The HM Receiver General, David Pett, lodged the plans in July, saying that the defences on the eastern side of Maîtresse Ile – the main island of the Minquiers – had significantly deteriorated over the years, sustaining damage during a storm in 2014 and partially collapsing in 2018.
According to Socrates Architects, which is involved in the project, the replacement sea wall will have a 100-year lifespan and will use a ‘recurve’ wall design to deflect incoming waves back out to sea – the same shape as the defences recently constructed at Beaumont.
Geomarine are due to carry out the work at the site, which lies within the Coastal National Park and the green zone and has RAMSAR Convention status which provides a conservation framework for wetlands of international importance.
According to the planning application, work on the island is due to begin this month to coincide with the end of the bird nesting season.
The Jersey Oyster Company’s Normandy Trader landing craft will be used to transport machinery and materials to the reef, which is just under ten miles south of Jersey.
It is the same boat which was recently used to retrieve a sunken yacht from the area. It is also used to dump sea lettuce – collected from St Aubin’s Bay – away from the Island’s shore.
The Planning Department approved the application with three conditions:
- That an archaeological plan is submitted before work starts to ensure that no items of archaeological interest are missed.
- Measures – aimed at mitigating any ecological impact the work may have – are implemented.
- A method statement is drawn up confirming which areas of the reef will be a ‘no-go zone’ for contractors.
Also accompanying the application was a planning officer’s report, which said: ‘The Historic Environment and Natural Environment officers have no objection to the reconstruction of the sea defence wall and, therefore, [it is] not likely to have any detrimental impact upon the wider setting of the site or on the landscape character of the area.’
According to an application, lodged by HM Receiver General David Pett, the existing defences on the eastern side of Maîtresse Ile – the main isle of the Minquiers – have significantly deteriorated over recent years, sustaining damage during a storm in 2014 and partial collapse in 2018.
La Maitresse Île’s current defence was battered during the 2014 storm and then partially collapsed two years ago.
Socrates Architects were tasked with drawing up the plans, which they hope will provide protection from the effects of climate change in the coming century, including rising sea levels and longer and more intense storms.
The islet is home to a cluster of huts dating from the 18th and early 19th century – known as ‘barraques’- which were traditionally used as seasonal shelters for fishermen and collectors of seaweed.
As such, it is not only of historical interest but also of architectural and archaeological interest.
Following the deterioration of one of the sea defence walls on the eastern side of the islet, which was damaged during the storm of 2014 and partially collapsed in 2018, Her Majesty’s Receiver General David Pett – who is responsible for administering land owned by the Crown – drew up a design brief for its repair.
The damaged wall is made up of loose rounded stones and boulders randomly placed on top of each other with the outer face sloping inwardly, leading waves to come over the top of it.
Mr Pett asked that the new wall not only be durable but also that the process of its reconstruction had minimal impact on the local environment and the aesthetic of the area, due to Les Minquiers’ unique status as a RAMSAR site.
Socrates Architects worked with structural engineers and sea wall specialists, Steve Hold Consulting, as well as GeoMarine and Nurture Ecology to come up with plans that would fit the brief.
While a robust structure such as a sea defense wall would normally require reinforced concrete, they decided to use the minimum of “wet cement” and no steel reinforcement, to limit the risk of future maintenance such as reinforcement corrosion being required at such a remote site.
The structural integrity of the wall will be provided by relatively large pre-cast mass concrete interlocking blocks, faced with masonry and reinforced from top to bottom with stainless steel “stitching anchors” that are drilled down into the bedrock for anchorage.
The top layer of the pre-cast blocks has been designed to create a “re-curve” which aims to prevent waves from going over the top of the wall as well as reducing the wave energy arriving at the wall during storms.
As part of the plans, the wall will also be better connected to a nearby one in an effort to get rid of an indentation which causes a funnel effect, creating very large waves and increasing their strength.
The wall will also be raised to combat the overtopping produced during high tide, storm surges and strong wind events from the East.
As with the reinforcing of the sea wall at Gunsite Cafe in St. Aubin, the top of the curved wall has been designed to be “future-proof”, meaning that, if needed, it will be easy to raise the wall further at a later point in time.
To carry out the work, the teams will be looking to keep equipment and plant to a minimum. They will however have to transport materials including sand, cement, aggregate, pea gravel and possibly graded crushed rock, as well a small lifting machine to Les Minquiers.
Due to the absence of potable water on La Maitresse Île, they will also have to bring water and find a way to store it.
The materials will be transported to the site daily with the workforce to be stored in one or more of the huts if possible.
Commenting on the plans which have been submitted to the Planning Department for approval, Socrates Architects said that while they proposed changes to the reef’s sea defence, they would enhance the character of the reef and its setting.
“The eastern wall is failing and this part of Les Minqueries is now in danger of serious storm damage for this and subsequent winter months,” Nicholas Socrates said.
“These are urgent repair works of which have been carefully considered and designed and engineered to not only be in keeping with the reef and its existing structures but also to act as an effective defence for the next 100 years.”