Shoreline Management Plans (SMPs), in the UK, set policy at a local level for the strategic management of flood and erosion risk. They encompass four principal approaches: * Holding the existing line, by maintaining or changing the standard of protection * Advancing the existing line, by building new defences on the seaward side of original defences * Managed realignment, by allowing the shoreline to move backwards or forwards through controlled movement; and * No active intervention, where there is no investment in coastal defences or operations