You are viewing a free preview of this lesson.
Subscribe to unlock all 13 lessons in this course and every other course on LearningBro.
Coastal erosion and flooding threaten homes, businesses, infrastructure, and farmland across the UK. However, protecting the coast is expensive and controversial. This lesson examines the different management strategies available, the conflicts they create, and detailed case studies of coastal management in action.
The UK coastline faces several threats:
However, not every stretch of coast can be protected — it would be prohibitively expensive. Decisions must be made about where to defend and where to allow natural processes to continue. This inevitably creates conflict between different groups of people.
Hard engineering involves building physical structures to protect the coast from erosion and flooding. These methods are often effective in the short term but expensive and can have unintended consequences.
| Method | Description | Advantages | Disadvantages | Approximate Cost |
|---|---|---|---|---|
| Sea wall | A concrete or stone wall built along the coast at the base of cliffs or along the seafront | Effective barrier against wave erosion and flooding; often has a curved top to reflect wave energy | Very expensive (£5,000-£10,000 per metre); can be undermined by waves; creates a strong backwash that scours the beach; visually intrusive | £5,000-£10,000/m |
| Groynes | Wooden or rock barriers built perpendicular to the coast to trap sediment and slow longshore drift | Trap sediment, building up the beach (which absorbs wave energy); relatively cheap | Cause sediment starvation further along the coast (the area downdrift loses its sediment supply); need regular maintenance | £5,000-£10,000 each |
| Rock armour (rip-rap) | Large boulders placed at the base of a cliff or along the coast to absorb wave energy | Effective at absorbing wave energy; relatively cheap; can look natural | Not as effective in severe storms; rocks can be displaced; may not suit the local geology visually | £1,000-£4,000/m |
| Gabions | Wire cages filled with rocks, placed at the base of cliffs | Cheap; absorb wave energy; can be filled with local material | Ugly; wire cages corrode in salt water (lifespan 5-10 years); not effective against powerful storms | £500-£1,000/m |
| Offshore breakwaters | Rock or concrete barriers built in the sea, parallel to the coast | Reduce wave energy before it reaches the shore; create a sheltered area where sediment accumulates | Very expensive; may create navigation hazards; alter wave patterns and affect other areas | £5,000+ per metre |
| Revetments | Slatted wooden or concrete structures placed on the cliff face to absorb wave energy | Break the force of waves; allow water to drain through | Expensive; need regular maintenance; can look unattractive | £2,000-£5,000/m |
Exam Tip: When evaluating hard engineering methods, always consider the downdrift effects. Groynes are the classic example — they trap sediment on one side but starve the coast on the other side, often transferring the problem rather than solving it.
Soft engineering works with natural processes rather than against them. These methods tend to be cheaper and more sustainable but may not provide the same level of immediate protection.
| Method | Description | Advantages | Disadvantages | Approximate Cost |
|---|---|---|---|---|
| Beach nourishment | Pumping or dumping sand/shingle onto a beach to replace eroded material and widen the beach | Looks natural; wider beaches absorb wave energy and protect cliffs; benefits tourism | Needs repeating regularly (every 5-10 years) as material is eroded away; expensive over time; sourcing material can damage offshore environments | £3,000-£5,000/m (per cycle) |
| Managed retreat (managed realignment) | Deliberately allowing the sea to flood low-value land, creating new salt marshes or mudflats that absorb wave energy | Creates natural habitats; salt marshes absorb wave energy; relatively cheap long-term; sustainable | Loss of farmland or property; compensation costs for landowners; politically controversial | Variable (includes compensation costs) |
| Dune stabilisation | Planting marram grass, installing fences, and creating boardwalks to protect sand dunes from erosion | Maintains natural coastal defence; dunes absorb wave energy; cheap; improves biodiversity | Restricts public access; slow to establish; dunes may still be damaged by severe storms | £200-£2,000/m |
| Cliff drainage | Inserting drainage pipes into cliffs to remove excess water and reduce the risk of mass movement | Reduces slumping and rotational slips in clay cliffs; relatively cheap | Does not stop wave erosion at the base; needs maintenance; limited effectiveness on very soft cliffs | £500-£2,000/m |
| Vegetation planting | Planting trees and vegetation on cliff tops and slopes to bind soil and absorb rainwater | Cheap; natural-looking; reduces surface run-off and mass movement | Slow to establish; does not prevent wave erosion at cliff base; limited effectiveness on steep, exposed cliffs | Low cost |
In England and Wales, the entire coastline is divided into sections, each covered by a Shoreline Management Plan (SMP). These plans set out the management strategy for each section over the next 20, 50, and 100 years.
Each section of coast is assigned one of four options:
| SMP Policy | Meaning |
|---|---|
| Hold the line | Maintain or upgrade existing defences to keep the coastline in its current position |
| Advance the line | Build new defences seaward of the current position (e.g., land reclamation) |
| Managed realignment | Allow controlled retreat of the coastline, creating new intertidal habitats |
| No active intervention | Let natural processes take their course; no defences built or maintained |
The choice depends on the economic value of the land, the cost of protection, the environmental impact, and the number of people affected.
Coastal management decisions create conflict because different stakeholders have different priorities.
| Stakeholder | Typical Priorities |
|---|---|
| Homeowners | Want maximum protection for their property; oppose managed retreat |
| Farmers | Want protection for farmland; may accept managed retreat if compensated |
| Businesses (tourism) | Want attractive beaches and safe coastlines; support beach nourishment and sea walls |
| Environmental groups | Support natural processes, managed retreat, and habitat creation; oppose hard engineering that damages natural habitats |
| Local councils | Must balance protection with cost; face political pressure from residents |
| National government (Defra, Environment Agency) | Allocate funding based on cost-benefit analysis; prioritise areas with the greatest economic or social value |
| Insurance companies | May refuse to insure properties in high-risk areas; influence where people can live |
| Future generations | Need sustainable solutions that do not simply transfer problems to the future |
Subscribe to continue reading
Get full access to this lesson and all 13 lessons in this course.