Mullion Cove - adapting to climate change

A storm wave hits the breakwater at Mullion Harbour

In the winter of 2014 the UK experienced one of its most prolonged periods of exceptional weather for more than a century. There were several gales with winds exceeding 80mph, waves more than 16m high and the heaviest rainfall since 1770.

The result was widespread, persistent flooding and serious damage along the coast. Erosion which had been expected to take place over several years occurred almost overnight. 

Massive waves pounded the breakwaters at Mullion Cove, causing significant surface damage. Granite coping stones and 6000 paving setts were washed away, and iron railings and bollards were damaged or lost. A small winch house was completely destroyed and the winch ruined. Despite this, the internal structure of the harbour walls withstood the onslaught and remained substantially intact. 

Specialist builders repairing Mullion Harbour
Repair work at Mullion Harbour after storm damage
Specialist builders repairing Mullion Harbour

Holding back the sea

Mullion Harbour has been withstanding the Atlantic waves since the 1890s, when it was built by the cove’s owner, Lord Robartes of Lanhydrock, to shelter the pilchard fleet. Today it provides a haven for a few fishing boats and a huddle of seafront properties, and attracts some 80,000 visitors a year. Since 1945 the National Trust has spent more than £2million repairing the breakwaters. Over the past 20 years an average of £1,500 a week has been spent as winter storms have become more frequent and violent. 

Specialist builders working to save the walls of Mullion Harbour
Specialist builders working on the harbour walls at Mullion
Specialist builders working to save the walls of Mullion Harbour

Given these rising costs, most of which were met from its own funds, the Trust needed to develop a strategy for the future, and in 2004 commissioned a comprehensive Mullion Harbour Study. This report included seabed surveys, an analysis of 20 years of wave data, and an inspection of the harbour by divers and bore holes, and geological, environmental, economic and archaeological surveys. 

Agreeing a way forward

The Mullion Harbour Study revealed that the 100 year old harbour was in relatively good shape, but concluded that sea levels would continue to rise, wave heights would increase and freak storms might become annual events by 2100. 

A stakeholder group of residents, fisheries and harbour associations, tourism and environmental agencies, and local authorities, was set up to discuss the Study and agree a way forward. It recommended that the National Trust should repair and maintain the harbour into the future, but it also recognised that if severe storms continued to inflict damage, and as the structure got older, a tipping point might be reached when it would be necessary to call a halt to repairs. 

At this point, with the involvement of local authorities and English Heritage, repairs would not be undertaken but the harbour walls might be consolidated to preserve most of the structure for as long as possible. 

Following the report, the Trust carried our extensive work to strengthen the breakwaters in 2006, and since then has continued to undertake repairs and maintenance. It is thanks to this work that the harbour survived the 2014 storms when other harbours suffered extensive damage.

To find out more about the National Trust’s strategy for coping with climate and coastal change click here