WATCH: What can Jersey do to cope with rising sea levels?

Thursday 04 July 2019

Higher and bigger walls around the island, land reclamation, flood gates... These are the options being considered as Jersey attempts to respond to climate change and rising sea levels over the next 100 years.

The government is currently working on a Shoreline Management Plan – which aims to address climate change issues and ensure that coastal defences can protect the island over the next century - and is seeking islanders' opinions on different policies.

The government started work on the plan in June 2018 with the help of AECOM, a multinational engineering firm, to address rising sea levels and more rainfalls, which have led to an increased risk of flooding has increased in some areas of the island.

According to the Jersey Sea Level and Coastal Conditions Climate Review from the National Oceanography Centre (NOC), the sea level around Jersey is currently rising by 3mm per year and the frequency of "extreme coastal events" is likely to increase.

Pictured: With rising sea levels and more rainfalls, the risk of flooding has increased in parts of the island.

To create the plan, the government has already analysed coastal processes – including erosion, transportation or deposition – as well as future coastal changes and reviewed coastal defences.

They have also split the shoreline into ‘coastal management units’ (CMU). For each unit, the risk of coastal flooding has been assessed and a policy option proposed for managing those risks. 

Four options have been considered, as well as their respective economic impacts and their implications for the community, environment and economy:  

• ‘No active intervention’: The shoreline would be left to naturally evolve without intervention, with no investment being made in coastal defences or maintenance work. This would be applied to natural areas of the coastline which are currently undefended, such as Beauport.
  

  

  Pictured: Beauport is one of the areas where no intervention would be made.
   
• Maintain the defence line: Where current defences provide a reasonable standard of flood protection or prevent erosion of the shoreline, the government could choose to simply maintain current coastal defences, with a potential decrease of flood protection in some locations over time due to climate change. 
  
  
  
  Pictured: The sea wall in St. Ouen would be maintained.
   
• Advance the line: New sea defences could be built closer to the sea in areas where there is a significant risk of coastal flooding or erosion, or where sea defences would deliver additional benefits for the community, environment and economy, such as creating a new amenity space.
  
  
  
  Pictured: Sea defences could be increased in the area around la Frégate.
   
• Adaptive management: Coastal flood risks would be proactively managed and mitigated with initiatives being adapted depending on the level of risk and the circumstances. This could include improving the standard of flood protection for an existing sea defence, constructing new defences, raising awareness of local flood risk or recommending property level flood protection.
  Similar work has already been carried out on Victoria Avenue where the sea wall was raised by 0.3metres with a special curve design aimed at deflecting waves. In total, 320 metres of the wall between the Gunsite and Le Perquage Car Park was raised to help combat flooding during storms and high spring tides. 
  
   
  
  Pictured: Sea defences could be increased in the area around la Frégate.

The Government is due to publish a full report on its plans for Shoreline Management on Friday and will be asking islanders for their views between July and September as part of a public consultation.

The Shoreline Management Plan consultation is one of four environmental initiatives being launched this summer.

As part of a new campaign entitled ‘Your Island, Your Say’, islanders are being asked to “help shape Jersey’s future” by taking part in consultations on the Island Plan, the masterplan for Southwest St. Helier and the climate emergency response plan.

Video: What Jersey would look like with higher sea levels. (Data from Flood Maps)

“Some people may only be interested in what they can do to offset carbon emissions, while others might only want to comment on a specific area of the Island Plan,” the Minister for the Environment, Deputy John Young, said.

“In every case, we are looking to involve the public at earlier stages of policy and planning as we prepare initiatives which will have a significant impact on Jersey’s environment over the coming decade and beyond.”

GALLERY: Climate trends in Jersey...

(Research from Paul Aked, Senior Meteorologist, Observations and Climatology)