About the Backbone
The backbone is a network of major water supply channels. The purpose of the backbone is to form the nucleus of a modernised and automated water supply system to efficiently transport large volumes of water to customer service points.
By concentrating intensive modernisation works on the backbone network of channels, NVIRP has already reduced water losses. The clear aim is for the works to ensure system affordability for irrigators in the Goulburn-Murray Irrigation District through a better supply system well into the future. Backbone works, which are almost complete, have also improved services levels of irrigators and enabled significant farm productivity improvements.
Although approximately 50 per cent of the existing irrigation network will not form part of the backbone network of channels, NVIRP's Connections Program is being undertaken to connect most irrigation supply points in the remainder of the system to the backbone. Click here to read more about this program.
Definition of Project Backbone
A definition of the Project Backbone has been adopted as follows:
A channel where a minimum of 20 megalitres per day (ML/d) of delivery share occurs and the landowner receives an enhanced level of service from channel automation at the upstream regulator plus any extensions approved by both NVIRP and Goulburn-Murray Water will be determined to be part of the Backbone.
This definition includes:
- Downstream Pools: Service points located below the last automated regulator will receive an enhanced level of service similar to the Backbone.
- Nibs: In a number of situations, the offtake to a spur is located some distance downstream from the designated Backbone. The section of channel between the Backbone and the offtake - referred to as a ‘nib' - basically operates as part of the Backbone, operating at the same supply level and receiving a similar level of service.
In both cases these sections of channel can be deemed to be Backbone.
Extensions of the Backbone
Extensions of the current designed Backbone are permitted, with all extensions approved by the NVIRP Board in consultation with Goulburn Murray Water. For an extension to be approved it must meet the following criteria:
- A minimum of 12 ML/d of delivery share must be attached to the extended Backbone
- An extension of the Backbone must result in a corresponding decrease in spur channels at a ratio of 3 to 1 and
- An extension will only be approved where it is cost effective to do so, soil types are conducive to irrigation, and implications on water savings are considered.
Mapping the Backbone
To determine the location of the backbone network of channels, NVIRP worked closely with Goulburn-Murray Water and specialist consultants to consider a wide range of criteria including:
Channel Use as Defined by Delivery Share
The minimum Delivery Share for the Backbone was established as 20 ML/d, which would supply approximately five to six large properties.
Suitability of Land for Irrigation
NVIRP examined a wide range of data to determine land suitability for irrigated agriculture. This included soil suitability, subsoil salinity, subsurface drainage, surface drainage, flooding, water table depths and waterlogging data.
Location of Large Water Use Businesses
Large businesses were categorised through historical water use data and valuations held by Goulburn-Murray Water, the Bureau of Rural Science and the Valuer-General's Victorian database.
Location of Prime Development Zones
Prime Development Zones include areas with good soils and topography as defined by studies prepared for the Victorian Department of Natural Resources and Environment. They are located within five kilometres of Backbone channels.
Local Trends Analysis
Local trends were analysed to concentrate investment on areas of sustainable irrigation; identify channels that should be retained for operational purposes; assess water use, enterprise and community trends and facilitate new connections.
Community Input
Extensive consultation was undertaken with Goulburn-Murray Water area operations staff, who provided local knowledge to identify potential operation issues, implementation priorities and system service constraints.
Following this initial feedback, extensive consultation was undertaken with Goulburn-Murray Water customers via Water Services Committees, a Reconfiguration/Modernisation Working Group and Modernisation Committees. Comments received through these groups were incorporated into the backbone planning process.
Letters were then sent out to all Goulburn-Murray Water customers and 13 public meetings were held across each irrigation area in the Goulburn Murray Irrigation District to further refine the backbone. These meetings were attended by approximately 800 people and resulted in further extension to the backbone in most areas.
Backbone Maps
Please click on the images below to view Backbone maps for each irrigation area. Please note these maps show the original designed Backbone and do not show approved extensions to the Backbone.
If you would like a copy of the map for your area please email waterforgrowth@nvirp.com.au or call 1300 163 006.
Central Goulburn |
Loddon Valley |
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Murray Valley |
Rochester |
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Torrumbarry |
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