Coast protection, flood defence and managed re-alignment

Coastal erosion and flooding pose a threat to people and their property at the coast. For generations, society has built defences to prevent erosion and protect land from flooding. Examples of these include groynes, sea walls and embankments (termed hard engineering).

Present day approaches also include soft engineering such as replenishing eroding beaches with sand, referred to as beach nourishment. Also, nature is occasionally allowed to take its course through managed retreat or coastal realignment, where existing hard defences are intentionally or naturally allowed to breach so recreating natural saltmarsh. This provides a place for high tides to spread out and would be most effective in firths.

Flood hazard and risk maps are available on the SEPA web site.  This includes the Potentially Vulnerable Areas (PVAs) and 'Coastal areas that may flood' (see check boxes on the 'map contents' menu on SEPA link below).

Light Detection and Ranging (LIDAR) can produce a high-resolution map of terrain, from which it is possible to identify man-made structures. LIDAR also allows for the monitoring of changes in coastal structures. In the image shading shows changes in altitude; lighter colours are lower, darker colours are higher ground. The gradual narrowing and lowering of the dune reach towards Cille Pheadair is clear in the LIDAR image, as is the extensive low-lying area inland of the dune ridge, which is the bed of a drained loch.