Nature-based solutions: making invisible value visible

Across Aotearoa New Zealand, expectations for water infrastructure continue to shift. Communities expect systems that do more than move and treat water. They are looking for solutions that support health and wellbeing, improve and protect ecosystems, protect communities and strengthen connections to place.

However, infrastructure decisions have not always kept pace with these expectations. Business cases often prioritise financial costs because they are easier to measure. Environmental, social and cultural benefits can be more difficult to quantify despite being highly valued by communities. Where only financial metrics are considered, this can create a disconnect between what communities want and what projects ultimately deliver.

Nature-based solutions can help bridge this gap. Unlike traditional “grey” infrastructure solutions, they work with natural processes to address flooding, improve water quality and respond to climate pressures while contributing to broader community outcomes. Wetlands, for example, can reduce flood risk, improve water quality and store carbon while also supporting biodiversity, recreation and connection to place.

The challenge is not whether these benefits exist, but how to make them visible within investment and planning decisions.  

Water infrastructure serves a pivotal role in supporting safe communities through the provision of water and wastewater services and the management of flood risk. It is increasingly recognised as part of a wider system that connects land, ecosystems and communities and must respond to this complexity. It needs to increase the resilience of our communities, support environmental recovery and reflect cultural values. These demands extend beyond the traditional role of water infrastructure.

Nature-based solutions align closely with this broader role. They enable water management approaches that deliver multiple positive outcomes that reach beyond conventional water management outcomes. However, when compared with conventional infrastructure in a manner that does not fully represent these benefits, they can appear less favourable within the typical scope of traditional evaluation processes.

This is not due to a lack of value, but to a gap in how value is measured, quantified and communicated. Business cases still often prioritise financial outcomes, even as expectations expand to include environmental and social impacts. As a result, broader benefits are not consistently and transparently assessed to be subsequently communicated alongside capital costs.

Addressing this gap requires a different approach to considering value and informing decision-makers. 

To help address this challenge, we developed a structured assessment approach that captures and compares the value of nature-based solutions in a form that can support a more holistic decision-making process.

Rather than relying on a single measure, the assessment considers six interconnected areas:

• Climate change
• Community liveability
• Cultural values
• Ecosystems
• Public health
• Water management

Each category reflects how infrastructure interacts with people and place.

Within these categories, the assessment considers 18 indicators across 33 criteria. A key distinction of the approach is that benefits are quantified in physical terms and, where possible, then translated into monetary values using project-specific data and established valuation methods. This creates a consistent framework to measure and compare key outcomes across different benefit areas.

The approach also captures outcomes that are often overlooked and allows them to be considered alongside traditional financial measures, supporting more informed decision-making. 

We applied this approach to Christchurch City Council’s Waitaki Street project, part of the wider Ōtākaro Avon River Corridor Regeneration Plan. While the project's primary objectives were stormwater treatment and flood management, it was intentionally designed to deliver broader outcomes that align with the council's six values for surface water management: ecology, drainage, culture, heritage, landscape and recreation.

The solution combined multiple nature-based interventions, including a 3-ha constructed wetland for stormwater treatment, 600 m of flood defence, restoration of 1.8 ha of tidal wetland along the river and establishment of 0.9 ha of coastal forest. Together, these elements demonstrate how working with natural systems can support core water management objectives while also creating opportunities for ecosystem restoration, improved amenity and stronger community connections to place.

Using the structured assessment approach, benefits were evaluated across climate change mitigation, community liveability, ecosystems, public health and water management. The assessment highlighted significant value from ecosystem restoration alongside benefits for climate resilience, community wellbeing and improved water outcomes. This is particularly important because nature-based solutions can sometimes involve higher upfront costs than more conventional infrastructure. By identifying and quantifying a broader range of benefits, the assessment helps demonstrate where the design solution and any additional investments can deliver value across multiple outcomes, providing decision-makers with a stronger evidence base for comparing options and justifying investment.

By making these broader outcomes visible alongside traditional infrastructure measures by quantifying physical benefits such as hectares of ecosystems restored or flood damage avoided and applying a monetary value to them, the approach was able to provide a more complete picture of the project’s overall value

Measuring a range of positive outcomes reveals the scale and interconnected nature of the value nature-based solutions can deliver. Rather than delivering isolated benefits such as stormwater conveyance, nature-based solutions create multiple outcomes through a single intervention. A wetland, for example, can simultaneously improve water quality, reduce flood risk, restore habitat, create recreational space and contribute to climate resilience. Yet this cumulative effect is often overlooked when value is assessed through a narrow economic lens.  

Shifting the focus from assets to outcomes changes how people understand water infrastructure. It highlights the role water systems play in supporting communities and landscapes. This shift also reshapes how decision-making defines value. Beyond technical performance and cost, it considers how infrastructure can simultaneously deliver water services, contribute to wellbeing, support environmental recovery and reflect local values.

In Aotearoa New Zealand, water connects closely to identity and wellbeing. It is part of a natural system that holds high cultural significance. Water management requires approaches that move beyond traditional fiscal assessment measures to better reflect these broader outcomes. 

Incorporating environmental, community and cultural indicators within investment decision-making frameworks allows these benefits to be more clearly represented in decision-making. This supports a broader understanding of value and creates space for conversations that better reflect community priorities alongside functional infrastructure needs. 

A consistent assessment approach strengthens decision-making across the project and asset lifecycle, which is becoming more important as water infrastructure is increasingly required to respond to climate pressures.

During early planning, it supports option screening by allowing different solutions to be compared across a broader range of outcomes. In business cases, it helps present a clearer understanding of project benefits beyond cost alone. At a programme level, it helps identify where investment can deliver the greatest impact.

Using a shared framework improves alignment between project teams, decision-makers and stakeholders by showing how different outcomes contribute to overall project success. 

There is a clear opportunity to move beyond traditional approaches to infrastructure delivery. Nature-based solutions expand the role of water infrastructure by shifting the focus from single-purpose assets to systems that deliver multiple outcomes to better support ecosystems and communities.

They also highlight how infrastructure interacts with the environment and communities over time. Making the value of these multiple outcomes visible strengthens the evidence base for decision-making by allowing financial, environmental and social benefits to be assessed using a common language for investment decisions.

Nature-based solutions do not replace conventional infrastructure. Instead, they broaden the range of options available and support more balanced decision-making. Most importantly, it shifts the focus towards solutions that respond to the complex needs and values of a place, rather than those that are aligned with a single objective and metrics that are the easiest to measure.

Water infrastructure designed in this way contributes to healthier waterways, more resilient systems and stronger communities. That is where infrastructure creates lasting value.