Hi-tech irrigation preserves city aquifer

Farmers irrigating just north of Christchurch are using the latest technology to ensure not a drop is wasted.

The water is drawn from the ancient, slow-moving aquifer that also supplies domestic drinking water to the southern city’s residents.

In the first project of its type in New Zealand, the latest in digital technology has been rolled out to Waimakariri Irrigation’s farmer-shareholders, taking the guesswork out of irrigating. The Waimakariri Irrigation scheme delivers river water to 200 shareholders and irrigates 23,000 hectares between Waimakariri and Ashley rivers.

While the scheme was unusual in that almost half its shareholders were smaller and lifestyle block-holders, it was the 108 farming operations – making up 90 per cent of its land area and take 95 per cent of its water – that were under increasing scrutiny to account for their watering decisions.

Environment Canterbury’s Waimakariri water zone committee chairman, David Ashby, said the area had serious challenges to address in terms of low flows, groundwater depletion, and water quality.

A small number of dairy farms concentrated in the Eyre area (on the north bank of the Waimakariri River) had the technology implemented first.

‘‘With 80 per cent of dairy development occurring in this area, which feeds into Silverstream, we have an issue with nitrate levels.’’

Ashby was confident that technology would improve water quality.