Weed eradication project to begin on Ōpāwaho Heathcote River

An ambitious project to rid the Ōpāwaho Heathcote River of a series of invasive pest plants is getting underway next month.

The upcoming project by the Ōpāwaho Heathcote River Network will work to remove the invasive Reed Sweetgrass (Glyceria maxima) from the riverbanks and margins of the Ōpāwaho Heathcote River.

The programme will begin in November and continue early into the new year, with works to complete the full weed removal continuing over several years.

The Network has plotted over 50 locations of clumps of Reed Sweetgrass between the Beckford Road bridge and Woolston Loop. These will be carefully treated and effects monitored over a number of years to eventually eradicate this pest plant from the river.

The current project builds on previous successes from the Christchurch City Council to remove the invasive weed from short reaches of the river in 2019.

The programme will also aim to remove a second invasive weed, Reed Canary Grass, from riverbanks above the Beckford Road bridge.

Project Lead for the Ōpāwaho Heathcote River Network Malcolm Long says the removal of Reed Canary Grass is really a trial to see if it is possible to control this grass on riverbanks.

“If the trial is successful, we will attempt to push Reed Canary Grass back down the river over several years. Complete eradication of this invasive weed from the river is probably not possible.”

The spraying programme will be undertaken from the riverbank and by boat, and is due to start in November (weather/tide dependant).

The project has been funded through Christchurch City Council’s Better Off Funding.