Top 7 Benefits of Nature-based Solutions for Shorelines

Hard armour tends to restrict or suppress the natural processes of the shoreline. For example, sea walls reflect wave energy, which leads to flooding and can alter sediment transport, leading to erosion (Eyzaguirre et al., 2020). If shoreline infrastructure does not seriously consider natural shoreline processes, the structures can become unstable and face the effects of coastal degradation (Eyquem 2021).

Nature-based solutions aim to support and enhance the natural shoreline processes, which allows them to dissipate incoming wave energy, prevent flooding, and prevent erosion by allowing the natural movement of sediment (Eyzaguirre et al., 2020). Moreover, natural shorelines provide habitat connectivity that increases replenishment of beaches with sediment, absorbs more impact from wave action and provides a continuous stretch of natural habitat benefiting people, wildlife and the environment (Côté and Domanski 2019). 

Studies have found that sea walls cause a disconnect between upland and intertidal habitats, negatively impacting the nutrient cycling process and leading to the bioaccumulation of toxins up the food chain (Eyzaguirre et al., 2020). Furthermore, hard armour structures, like old wharves and pilings, can often leak toxic compounds (i.e., creosote) and pollute the riparian areas along the shoreline.

Nature-based solutions utilize natural landscaping methods, and establishment of healthy native riparian vegetation to filter potential pollution from the upland to prevent it from entering the shoreline environment. This promotes healthy environments for wildlife and people. Nature-based solutions promote the use of environmentally friendly building materials for overwater structures and landscaping features in the riparian buffer. In addition to preventing pollution, natural shorelines improve air quality, nutrient cycling and wastewater treatment, all leading to healthier shoreline environments for wildlife and people (Eyzaguirre et al., 2020).

Nature-based solutions for shorelines support biodiversity by creating and protecting habitat for both aquatic and terrestrial life, including amphibians, invertebrates, fish, birds, mammals, insects, and other wildlife. A natural shoreline functions as a healthy ecosystem that supports significant biodiversity. For example, the shallow intertidal zone of the shoreline is home to many species such as clams, burrowing crustaceans and marsh plants, mangroves, and seagrasses (Gittman et al., 2016). The plants can filter pollutants, and the clams are part of the food web for shorebirds that forage in the intertidal zone (Gittman et al., 2016).

Nature-based solutions ensure that habitat is maintained by planting native vegetation and ensuring the shoreline has the appropriate sediment for intertidal species including forage fish. Planting vegetation such as native shrubs and trees provides shade and temperature regulation during the summer, creating microsites suitable for various wildlife such as amphibians, fish and small mammals. In turn, dead leaf matter and insects that drop from from overhanging vegetation becomes a food source for invertebrates that sustain healthy soils and riparian and intertidal communities. Incorporating sediment, large woody debris and rocks provides spawning and foraging habitats for fish and migratory birds along the shoreline. In contrast, sea walls reduce the quality and quantity of habitat (Gittman et al., 2016) and restrict adaptation upward on the shoreline as required for higher water levels from sea level rise. This is a condition known as coastal squeeze and represents a significant degradation and loss of habitat that in turn results in a reduction of biodiversity, which can be detrimental to the shoreline ecosystem (Gittman et al., 2016).

All shoreline projects have associated costs such as permitting, design, engineering, biological studies and cultural investigations, as well as other expenses like materials, equipment, and labour (Côté and Domanski 2019). Hard armour, such as a rip rap bulkhead installation, is one of the most expensive practices that can be done on the shoreline, considering the cost of required materials and labour (Côté and Domanski 2019). The least costly option is sustaining a healthy natural shoreline. It has been calculated that the average cost for hard armour installations is between $50,000-$60,000 USD per 100ft piece of shoreline; in comparison, soft shore installation is about half of that price, between $25-30,000 USD (Côté and Domanski 2019).

Once installed, nature-based shoreline protection needs minimum maintenance. For example, it was calculated that only 4% of soft shore installations in the US needed maintenance of any type since the 1990s (Côté and Domanski 2019).

Nature-based solutions have higher cost savings than hard armour approaches. For example, nature-based solutions help restore and sustain natural ponds and wetlands that, in turn, mitigate flooding hazards to property owners. Healthy wetlands provide flood reduction, stormwater storage, water quality improvement, and carbon sequestration. Without functional wetlands on-site, flooding can lead to financial losses to property owners. Thus, nature-based solutions can help save costs on flood control and flood damage, which can cost homeowners tens of thousands of dollars in repair (Moudark et al. 2018).

Nature-based shoreline solutions like Green Shores® provide a return on investments and economic benefit – both now and into the future. Healthy shorelines that rely on nature-based solutions provide goods and services that can be used for long-term sustainable consumption, such as food (e.g., fish, shellfish, oysters, etc.), wood and other materials (Eyzaguirre et al., 2020). In addition, property value with a natural shoreline may be increased due to the increased aesthetic value of the property, improved shoreline access, and enhanced ecosystem services like flood control, air, climate and water regulation, and pollination (Eyzaguirre et al., 2020; Côté and Domanski 2019). For example, in one study, beach nourishment provided by nature-based solutions also offered an increased value to adjacent inland properties due to improved beach access (Kriesel and Friedman 2002). Another study showed that every one-metre additional increase in beach width from the installation of a nature-based design, resulted in a $323 increase in total property value (Landry et al., 2003). This is particularly important for properties located in high-erosion zones and areas prone to flooding.

On a larger scale, nature-based solutions benefit social welfare and the economy. For example, in 2020, a two-year socio-economic assessment of Stewardship Centre’s Green Shores for Shoreline Development program revealed that the nature-based Green Shores program provides a benefit:cost ratio of 7:1, such that each $1 invested in a Green Shores for Shoreline Development project generates $7 in a multitude of benefits including social welfare in BC (ESSA 2020). Further, investments made as part of the Green Shores program have made noteworthy contributions to the BC economy by, for example, supporting 74 to 83 jobs (ESSA 2020).

Nature-Based solutions provide many goods and services, referred to as “ecosystem services,” that contribute to human well-being (Eyzaguirre et al., 2020, Eyquem 2021).

First of all, natural shorelines provide provisioning services such as being the source of raw materials that include food, water and medicine (Eyzaguirre et al., 2020). This is particularly important for direct consumption and future sustainable uses of materials found along natural shorelines. For example, nature-based solutions use sediment and native vegetation to create aquatic and terrestrial wildlife habitat, which can then support wildlife species harvested by people, such as fish, oysters, edible plants and more. Native riparian vegetation also filters pollution and improves water and air quality as a benefit to humans and wildlife

Second, healthy shoreline ecosystems provide recreational opportunities, aesthetic value, and spiritual and heritage values for adjacent properties, contributing to increased cultural significance and use of the shoreline (Eyzaguirre et al., 2020, Eyquem 2021). These non-consumptive values can improve human well-being and property value.

Côté J. and Domanski A. (2019). Benefit Cost Analysis of Shore Friendly Practices in Island County. Island County Department of Natural Resources. Source link.

Eyquem, J. L. (2021). Rising Tides and Shifting Sands: Combining Natural and Grey Infrastructure to Protect Canada’s Coastal Communities. Intact Centre on Climate Adaptation, University of Waterloo. Source link.

Eyzaguirre, J., Boyd, R., Prescott, S., Morton, C., Nelitz, M. and Litt, A. (2020). Green Shores 2020: Impact, Value and Lessons Learned, Final Project Report. Prepared by ESSA Technologies Ltd. Prepared for the Stewardship Centre for British Columbia. Source link.

Glick, P , Powell, E , Schlesinger, S , Ritter, J , Stein, B A , and Fuller, A. (2020). The Protective Value of Nature: A Review of the Effectiveness of Natural Infrastructure for Hazard Risk Reduction. Washington, DC: National Wildlife Federation. Source link.

Kriesel, W. and Friedman, R. (2002). Coastal Hazards and Economic Externality: Implications for Beach Management Policies in the American Southeast. Heinz Center Discussion Paper. Source link.

Landry, Keeler, Kriesel, W. (2003). An Economic Evaluation of Beach Erosion Management Alternatives. Marine Resource Economics, Vol 18, pp. 105 – 127. Source link. 

Moudrak, N , Feltmate, B , Venema, H , and Osman, H. (2018). Combating Canada’s Rising Flood Costs: Natural Infrastructure is an Underutilized Option. Prepared for Insurance Bureau of Canada Intact Centre on Climate Adaptation, University of Waterloo. Source link.