River nutrient study

Back in December 2021 sharp-eyed folks crossing the footbridge would have noticed this mystery device. It appeared to be monitoring river flow.

It wasn’t though. Instead it’s been continuously monitoring the height of the river and sending the data back to Horizons Regional Council as part of a project.

On Thursday 31 March 2022 a small team from Horizons Regional Council spent about 12.5 hours from 6.30 am sitting beside the Waikawa Stream as part of a project measuring nutrients in the water column.

At this stage, this site is one of only 4 in the country involved in the study.

The researchers had set up some floats in the water: one on the surface and one closer to the bottom of the river. They had also set up a pulley system across the river. Every 15 minutes they pulled the ‘HMS Octopussy’ across the river. A sophisticated sensor on the bottom took measurements across the full depth of the water column, and sent data back to the team.

They spent 12.5 hours there because they needed to get data across the whole tide cycle.

The data will eventually be available to the public.