Is Coastal Protection Worth It?

By Meredith Ho Yau Chung

In 2018, an estimated 9,000 properties in England are located in areas likely to be lost to coastal erosion by 2025 [1]. While coasts have always been eroding, climate change as a result of development in recent decades has exponentially sped up the process of coastal erosion, causing many coastal populations to fall victim to its drastic impacts. Coastal protection methods are plentiful and varied, but are they still effective against increasingly strong erosion? Has climate change reduced coastal protection to a Sisyphean burden, with governments tirelessly attempting to defend their coasts only for the sea to destroy all efforts? 

As mentioned, climate change is a key factor in the worsening effects of coastal erosion. Increasing amounts of heat and greenhouse gases emitted from burning fossil fuels cause the global temperature to rise, leading to the melting of polar ice caps, thus raising sea levels. The rising of sea levels allow waves to extend further up shorelines, and thus become stronger from longer fetches. As waves continue to go inland and gain energy, erosion occurs at a much faster rate, taking away from the coastline and weakening the area. There are many methods of coastal protection, some more efficient than others. 

Examples of Coastal Protection

Seawalls are structures built from concrete, sheet piles or masonry, angled along the coast to reduce energy of oncoming waves, minimising the impact of coastal erosion. The UK Department for Environment, Food and Natural Affairs states indicative costs of building seawalls are £2,000-5,000 per metre, and capital costs are deemed high [2]. Aside from building costs, seawalls also require monitoring, maintenance and replacement [2], consistent care for 30-50 years [3] before it falls into disrepair. 

Seawall at Lyme Regis, UK 

Revetments are sloping surfaces along the coast to absorb wave energy [2], which are permeable slopes of wooden planks. Indicative costs for revetments are £1,350-6,000 per metre, and high capital costs according to DEFRA [2]. Hardwood revetments have a lifespan of only 15-20 years on exposed beaches [4], due to the weak nature of the wood material. 

Revetments at Great Yarmouth, UK

Groynes are artificial structures built perpendicular to the coast to reduce longshore drift and trap sediments, maintaining the size of a beach. DEFRA states indicative costs for groynes are £10,000-100,000 per structure, with high capital costs [2]. Groynes have a lifespan of about 10-25 years [5], and require copious amounts of time and effort to collect data and design [5].

Groynes at Bognor Regis, UK

Why is Coastal Protection Such a Hassle? 

These protection methods are all considered Hard Engineering. As indicated above, some coastal protection methods are long, laborious and costly processes. Before the construction, planning in the forms of data collection, environmental impact assessments and more have to be carried out. The construction itself requires contract payments, material and labour sourcing and supervision. The years after construction then calls for frequent maintenance and replacement. The strenuous efforts made by coastal cities to protect their shores likely hinder their economic development and Quality of Life for residents, as most of the area’s budget is likely spent on coastal defence and renovations instead of expanding businesses and enhancing recreational space. 

How Coastal Protection Affects an Area — Holderness Coast

A majority of the East Riding of Yorkshire coast are mixed residential and non-residential areas, therefore many homes and businesses are at high risk of collapse due to prolonged erosion of the coast. (Plumplot map)

Holderness Coast in the East Riding of Yorkshire has the fastest rate of erosion in Europe of 1.5-2.0 metres per year [6]. Its location in the east of England is subject to Polar Continental winds from Central Europe [7], bringing forth strong destructive waves. The coast consists of boulder clay and chalk formed in the Ice Age [6], which are soft materials that are easily eroded. Towns such as Hornsea, Withernsea and Mappleton on the coast are heavily affected by the coastal erosion occurring. The B1242 road running along these towns is a valuable asset vulnerable to collapse, which halts transport between local towns, interrupting flow of tourism and trade of agriculture. The Easington gas terminal near Hornsea is another important asset to the area, as it sources 20% of all gas energy to Britain [8], so its collapse would cause an international energy crisis. 

To defend against these threats, the government has implemented many different coastal protection methods over time. For instance, £6.3 million pounds were spent on the construction of seawalls in Withernsea [6], which later required upgrading. Cliff stabilisation through slope reduction and planting vegetation was implemented in Mappleton, proven to be effective as there are no signs of slumping along the cliff afterwards. 

The vast amount of money spent on building and maintaining defence structures in the East Riding of Yorkshire limits government spending on other important aspects to Quality of Life such as healthcare. Between 2019-2021, life expectancy in the East Riding of Yorkshire decreased overall, with male life expectancy lowering from 80.7 to 77.8 years [9]. Instead of allocating more funds for healthcare during the height of the COVID-19 pandemic to ensure the health and protection of residents, an £11 million pound project was implemented in 2020 for the construction of a 600 metre long concrete barrier [10], yet another Hard Engineering structure. 

Adaptation Over Prevention

Hard Engineering structures such as seawalls and groynes are constantly becoming eroded by destructive waves, then renovated using money, then eroded again, then renovated again, and again and again as the coast slowly but surely retreats. It may seem like an endless process that results only in the loss of money, as the destructive sea continues to triumph over the man-made structures. How else can we protect the residents and sites of the coast then? 

Instead of focusing on preventing coastal erosion through building Hard Engineering structures, methods of adapting to the process of coastal erosion can be more sustainable over time. Relocation of residents and settlements further inland is a secure method of ensuring the safety of residents, as their homes are no longer on fragile land and at risk of collapse. A one-time move is also far more cost-efficient than the restoration and renovation of homes whenever severe damage is done to coastal settlements. 

Another economical yet lasting method of adaptation is habitat restoration. Growing vegetation along the coast stabilises the sand dunes and beaches [11], allowing them to resist the effects of coastal erosion. Replenishing reefs and planting mangroves if the coast is suitable also helps filter water entering the coast and lessen wave energy, reducing the physical and chemical strength of coastal erosion. 

Mangroves in Hong Kong

So is Coastal Protection Worth it or Not?

To answer the question “Is coastal protection worth it?”: yes, when done sustainably. Coastal erosion is an unstoppable force, but we can only build so many protective structures. Choosing adaptive measures over preventive measures is the key to sustainably protecting the coast. Coastal protection does not have to be the Sisyphean task it seems to be; through relocating populations and restoring the natural coast environment we can be protected against coastal erosion for years to come. 

Bibliography

1. Coastal erosion is unstoppable – so how do we live with it? (2022) PreventionWeb. Available at: https://www.preventionweb.net/news/coastal-erosion-unstoppable-so-how-do-we-live-it (Accessed: 26 October 2023). 

2. Hudson, T., Keating, K. and Pettit, A. (2015) ‘Cost estimation for coastal protection – summary of evidence’. Bristol: Environment Agency. 

3. Gibson (2012) Gibson, Gibson Marine Construction. Available at: https://gibson-marine.com/2012/01/25/how-to-know-when-your-seawall-needs-repair-or-replacement/#:~:text=A%20seawall%20that%20is%20properly,as%20little%20as%2020%20years (Accessed: 26 October 2023). 

4. Timber Revetments (no date) Coastal Management Webguide - RISC KIT. Available at: https://www.coastal-management.eu/timber-revetments.html (Accessed: 26 October 2023). 

5. Groynes, breakwaters and artificial reefs (no date) Groynes, breakwaters and artificial reefs - English. Available at: https://climate-adapt.eea.europa.eu/en/metadata/adaptation-options/groynes-breakwaters-and-artificial-reefs#:~:text=Wooden%20groynes%20have%20a%20lifetime,etime%20of%20only%201%2D5years (Accessed: 26 October 2023). 

6. College, M.C. (2021) Case study of one coastal landscape that is being managed, ArcGIS StoryMaps. Available at: https://storymaps.arcgis.com/stories/843601cebe404ca7901500ebf7a75366 (Accessed: 26 October 2023). 

7. Powell, C. (2020) Where does our weather come from? why wind direction is so important, ITV News. Available at: https://www.itv.com/news/2020-11-23/where-does-our-weather-come-from (Accessed: 26 October 2023). 

8. Securing gas supplies to Great Britain (no date) KONGSBERG. Available at: https://www.kongsberg.com/kmagazine/2012/9/securing-gas-supplies-great-britain/ (Accessed: 26 October 2023). 

9. Pells, M. (2023) East Yorkshire life expectancy declining, This is the Coast. Available at: https://www.thisisthecoast.co.uk/news/local-news/east-yorkshire-life-expectancy-declining/ (Accessed: 26 October 2023). 

10. Flood risk strategy (no date) Flood Risk Strategy. Available at: https://www.eastriding.gov.uk/council/plans-and-policies/other-plans-and-policies-information/flood-risk/flood-risk-strategy/ (Accessed: 26 October 2023). 

11. ‘Adaptation options for coastal environments: ecosystem management’ (no date). CoastAdapt.