A report on shoreline management, released today, outlines potential measures to strengthen sea defences in vulnerable areas, painting a stark picture of the likely damage bill should no action be taken.
Officers from the Growth, Housing and Environment Department, and experts from climate consultancy firm Aecom have published the plan to manage and adapt the Island’s coastline.
Coastal flooding has previously been associated with waves washing over sea walls during periods of strong winds and storm surges, but the report spells out that rising sea levels may cause flooding whenever there are particularly large high tides, irrespective of weather conditions.
‘Still water level flooding is a new threat that’s likely to occur in the future, and that’s what we need to protect against,’ said senior infrastructure engineer Jamie Mason.
Different parts of the Island coastline have been divided into four categories, according to the approach that may be best suited to combat rising sea levels. The estimated cost of the work, at today’s prices, totals £79.2 million and is split into three time periods: £32.2 million from 2020 to 2040; £37.8 million from 2040-2070; and £9.2 million from 2070 until 2120.
The benefit-cost ratio cited in the report, measuring the value for money that would be achieved by investing in enhanced sea defences, estimates a damage bill of £439 million at today’s prices if nothing was done. This means that every pound invested should save £5.54 in costs.
Mr Mason stressed the importance of a 12-week consultation process, which begins today, and will shape the final report.
‘People will be able to look at the part of the coastline where they live and work, and see the options for managing sea defences in that area,’ he said. ‘When the final version of the report goes into the Island Plan, we want to know that the community has been involved and people have had a chance to have their say.’
Infrastructure Minister Kevin Lewis said: ‘Rising sea levels are a global problem which sadly we share – but we are ahead of the game and must ensure we stay ahead.
‘We need to take a measured approach – we can’t just build 50ft walls. There are several low-lying areas, mainly in the south of the Island, where there’s been remedial work, and these areas will remain a focus.’