An apparatus for flood defence comprises a plurality of slab units (3) rotatable about an axis (4) between a lowered position and a raised position which slab units (3) are substantially balanced about the axis (4). The slab units (3) form a path when in their lowered position, and form a flood barrier when in their raised position. When the slab units (3) are in their raised position, they form a seal with the base (5) of the apparatus and removable boards are placed in the gaps between adjacent raised slab units (3) and between a raised slab unit and an abutment. These boards are then clamped to seal the gaps.
