This option is a baseline only against which to evaluate the economic benefits of the other options. It allows the existing tidal flood risk management assets to degrade and ultimately fail.
This option is not considered any further based on social, economic and sustainability grounds.
Do minimum - maintain
This option involves the continued maintenance of the existing wall along the east side of the A12 Waveney Road, which forms the foundation for ABP’s security fence and provides an informal tidal flood defence.
This wall only prevents tidal flood waters up to a level of 2.90mAOD from flowing into the town centre directly from the Outer Harbour. It does not prevent tidal flooding from other routes from inside Lake Lothing.
This wall, in combination with the restrict of flood water flows through the Bascule Bridge opening, only provides a very low standard of flood protection and was overtopped during the flood event in December 2013.
Improve – Flood walls only
This option involves the construction of 5km of flood walls to the north and south of Lake Lothing, as well as in front of the Royal Norfolk & Suffolk Yacht Club to the south and along the perimeter of the Outer Harbour to the north where it ties in with the existing coastal flood defences at the north-east corner of Hamilton Dock.
The flood defence wall on the north side of Lake Lothing would need to tie into high ground at its western end. This can only be achieved by either a flood gate across the dual Norwich to Lowestoft railway line near the Peto Way/Barnards Way roundabout or by a further 750m of wall construction to the west. On the south side the wall would need to tie into high ground at its western end close to Waveney Drive.
There would be numerous floodgates, especially on the north side, to allow access to the port quayside area in front of it. The walls between 0.4m and 1.7m in height would also be crossed by a significant number of drainage outfalls.