Water – more than just meets the eye

Luke Guyton carries out monthly water testing for the Waihao Downs Irrigation Scheme. He uses the bathyscope to assess the amount of fine sediment in the Waihao river.

A ‘get out there and do it’ approach to water monitoring and sampling is important to a South Canterbury irrigation scheme.

The Morven Glenavy Ikawai Irrigation Company, known as MGI, is responsible for the Redcliffs; Morven, Glenavy, Ikawai; and Waihao Downs Water Schemes. The Redcliffs scheme is one of the oldest in New Zealand, when it was constructed as a depression relief project in the 1930s. The Morven, Glenavy, Ikawai scheme was then built by the Government in the 1970s. MGI purchased the two schemes from the Crown in 1989 and is now responsible for supplying water from the Waitaki river to 28,000 hectares of farmland in South Canterbury.

MGI Environmental Manager Judith Neilson said water sampling was an important part of water quality management for the company, and said it was fundamental it was done frequently.

She said every month in the Waihao Downs Scheme surface water samples were taken from four sites within the scheme’s area, with groundwater sampling occurring during the irrigation season, as well. Water quality sampling is a requirement of the water take consent which MGI holds as a company on behalf of its shareholders.

“We test both groundwater and surface water quality; and undertake additional monitoring for macrophytes (aquatic plants), matting and filaments; as well as periphyton. It’s really important that we get out and do it each month, so we have consistent data across seasons from year to year, that represents what’s going on, over time.”

Ms Neilson said long-term it allowed them to identify any trends that might develop; and to confirm testing parameters, to be able to monitor and respond to what was happening in the different waterways most effectively.

“We monitor to see if there are any effects over time, so that we can then respond to them. It is important to determine whether or not any changes are due to scheme operations.”

Luke Guyton has been working for MGI for two years and took up the role of irrigation Operator which was previously held by his grandfather Andy Guyton.

On a day-to-day basis Mr Guyton oversaw supplying water throughout the scheme, however each month he enjoyed a change by undertaking the water sampling.

“It’s a good opportunity to see a different part to what I do every day, you become really aware of what is going on when you are out eyeballing the sites … it’s lots of fun in the summer and it can be very cold in the winter, but it’s all worth it.”

Mr Guyton said often when he was out sampling, he would have people stop and ask him what he was doing.

“I’m always more than happy to explain. Farmers are especially interested in what is happening in the water and will often stop and ask how it is looking.”

The water samples are sent to an independent laboratory for analysis and from there the scheme is able to compile the data over time, to determine trends.

Ongoing water quality monitoring remains an important activity for both MGI and its shareholders, who all want to achieve the same goal of environmental sustainability and good water quality.

“I’m always more than happy to explain. Farmers are especially interested in what is happening in the water and will often stop and ask how it is looking.”