Irrigators set to open $8m piping scheme

Ashburton Lyndhurst Irrigation Ltd
NEWS RELEASE
May 6 2009

Irrigators set to open $8m pressurised piping scheme

History is in the making for Ashburton Lyndhurst Irrigation Ltd (ALIL) as it plans the opening of its underground water delivery set to save electricity equivalent to that of the average power used by 300 houses in Ashburton per year.

The directors of ALIL are pleased to announce the successful completion of the pressurised piping scheme following a three year development project.

Following discussions within the scheme the group of farmers representing 33 properties banded together to implement the project that will improve the efficiency of distribution and water use within the scheme.

The irrigation scheme has piped 31 kilometres of water delivering water for irrigation to 4000ha.

The $8m project was driven by innovation and sustainability.

The ALIL was a 24,500ha irrigation scheme using water from the Rangitata Diversion Race (RDR). The open race system servicing an area bounding the north branch of the Ashburton passed through an area of light porous country. The water losses from open races in this area were in excess of 15%, ALIL chairman John Van Polanen said.

An area of 3,500ha was identified to be serviced by the pipe which gave maximum efficiency and economy of pipe size. A further 550ha is now irrigated by the 15% efficiency gain, an area that was within the scheme but previously not irrigated.

Three open water channels and headraces have been closed down and replaced with pipe varying in diameter from 250mm to 1000mm, depending on the stage of water delivery with the bigger pipes being used at the top end of the scheme and the smaller as less water is delivered down the track.

The scheme will now supply pressurised water to the farm gate taking advantage of a natural 160m fall in altitude from the source to its end meaning farmers will no longer require electricity to pump irrigation water.

Van Polanen said the project was all about efficiency in terms of water and electricity.

Power savings created by not having to use pumps equates to around 3,000,000 KW hours per annum. This is equal to the average power used by 300 houses in Ashburton per year.

“Farmers now have a constant flow of water on demand and no pumps.”

Given there was no need for pumping requirements a number of farmers have taken the opportunity to change their on farm irrigation systems to more efficient spray irrigation systems.

“Overall the new piped scheme has huge benefits for the both the community and the farmers given the electricity and cost savings and environmental benefits with more efficient and sustainable water use,” Van Polanen said.

The project had received 98% support from the overall scheme membership.

“So we had a clear mandate and very good support to proceed.”

The piped scheme takes in an area between Ashburton-Methven Highway and the Ashburton River north branch.

The piped scheme was designed to carry a maximum 2000 litres per second but initially it would not be working to capacity.

“We have planned ahead and allowed for additional capacity within this scheme as the case may arise.”

The $8 million scheme was funded by income generated from the additional 550ha being irrigated, topped up with a bank loan that will be repaid over a 30-year period, this period is in line with the length of the RDR water consent.

Any further developments in the ALIL scheme would be driven by farmer demand, van Polanen said.

Water Dynamics, a division of Tyco Flow Control Pty, designed the scheme and has undertaken its development and commissioning.

The official opening of the ALIL pressurised piping scheme is scheduled for May 18. Those wishing to attend are to meet at the Methven Rugby Clubrooms at 10.30am to join the bus transport around the scheme. There will be lunch at the clubrooms on return at 1pm.

Intention to attend must be notified to Heather Ford phone: 03 3085104

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