COASTAL DEFENCES

GROYNES

• Groynes are wooden fences that are built down the beach.
• They stop materials from being removed from the beach.
• Groynes usually last for 20-30 years.

SEA WALLS

• Sea walls protect areas near coasts from tides and waves.
• They often prevent flooding.

REVETMENTS

• Revetments are structures placed on cliffs or beaches.
• Revetments absorb the energy from incoming water.
• They calm or slow down waves.

GABIONS

• Gabions are often used to protect sand dunes.
• A gabion is a cage, cylinder or box filled with rocks and concrete.
• They act in a similar way to a sea wall.

ROCK ARMOUR

• Rock armour is material used to protect shorelines, stream beds and other shoreline structures.
• Rock armor is built using a different variety of rocks and stops coastal erosion.

BEACH REPLENISHMENT

• Beach replenishment is a process which replaces sources of an eroding beach.
• Sand is dumped so the beach remains.

SAND DUNES

• Sand dunes are formed by wind blown sand that is deposited against a bush, driftwood or rock.
• The plants that grow hold the sand in place.