The popular coastal route closed since a 2021 rockfall may not see a permanent engineering “fix,” according to recent assessments. Documents prepared by consultants RPS suggest that erosion should be treated as an unavoidable baseline condition that must be managed over time rather than eliminated.
A Shift Toward Managed Retreat
For the first time, engineers have applied a quantified long-term regression model to the full length of the cliffs overlooking Greystones North Beach. This modelling applies an annual retreat rate of up to 0.39 metres per year, based on historical data, recent inspections, and worst-case storm intensity allowances.
Rather than attempting to stabilise the cliff line in its current position, the analysis assumes a steady inland movement of the cliff edge. This process continues until the slopes flatten naturally to a more stable inclination of 25 degrees.
This strategy aligns with “managed retreat” approaches used in coastal engineering. Under this framework, authorities accept ongoing land loss instead of attempting to permanently defend eroding shorelines.
Imminent Risks and Material Failure
The urgency of these findings was reinforced by post-storm inspections in February 2026, following severe weather caused by Storm Chandra. Engineers warned the council that landslide features near the path represent a “significant risk to the path and any persons using the path.”
While the precise timing of individual collapses cannot be predicted, engineers stated that these features “will in time collapse.” They also noted that some sections of the sea cliffs were unsafe to access, meaning further unidentified instability could be present along the route.
The reports identify “Irish Sea Till” as a primary concern, describing the material as susceptible to softening and failure when exposed. Current cliff inclinations are generally considered too steep for these materials to remain stable.
Infrastructure Concerns at Kilruddery Stream
A technical assessment was also conducted on a footbridge near where the route crosses the Kilruddery Stream. While a February 2026 visual inspection found the bridge structure to be in generally good condition, significant erosion was identified in the stream channel beneath it.
The stream bed has eroded to approximately 1.5 metres below the visible level of the bridge abutments. Engineers believe the abutments likely sit above the current base of the channel, creating a risk of undermining if erosion continues.
Proposed protections include rock armour, boxed culverts, and reinforced concrete channels. However, consultants warned that the stream is likely to erode below any protective measures over time, necessitating routine inspection and replacement.
Next Steps for the Route
Wicklow County Council is continuing to work with consultants on further investigations. These may include drone inspections, rope access surveys, and ecological assessments.
ongoing engineering and environmental assessments are exploring potential fresh access arrangements from Greystones North Beach.
Frequently Asked Questions
Why has the coastal route been closed?
The route has been closed since a rockfall occurred in 2021.
What is the predicted rate of cliff retreat?
Consultants applied an annual retreat rate of up to 0.39 metres per year based on historical data and worst-case storm intensity.
Is the footbridge at Kilruddery Stream safe?
The bridge has not been declared unsafe and its structure is in generally good condition, but engineers warned that protective works are required to prevent continued scour beneath the structure.
Do you believe managed retreat is the most sustainable approach for protecting coastal infrastructure?
