You can read more about how the ORC works to identify risks and help communities coordinate, prepare, respond in emergencies and recover on our Otago's natural hazards page.

ORC’s work on the Leith channel in Dunedin shows hard engineering alongside NbS can deliver a solution which has worked in times of flooding.

The ORC plays a crucial role in protecting and managing Otago's natural resources, including land, water, and air.

We have a strategy to manage the impacts of flooding in the region. It includes infrastructure like culverts and flood banks, drainage management, planting and river maintenance, community education and robust emergency response plans.

But as climate change is expected to increase flooding and other natural hazard risks, it’s important that together, we continue to look for new and sustainable ways to build resilience.

Taking a nature-based approach to resilience is part of central Government’s plan to address climate change and biodiversity issues but local government is uniquely placed to deliver nature-based solutions (NbS) ‘on the ground’. 

Feasibility Study

Scientists and ecologists are currently studying Te Hakapupu catchment and modelling how it could respond during flood events, both today and in the future.

The modelling characterises how the current catchment will likely respond during an extreme rainfall event, in this case a one-in-100-year rainfall event (100-year annual return interval) with the added effect of climate change.

The model simulates how rain, captured in the steeper inland areas of the upper catchment, flows through the main channels of the Hakapupu/Pleasant River, Owhakaoho/Trotters Creek, and Watkin Creek into the flatter areas of the lower catchment, causing flooding of farms, homes, and roads.

Once the modelling is complete, we will be assessing the feasibility of three potential nature-based solutions within the catchment to understand what solutions may be effective, practical to implement and sustain, and provide other important benefits for biodiversity, farming, and the wider community. 

We will be talking to local iwi, farmers, foresters and other stakeholders to help shape the development of these three options for nature-based solutions in this catchment.  

The Feasibility Study for Te Hakapupu is expected to be complete by early 2025. 

Reviving wetlands and native forests: This helps to drawn down carbon, filter and store water, and provide habitat for native species. 

Planting trees and vegetation: This can help slow and filter water, reducing soil erosion and flooding impacts, as well as improving air quality. 

Creating ecological corridors: This allows native species to move across landscapes, from one habitat to another, which is important for their survival.

Using natural materials for infrastructure: For example, using timber instead of concrete in construction can help to reduce carbon emissions. 

Some nature-based solutions can result in cost-savings for communities and farmers, by reducing the need for chemical inputs, enhancing water retention, and preventing soil erosion

Globally there are examples of how nature-based solutions can create new economic opportunities through green jobs, eco-tourism, and sustainable agriculture.

You can read more from the International Labour Organization: How Nature-based Solutions can power a green jobs recovery.

 Yes. Our landscape offers a range of options for Nature-based Solutions, including:   

• Restoring wetlands: Absorbing floodwaters, filtering water, and supporting native wetland birds. 
• Planting native trees: Reducing erosion, sequestering carbon dioxide, and providing habitat for native birds and insects. 
• Creating riparian buffers: Stabilising riverbanks, reducing erosion, and improving water quality. 
• Using green infrastructure: Rain gardens, green roofs, and bioswales help manage stormwater and improve urban environments. 
• Adopting regenerative agriculture: Practices like reduced tillage and cover cropping improve soil health, reduce erosion, and enhance biodiversity.  

Research and real-world projects show Nature-based solutions can be very effective. For example, restored wetlands can reduce flood peaks by up to 50%, and native forests can store significant amounts of carbon dioxide. 

Globally, high-quality nature-based solutions have the potential to save up to 10GT* of CO₂e per year (more than the emissions from the entire global transportation sector) as well as the potential to reduce the intensity of climate hazards by 26%, with potential cost savings from climate change impacts of USD 104 billion by 2030 and USD 393 billion by 2050.

*Gross tonnage 

Farmers, forestry, communities, local councils, businesses, and government agencies are all increasingly adopting nature-based solutions. The Ministry for the Environment provides funding and support for NbS projects through initiatives like Jobs for Nature. The ORC uses planting and wetlands in some areas too, and this project will look at how we could build on that work.

Examples of nature-based solutions projects can be found on the MfE website: 

• Working with nature
• Natural environment

and other global reports, including:

• Nature-based Solutions for climate change mitigation (UNEP)
• Assessing the Benefits and Costs of Nature-Based Solutions for Climate Resilience (World Bank)
• Nature-based Solutions for climate (IUCN)

Otago's diverse landscape faces various challenges, from flood risks and biodiversity loss to coastal erosion and climate change. Nature-based solutions could offer promising options for tackling all of these issues. 

For our project, we are focusing more on flood mitigation and water management and we’re looking into restoring and / or creating wetlands and planting.

Healthy wetlands are able to naturally absorb and store floodwaters, reducing peak flows and protecting communities from flooding while improving water quality and increasing biodiversity. 

Planting native trees and shrubs along riverbanks can slow down water flow and prevent erosion while providing habitat for native species.

Nature-based solutions are most effective at scale but when this isn’t possible, due to cost or the loss of productive land, a number of solutions dotted around a catchment subject to flood risk can work together to reduce the impacts of excess rainwater.

It’s early days but if we were to work with landowners in future, it would need to be collaborative, involving council land, farms, lifestyle blocks, and large landholdings. If lots of land users do a little bit, the cumulative effect will be widely felt.

We’re going to explore this as part of this work. We want to understand how much funding would be needed to enable NbS to be used across Otago and how this cost could be shared. With shared benefits for landowners, locals and the wider community and, it follows that cost would also be shared, and this is how NbS are working in other parts of the world. 

Nature-based solutions can be a cost-effective alternative to ‘hard’ infrastructure like concrete levees or water treatment plants, but they do require significant investment. They can also complement infrastructure and traditional engineering solutions, helping to build greater resilience. It's all about finding balance and the right solution for a particular problem.

‘Hard’ engineering solutions that are currently used to manage flood risks in New Zealand, include things like stop banks, rock reinforcements on stream banks and gabion walls.

In some cases, water channels are diverted, straightened, or deepened and armoured to increase capacity and reduce flood risk – and larger interventions could include dams and reservoirs.

ORC provides flood protection and land drainage for approximately 43,000 hectares of rural and urban land in Otago, with more than 200km of floodbanks, 14 pumping stations, 42 bridges, 369 culverts and various other infrastructure including weirs, walls, trees and groynes. You can find out more on our Flood defences page.

No. Hard solutions are found to be much more effective when used in combination with nature-based solutions, which can help to relieve the pressure on such infrastructure during large flooding events.  The downside being they strip away existing habitat, limit biodiversity and do not benefit existing water quality.

Nature-based solutions can help to protect land and make it more resilient by reducing the impacts of flooding and erosion, improving soil health and water quality.

NbS provides an opportunity for farmers and landowners to work with Council and gain support to implement solutions that are both beneficial for their land and the wider environment. 

Globally, co funding by landowners, users and local government has created recreation and tourism opportunities, as well as economic benefits around planting trees or crops that can be harvested. Learn more about MfE case studies on the Ministry for the Environment website.

In a broader sense - it’s also an opportunity for farmers and growers to continue being world-leaders in sustainable land and water care practices. 

The Toitū Te Hakapupu Restoration Project is a separate project that is funded by the Ministry for the Environment and started in 2021. The aim of this Project is to work with local Mana Whenua, community and stakeholders to improve water quality in the catchment.

While the nature-based solutions project has a flood-prevention focus, one of the potential benefits of their installation is improved water quality – meaning there is a lot of cross-over between the groups and individuals interested in both projects. As a result of this cross-over, the nature-based solutions project will draw on the technical findings, engagement learnings, and relationships that were built in this catchment during the Restoration Project and use them as a starting point for their investigations. 

For the Feasibility Study in Te Hakapupu catchment, we are working with local land users and stakeholders to test implementing nature-based solutions on their land and we will share information about our work through community newsletters and our website.

The Engagement Study involves targeted engagement across the whole of Otago with Iwi partners and representatives from stakeholder groups such as farming, forestry, lifestyle block owners and volunteers working in various catchments. There will also be a digital survey available for people interested in taking part in this early stage. The findings of the Feasibility Report and Engagement Study will advise Council on decisions that need to be made for NbS to be promoted into the future.

Through prior consultation with our regional catchment groups on other projects, we’ve heard many land users would like to work together to improve water quality and would like to work with ORC to gain access to support, expert knowledge and funding.

This project is about  building on that and working with the community to gauge interest and understand the extent of the support that people would need to make a rollout feasible.

Any future decisions would involve further engagement and conversations.