Award-winner brought innovative methods to irrigation scheme

Aquaduct NZ's contribution to the Valetta Irrigation Scheme in Canterbury has earned it the prestigious 2014 IrrigationNZ Innovation Award.

Aquaduct's entry, alongside associate company Bosch Irrigation Ltd, included its ground- breaking solution for the manufacture of irrigation pipe for the scheme's new 84km underground pipe network.

A factory to produce pipe on- site was created in a paddock within the scheme's boundaries, slashing welding requirements by 80 per cent and reducing installation time and costs. The company supplied more than 80km of pipe in sizes from 1.6m diameter to 200mm and in lengths up to 250 metres. The factory produced 5800 tonnes of pipe in 60 days.

Aquaduct's involvement with Valetta included machinery designed and adapted specifically for the Canterbury plain's unique cobblestone conditions and vibrating technology which perfectly bedded the irrigation scheme's pipe network, greatly increasing its longevity.

Its founder, Gerard van den Bosch, says the future of sustainable world development would rely on clean water and energy and Valetta's piped gravity- fed irrigation scheme created and delivered efficient use of both.

"The main driver for the Valetta project was the desire to eliminate water loss and allow 37 per cent more land to be irrigated from same quantity of water," he says.

"The use of gravity to reduce pumping and save the farmers huge production costs was also a strong motivation. The lost economic potential from the open channels was an irresistible challenge and meeting the challenges required multifaceted innovations and efficiencies."

The judging panel of former IrrigationNZ CEO Terry Heiler, Magdy Mohssen, Andy McFarlane and Tony Devries said Aquaduct's win resulted from its potential for large-scale adoption with significant efficiency gains and a long life span.

IrrigationNZ CEO Andrew Curtis says Aquaduct deserved national recognition for setting the bar high for other irrigation schemes.

"The newly piped scheme provides better water allocation through the gravity-fed pressurised supply which improves water efficiency and the amount of land that can be irrigated in this part of Mid Canterbury," he says.

"What Aquaduct and Mr van den Bosch achieved was literally a world first, manufacturing large- bore polyethylene pipe onsite. Their contributions to reduce the environmental footprint of the scheme can't be overlooked either."

The Valetta Irrigation Scheme is supplied by an open channel from the Rangitata Diversion Race to the Valetta district irrigation area of 13,000 hectares at a flow rate of up to 4.5 cumecs supplying 45 farms.

In 2012, the open race system was replaced by a closed polyethylene pipe system to provide water under pressure for farmers on the scheme. This resulted in significant savings by recouping the evaporation and seepage loss of channelled water, saving on-farm pumping costs and allowing some electricity generation where water pressure permitted.

Aquaduct NZ Ltd was also the joint Supreme Award winner at the NZ Plastics Industry Design Awards 2012.

It is currently working in the Hakataramea Valley where it is supplying and installing 18 km of pipe to take water from the Waitaki River over a 150-metre rise using two multi-pump stations.

The Press