How the Internet of Things can help monitor water quality in important NZ catchments

Water quality monitoring in real-time
Real time sensors in the Waikato are delivering real-time data for the first time. Photo credit: Supplied

The Internet of Things (IoT) often brings to mind the likes of fridges and washing machines connected to the world wide web, but it can have much more important functions.

A good example is the automated water quality sensors collecting hourly information in the Manga-o-tama catchment area in the Waikato.

The sensors gather data from Manga-o-tama Ōhaupō Peat Lakes to Waipā River Connection project and deliver it directly to an online dashboard using Spark's IoT network.

The catchment is an important route for native fish species, such as short finned and long finned eels, but is also a haven for plenty of other natives.

That includes several rare animals, including the pūweto (spotless crake) and pekapeka-tou-roa (long tailed bat), one of only two remaining species of native land mammals in Aotearoa.

The Manga-o-tama catchment project is supported by Living Water, a partnership between the Department of Conservation (DoC) and Fonterra.

Living Water freshwater science lead Dr Katie Collins says for the project the organisation wanted to ensure water quality information could be collected easily and reliably.

"Monthly data provides good information for establishing long-term trends and in large, stable bodies of water but results can be highly weather dependent and collection of samples is time consuming," she said.

"Real-time water quality monitoring allows us to see daily patterns and changes as they happen, including the impacts of high rainfall events and different flows."

Every hour the sensors record nitrates, turbidity, total suspended solids, total dissolved solids, dissolved oxygen, water temperature, conductivity and pH.

The information is accessible on a smartphone or computer, to anyone in the catchment who would benefit from the data, such as catchment groups, iwi and hapū, scientists and farmers.

Collins said the real time monitoring will allow Living Water to understand long and short-term water quality trends in the catchment.

Tony Agar, Spark IoT lead, said smart technology can play a hugely critical role in helping ensure New Zealand's freshwater lakes, streams and rivers are clean, swimmable and fit for recreational activities.

"Farming is central to New Zealand's economy, but it can have a significant impact on our lowland freshwater ecosystems," he said.

"By using sensors to provide real-time data to a web-based platform, Living Water can easily see data visualisations of patterns, helping them to quickly identify any issues that need fixing."

Collins said there was a large variation in the quality of water day to day and the organisation doesn't have a lot of information about those trends because there had been now way to collect the data.

"This data will let us know if the interventions like riparian planting, wetland restoration, fencing setbacks and on-farm changes are having an impact," she said.

"Many of the interventions... reduce sediment entering waterways in high rainfall when it's dangerous to gather water samples. These sensors are designed to withstand high flow conditions and will continue to provide real-time data in even the worst conditions."