Weed control projects to enhance Waihao River tributaries

The Lower Waitaki Water Zone Committee has supported the allocation of more than $40,000 of Immediate Steps biodiversity funding over two years on two weed control projects in tributaries of the Waihao River.

These projects were presented by our southern zone biodiversity officer Kennedy Lange at a recent zone committee meeting.

Both sites at risk of being overrun by willows

“It’ll be great to see these projects getting underway soon as both sites have some natives underneath a bit of a canopy of weeds which makes it hard for them to survive," Lange said.

“If we were to leave the site as it is, they’d be overrun by the willows. The added problem there is that willow roots grow into the streams and block up the stream for native fish, so it can be an issue not only for the plants but for the native species in the stream too.”

Each site connects to riparian wetland areas and then into Waihao River and Wainono Lagoon.

Mudfish to benefit at Buchanan’s Creek site

This $32,500 proposed project (of which Environment Canterbury will contribute $24,500) could benefit the threatened native Canterbury mudfish / kōwaro, which are present at the Buchanan's Creek site.

The project aims to diminish the dominance of willows and narrow riparian margins, which limit the ability of the native biodiversity, flora and fauna at the site to flourish and grow.

With Immediate Steps funding secured, the project will remove the willows and halt the site’s decline through aerial and on-ground control, the removal of dead spars and planting the site out to increase the stream’s shade.

Wetland plant species to be protected at Lower Waihao River

The second project recommended for funding targets willows in a tributary of the Lower Waihao River, aiming to improve the habitat for wetland plant species and indigenous fish.

Aerial control of the pests, plus excavator removal of dead spars account for the $24,000 spend (of which Environment Canterbury will contribute $18,000), protecting the likes of the native longfin eel / tuna.

Lange said another positive of the project was the long-term benefits of the funding.

“Both projects have funding to have a digger come in after a few years and remove the (willow) stumps, which until then will have provided shade for the area, allowing natives to regenerate naturally,” he said.

These projects align with the water zone committee’s goals of maintaining and improving water quality in the northern catchments, improving traditional mahinga kai sites, and protecting indigenous fish and their habitats.

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