Community collaboration creates wetland to clean water in Central Otago

The Manuherekia Catchment Group and local community members transformed a boggy, willow-choked corner of a farm into the 5 hectare Orkney Wetland in Central Otago, New Zealand.

This project aimed to reduce run-off pollution, including sediment, nutrients, and faecal contaminants, before it reaches the Manuherekia River. The initiative utilized $2.8 million in funding to create a system of deep sediment traps and a 1km long serpentine channel designed to filter water through natural processes.

The project brought together a diverse group of stakeholders, including farmers, Ngāi Tahu, local businesses, and several government agencies. Construction took place primarily in 2023. The wetland now supports a variety of birdlife, including a thousand rare black-billed gulls and a marsh crake. It also serves as a habitat for the roundhead galaxiid, a native fish species whose population is being protected by a concrete fish barrier and speedhumps to prevent predation by trout.

The project has changed local dynamics by reducing tensions between landowners over water use and fostering community involvement. Students from Omakau School now participate in water monitoring, while volunteers from Omakau regularly perform weed removal and predator trapping. While the wetland improves water quality, the regional council says they are still waiting on new government legislation before they can establish permanent minimum flow limits for the Manuherekia River.