lease arrangement the water entitlement is retained by the seller and a temporary transfer to a person (who does not require a licence) is permitted to overcome a significant water shortage.

Source: (NWC 2007)

term transfer (NSW)

Fixed term transfer of rights under a licence to another person.

Source: (NWC 2007)

terminal seepage rate

The constant rate of seepage attained once the groundwater mound caused by channel seepage rises to the elevation of the water surface in the channel.

Source: (ANCID 2001)

Source: (NWC 2007)

tertiary treatment

Principally designed to remove nutrients, such as phosphorus (typically <2 mg/L) and/or nitrogen (typically <15 mg/L). A high per centage of effluent suspended solids (typically >95 per cent) are also removed. Tertiary treatment may additionally target other contaminants of concern, eg toxicants and salt. Typical tertiary sewage treatment processes may include biological nutrient removal plants, chemical dosing of secondary plants for nutrient removal (including lagoons), enhanced pond treatment systems for nutrient removal, reverse osmosis and advanced filtration systems, membrane bioreactors and secondary treatment plus grass plots or wetlands for nutrient removal. The further processing of wastewater, which has already had secondary or advanced secondary treatment. Treatment may involve further reduction in nutrient levels, filtration, use of constructed wetlands and higher levels of disinfection, using UV radiation, ozone etc., to inactivate pathogens.

Source: (NWC 2007)

Source: (National Performance Framework 2006)

Source: (toolkit 20091023)

tile drain

A kind of tube drain system with linings constructed from joined slotted plastic pipes or terracotta pipes laid end to end.

Source: (ANCID 2001)

Source: (NWC 2007)

time series

A set of observations arranged in monotonically increasing order of time-stamp. The expression "time series" refers to the abstract concept. In an adjectival situation, use "time-series".

Source: (anonymous 2009)

time series demand

A specific instance of a water user node.

time-series

Source: Australian Water Resources 2005

To emit or give off water vapour through the surface, as of the body, of leaves etc.

Source: Macquarie Dictionary

Source: (NWC 2007)

travel time

Time required for a representative flow to travel along a reach (link).

Source: River Systems specification

treated effluent discharge

Where wastewater treatment plant effluent is not reused, the treated effluent may be disposed to land, evaporative ponds, rivers and other streams or the ocean. For the purposes of the water balance, we are interested only in treated effluent discharged back to rivers and other streams.

Source: Australian Water Resources 2005

Source: (NWC 2007)

treatment train

The sequencing of structural Best Management Practices to achieve optimal flow management and pollutant removal from urban stormwater

Source: (toolkit 20091023)

tributary

A stream that joins another stream or body of water.

Source: (Stanley, K. 2007)

tributary inflow

The volume of water flowing from a tributary river over a period of time.

Source: Water Resources Observation Network

Source: (NWC 2007)

trickling filters

Concrete containers of rocks, over and through which primary-treated effluent passes.

Source: (toolkit 20091023)

tube drain

Buried horizontal pipeline containing openings (or slots) to allow gravity entry of excess groundwater which is then led to a suitable point of discharge or pit.

Source: (ANCID 2001)

Source: (NWC 2007)

U

un-supplemented water (Qld)

A water supply where reliability is not enhanced by the operation of water storage infrastructure.

Source: (NWC 2007)

unaccounted difference node

A node model available in Source. A variant of the gauge node, the unaccounted difference node is used to forecast unaccounted differences. Unaccounted differences functionality can also be used to override modelled data with observed data. This is useful for calibration.

unaccounted for water

The difference between the volume of water entering a reticulated system and the recorded use, due to system leaks and un-metered uses.

Source: (toolkit 20091023)

unbundling

The separating of historic water entitlements which bundled water, land, water use, delivery and works approvals, into separate entitlements or licences.

Source: (Productivity Commission 2006)

Source: (NWC 2007)

uncertainty

The term used in this document to describe lack of knowledge about models, parameters, constants, data, and beliefs. There are many sources of uncertainty, including: the science underlying a model, uncertainty in model parameters and input data, observation error, and code uncertainty. Additional study and collecting more information allows error that stems from uncertainty to be minimised/reduced (or eliminated). In contrast, variability (see definition) is irreducible but can be better characterised or represented with further study. A person lacking confidence about the specific outcomes of an event or action is said to be uncertain. Reasons for this lack of confidence might include a judgement of the information as incomplete, blurred, inaccurate or potentially false or might reflect intrinsic limits to the deterministic predictability of complex systems or of stochastic processes.

Source: (USEPA-CREM)

Source: (Refsgaard et al, 2005b)

uncertainty analysis

Investigates the effects of lack of knowledge or potential errors on the model (e.g, the âuncertaintyâ associated with parameter values) and when conducted in combination with sensitivity analysis (see definition) allows a model user to be more informed about the confidence that can be placed in model results.

Source: (USEPA-CREM)

uncertainty and variability

One of EPAâs five Assessment Factors (see definition) that describes the extent to which the variability and uncertainty (quantitative and qualitative) in the information or in the procedures, measures, methods or models are evaluated and characterised.

Source: (USEPA-CREM)

unconfined aquifer

An aquifer in which there are no confining beds between the saturated zone and the surface. There will be a watertable in an unconfined aquifer.

Source: (ANCID 2001)

Source: (NWC 2007)

undershot gate

A channel regulator where an adjustable sliding gate allowing flows to pass beneath the gate, the rate of flow being controlled by the size of the opening.

Source: (ANCID 2001)

Source: (NWC 2007)

unincorporated areas

Unincorporated areas include any groundwater resources located outside of the groundwater management units for that jurisdiction. Unincorporated areas may be defined on the basis of hydrogeological basin or aquifer type.

Source: (NWC 2007)

Source: Australian Water Resources 2005

unplanned water supply interruption

Occurs when the customer has not received at least 24 hours notification of the interruption. It also includes situations where the duration of a planned interruption exceeds that which was originally notified. In this circumstance the length of the entire interruption is counted. All un-notified interruptions caused by third parties should be included. This differs from the asset performance definition, which excludes interruptions caused by third parties as this is not necessarily a result of asset failure, as the end result is a loss of service to the customer.

Source: (NWC 2007)

Source: (National Performance Framework 2006)

unprotected catchment

The area upstream of a water storage where many types of land uses are allowed, without concern for potential harmful effects on water quality.

Source: (toolkit 20091023)

unregulated resource assessment system

A way of characterising a resource assessment system based on its resource type.

unregulated river section

refers to a section of a river system which is not operated for the purpose of satisfying water requirements. Users in the unregulated river section may or may not be able to extract water depending on licence restrictions, but there is no concept of ordering water. Licence types are usually stock and domestic, small scale irrigation licences or water-harvesting. Unregulated river sections, but not always, sit above regulated river sections in headwater catchments.

Source: eWater CRC

unregulated rivers

All rivers that are not regulated, including rivers where the flow is controlled by dams or weirs constructed by urban water suppliers or private users.

Source: (Welsh, Podger 2008)

unregulated surface diversion service

A drainage surface diversion service that enables customers to pump or divert under specified conditions from a surface water source, typically a stream, that is not regulated or controlled by a structure or structures operated by a rural water delivery agency.

Source: (NWC 2007)

Source: (National Performance Framework 2006-07)

unregulated system

River system where flows are not regulated by the operation of structures such as major dams or weirs.

Source: Australian Water Resources 2005

Source: (NWC 2007)

unregulated water

is either all the water in an unregulated river section, or water in a regulated river section that does not come from a regulated source or does not form part of the regulated supply. For example, if a regulated storage spills and there is water in excess of demand requirements downstream then this excess water is considered to be unregulated water.

Source: eWater CRC

unreinforced concrete

Concrete that is not reinforced.

unsaturated zone

The zone between the land surface and the watertable. The pore spaces contained water at less than atmospheric pressure, as well other gases. Also called âZone of Aerationâ and âVadose Zoneâ.

Source: (ANCID 2001)

Source: (NWC 2007)

unseasonal surplus flows

are generated from river freshes and rain rejection flows. Also referred to as âexcess flowsâ.

Source: (toolkit 20091023)

upper bound pricing

The level at which, to avoid monopoly rents, a water business should not recover more than the operational, maintenance and administrative costs, externalities, taxes or tax equivalent regimes, provision for the cost of asset consumption and cost of capital, the latter being calculated using a weighted average cost of capital.

Source: National Water Initiative

Source: (NWC 2007)

Source: (USEPA-CREM)

variation (SA)

In relation to a licence, to add or remove land where the water may be used, change a purpose, or modify the conditions. (This is the means by which change of location occurs)

Source: (NWC 2007)

variation (Vic)

In relation to a water share, to change the specified water system, or zone within the water system, or reliability class.

Source: (NWC 2007)

verification

Strict tests, such as of model code where analytical and numerical simulations are compared. Should not be used in relation to model testing against real data. Examination of the algorithms and numerical technique in the computer code to ascertain that they truly represent the conceptual model and that there are no inherent numerical problems with obtaining a solution.

Source: (eWater CRC 2008)

Source: (USEPA-CREM)

vertical flow

Leakage away from a basin that occurs vertically through the underlying groundwater.

Source: (toolkit 20091023)

volume

The amount of space that a substance or object occupies, or the amount of space within a container.

volumetric limit (Qld)

The maximum amount of water that may be taken under a water allocation for un-supplemented supply in a water year.

Source: (NWC 2007)

W

wastewater

Water which has been used at least once and hence regarded as unsuitable for immediate reuse for that purpose without treatment; water collected from domestic and industrial sources to be treated prior to discharge to the environment or for recycling for other uses.

Source: (toolkit 20091023)

water

The liquid which in a more or less impure state constitutes rain, oceans, lakes, rivers, etc., and which in a pure state is a transparent, odourless, tasteless liquid, a compound of hydrogen and oxygen, H2O, freezing at 32 degrees Farenheit or 0 degrees Celsius, and boiling at 212 degrees Farenheit or 100 degrees Celsius.

Source: Macquarie Dictionary

Source: (NWC 2007)

water access entitlement

A perpetual or ongoing entitlement to exclusive access to a share of water from a specified consumptive pool as defined in the relevant water plan. A perpetual or ongoing entitlement, by or under law of a State, to exclusive access to a share of the water resources of a water resource plan area.

Source: National Water Initiative

Source: (NWC 2007)

Source: Water Act 2007

water access entitlement (ACT)

An entitlement to the amount of surface water or groundwater stated in the entitlement.

Source: (NWC 2007)

water delivered or protected under rules

Reduction in volumes of water committed (set aside) in storages for environmental water rules by release or delivery in accordance with the rules.

Source: (NWC 2007)

Source: (Sinclair, Knight, Merz 2006)

water delivery right

A right to have water delivered by an infrastructure operator.

Source: Water Act 2007

Source: (NWC 2007)

water dependent ecosystems (WA)

Those parts of the environment, the species composition and natural ecological processes of which are determined by the permanent or temporary presence of water resources, including flowing or standing water and water within groundwater aquifers.

Source: (NWC 2007)

water entitlement

A legal right to access water. An entitlement can be specified as a share of water from a consumptive pool of water as defined in the relevant water plan, or a fixed annual volume which may be restricted according to the resource assessment. Note that the licensing system in many jurisdictions has two parts to it: 1. A water access licence (i.e. the entitlement, as defined here), which is a permanent property right in the same way as land ownership title but is not associated with land title, and is tradeable. It can be expressed in terms of unit shares or some other measure, as described above. In the context of Source, each entitlement also has an account type and an account associated with it. 2. A water use licence, which is associated with a specific location and usage, and is not tradeable. In the context of Source these come into consideration when defining the properties of water users for modelling - location, demand characteristics, etc â but otherwise they do not need to be modelled.

Source: (toolkit 20091023)

water harvesting (Qld)

The taking of un-supplemented water during specified high flow events. It generally involves the pumping of water into on-farm storage for later use.

Source: (NWC 2007)

water irrigation area

The area under control of an individual water service provider (eg. an irrigation corporation, cooperative or trust, or water authority).

water orders

Water ordered by a user in a regulated river system to be supplied by the system operator. Normally the water must be ordered in advance.

Source: (Welsh, Podger 2008)

water ownership

Water ownership is concerned with assigning and tracking the ownership of parcels of water as they enter, are stored in, transit through, and exit systems. Water can be traded, both within storages as well as in transit.

Source: (eWater 2009)

A description of the variation of flow rate or water level over time; it may also include a description of water quality.

Source: (NWC 2007)

water resource

(a) surface water or groundwater; or (b) a watercourse, lake, wetland or aquifer (whether or not currently has water in it); and includes all aspects of the water resource (including water, organisms and other components and ecosystems that contribute to the physical state and environmental value of the water resource).

Source: Water Act 2007

Source: (NWC 2007)

water resource (Tas)

The waters from which water may be taken under a licence. May be a specific watercourse (eg lake, dam etc) or a variety of watercourses.

Source: (NWC 2007)

water resource plan (Qld)

Water resource plans are plans for a catchment that establish the consumptive share and environmental share of a water resource. These plans also identify any additional water available for allocation.

Source: (NWC 2007)

The integration of urban planning, with the management, protection and conservation of the urban water cycle, that ensures urban water management is sensitive to natural hydrological and ecological processes.

Source: (NWC 2007)

water share (Vic)

Is an on-going share of a consumptive pool of water in a particular water system. Specifies: â¢ The declared water system that the water share is tagged against. â¢ The use and source trading zones that the water share is associated with. â¢ The water system which the water share is associated. â¢ Share, expressed as the volume of the water system. â¢ Water use licence/registration with which the water share is associated (optional) â¢ The reliability class, ie whether the water share is a higher or lower reliability water share.

Source: (NWC 2007)

water sharing rules (Qld)

The water sharing rules for a water allocation specify how available water will be shared or apportioned between water allocation holders. The water sharing rules may include: â¢ rules for making announced allocations â¢ critical water supply rules-rules for sharing water during periods of low water availability â¢ carry over rules-rules about the extent to which an allocation holder can store announced allocation in water storage infrastructure for use in a subsequent year â¢ seasonal water assignment rules â¢ rules for when water may/may not be taken.

Source: (NWC 2007)

water stock

Surface and groundwater resources available in Australia for economic and environmental use.

Source: Australian Water Resources 2005

Source: (NWC 2007)

water storage

Includes barrages, dams, reservoirs, turkey nests, tanks, weirs, constructed for or provided to contain water, regulate flows, mitigate floods, for irrigation use, power generation or for domestic and industrial consumption.

Source: (toolkit 20091023)

water supply

The system of dams, pipes, etc., by which water is supplied to a community or region.

Source: Macquarie Dictionary

Source: (NWC 2007)

water supply interruption

In water transfers on substitution, to allow transfer of a particular volume of water entitlements from Zone A to Zone B, requires the same volume to be transferred from Zone B to Zone A.

Source: (toolkit 20091023)

water treatment plant

An individual location receiving raw or partially treated water for treatment and ultimate delivery to customers.

Source: (National Performance Framework 2006)

Source: (NWC 2007)

water use

A modelled entity in Source that can order and/or use water.

Source: River Systems specification

water user node

A node model available in Source. A water user node provides a mechanism for defining demand. It can be used to generate orders, manage water extractions, and provide drainage return flows.

water user storage

An off-river storage associated with a particular water user. This encompasses both on-farm storages (OFSs) used for irrigation and off-river storages used to meet urban or environmental demands.

Source: Source Scientific Reference Guide

water vapour

Gaseous water, especially when diffused and below the boiling point, distinguished from steam.

Source: Macquarie Dictionary

Source: (NWC 2007)

water year

A continuous twelve-month period starting from a specified month for water accounting purposes. The water year varies between systems. Two common Water year periods are 1 July to 30 June, and 1 October to 30 September. A means of defining the start and end of a year with the intention of analysing a particular water resources or hydrological phenomenon. Often the water year is not the same as a calendar or financial year. For analysis of floods, water years are often chosen to start and end in the dry season for that catchment to avoid floods crossing the water year boundary. For water resources analysis (particularly in irrigation areas) water years are often chosen to start and end in the wet season so that the entire irrigation season is within one water year.

Source: (Welsh, Podger 2008)

water year (Qld)

A continuous 12 month period starting from July or any other month as prescribed under the Water Regulation or a resource operations plan.

Source: (NWC 2007)

A movement of the surface of a liquid body, such as the sea or alake, in the form of a ridge or a swell.

Source: Macquarie Dictionary

Source: (NWC 2007)

weight

The relative mass of a quantity of matter typically measured by reference to the downward force exerted under the Earth's gravitational field. More strictly, the force exerted on the mass of a body by a gravitational field.

weir

a structure on a river to facilitate regulation of flow or diversion to storages or supply networks. A structure usually of concrete, across a stream to impound water, with any surplus flowing over the crest; in a water treatment plant, a concrete wall of a settling pond, over which clarified water flows into the next stage of the process.

Source: (National Performance Framework 2006-07)

Source: (NWC 2007)

Source: (toolkit 20091023)

well

A hole drilled into the earth, generally by boring, to obtain water.

Source: Macquarie Dictionary

Source: (NWC 2007)

wetland

An area transitional between land and water systems, which is either permanently or periodically inundated with shallow water, and either permanently or periodically supports the growth of aquatic macrophytes (eg marsh, swamp, fen, bog).

Source: (toolkit 20091023)

wetlands

Areas of marsh, fern, parkland or water, whether natural or artificial, permanent or temporary, with water that is static or flowing fresh, brackish or salt, including areas of marine water, the depth of which at low tide does not exceed 6 metres. Areas of low-lying land covered with either fresh or salt water, whether irregularly or permanently; water habitats either natural eg billabongs, lagoons, lakes, creeks, weirs, estuaries, salt marshes, swamps, mound springs or constructed eg dams, canals, bore, drains, channels, rice fields.

Source: Ramsar Convention

Source: (NWC 2007)

Source: (toolkit 20091023)

works license (Vic)

Authorises the owner to implement works to take water from a water system; ie to install a groundwater pump, or a pump to take water from a river, etc.

Source: (NWC 2007)

works permit (ACT)

To construct or alter a dam, water storage or other water control structure in a waterway.

Source: (NWC 2007)

Z

zone (Qld)

A geographic location, eg a reach of a watercourse. Zones are for defining the location from which water may be taken under a water allocation.

Source: (NWC 2007)

zoo-parasites

Single-celled organisms, order Protozoa, living in a parasitic relationship with a host. While often not causing any symptoms of illness, some (eg Cryptosporidium and Giardia) may cause infection through direct contact or through contaminated water"

Source: (toolkit 20091023)