Enclosing open ditch irrigation channels


PIPA and the Environment Plastics Industry Pipe Association of Australia Ltd

Enclosing open ditch irrigation channels

SMH 1971

Background

Water is the key resource for a country's development and is the greatest factor controlling Australia's potential growth. Australia is the world's driest continent but wastes more water per capita than any other country. The demand for water is increasing as the population and the economy rise. Irrigation has always been limited by Australia's scarce water resources, however since 1945 with the expansion of dams and numerous irrigation schemes up to 12m acres came under irrigation.

Even so, the rosy future still envisaged in the late 60's has not eventuated. With virtually no runoff into the main storages coupled with high water use due to extreme evaporation rates, there has been no chance of increasing allocations. With 99 per cent of Australia in the grip of a devastating drought, water efficiency became more important than ever in the 21st century.

In 2002, businessman Richard Pratt called on the Federal Government to issue water bonds to raise money to pipe Australia's open irrigation channels which currently lose up to 80% of their water volume through evaporation and seepage. Mr Pratt said a significant proportion of the water saved could be returned to rivers to help restore environmental flows. The Member for Riverina, Kay Hull, worked tirelessly with Richard Pratt to place this issue on the national agenda.

On 25 October 2002, the Hon John Anderson said Federal Government would give priority consideration to the Pratt plan to conserve water by containing leakage from irrigation channels. The Pratt Water Group is asking the Federal and NSW governments to give $8.8 million for a feasibility study that would also look at on-farm monitoring of water use, management of irrigation, and different irrigation methods. Mr Pratt's summary of the plan estimates that, by covering and lining channels, 50 per cent of the water that is lost through evaporation and seepage would be saved. The Murrumbidgee was chosen for the initial project because it has large irrigation systems that were installed over many decades and are in varying stages of repair.

NSW Minister for Land and Water Conservation, John Aquilina, on 19 December 2002, expressed the desire to make the Murrumbidgee Valley one of the world’s top 10 irrigation performers. "To achieve this, we need a rigorous analysis of a range of on-farm water efficiencies, including irrigation channel management and river operations." He went on to announce that the State Government will join the Pratt Water Group and the Commonwealth in investigating water efficiencies in the Murrumbidgee Valley. The feasibility study will commence in February 2003, and is expected to take 12-18 months to complete.

PIPA recommendations

David Sumner, Chief Executive,
October 2002

The Plastics Industry Pipe Association (PIPA), represents over 95% of plastics pipe and fittings manufacturers in Australia. Our members manufacture pipes for a range of applications including water, sewer, plumbing, irrigation, drainage, mining, and electrical/telecom conduits.

While there have been recent representations on this subject, including using pipe as a means of enclosing open ditches, PIPA would sound a note of caution on the type of pipe materials proposed. The Pratt Water Group's proposal for a feasibility study about water savings in the Murrumbidgee Valley has real merit, and PIPA would like to comment on the issue of proposed pipeline materials. The project envisaged presumably will involve the use of large diameter pipe, and thus will be a high cost investment. Given a high capital cost, it is important that the pipelines have a long service life, ideally greater than 100 years.

Irrigation channel

For this reason, PIPA recommends the use of pipe materials that meet Australian Standards, and have a proven successful history in this type of installation. PIPA believes the best materials are Polyethylene (PE), and Polypropylene (PP), properly formulated to resist UV radiation and stress cracking.

Pipelines made from these materials when designed in accordance with Australian Standards, operate at a range of temperatures and pressures, and are totally resistant to corrosion. PIPA members have been involved in many enclosed ditch applications using PE and/or PP pipe up to 3m diameter.

PIPA has extended support and services to Richard Pratt regarding this study and hopes to meet with him and his representatives to discuss the proposal further. Like the Pratt Water Group, PIPA remains committed to the search for long term constructive and viable solutions to drought and water conservation in Australia.

Given the considerable expertise and experience of Australia’s plastics pipe industry spanning over forty years, PIPA would like to offer its services to any government consultative forum that might be established to find long term constructive and viable solutions to the drought and water conservation.

Responses

The Office of the Deputy Prime Minister and Minister for Transport and Regional Services has replied to indicate that 'in this term of office there will be a focus on sustainable water systems such as replacing open channels with piping and new innovative water infrastructure projects. Currently the Federal Coalition Government is contributing to the Northern Mallee Pipeline to replace the existing open channel stock and domestic water supply system.'

The NSW Department of Land and Water Conservation (DLWC) votes PIPA's concern on the type of materials proposed and indicates that 'the project will assess all relevant technical, economic and environmental parameters. At this early stage no decisions have been made on the type of plastic. Among the many options, pipes made from recycled plastic will be considered.' Further input from PIPA would be welcomed.

References

PRATT WATER GROUP FEASIBILITY STUDY (New South Wales) Release Date: 25/Oct/2002 as reported in Media Release by the Hon John Anderson

Sundry Media Releases as reported by NSW Department of Land and Water Conservation (DLWC) on their web site.

Talking Water, Newsletter of Murray Irrigation Limited; 19 February 2003

Pratt and Garrett call for action on Australia’s water Visy News,18 June 2002.

For Further information please contact :
Plastics Industry Pipe Association of Australia Ltd
Suite 246, 813 Pacific Hwy, Chatswood NSW 2067
or email plasticspipe@pipa.com.au