Managing the coast

Why manage the coast?

Coasts are managed to protect homes, businesses, roads and railways, farmland and from erosion and flooding.

In England and Wales, Shoreline Management Plans decide what to do for each stretch of coast. There are four choices:

hold the line: keep the coast where it is;
advance the line: build out into the sea;
managed realignment: let the sea move inland, in a controlled way;
no active intervention: do nothing.

The choice depends on what is at risk, and on whether the benefits are worth the costs (a ).

Hard engineering

builds structures to stop the sea.

Method	Benefits	Costs
a concrete wall that reflects waves back	Strong; protects the land behind; often has a promenade	Very expensive; ugly; reflected waves scour the beach
large boulders piled at the foot of a cliff	Absorbs wave energy; cheaper than a wall	Boulders can be moved by storms; can look out of place
Gabions: wire cages of rocks	Cheap; absorb wave energy	Ugly; the wire rusts
wooden or rock fences down the beach	Trap sand moved by longshore drift, building a wider beach	Starve beaches further along of sand, so they erode faster

Key terms

Soft engineering

works with natural processes.

Method	Benefits	Costs
adding sand or shingle to a beach	A wider beach absorbs wave energy and is good for tourism	Must be repeated, as the sea washes it away; dredging can harm the sea bed
Reprofiling: reshaping the beach, often after storms	Cheap; uses the beach's own material	Only lasts until the next storm
planting marram grass and fencing off dunes	Cheap; dunes protect the land and are a habitat	Takes time; people must keep off them

Common mistake

Groynes protect one beach but can make erosion worse further along the coast.

Key terms

Managed retreat

(or managed realignment) lets the sea flood low-value land, such as farmland, on purpose. A new defence is built further inland, and the flooded land becomes , which absorbs wave energy and is a habitat for birds.

For example: at Medmerry, West Sussex, the Environment Agency let the sea break through an old shingle bank in 2013, behind new banks inland. It cost about £28 million, protects 348 properties, and became an RSPB nature reserve.

Benefits: cheaper to keep up than hard defences; creates habitats; works with nature.
Costs: farmers and landowners lose land, and may need compensation.

Key terms

Exam practice

Plan your own answer first, then open the model answers to see what each level looks like.

9 marks · about 9 minutes

Evaluate whether managed retreat is a better way of managing coastlines than hard engineering.

Evaluate means: Judge strengths and weaknesses or successes and failures, then reach a conclusion.

Level 1 (Basic)· 3/9 marks (band 1–3)

Managed retreat is cheaper than hard engineering, but people lose land. Sea walls protect towns but are expensive. I think managed retreat is better.

Why this level: Simple points on both sides with no examples, and a judgement that isn't explained. To reach Level 2: explain how each works, with named examples and evidence.

Level 2 (Clear)· 5/9 marks (band 4–6)

Managed retreat lets the sea flood low-value land. At Medmerry in 2013, this created salt marsh, which absorbs wave energy and became an RSPB reserve, protecting 348 properties at a cost of about £28 million. Hard engineering, such as sea walls, gives strong protection to towns, but is very expensive to build and maintain.

Why this level: Clear explanation of both approaches with a named example. But the costs and benefits aren't weighed, and there's no conclusion. To reach Level 3: compare them directly, including who gains and who loses, and judge when each is better.

Level 3 (Detailed)· 8/9 marks (band 7–9)

Managed retreat works with nature. At Medmerry in 2013, the sea was let through the old defences to flood low-lying farmland behind a new inland bank. The salt marsh that formed absorbs wave energy, and became an RSPB reserve, protecting 348 properties at a cost of about £28 million. Once built, it needs little maintenance, and creates habitats. However, farmers lose land, and it only suits places where the land is low-value. Hard engineering, such as sea walls and rock armour, gives strong, immediate protection to towns with valuable homes, roads and businesses. But it is very expensive to build and maintain, can reflect wave energy and scour beaches, and may push erosion further along the coast. Overall, managed retreat is better where land is low-value, because it is sustainable and cheaper in the long term. But it can't protect towns, which still need hard defences, so the better choice depends on what is being protected.

Why this level: Detailed evaluation of both approaches with a named example, considering costs, benefits and who gains or loses, and a judgement that depends on place. This is Level 3.

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