£100m Havre de Pas Flood Alleviation Scheme details revealed by Jersey government

  • ITV Channel reporter Rory O'Regan has been taking a look at what could be a £100 million project

Jersey government has shared details on how they hope to protect the island's south coast from flooding.

The Havre de Pas Coastal Flood Alleviation Scheme would see mile-long protections from the end of the rock armour at La Collette to La Grande Charriere Slipway.

There are four shortlisted options, with the government's most preferred choice to create a primary wall 5-10 metres seaward, with a smaller, secondary wall behind it.

The project could cost "in the ballpark" of £100 million, with five years worth of construction expected to start in 2028.

It's all part of the island's Shoreline Management Plan - published in 2020 - that aims to protect Jersey from coastal flooding over the next 100 years.

Two of the four shortlisted options would see land reclaimed to create a wider promenade space, a cycle lane, and new green spaces. Credit: ITV Channel

Local residents like Blake Bellot have already seen how concerning flooding can be in the area.

He explains: "Last year, we saw it can get quite dangerous, so you get quite a lot of flooding in the driveway when you have the combination of high winds and high tides so it's definitely a concern.

"We've not had anything too major in terms of accidents yet but it's definitely a concern going forward."

"We're looking at protecting the island in a sustainable fashion over the next 100 years." - Steve Fitzgibbon Credit: ITV Channel

Steve Fitzgibbon, the Lead Coastal Engineer from the Infrastructure and Environment department, says they have shortlisted four options, but still say they are "very early in the process".

He explains: "We'll have a local model that looks at this area, and that'll give us the idea of what the sea defences need to do. And that's [protecting the coast from] a one-in-every-200-year storm.

"It's not a storm that happens every 200 years, it's one that statistically could happen every 200 years, so it could happen tomorrow, next year, or not at all in the next decade."

The government estimates a storm of this magnitude could cause £1.3 billion in economic, health, property, and business losses if it hit Havre de Pas with its current defences.

Havre de Pas Coastal Flood Alleviation Scheme: the four shortlisted options

1. Do Minimum

  • This plan will just maintain the existing defences.

  • This is the baseline case that acts as a control plan.

  • It can be used to measure the cost-benefit of the other options.

  • Steve says this is really "not an option" and will instead help the government understand the potential losses if nothing is done.

  • It is estimated the potential losses could be £1.3 billion if a 1 in 200 year storm event hit the island.

2. Adaptive Management (AM)

  • The shoreline will be proactively managed to ease flooding and erosion risk.

  • This plan will use the existing defence location, but increase the height of defences.

  • The profile of defences will change, similar to the seawalls near the Gunsite Cafe.

  • The AM option will also alter the slipways.

  • The downside would be the plan relies on one, higher primary wall to take the brunt of strong high water.

3. Advance The Line (Primary Wall Only)

  • This and the fourth option would push the 'line' of current flood defences seaward.

  • The wall would be around 5-10 metres seaward at the most.

  • It would create a new mile-long promenade to widen footpaths and make the area less congested.

  • It would also create a new cycle path and green spaces.

  • The primary wall would have to be higher than the fourth option, meaning it would take all of the force of high water and waves.

4. Advance the Wall (Primary and Secondary Walls)

  • This is the same as the third option but the primary wall would be smaller to allow water to come over during severe sea weather.

  • A secondary, smaller wall will be built behind to stop the water that comes over the primary wall.

  • It would mean two separate defences would share the brunt of high water.

  • The walls can be made higher throughout the decades to keep up with rising sea levels.

  • A new promenade space, cycle lane, and green spaces would still be in these plans.

  • This is currently the preferred option from the government.

Steve adds that the sea defences also need to protect against how far sea levels will have risen by the year 2120.

He explains: "We know we have issues with flooding, so we're at the very early engineering developments where we are looking at the Heritage impacts, environmental impacts, what's of international importance, how we manage the scheme and what the scheme looks like."

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