Hopton coastal defences – failure to replacement in 24 months

Hopton-on-sea resides approximately 3.5 km south of Great Yarmouth on the east coast of UK and faces eastward on to the North Sea (Figure 1). Hopton is a small village community whose main local employers are two Holiday Parks. One of the Parks owned by Bourne Leisure occupies an 800 m shoreline frontage at the northern end of the village. The shoreline is protected by coastal defences constructed in the 1970s and owned by the local Authority. The defences comprised a linear timber revetment with steel sheet-piled toe fronted by a series of timber/steel groynes that originally extended up to 75 m to seaward of the timber revetment but which by 2013 were only effective out to about half of their original length (Photograph A). Beach levels against the timber revetment had remained above their level in 1970 up to 2007 with a wide beach (15m) above the level of highest astronomic tide. As a consequence the timber revetment had been substantially buried over much of its service life since 1970. Once exposed after 2007 a walkover inspection showed a structure that with minor maintenance was likely to provide satisfactory service for a further 25 years provided beach levels remained at or above minimum design level (0.5m below the top of the vertical steel sheet-piled toe). Beaches to the south of Hopton had been eroding since the early 1990s whereas beaches to the north of Hopton had been generally stable or accreting over the same period.