The technology was developed at Massey University and adopted by Fonterra and the Department of Conservation’s (DOC) Living Water partnership.
The wetlands consist of native wetland plants, tethered to buoyant mats or “rafts” that sit on the water surface.
The rafts filter water in drains and runoff before it hits waterways.
Living Water installed a number of the floating wetlands in nutrient-enriched drains around Lake Areare to monitor the technology.
DOC community ranger Michael Paviour is excited by the early results from the trial.
“The floating treatment wetlands have only been installed for a relatively short time but initial tests and the rapid plant growth indicates that they are doing a good job removing nutrients from the water.
“The floating wetlands are by no means a silver bullet for solving water quality but when used alongside other activity such as silt traps and riparian planting they are proving to be a practical and effective method for improving water quality.”
Fonterra Living Water programme lead Tim Brandenburg said the floating wetlands were an innovative new tool for nutrient management and had the potential to be very useful on farms.
“If the positive results from this trial continue, this technology could prove very appealing to our farmers as a simple tool for managing nutrient levels in ponds and drains.
“The great thing about the floating wetlands is that they don’t just remove nutrients from waterways, they also attract bird and insect life and the grasses have the potential to be harvested as supplement feed for stock.”
Living Water will run the trial until the middle of next year and if the positive result trend continues the floating wetlands could be rolled out in waterways around the country.
