With the 2018 hurricane season in full swing, coastal infrastructure must now withstand chronic, long-term challenges coupled with the looming threat of a severe tropical storm. To strengthen the effectiveness of existing infrastructure, coastal communities across the country may want to consider supplementing traditional “hard infrastructure,” with natural and nature-based infrastructure solutions like dunes and marshes, which offer economic and environmental benefits while strengthening existing coastal barriers and infrastructure.
Traditionally, the preferred approach for coastal communities to mitigate the effects of climate change and natural disasters has been to armor their shores with various forms of hard infrastructure – such as sea walls, rock-revetments, jetties and groins. A 2015 study determined that 14 percent of the U.S. coastline is currently armored using some form of hard infrastructure.
Although armoring with hard infrastructure may offer a sense of security to coastal communities and property owners, when it is relied on as the sole means of defense, it can often present numerous unforeseen negative impacts, including:
- Increased rates of erosion
- Degradation of water quality
- Loss of natural habitat and recreational space
- Unsustainable levels of spending towards maintenance and repair of infrastructure and property
To mitigate these impacts some experts from leading environmental organizations, like the National Oceanic and Atmospheric Administration (NOAA) and the Nature Conservancy, suggest incorporating forms of “natural” or “nature-based” infrastructure into coastal resilience approaches.
Natural infrastructure refers to the utilization of naturally occurring coastal ecosystems as a means of defense for coastal communities; while “nature-based” infrastructure is defined by Kim Penn of the NOAA’s Office for Coastal Management as “engineered systems that are designed with the intent of mimicking the natural functions.”
Examples of natural infrastructure include:
- Dune systems
- Maritime forests
- Coral reefs
Examples of nature-based infrastructure include:
- Oyster reefs
- Permeable surfaces such as rain gardens and bioswales
Both natural and nature-based infrastructure can provide many benefits to coastal communities who implement them. Examples include invaluable natural habitat for coastal biodiversity, nesting sea birds, sea turtles, and juvenile fish species that provide ecotourism opportunities and help replenish commercial fish stocks.
Natural areas also support numerous economic benefits through recreational opportunities such as hiking, kayaking, and fishing. Although more difficult to quantify, natural infrastructure also brings aesthetic value and natural beauty to local residents and visitors alike.
Yet despite the benefits, implementation of natural or nature-based infrastructure within coastal communities has been limited because these benefits are often difficult to quantify when compared to the traditional “hard-infrastructure” approach.
Some experts like Ariana Sutton-Grier of NOAA, argue that utilizing natural infrastructure, either on its own or in tandem with existing hard infrastructure is far more cost-effective than relying on hard infrastructure alone. Implementing a natural-infrastructure approach may seem difficult for highly developed coastal communities. However, a recent study authored by Sutton-Grier shows that more developed communities can use a “hybrid-approach,” as an effective solution for providing coastal resilience.
Hybrid approaches allow communities to protect investments made in hard infrastructure by combining them with various nature-based approaches, like oyster reefs and wetland or dune restoration projects. Doing so creates multiple lines of defense for coastal communities – creating a system that is capable of adapting to the various physical and environmental changes occurring in coastal areas.
Although there is no single, “one size fits all” strategy when it comes to coastal resilience, incorporating some form of natural or nature-based infrastructure is something that all coastal communities might want to consider to enhance their resilience to sea level rise and natural disasters.