Allocation or Water Allocation
Water for use in a particular irrigation season depending on how much is available in storage. For example, if a seasonal water allocation during a drought was 50 per cent, an entitlement holder with a 100 ML high-reliability water share would be allocated 50 ML of water for use.
Automated Outlet
Open and close without any manual operation at the site. The landowner places an order with Goulburn-Murray Water, which is then relayed via radio link. The automation can also regulate the flow during each irrigation. The electronic motors at the site, which open and close the outlet, are powered by a battery and solar panel.
Automation (Channel)
A system of remotely controlled regulators and gates linked to a computerised system. The computerised system automates the ordering, delivery and measurement of supply in irrigation channels. This automation may include customer service points.
Backbone
A large capacity water supply channel (carriers and trunks). The backbone will form the nucleus of a modernised and automated water supply system to efficiently transport large volumes of water to customer service points.
Channel
Open channel or flume constructed to convey water from an upstream water source to farms.
Connection
Either public or private, piped or open channels that allow individual properties, or a cluster of properties, to receive their water from the backbone.
Delivery Share
The right to have water delivered by Goulburn-Murray Water and a share of the available flow in a delivery system. Delivery share may be transferred to other landowners supplied from the same channel or to channel systems where capacity is available or relinquished through a termination payment being made to the water corporation. Farmers are encouraged to transfer delivery share to the backbone to secure access to the modern system.
Dethridge Wheel or Meter Outlet
The positive displacement flow measurement device used to determine water volumes supplied from a supply channel to an individual farm. The meter is available in several sizes. Dethridge Wheels are being replaced as part of the modernisation process.
Distribution Losses
Water losses that occur from distributing irrigation water. Causes of these losses include evaporation, seepage, metering error and leaks in irrigation infrastructure.
Electronic Magflow Meter or Magnetic Flow Meter
Can provide high and low flow rates. The water is supplied through a pipe on to the farm with an electronic meter built into the design. Most flow meters have a door on the farm side of the pipe with unrestricted access along the channel bank.
FlumeGateTM
Provides a high flow of water from the supply channel to the farm channel. The flow on to the farm is controlled by measuring upstream and downstream water levels and adjusting the opening of the gate to match the ordered flow rate. Operation of FlumeGatesTM is similar to the new regulators that have replaced drop bars. Electronic Flow Meters and FlumeGatesTM can be automatic or manual. They sustain less headloss than a Dethridge Wheel and provide accurate measurement while flow rates and volume can be viewed at the meter. They can both provide a link to other technologies such as soil moisture monitoring and on-farm irrigation automation.
Gigalitre
One billion litres or 1000 megalitres.
GMID
Goulburn Murray Irrigation District, the water supply system operated by Goulburn-Murray Water.
Irrigation Area
A defined part of the Goulburn Murray Irrigation District which comprises six irrigation areas e.g. Central Goulburn Irrigation Area.
Leakage
Loss of water through the banks of a channel (and around service points) via macro-pores.
Magnetic Flow Meter
See Electronic Flow Meter.
Megalitre (ML)
One ML is equivalent to 100 mm of water over a hectare or about one Olympic size swimming pool or 1,000,000 litres.
Ordering Time
The time between ordering water from the water provider and delivery to a customer.
Reconfiguration
Changing the farm irrigation system layout as a result of the modernisation process.
Remediation
Lining water supply channel bed and banks or rebuilding channel banks to reduce water losses. Impermeable membranes or compacted clay may be used to line channels. Remediation is a water savings intervention.
Seepage
Water lost through micro-pores in channel beds and banks in earthen channel systems.Service point: is the point on the public water supply system that a customer receives water, usually through a meter. A service point may also be known as a meter, wheel or outlet.
Spur Channel
A channel downstream of the backbone.Standard of service: the nominated level of service is a quantification of flow rate, flow rate consistency, command, water ordering time, water delivery period, reliability and water delivery season length.
Supply Level
Is defined for each channel pool and is the minimum water level in each pool under no flow conditions.
Supply Point (Farm Offtake, Outlet or Service Point)
The point of delivery from an irrigation corporation supply system to an individual farm. A supply point from a channel system usually comprises a small-gated regulator or pipe outlet, which may incorporate a measurement device (meter).Unbundling: unbundling separates the existing water entitlements into a water share and delivery share:
- water share - high reliability and low reliability where irrigators previously had access to sales water
- delivery share, or extraction share for regulated diversion licences
- water use licence
Water Right
Rights or entitlements to water held by irrigators in an irrigation district. Now generally referred to as water share (see below).
Water Savings Measure or Intervention
An action taken to generate water savings. For example, channel remediation.
Water Share
A legally recognised, secure share of the water, in storage or yielded in the catchment, available for use in a water system. The entitlement volume can be traded temporarily or permanently. A high reliability water share has been converted from existing water right or diversion licence volume (e.g. 100 ML of water right becomes 100 ML of high-reliability water share). Seasonal allocations will depend on how much water is available in storage. If a seasonal water allocation during a drought was only 50 per cent, an entitlement holder with a 100 ML high-reliability water share would be allocated 50 ML of water for use. A low reliability water share is the share of the low reliability pool.