Alde and Ore estuary, U.K. – levee overtopping performance – defence upgrade with 50 km of simultaneous overtopping

The Alde and Ore estuary is protected from open coast attack by the longest shingle spit in northern Europe, extending 17km from Aldeburgh in the north to Shingle Street in the south. The low lying land adjacent to the tidal estuary is divided into a number of flood cells protected by more than 50 km of levees, locally referred to as “river walls”.
Last heightened following a catastrophic North Sea storm surge in 1953 the additional weight of the defences has resulted in significant consolidation settlement, by up to 1m.
With little or no government funding for improvements to the existing degraded defences an innovative approach has been required to ensure an affordable solution. This strategy being given more impetus following a North Sea tidal surge in December 2013, recorded as a 1:17 year event, which left the defences wanting.