Shoreline Management Plan: protecting our Island from coastal flooding over the next 100 years

​​​​​​​​​​​​​​​The Shoreline Management Plan assessed flood and erosion risks for our coast​ and set out how we'll manage them. 

It sets out how we'll maintain and enhance our coastal defences to protect our Island over the next 100 years.

The plan is updated every 10 years. The next update is ​due in 2030.

Why we need it​​​​

Global warming is causing the rate of sea level rise to accelerate. Our sea levels are currently rising by around 3mm per year. By 2070 this could increase to around 9mm per year. 

This means we could see our sea levels rise by 0.82m by 2120. At this level, many of our sea defences would struggle to provide protection against flooding.

The risk of coastal flooding is particularly high on our south coast, because of low lying land. 

We need a plan in place to protect our coast from climate related threats, such as:

• rise in sea levels
  
• bigger waves
• more intense and frequent ​storms

Climate emergency

What the plan does​

The plan sets out the actions needed to protect our coastline. These are detailed for 36 coastal areas called Coastal Management Units (CMU), with the biggest actions focusing on the most vulnerable areas. 

It lays out the approach to protect these CMUs across 3 set time frames, known as Epochs:

It suggests coastal management solutions for each specific location and uses the following key management strategies:

Our priorities

Our priority is to provide sea defence upgrades to 8 areas. These areas have been selected based on a variety of flood risk factors. 

In order of priority, they are: 

• Havre des Pas (including Greve d’Azette to La Grande Charriere Slipway)
• St Aubin's Harbour
• St Aubin's Bay (First Tower to West Park)
• La Greve d'Azette (east from La Grande Charriere Slipway)
• Le Hocq / Pontac
• St Aubin’s Bay (La Haule to First Tower)
• Royal Bay of Grouville
• St Brelade's Bay 

These areas are considered at risk from coastal flooding from a 1 in 200 year flood.  

This does not mean that a flood could only happen 1 time every 200 years. It could happen many times in 100 or 200 years, or not at all. 

Havre des Pas​

The Havre des Pas area covers the coast from La Collette to La Grande Charriere Slipway.

Havre des Pas has a vast history stretching from the early construction of shipyards to the opening of The Lido in 1895, right up t​o today where it's still loved by locals and tourists.

It sits within the southeast coast Ramsar site and in​cludes the inland ecological SSI - La Rue des Prés and over 30 listed buildings. 

Havre des Pas is a popular and well loved beach location for locals and tourists. We're committed to making sure any s​ea defence upgrades complement the existing facilities.​

Flood ri​sk at Havre des Pas

​Havre des Pas has a range of coastal defences that are in good condition, however it's at risk from waves coming over the sea walls. By the early 2040s still water levels will become an even greater risk.

350 properties are currently at risk from flooding in a 1 in 200-year flood, increasing to around 1,000 by 2120.​​

Other areas that could be affected by flooding include:

• people
  
• property 
  
• historic buildings and structures
• transport routes
• critical infrastructure assets

How we plan to protect Havre des Pas

Havre des Pas is the highest priority for coastal defence upgrades on the Island. 

We plan to provide protection to this area by integrating sea defences into the coastline. This will benefit the cultural and heritage value of the area, supporting the Future Jersey objectives and Island Plan policies. 

In Epoch 1 (2020 to 2040), we plan to develop and improve coastal defences to provide long term protection from waves coming over the sea wall and rising still water levels. This will improve defences to a 1 in 200 year standard of protection. 

In some areas sea defences could be extended into the sea. This decision will be based on the findings of engineering and environmental assess​ments and subject to public consultation. 

For Epochs 2 and 3 (2040 to 2120), we will maintain the existing coastal defences. ​​​

The current timeline for this area is:​

• engineering design: 2023 to 2028
  
• construction: 2028 to 2033
  

St Aubin's Harbour

This area covers St Aubin's Harbour and the section of St Aubin's Bay outside the harbour to the La Haule promenade. 

St Aubin's Harbour has a wealth of history stretching back to the 17th century when it became the main port for commercial trade in Jersey. 

The iconic St Aubin’s Harbour is a Grade 1 listed place. The merchant houses and other marine amenities are Grade 2, 3 and 4 listed buildings.   

Flood ri​sk at St Aubin's Harbour

St Aubin's Harbour and the section of St Aubin's Bay outside the harbour to the La Haule promenade are flood prone.

Current flood risks areas are the inner harbour area, St Aubin's Yacht Club slipway and along St Aubin's Bay promenade. 

The high street and main road are also at significant risk from waves coming over the sea wall. By 2120 the sea level rise could meaning flooding spreads further inland.​

Properties behind the harbour are at risk of overtopping and flooding from still water levels from a 1 in 20 year flood.

St Aubin's has a wide range of areas that could be affected by flooding, including:

• people
• property
• historic buildings and structures
• transport routes
• critical infrastructure assets

We recognise the importance of St Aubin’s Harbour as an attractive, lively and popular harbour loved by boat owners, locals and tourists. We're committed to ensuring that any sea defence scheme complements the existing setting.​​

How we pla​n to protect St Aubin's Harbour​

St Aubin’s Harbour to La Haule Promenade is the second highest priority for coastal defence upgrades on the Island.​

In Epoch 1 and 2 (2020 to 2070), we plan to develop and improve coastal defences to provide long term protection from waves coming over the sea wall and rising still water levels. This will improve defences to a 1 in 200 year standard of protection. 

In some areas sea defences could be extended into the sea. This will provide better protection where the flood risk is greater, and more land for business development and economic growth. This decision will be based on the findings of engineering and environmental assessments and subject to public consultation. ​

In Epoch 3 (2070 to 2120), we will maintain the existing coastal defences.

The current timeline for this area is:

• engineering design: 2024 to 2029
• construction: 2029 to 2036

St Aubin's Bay: First Tower to West Park

This area includes St Aubin’s Bay which stretches from St Aubin’s Harbour to West Park. 

The coastal defences along the bay are mostly masonry defences constructed in the late 1800’s to provide protection to the railway that used to run between St Helier and St Aubin’s Harbor.

Today the railway has been replaced by a walking and cycling promenade.

We know how important St Aubin’s Bay is as a gateway to St Helier from the West and it's potential to drive investment into St Helier, supporting wider Island Plan Policies. Any upgrades to this area will complement the existing setting.

Flood risk at St Aubin's Bay

The flood risk along this area is well known. The promenade and road is closed several times a year due to storms and high tides.

In 2008 we had significant flooding in Gloucester Street when a section of the sea wall was damaged during a storm.

Around 20 properties are currently at risk from a 1 in 200 year flood in the present day, increasing to around 170 by 2120.

Flooding could also impact St Helier, particularly around the hospital and Esplanade.

Other areas that could be affected by flooding include:

• people
• property 
• historic buildings and structures
• transport routes
  
• critical infrastructure assets
  

How we plan to protect St Aubin's Bay

St Aubin’s Bay from First Tower to West Park is a high priority for coastal defence upgrades on the Island.

In Epochs 1 and 2 (2020 to 2070), we plan to develop and improve coastal defences to provide long term protection from waves coming over the sea wall and rising still water levels. This will improve defences to a 1 in 200 year standard of protection and could involve major engineering works along this coastal section for construction in Epoch 2.

In Epoch 1 we plan to provide interim sea defence assets that will protect St Helier for the next 30 to 40 years and allow the detailed appraisal of potentially larger schemes.

In the longer term and in some areas sea defences could be extended into the sea. This will provide better protection where the flood risk is greater, more land for business development and economic growth and protect the urban environment in St Helier. This decision will be based on the findings of engineering and environmental assessments and subject to public consultation. 

In Epoch 3 (2070 to 2120), we will maintain the existing coastal defences.

The current timeline for this area, for the interim protection, is:​

• engineering design: 2024 to 2026
• construction: 2026 to 2037​

Greve d'Azette

This area covers Greve d'Azette from La Grande Charriere Slipway​ to Green Island. 

Coastal defences here are mostly masonry wall defences with several slipways. The seawall protects the land here and allowed the area to be developed from farmland to the beautiful coastal residential areas that we see today.

The coastline forms part of the southeast coast Ramsar site, it includes listed buildings with heritage value and the Green Island Geological SSI.

Flood risk at Greve d'Azette

This area is currently at risk from waves coming over the sea walls during storms, however, as sea levels rise over the next 100 years the still water risk will increase. 

This will be a particular risk at slipways, for example La Mare slipway, where we are already experiencing large waves crashing on to the road during high tides.

Not as many properties are at risk along this section of coastline compared to other areas, but there is a hazard to vehicles and people travelling along the coast.

Other areas that could be affected by flooding include:

• people
• property 
• historic buildings and structures
• transport routes
• critical infrastructure assets 

How we plan to protect Greve d’Azette

Greve d’Azette is our fourth highest priority for coastal defence upgrades on the Island.

In Epochs 1 (2020 to 2040), we'll begin making improvements to the slipways and in Epoch 2 (2040 to 2120) we'll make major improvements to the sea defences to a 1 in 200 year standard of protection. 

In Epoch 3 (2070 to 2120), we will maintain the existing coastal defences.

St Aubin's Bay: La Haule to First Tower​

This area of St Aubin’s Bay is between La Haule Promenade and First Tower including the promenade and cycle route to St Aubin’s Harbour.

The sea defences along this section are a mix of masonry sea walls and more recent sections of anti-tank wall built during the German Occupation.

Flood risk at La Haule and First Tower

This area is a well known flood risk. Waves often break over the seawalls during high tides, affecting the promenades.

Whilst the sea walls have been upgraded in recent times, more work is needed to protect the surrounding areas from flooding.

How we plan to protect La Haule and First Tower

St Aubin’s Bay from La Haule Promenade to First Tower is a medium priority for further coastal defence upgrades within the next 20 years.

Recent upgrades were made to protect the Beaumont area from flooding​. This included upgrading sections of the wall around the Gunsite Café, adding a curve to the top of the sea wall to return waves back to sea and adding an extra set of flood gates.

Later in Epoch 1 and in Epoch 2 (2020 to 2070), we plan to continue raising the sea walls and adding a curve on top to redirect the waves back to sea as we did at the Gunsite. This will provide 1 in 200 year protection against 2120 sea levels.

In Epoch 3 (2070 to 2120), we will maintain the existing coastal defences.​

Le Hocq and Pontac

This area covers Le Hocq and Pontac along the south-east coastline of the Parish of St Clement. The coastline here is mostly rocky, with a range of coastal defences and slipways.

Flood risk at Le Hocq and Pontac

This area is currently at risk from waves coming over the sea wall, especially at slipways, however, there is also a risk of flooding from still water levels from a 1 in 200 year flood, due to rising still water levels. 

Erosion between Green Island and Le Hocq is a low risk but due to the soft geology it can occur but this is at a very slow rate and localised.  

How we plan to protect Le Hocq and Pontac

In Epochs 1 and 2 (2020 to 2070), we plan to add new defences along the front at Le Hocq to provide long term protection. In the first Epoch we will concentrate in building resilience, particularly at slipways, with major d​efence upgrades being in Epoch 2. 

In Epoch 3 (2070 to 2120), we will maintain the existing coastal defences.

Royal Bay of Grouville

This area covers the east coast of Jersey, from La Rocque to Gorey Harbour.

It includes a large bay popular with locals and tourists alike, the southeast coast Ramsar site, the Grouville Marsh ecological​​ SSI, oyster farms and La Rocque Harbour. It's included in the Coastal National Park and received its name during Queen Victoria's visit in 1846.

Flood risk at the Royal Bay of Grouville

This area is at risk from overtopping at La Rocque and Le Hurel from a 1 in 20 year flood. Le Hurel is also at risk of flooding from still water levels from a 1 in 200 year flood, due to rising still water levels. 

There is no risk of erosion in this area.

How we plan to protect the Royal Bay of Grouville

We will protect this site without introducing new infrastructure which could change the character of the coastline. 

Later in Epoch 1 (2020 to 2040), we plan to build resilience, particularly at slipways, with major defence upgrades planned for Epoch 2 (2040 to 2070) and improve sea defences to a 1 in 200 year standard of protection. Defences along the front will be improved to provide long term protection from flood risk.

We also plan to introduce community awareness schemes to help people prepare for the impacts of flooding and engage with the community to improve the defences to a 1 in 200 year standard of protection. 

We'll improve signage about flood risks to make the public aware of impact to travel and access during storm events.​

In Epoch 3 (2070 to 2120), we will maintain the existing coastal defences.

St Brelade's Bay

St Brelade’s Bay is a popular beach location, named the third best-rated beach in Trip Advisor's Traveller’s Choice Awards UK in 2019.

We're committed to ensuring any sea defence upgrades here complement the well loved and extensive facilities in the area.

Flood risk at St Brelade’s Bay 

The bay has a range of defences protecting it from coastal erosion, but it's still at risk from overtopping in a 1 in 75 year flood.

One property is at risk of flooding behind La Route de la Baie. 

This risk is expected to continue into the future due to rising still water levels. 

How we plan to protect St Brelade’s Bay ​

​Later in Epoch 1 (2020 to 2040), we plan to build resilience, particularly at slipways, with major defence upgrades not required until Epoch 2 (2040 to 2070) and improve sea defences to a 1 in 200 year standard of protection. ​

Defences along the front will be improved to provide long term protection from flood risk. ​

In Epoch 3 (2070 to 2120), we will maintain the existing coastal defences.