Sea level rise and climate change are major threats to the Wash coast and fenland environment. Sea level is predicted to rise by at least one metre by 2100 and sea temperatures, already 1°C higher, are increasing by 0.4°C each decade. Storm surges sufficient to overwhelm the Wash coastal defences are becoming ever more likely.

Raising the height of existing coastal defences would not only be prohibitively expensive, but also have a major impact on marginal habitats such as salt marsh, inter-tidal mudflats and sandbanks.

A tidal barrier across the Wash will provide us with the opportunity to manage the tide height and range within the Wash. The Barrier also offers a number of additional benefits – in particular, the generation of a large and reliable amount of green electricity and flood protection for more than 500,000 people, 300,000 hectares of grade 1 agricultural land and billions of pounds’ worth of assets.

The Wash Tidal Barrier Corporation plc is a private company, founded by Cambridgeshire-based entrepreneur Peter Dawe specifically to promote and build a barrier.

The proposed barrier will span the Wash from Hunstanton in Norfolk to just south of Skegness in Lincolnshire, a distance of approximately 18km, with an additional 5km of barrier in Lincolnshire in order to reach high ground.

Following are many of the design considerations we need to assess.