NI can replace gray (conventional) infrastructure for projects with goals including:

1. Treating industrial process water and wastewater treatment
2. Rehabilitating degraded land
3. Remediating contaminated or polluted areas
4. Reducing risk, and building more resilient infrastructure
5. Managing stormwater
6. Securing access to water in quantity and quality

Some NI solutions have greater land requirements than gray infrastructure. If insufficient land is available, there may be options to partner with neighboring land owners in support of shared NI goals. However, there are also examples of NI that have very small land requirements, such as a green roof or a bioswale in a former drainage ditch in an industrial and office park or between a sidewalk and road in a city. Consider working with a technical expert to understand if you have sufficient land requirements.

NI can also be used to enhance gray (conventional) infrastructure projects, including:

1. Building construction (e.g., roadside trees, permeable pavement, green roofs, green walls, planter boxes, rain barrels, rooftop gardens, as well as for heat island and local climate regulation and habitat)
2. Road and bridge construction (e.g., landscape preservation and restoration)
3. Wastewater or stormwater polishing treatment, when a gray solution is not sufficient (e.g., natural treatment systems, constructed wetlands, and phytoremediation)
4. Flood hazard mitigation (e.g., habitats, such as oyster beds, coral reefs, salt marshes, or mangroves could enhance the performance of levees)
5. Watershed protection and restoration to enhance the performance of a water treatment facility (this could include riparian habitat, wetlands, and soil and landscape restoration)
6. Air quality improvement (such as afforestation and reforestation)

Figure 1 identifies many of these examples and their applications

Implementation of NI solutions requires a cross-functional team of subject matter experts that can include expertise in biology and ecology, landscape architecture, civil and water resource engineering, and stakeholder engagement expertise. If you do not have this expertise within your organization, consider partnering with universities, non-profit organizations, and engineering firms with this expertise.

Many countries and municipalities have regulatory guidelines in place for use of NI solutions, or promote their use through various initiatives and best practice guidance documents. Research government websites for local standards and guidance documents similar to these:

1. European Commission Green Infrastructure Strategy.
2. The U.S. Environmental Protection Agency (USEPA) Strategic Agenda to Protect Waters through Green Infrastructure seeks to expand the use of NI.
3. The U.S. Army Corp of Engineers’ North Atlantic Coast Comprehensive Study Report recommends the use of natural and nature-based solutions as part of an integrated set of solutions for coastal resilience.
4. Singapore’s Inter-Ministerial Committee on Sustainable Development Public Utilities Board (PUB) has published guidelines that include green infrastructure design considerations (PUB, 2014).

Implementation of NI solutions often supports company sustainability goals and can provide additional incentives and financial or management support for completing these projects. Consider whether your company has committed to contribute to the Sustainable Development Goals (#6 and #15) and other societal and global goals or frameworks (CBD Aichi Targets, UNFCCC, UNCCD or the Bonn Challenge).

Businesses are increasingly facing risks from climate change. This may result in regional temperature shifts, variable precipitation and water supply, and more frequent and extreme weather events. Under these conditions, hazards, such as inland floods, drought, heat waves, fires, high winds, and coastal waves and storm surges, may increase the risk of damage to business assets, supply chain interruption, and impacts to consumers and employees. NI solutions can offer increased resilience to these hazards or a means to adapt to future hazards.

NI solutions can effectively address stakeholder goals, such as local communities’ concerns about scarcity of natural resources and regulators’ expectations regarding compliance. They can also provide engagement opportunities for education, volunteerism, and recreational activities.

Outcome options:

1. NI options are not appropriate for your project at this time. Consider these options in the future in case conditions change.
2. Consider partnering with universities, nonprofit organizations, or third-party consultants to support your team.
3. NI can be considered, but you may not be able to capitalize on the co-benefits often associated with NI.

Consider NI options for your project – Move to Checklist and Project Select™.