The 100 year old Dethridge wheel has now been replaced with electronic water meters.
The 100 year old Dethridge wheel has now been replaced with electronic water meters.
This is the drop bar regulator used to control water flow in the irrigation channels.
This is the drop bar regulator used to control water flow in the irrigation channels.
Water flowing into the irrigation channels.
Water flowing into the irrigation channels.
The new automated channel control gates in action.
The new automated channel control gates in action.

Introduction

Irrigated agriculture accounts for approximately 25-30% of Australia’s total agricultural output and uses approximately 72% of the country’s natural water supply. Irrigation was established in the late 1800s as a way to facilitate viable farming in dry and unpredictable environments. Early pioneers developed an elaborate irrigation system comprising dams, weirs and channels which supplied water directly to farms.

Much of Australia’s irrigation system is made up of earthen gravity channels with flows managed manually using drop-bar regulators. Water is supplied to service points on properties via Dethridge meter wheels. This system of irrigation is highly inefficient with one third of the water releases from storages lost to outfalls, leakage, evaporation and inaccurate metering.

While this system was acceptable in the last century when water availability was secure, climate change and a along period of drought has plunged Australia’s rivers and catchments into crisis.

Addressing the inefficiency of the country’s massive network of irrigation is a major focus of the State Government’s ‘Our Water, Our Future’ campaign. It also includes the Federal Government’s investment of AUS$13 billion in 2009 towards overhauling the country’s ailing irrigation system.

In 2008, Goulburn-Murray Water (G-MW) established the FutureFlow alliance to perform AUS$283 million worth of irrigation renewal activities throughout its six irrigation areas. The Alliance partners were Transfield Services Australia, Sinclair Knight Merz and Comdain Infrastructure. PLUM Communications and Sage provided specialist contractor services. The project was funded by the Department of Sustainability and Environment via the Living Murray Initiative, Water for Rivers and the Northern Victorian Irrigation Renewal Project.

In two years, FutureFlow’s Irrigation Modernisation Project has transformed 2,000 km of manually operated irrigation channels and 3,800 irrigation infrastructure assets in the Goulburn Murray Irrigation District (GMID) into a fully automated IT-based system. The GMID is the largest rural irrigation network in Australia and comprises more than 6,000 km of irrigation channels. A total of AUS$14.5 million was saved by changing existing work processes and modifying irrigation infrastructure assets. In the long-term this will provide an average water saving of 94 gigalitres per year for less than AUS$2,900 per megalitre.

Out with the old and in with the new

The new integrated water management system is a quantum leap in the way water is delivered to irrigators. The old system required irrigators to place orders up to four days in advance and required G-MW to manually plan orders, release flows from storages and manually regulate flows down an open channel system using drop-bar regulators.

Customers then had to use a Dethridge wheel meter to divert the ordered volume to their farm according to the scheduled time of their order. The manual nature of the system resulted in significant water loss and was a hindrance to irrigators wanting to be competitive in world agricultural markets. Throughout the project, 3,000 Dethridge meter wheels were replaced with new electronic meters and 500 were rationalised.

Independent farm designers consulted with each irrigator to provide advice about the meter size and flow rate which would be best to meet their individual farm needs. FutureFlow also employed its own team of customer consultation staff to ensure customers were consulted about all aspects of the meter installation and operation.

Six new electronic meters have been installed on dairy farmer Everty Worm’s property in Dhurringile, he commented: “We’ve just done our second watering since the meter installation and it’s absolutely marvellous. The channels are always up to scratch. Years ago the channels had manual wooden structures and the levels would fluctuate [by] 200 to 300 mm. Now the new FlumeGates in the channel mean the water is the same all the time. I am very happy.”

Irrigation infrastructure concept

The solution adopted by G-MW and FutureFlow is based on SCADA and Total Channel Control (TCC), a specialist irrigation technology developed by Rubicon Systems Australia. The TCC system automatically processes orders and delivers the exact amount of water when and where it is required. This eliminates outfalls from the system while improving customer service.

Rubicon’s solar-powered, FlumeGates have been installed to replace drop-bar regulators. These automated channel regulators are all connected via radio telemetry to provide a fully integrated system. This means that hundreds of daily customer orders received via phone or the Internet, can be automatically scheduled using TCC software. The software used flow and channel level data received from the FlumeGates to provide accurate water delivery. A total of nine new communication node towers were installed and another 22 upgraded. The communications network integrates more than 750,000 data points into one control network, making it the largest radio canopy network in the world.

The TCC system continually delivers electronic instructions to the FlumeGates, which in turn adjust channel operating levels to ensure the exact amount of water is delivered to the farm. The GMID network connected to TCC is controlled 24/7 by G-MW’s Operations Support Centre.

TCC has reduced water ordering times from four days to 12 hours and has reduced the amount of water spilled at the end of the channels (outfall) by 90%. By 2012, G-MW’s five irrigation districts will be fully integrated into the TCC system and will include more than 15,000 radio sites.

Following the automation of the channels and meters, the alliance analysed flow data to identify sections of the channel with the highest water loss. These channels were then replaced with pipelines or remodelled and lined with a high density plastic.

FutureFlow had a team dedicated to rehabilitating high loss irrigation channels. During the first irrigation shut down period, a total of 26 km of high loss channel was remodelled and lined with a high density polyethylene plastic which reduces leakage and seepage by up to 90%. FutureFlow also carried out some smaller scale bank remodelling to fix leaks and erosions which were less than 20 metres in size.

East Goulburn main offtake structure

The East Goulburn main channel offtake structure supplies water from Lake Nagambie to the Shepparton Irrigation Area. The existing site was a manually operated system which needed to be replaced with automated FlumeGate regulators in order to link into TCC. The new site needed to be designed to meet three critical requirements:

• To automatically control flows into the Shepparton Irrigation Area.
• To accurately record flows into the area for bulk measurement purposes.
• To act as a flood prevention device in extreme wet weather events.

The AUS$2.6 million upgrade had to be designed, procured and constructed in five months, ready to supply water for the 2008/09 irrigation season. The design also has to be developed in stages, which provided information for construction tendering and procurement of major materials. Once the contractor was engaged, the design continued to evolve to improve constructability and reduce timeframes. Strict operational rules for the site were imposed in order to minimise fluctuations in water levels in Lake Nagambie, which is a popular recreational water body. FutureFlow analysed the channel downstream of the structure to identify additional storage opportunities to overcome these restrictions and continue to supply water on demand.

Waranga Basin offtake structure

The Waranga Minor is a 100-year-old offtake structure on the Waranga Basin and supplies water to much of the Central Goulburn Irrigation Area. The manually operated structure needed to be automated in the winter of 2008 to enable the downstream channels to operate in TCC.

The structure required AUS$1 million worth of upgrades and, like the East Gouldburn main, had to operational for the start of the 2008/09 irrigation season. Due to the critical nature of the site, the removal of the old infrastructure and preliminary works could not commence until the new equipment was delivered to site.

A large coffer dam was constructed to isolate the structure from the water in the Waranga basin and construction commenced seven days a week. The automated gates were manufactured and quality tested in the US and delivered via airfreight to accelerate timelines. More than 16 tonnes of gate were delivered just days before the installation deadline. The electrical and controls systems were commissioned and the site was operational in time for the irrigation season.

Katandra pipeline

The project to replace Katandra’s outdated and inefficient open concrete channels (EG22) and EG24) with a new gravity fed pipeline and Magflow meters was completed as part of the FutureFlow project.

The project included the construction of approximately 27 km of gravity fed pipelines, removal of existing channels and the replacement of Dethridge meter wheels with new Magflow meters. The pipeline provides up to 20% greater flow than the previous channels, offers irrigators a more ‘on demand ‘service and a higher effective water level than in channels, allowing the irrigation of higher land.

Shepparton Irrigation District

FutureFlow’s rationalisation team was set up to identify and negotiate the removal of under-utilised and redundant channel and assets from the irrigation system. From February 2008 to June 2010, FutureFlow negotiated the removal of approximately 46 km of channel across the Shepparton Irrigation District – 15 km more than originally identified in the project’s scope.

FutureFlow’s rationalisation team worked with both independent farm assessors and individual irrigators to help design new supply arrangements and negotiate compensation packages to adjust on-farm infrastructure to suit the new system layouts.

Rationalisation has provided a great outcome for Australia’s largest apple and pear producer, Jef Tomson, providing better flow rates and saving approximately 74.4 megalitres of water each year.

The Shepparton-based company has eight major orchards producing approximately 10,000 tonnes of apples and pears each year. Four years ago it purchased a 500 hectare property at Nathalia and after producing a whole farm plan, realised 1.7 km of irrigation channel and some associated water assets were not required.

“We met with FutureFlow on a number of occasions to work out how to reconfigure the property and resolve all issues associated with the decommissioning and relocation of the pump shed and installation of another meter,” explains Garry parker, managing director, Jef Tomson. “It was a complicated rationalisation but because FutureFlow took the time to consult with us and work together the results have benefited everyone.”

Project management

One of the biggest challenges of this project was to manage complex logistics in a short timeframe. The majority of the project’s work was carried out during the three month irrigation shutdown period in 2008. During this time, AUS$117 million of the AUS$283 million project was implemented. FutureFlow installed 1,680 FlumeGate and channel regulators, built four major offtake structures, lined 26 km of high loss channel with plastic lining and installed or upgraded 18 radio communication towers.

Due to the unprecedented scale of the works, it was a challenge to confidently predict the amount of resources or time required to complete the works. To handle this, schedulers developed programmes well in advance of construction. This approach gave the team confidence that it had the appropriate resources in place to complete the works in time. Once the baseline schedule was produced, progress was monitored and updated every day to identify any areas of slippage. Reporting was done via earned value graphs (or S-curves). These helped identify trends early so resources could be added or adjustments made where required.

In 2010, the Irrigation Modernisation Project was recognised for their management skills, winning the International Water Association’s (IWA) Asia Pacific Regional Project Innovation Award (PIA) for Operations/Management [1].

Environmental benefits

More than 100 billion litres of water will be saved annually from the works FutureFlow are undertaking. The majority of these savings are to be returned to Northern Victoria’s stressed rivers and wetlands via environmental flows. The automated channel system will also pass flows into receiving rivers and wetlands in a more controlled fashion, better mirroring natural flow patterns.

A proportion of the savings will also be returned to local irrigators to increase their water entitlements, further enhancing the viability of their individual enterprises.

The gravity irrigation system is an extremely low energy system. The exclusive use of solar power on the irrigation infrastructure maintains this low energy profile. It is estimated that 215 kW of renewable power is generated from the solar powered system.

Conclusions

Guaranteeing the ongoing viability of the irrigation industry in Northern Victoria is the main driver and benefit of the Irrigation Modernisation Project. A total saving of AUS$14.5 million has been achieved through changing existing work processes and modifying irrigation infrastructure assets. The size and scale of the automated channel network is a world first which was completed in record time by using new approaches to project delivery.


[1] The International Water Association (IWA) Project Innovation Awards (PIA) programme was created to recognise excellence and innovation in water engineering projects around the world, and highlight the belief and emphasis within the IWA community that solutions to our water challenges can be achieved through innovative and practical solutions.

Projects are submitted for competition in one of the following five award categories – Applied Research, Design, Operations & Management, Planning, and Small Projects – with entries first competing at one of four regional bases i.e. Asia Pacific, East Asia, Europe and North America for the regional awards. The regional winners are then advanced to the global level to compete for the Global Awards, which will be presented at the Global Project Innovation Awards Ceremony and Dinner on 22 September 2010 at the IWA World Water Congress and Exhibition in Montreal, Canada.

For more information on the PIA programme and executive summaries of all the regional winners, please visit the IWA website or email.