The concentration of industrial, residential and agricultural activity on the lowlands surrounding our estuaries has led to an increasing problem of flood risk in these areas. However, flood hazards have been, in large part, the result of past human interference in the estuary system and as such may be reduced by more enlightened management. This paper examines the problems of flood risk and discusses some of the research that has been conducted into its alleviation. In particular, it concentrates attention on the programme of 'managed retreat' in the UK, which attempts to restore previously reclaimed areas in order to reduce flooding and other hazards of the estuarine system.