$2bn irrigation modernisation has liquid pay off for Melbourne

By Rosemary Ann Ogilvie

Concurrently, those contractors involved in the two-stage, $2bn modernisation of the Goulburn-Murray Irrigation District (GMID) supply system are poised, ready to move onto multiple worksites and complete significant levels of work, during the May to August downtime.
However, winter brings a whole set of challenges: teams of workers in each of the five regions regularly have to deal with mud while using excavators, concrete pumps, cranes, dump trucks, and the full gamut of power tools.
The associated hazards represent an OH&S nightmare. Yet during winter 2009, the Northern Victoria Irrigation Renewal Project (NVIRP) – the state owned entity engineering the modernisation – achieved its goal of zero lost time injuries. Quite an achievement when you consider this involved more than 300,000 hours of labour across 300 worksites.
NVIRP’s managing contractor, Transfield Services Australia, awarded tenders to four companies for the winter 2009 works, the second year of the renewal scheme: Comdain Civil Constructions p/l ($3m – Pyramid-Boort region); J&C Reid Earthmoving p/l ($1m – Murray Valley); Ward Brothers/Underground Constructions ($4.5m – Rochester and Torrumbarry) and Bilfinger Berger Services (Australia) p/l ($1m – Central Goulburn).
Risk management
The 450 construction site and contracting staff involved in the project underwent a stringent ‘planning, prevention and training’ induction program. Each morning before work started, site supervisors assessed their sites and identified hazards such as power lines, underground services and wet and slippery conditions. The supervisor and workers then devised a plan together to manage those risks.
This is Australia’s largest-ever irrigation renewal project, covering an area of 68,000km², from Yarrawonga 300km northeast of Melbourne on the Murray River to Swan Hill 350km northwest of Melbourne, also on the Murray. This area happens to be Australia’s largest single supplier of dairy products and processed tomatoes, and a major source of stone fruit and pome fruit. The upgrade is not before time: the government owned channel system, installed by horse and dray 100 years ago, is extremely inefficient, with an estimated 900 gigalitres of water lost each year through leaks, evaporation and poor transmission.
Irrigating farmers though, started laser levelling in the early 1970s, to more efficiently use the water they did get. The result was that they were able to get water on and off quickly for more efficient growth. As well, many built on farm dams to recover for reuse, any water that ran off when irrigation of a particular bay finished.
A combination of methods is being used to update the irrigation system, including automation of the main irrigation channels with radio-controlled, solar-powered technology to open and close the channel gates and continually monitor flows 24 hours a day. Modern meters will replace inaccurate on-farm meters.
Channel focus
Redundant and obsolete infrastructure will be removed and supply systems restructured. Channels in poor condition are to be lined with plastic or clay to reduce water loss through seepage and leakage, while remediation of channel banks will further reduce water loss.
This state-of-the-art channel automation technology is creating a world’s best practice irrigation system. This technology can detect discrepancies in water delivery - who is stealing water for example - and identify where maintenance is needed.
Automated gates monitor water levels and flow, ensuring precise amounts of water are delivered where and when required. For the farmer, this means shorter ordering times, and quicker, more consistent and reliable delivery of water as there will be a stronger flow.
Installing the regulator gates is the biggest component of the works. In 2008, 1530 gates were delivered to NVIRP by Rubicon Systems, which developed the technology with Melbourne University. A further 3900 have been ordered. Made in the company’s 10,000m² Shepparton facility, the gates are also being installed in China’s Yellow River irrigation system.
Funding for what is currently Victoria’s major infrastructure project, is coming from the Victorian government ($600m), Melbourne Water ($300m) and Goulburn Murray Water ($100m). The federal government will provide up to $1bn for stage two.
Water saving
The first stage, which is expected to be completed by 2012, should save 225GL of water or 40% of a Sydharb, one third of which will go back to farmers. Another third will be diverted to Melbourne via the Sugarloaf pipeline. “One reason the funding was provided, was the promise of water to help secure Melbourne’s water supply before the desalination plant comes on board,” says CEO Murray Smith. ‘So this decision means the project is not without controversy.”
The final third is earmarked for the environment: some will be stored in parched Lake Eildon, and the water will be released into stressed rivers and streams as required. This water will be over and above the Living Murray and Snowy commitments, and will primarily target the use of environmental water for priority Victorian wetlands and tributaries. Stage two is expected to bring further savings of 200GL, which will be split equally between the farmers and the environment.
As can be expected, some irrigators don’t want the system upgraded. “We’re talking to every farmer as we go through each region, determining what their requirements are for the future, how they can best work with this technology, whether they need soil moisture monitors – and determining whether they want to actually stay in farming,” says Smith. “We don’t want to install expensive infrastructure, only to find in five year’s time, those people have gone from the farm, or have sold their water just to sustain themselves.”
However, attitudes are slowly changing. “There are incentives for them to change. There’s certainly incentive for them to connect to the backbone. We’re putting the money in, so it won’t cost them any more. We’re also assisting them to take out the old Dethridge wheels and put in the modern technology.”
Fed up farmers
Still, there are issues such as age, with farmers wanting to retire, and farmers fed up after coping with ten years of drought. “So in those instances, we work with the Rural Bank to try to link people, so they may consider purchasing the neighbouring property to become more viable: this area was largely set up on soldier settlement blocks. We want it to be win-win for everyone.
“We’re securing farmers’ futures in the region,” says Smith. “Upgrading the irrigation system underpins regional development here.”
Those interested in tendering for work on this project should check the TenderLink website for opportunities.