Environment
- Waituna Lagoon will be mechanically opened to prevent ecological damage and assist the community.
- High water levels have been affecting local roads, paddocks, and farming activities for weeks.
- Lagoon opening aims to flush nutrients and sediment, resetting the environment for summer.
Environment Southland has decided to use its emergency powers under the Resource Management Act to open Waituna Lagoon. The lagoon’s water levels have been unusually high for several weeks, sitting above 2.5 metres. This situation has impacted local communities, damaging roads, paddocks, and farms in the surrounding area.
Lucy Hicks, general manager of integrated catchment management, said the decision was made to safeguard both the community and the lagoon’s ecological health. "Our scientists, alongside experts from the Department of Conservation, have been assessing the impact of consistently high water levels on the environment, particularly as we approach summer," Hicks explained.
To address the issue, diggers will remove gravel from the lagoon’s bar, creating a channel that will allow the water to flow into the sea. However, the timing of this operation is crucial to ensure it is carried out safely and effectively.
"Opening the lagoon now has both benefits and challenges," Hicks said, noting the need to flush nutrient-heavy waters to prevent algal blooms while also considering the requirements of native aquatic plants. "We aim for this opening to flush nutrients and sediment, resetting the lagoon and reducing the need for future openings."
Efforts will also be made to close the lagoon before summer, though this depends on wind and sea conditions, which help return gravel to the channel.
Waituna Lagoon, part of the Awarua-Waituna wetland complex, holds international significance. It is home to various native species and is culturally important to Ngāi Tahu. The area is also valued for recreational activities, including trout fishing and walking.