The UK Government and National Agencies such as councils are notoriously bad at documenting flood impacts, and there is certainly no consistency in the manner with which they approach the task.
A project I am now collaborating on is SurgeWatch, which aims to establish a comprehensive database of UK Coastal Flood events.
If you have any pictures or info, or are doing research and want information about a certain event, then head over to the SurgeWatch website. There is information on flooding sources, pathways to land and the receptors/consequence. There is also a wealth of information on individual storm tracks, high water levels, and return periods.