Project restores biodiversity values along Waipara River

Teamwork between Hurunui District Council and Environment Canterbury (ECan) is restoring biodiversity values along the Waipara River.

At this month’s Hurunui District Council Strategy and Community Committee meeting, ECan Zone Manager Andrew Arps said 47 hectares of woody weed, such as willow and other exotic trees, are in the process of being removed from the Waipara River following the aerial spraying of the trees in February.

Hurunui District Mayor Marie Black said the visual impact of the clearance of the fallen trees in the fairway was already generating positive feedback from residents travelling on State Highway 1.

The project was initiated after the two councils got together following community concerns. Funding had taken three years to secure, said Arps. The programme is being funded by Braided River Revival - Whakahaumanu Ngā Awa ā Pākihi.

Hurunui District Council’s Water and Land coordinator Rima Herber has been assisting ECan’s river engineers ahead of the willow control work, organising three field trips with ECan staff to assess the unique challenges in the river. These include the extent of the willow invasion, the amount of gravel build-up and the large, permanent islands that the trees have created in the fairway of the river.

“At the bridge on Double Corner Road, mature willows had established right across the river, leaving gaps of only a few metres between each tree. There had been a large build-up of gravel in this area, due to the willows preventing the flow of gravel downstream in high-water events. This site, particularly, showed the extent of the problem willows were causing in the river,” Herber said.

Arps said the project’s aim is to restore a more natural braiding pattern for the Waipara River and Weka Creek to reduce flood and erosion risk, and to improve habitat for native flora and fauna.