One of the key advantages of nature-based solutions (NbS) over grey solutions is their potential to deliver on multiple benefits. NbS are usually initiated and/or designed to serve one or more primary driving challenges that stakeholders, project developers, or funders are most interested in. The additional benefits that the intervention may deliver are often called co-benefits, since they are secondary to the primary benefits but may still be of value to those involved in the project or other potential supporters.
Equally, if not more, important are the trade-offs that should be considered when investing in specific NbS. Trade-offs are the negative aspects of a given intervention or suite of interventions, including detrimental impacts, the non-delivery of a benefit of interest or some other aspect of the solution set that is undesirable.
Determining who receives the benefits, and who might be negatively impacted by NbS, is critical to the long-term success of an NbS program. Knowing who might benefit can help identify program investors. It also helps avoid or mitigate negative impacts on different groups of stakeholders, including local communities and Indigenous Peoples. For example, protection of a forest may benefit a water utility company in a downstream city, whose water treatment costs are stabilized due to avoided increase in sediment loading. At the same time, protection may benefit local communities in terms of jobs, health, and well-being, but, depending on how the protected area is structured, it may also exclude Indigenous Peoples and local communities from those lands and waters.
The geographic scale, or the where, of benefit delivery is also an important factor in understanding the flow of benefits and what this means for program funding and stakeholder engagement. Some benefits are delivered at or close to the implementation site, while others are experienced farther downstream or even outside of the watershed, e.g., the global community may benefit from carbon sequestration. For many interventions there is a strong correlation between the scale of implementation and the ability to deliver benefits farther downstream in the watershed. For example, riparian buffers along a small stream length may deliver water quality benefits immediately downstream of the intervention but then might be offset by additional sources of diffuse pollution downstream. However, if riparian buffers were placed along a significant portion of a stream length, the likelihood of delivering water quality benefits to downstream water users increases.
Just as critical, is when NbS benefits will be delivered or experienced. The trajectory of benefit timing varies widely depending on NbS type and local context. The NbS Factsheets Deep Dive details illustrative graphs for delivery of water security outcomes for each NbS intervention type, including how quickly benefits are expected to be delivered. For example, forest protection starts providing benefits immediately, while forest restoration takes several years to reach full potential benefits, with differences in timing of delivery of recreation, water security, carbon and biodiversity benefits. Timing of benefit delivery can sometimes create a challenge in securing funding for NbS programs, as some investors might look for more immediate returns. A strength of NbS, however, is that benefits are often maintained for a much longer time period, in many cases indefinitely, which is in contrast to many grey infrastructure solutions whose benefits can degrade over time.
For any project planning or design process, it is critical to consider the trade-offs that come with selection of a particular intervention or set of solutions. Balancing the needs and values of different stakeholders is not easy, but it’s important to be transparent about the positives and negatives, or benefits and trade-offs, for all options. Some examples of possible trade-offs from specific NbS include the following:
- Increase in vegetative cover, such as from reforestation, can reduce annual water availability due to an increase in evapotranspiration from the additional vegetation.
- Protecting or restoring natural land cover does not allow that land to be used for productive uses, which could result in increased incomes for specific stakeholders, such as row crop agriculture, or for development.
- Restoration of formally inhabited lands requires residents to move elsewhere, which could have a variety of negative impacts on individuals and families. For example, floodplain reconnection may require homes that have been built behind levees to be removed and their inhabitants to relocate. Demand for land to conduct large-scale implementation of certain NbS categories is a material issue, especially for marginalized communities, and therefore integrating equity considerations and free prior informed consent into stakeholder consultation processes is essential to ensure sustainable WIP execution.
In some cases, it might be possible to mitigate against possible trade-offs. One way to do this is through the specific design or implementation approach of an NbS. For example, rules for a protected forest may still allow local community members to hunt and gather food, avoiding negative impacts on traditional food sources. Another way to mitigate for a potential trade-off is to compensate a stakeholder group for lost benefits, or to provide other benefits that are equal to or better than the lost benefits. For example, fencing of a streambank to promote riparian vegetative growth may result in loss of access to water for ranging cattle, but the project could provide funding for an alternative water supply for the cattle.
Read the Deep Dive to learn more about how to account for benefits and trade-offs of Nature-based Solutions.
Resources
Nature-based Solutions Benefits and Trade-offs
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