Waikato river marae to trial first nitrate wireless sensor

By Mānia Clarke
  • Waikato/Bay of Plenty

In a first, a scientific research charitable business is working with a Waikato marae to release a wireless sensor that measures nitrate levels in rivers. Lead project researcher Dr Leonie Jones says it will give local iwi the tools to care for their ancestral Waikato river.

The Waikato River of a hundred taniwha - at every bend a taniwha can be found. The ancestral waters will soon have sensors to take care of its waters

Dr Jones says, “The project gives kaitiaki tools to help them better monitor the river, so it allows them to get data that is substantial and comprehensive. So that gives them a footing in the door of councils.”

The wireless sensor prototype has been in development since 2016, with a $250,000 fund from the governments Science for Technological Innovation. It will measure nitrate levels in real time.

Chief Scientific Officer Assoc Prof Ashton Partridge says, “We're not testing the river enough so we don't really know what's going on, so we need to be able to test. It needs to be a cost effective manner along the length of the river.”

The 425km river, the longest in the country was once an abundant food source for the people of Waikato.

Local Pat Kingi says, “In those days many people settled along the river. I recall the time (King) Tāwhiao came here to the plains of Waikato. He thought about his people living along the river who were destitute. They were inspired by him and it was known as a peaceful area.”

A certain section of the Waikato river through to the Port of Waikato is one of the most polluted in the country with high levels nitrate. Eventually all seven riverside marae to the Port will be involved.

“There was once an abundance of kaieo (small mussels), watercress, eels, now it's been depleted. Why? Nitrate has caused this.”

Dr Jones says, “There's alot of activity along the river. We've got farming, industry, agriculture that's all dumping nitrate into the river through runoff and leaching.”

Non-profit enterprise manufacturer Digital Sensoring Ltd says the river clean-up project needs to be met by government agencies.

Prof Partridge says, “The government needs to support this development. Farmers cannot support it and so it needs to be either the regional councils or the government that does it.”

The first sensor is expected to be launched along the river at Horahora marae at the end of the month.