Nature-Based Solutions (NBS)
What are Nature-Based Solutions?
Nature-based solutions are strategies that use, as their guide, the functioning of natural systems such as coastal dunes, composite (cobble, gravel, sand) beaches, or coastal marshes to address a hazard such as coastal erosion or flooding. These alternatives are indented to be dynamic and adapt with a changing coastline and promote accretion of sand. Nature-based solutions usually have multiple benefits; they could address erosion or flooding, but also could promote habitat, clean water, or carbon storage.
The following are a few examples and photographs of nature-based solutions for context:
From left to right: Dynamic revetments, Large wood, Vegetative slope stabilization, Living Shoreline
Coastal dunes are natural features that can mitigate outer coastal flooding, but also promote carbon storage, habitat, and/or diversity in vegetation depending on management goals. Dunes can be made or enhanced by planting vegetation that will trap sand, by placement of sand, or by placement of sand fences.
Composite beaches are natural beaches with sand on the foreshore and cobble on the backshore that mitigate coastal erosion during wave impact. The movement of the cobble during wave runup and downrush dissipates wave energy. Dynamic revetments are an engineered analog of composite beaches, where a cobble berm is constructed on the backshore of a sandy beach, ideally in a location where some cobble already exists.
Coastal marshes are a natural feature that can reduce erosion and coastal flooding, and they provide habitat and carbon storage within estuaries or bays. In estuaries, marsh restoration can be accomplished by planting vegetation in the marsh and placing more sediment to build the marsh platform and by protecting the toe of an existing marsh or a restored marsh from erosion using a living shoreline sill. The sill can be constructed from stone, oyster shells, logs, coir tubes, and other materials depending on the system.
Coastal Erosion Control Snapshots
Interested in seeing visualizations of nature based solutions and learning about how and where to apply them on the coast?
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Information to Support Understanding Nature-Based Solution Implementation
Environmental setting, policy framework, and rules and regulations must be considered in order to effectively implement nature-based solutions. Here, we provide background on considerations specific to the Oregon outer coast.
The Oregon coast is one of the most dynamic coastal landscapes in North America, evident by long beaches (sandy, cobble, and composite), sheer coastal cliffs, dramatic headlands and vistas, and ultimately the power of the Pacific Ocean that serves to erode and change the geomorphology of the coast. The coast of Oregon is tectonically active, with the region exposed to mega-earthquakes and tsunami associated with the Cascadia Subduction Zone. The active tectonics of the region modulate relative sea level rise which, along with differences in sediment supply and geomorphology, can impact the coastal change rates experienced along the state’s outer coast.
The wave climate of Oregon is severe, with winter storms commonly generating deep-water significant wave heights (SWH) greater than 10 m (about one event of this magnitude per year), with the largest storms in the region having generated SWHs in the range of 14 to 15 m. Deep-water SWHs and wave periods have annual averages of about 2 m and 10 seconds (s), respectively. High, long-period waves (averaging about 3 m in height and 12 to 13 s in period), high water levels, and a west-southwest direction of wave approach characterize the winter months (November through February), whereas smaller waves (1-m SWHs and 8-s periods), low water levels, and wind and waves from the west-northwest are the typical summer (May through August) conditions. Tides along the Oregon coast are mixed semidiurnal with a 2- to 4-m mesotidal tidal range. Water levels also have a distinct seasonal cycle, generally due to month-to-month variations in water temperature and, to a smaller degree, salinity.
Along the Oregon coast, each stretch of shore within a littoral cell is in effect a pocket beach, with its sand generally unable to pass around the headlands that extend well offshore into deep water. These littoral cells range widely in their alongshore lengths, from a few to tens of kilometers, governed by the distances between the bounding headlands. During typical years there is a quasi-equilibrium, with the winter storm waves predominantly arriving from the southwest, transporting sand alongshore to the north. The calm weather waves from the northwest return the sand to the south, and in the long term, some littoral cells experience close to a net-zero longshore sediment transport.
Strong El Niño events, such as those experienced in 1982-83 and 1997-98, feature an increased frequency of storms tracking from the south-southwest and higher than typical sea levels. During years when a major El Niño event takes place, the pattern of coastal change involves erosion north of headlands and also north of inlets due to their migration; in addition, there can be erosion where inlets are controlled by jetties because these structures act much like mini headlands. At the same time, beach sand accumulates south of the headlands. These changes are produced by an unusual degree of northward transport and displacement of the beach sand during El Niño winters, far greater than during typical years. Recent research, however, suggests that the relationship between climate variability and coastal change is more complex than previously understood with some stretches of coast in Oregon experiencing erosion and accretion trends at interannual to multi-decadal scales. The complexity of coastal change patterns in the state is one of the motivating factors behind this series of Coastal Erosion Snapshots.
Sources of Information:
- Ruggiero, P., Kratzmann, M., Himmelstoss, E. A., Reid, D., Allan, J., & Kaminsky, G. (2013). National assessment of shoreline change: historical shoreline change along the Pacific Northwest coast (Open‐File Report No. 2012–1007). U.S. Geological Survey. https://doi.org/10.3133/ofr20121007
Oregon Statewide Planning Goals
Oregon’s Statewide Planning Goals 16, 17, and 18 are land use policies designed exclusively to protect and manage the economic, ecological, and recreational resources of the Oregon coast. They dictate how local governments
must zone, regulate, and permit development in coastal environments. Goal 16 and 17 are focused on management of coastal shorelands and estuaries. Goal 18 sets strict planning and development standards for coastal beach and
dune areas in order to reduce hazards from erosion and flooding. Goal 18 is referenced extensively in the Snapshots. Importantly, Goal 18 states that structural non-nature-based and structural nature-based strategies
can only be considered for permitting on lots where parcel boundaries were established prior to January 1, 1977, unless an exception to Goal 18 is granted; in estuarine environments erosion control strategies are subject
to Goal 16 and 17.
Definition of Structural and Non-Structural
There are three categories for permitting coastal erosion control alternatives implemented on the outer coast of Oregon: non-structural nature-based, structural nature-based, and structural non-nature-based. Of note, Oregon Senate Bill 504 requires Oregon to make formal definitions for each of the following alternative types by January of 2028. Each of the Snapshots includes a sub-title designating the alternative as fitting into one of these three categories.
- Non-structural nature-based alternatives are coastal erosion control strategies that use, as their guide, the functioning of natural systems such as coastal dunes and composite (cobble, gravel, sand) beaches. These alternatives are indented to be dynamic and adapt with a changing coastline and promote accretion of sand.
- Structural nature-based alternatives are coastal erosion control strategies that employ nature-based concepts and also use non-biodegradable and/or non-mobile (riged) elements in their design. These are only permittable if the property is Goal 18 eligible.
- Structural non-nature-based alternatives are coastal erosion control strategies that use non-mobile (riged) materials. These are only permittable if the property is Goal 18 eligible.
- Hybrid structures could employ elements from each of the three categories above
Sources of Information:
All coastal erosion control strategies are intended to slow erosion, but none will stop erosion from happening. Each strategy requires routine monitoring and regular and adaptive maintenance schedules. Routine maintenance may include checking for survival of vegetation and watering vegetation on hot days. Adaptive maintenance may include scheduling repairs post storm impact.
Adaptive management decision making is built in during design, the framework outlines a set of critical decision points where a modification or new direction will be implemented if those conditions are met. “If ABC happens, then we will do XYZ”. This mindset is important for nature-based solution success because it integrates critical decision points at the onset of the project. Often there are several critical decision points set with increasing severity and response.
Sources of Information:
- Bond, H., Wengrove, M.E., Conlin, M.P., Wilson, G. and Allan, J., 2025, April. Prediction of Alongshore Transport of Cobbles on Open-Coast Composite Beaches and Dynamic Cobble Berm Revetments. In Coastal Dynamics conference (pp. 217-223). Cham: Springer Nature Switzerland.
- Straub, J.A., Dusek, G., Brown, J.A., Elko, N., Serafin, K., Ruggiero, P., Palmsten, M.L., Hannides, A.K., Puleo, J.A., Wengrove, M.E. and Siders, A.R., 2026, February. The Future of Coastal Processes Research: A report from the US Coastal Research Program. In American Geophysical Union, Ocean Sciences Meeting (pp. CP52A-08).