Work is starting this week (30 September) to repair St Catherine's breakwater
The area was damaged during Storm Ciarán in November 2023, and was further hit in February this year by storm force winds.
It led to cracks ranging from five to 15 cm wide.
A survey in March by UK-based storm defence specialists AECOM assessed the damage using drones and ground-penetrating radar to determine what repairs were needed.
It found that the northern buttress of the breakwater is at risk of more damage and needs immediate attention.
Work will start there, addressing areas where stones have been dislodged, exposing the infill.
The breakwater is Grade 1 listed, and work has had to be agreed by the government's planning, heritage and coastal defence teams.
Geomarine will be doing the work over a week or two, at times of low water.
Ports of Jersey says the breakwater will remain open but access might be restricted at certain times.
The next phase of work will focus on repairing and stabilising the slipway. Planning is ongoing to decide the best approach to future-proof the structure.