Murihiku Slow the Flow delivers promising findings

A two-year programme designed to explore how Murihiku Southland could broaden its thinking to include nature-based solutions to help reduce flood risk is coming to an end – and the early findings look promising.

Murihiku Slow the Flow project manager Ella Lawton said it was a collaborative pilot led by Environment Southland and Te Ao Mārama Inc. in association with multiple organisations.

It explored how nature-based solutions, such as wetlands, detainment bunds, native vegetation and re-connecting rivers with floodplains, could help reduce flood risk, build community resilience and improve the health of our land and water.

“It drew on a wide range of expertise to inform an integrated catchment approach from both a Western science and Mātauranga Māori lens.”

The project focused on the upper Mataura catchment, where flooding in February 2020 forced the evacuation of more than 4500 people.

As the region’s changing climate increased the intensity and frequency of extreme weather, reducing the peak flow of the Mataura River was critical for downstream communities like Gore and Mataura, she said.

“We tested how a collaborative approach — bringing together technical, cultural and local knowledge — could be used to assess the potential for nature-based solutions to reduce flood risk and improve catchment-wide environmental wellbeing.”

Assessing the feasibility of including nature-based solutions in a catchment approach to flood risk would be a key aspect of future planning, Ella Lawton said.

One example of a tool tested through the project was the rural ‘More Than Water Tool’ prototype.

The tool reflects the concept that nature-based interventions can deliver multiple co-benefits and cost-related advantages, in addition to more traditional flood management methods, such as flood banks.

It offered a practical way to summarise the broader benefits of potential interventions and identify priority outcomes, while also highlighting where evidence is strong or weak, she said.

“It generated insights into the benefits and opportunities of using nature-based solutions at a catchment scale to reduce flood risk.”

The project team would now consider whether this tool or a similar approach, could be used in future decision-making for the Mataura catchment.

The full Murihiku Slow the Flow results will be workshopped with Environment Southland councillors in the coming months, and the final project report will be made available on the Environment Southland website.

The project was supported by funding from the Ministry for the Environment. Murihiku Slow the Flow was one of 21 regional pilot projects across the country running from mid-2023 to mid-2025 – and there would be opportunities to learn from the other projects, Ella Lawton said.

You can find out more about Murihiku Slow the Flow here.