Coastal Management & Conflict
A Rising Risk
Around 5 million homes and businesses in England are in places at risk of flooding from the sea or rivers, and the figure is rising. The Holderness coast loses about 2 metres a year. The villages of Happisburgh in Norfolk and Fairbourne in Wales are slated for managed retreat. Climate change is making the threat worse: the UK’s sea level has risen by about 17 cm since 1900 and is projected to rise a further 30–110 cm by 2100. Storms are also becoming more frequent and more powerful. Decisions about whether and how to protect each stretch of coast are now among the most urgent in UK geography.
Why the Risks Are Increasing
Three changes are increasing coastal flood risk. First, rising sea levels from melting ice sheets (Greenland and Antarctica) and the thermal expansion of warmer ocean water. Second, more powerful storms with higher waves and bigger storm surges — storm Babet (2023) and Eunice (2022) caused widespread coastal flooding. Third, continued building on the coast — new homes are still being built on coastal and estuary land, putting more property in harm’s way.
UK sea level has risen about 17 cm since 1900 and is projected to rise a further 30–110 cm by 2100. Storms are stronger and more frequent. Building near the coast continues. Around 5 million homes and businesses in England are at risk of flooding.
Hard Engineering
Hard engineering uses solid structures to block the sea or interrupt sediment movement. Sea walls are concrete or steel barriers along the shoreline that reflect waves back. They protect property well but cost £6,000–10,000 per metre and look ugly. The wall at Bridlington protects the town but reflects wave energy, scouring the beach away in front. Groynes are wooden or rock fences built out at right angles to the shore. They trap sand carried by longshore drift, building wider beaches that absorb wave energy. Groynes installed at Mappleton in 1991 protected the village but caused rapid erosion immediately to the south — a classic downdrift effect. Rock armour (or rip-rap) is large boulders piled at the cliff base; it is cheaper than a sea wall and absorbs wave energy.
Soft Engineering
Soft engineering works with nature rather than against it. Beach replenishment (or nourishment) involves pumping sand from offshore onto eroding beaches. The wider beach absorbs wave energy and protects the cliffs behind. Bournemouth has replenished its beach roughly every five years since the 1970s; the cost is around £3 million per kilometre but the protection is renewable. Slope stabilisation uses drainage, replanting and netting to hold cliffs in place — effective at Lyme Regis, where deep drains were installed under the Black Ven landslide complex. Dune restoration plants marram grass to bind sand and trap it: the dunes at Studland Bay are stabilised using fenced walkways to keep walkers off.
Costs and lifespans vary widely. A sea wall costs roughly £6,000–10,000 per metre and lasts 50–100 years. Groynes cost £5,000–10,000 each and need replacing every 25–30 years. Rock armour costs around £1,000 per metre. Beach replenishment costs about £3 million per kilometre but must be repeated every 5–15 years. The cheapest option of all is to do nothing — useful for low-value land but politically very hard where homes and businesses are at risk.
Sustainable Approaches: Doing Nothing and Strategic Realignment
A new generation of policy approaches treats the coast as a system. Do nothing means accepting that some land will be lost. The Environment Agency uses this approach for low-value coastline (e.g. parts of Suffolk) where defending would cost more than the property is worth. Strategic realignment goes further: existing sea walls are deliberately breached or pulled back to let the tide flood farmland behind, creating new salt marshes. The marsh absorbs wave energy, defending what lies further inland and providing habitat. The Medmerry Managed Realignment Scheme in West Sussex (opened 2013) breached a sea wall to flood 183 hectares of farmland. It now protects 348 homes from flooding and has become an RSPB nature reserve.
All of this sits within Integrated Coastal Zone Management (ICZM) — the idea that the entire stretch of coastline should be managed as one connected system. ICZM coordinates between councils, the Environment Agency, landowners and conservation groups, and tries to balance flood risk, wildlife, economy and heritage in one Shoreline Management Plan.
Coastal management decisions create conflict. Residents of Happisburgh in Norfolk wanted a sea wall to save their village; the Environment Agency calculated that defending was poor value for money and chose to do nothing. Houses have collapsed into the sea since. At Mappleton in Holderness, two rock groynes and a rock revetment protected the village from 1991 onwards — but accelerated erosion immediately south, which residents of nearby Aldbrough now blame for losing their homes. Engineers, councillors, residents and farmers often disagree, and decisions made for one area inevitably affect those next door through the sediment cell.
Hard engineering (Mappleton groynes, Bridlington sea wall) blocks erosion but is costly and disrupts sediment cells. Soft engineering (Bournemouth beach replenishment, Lyme Regis stabilisation) works with nature but must be repeated. Sustainable approaches like Medmerry realignment and ICZM are increasingly preferred.