Tarr Steps: Britain's Longest Clapper Bridge Is Washing Away Faster Than It Can Be Rebuilt

Five flood-driven collapses in nine years signal a climate-resilience crisis for heritage infrastructure. An ancient structure that survived centuries now faces a repair cycle it cannot outrun.

Tarr Steps, the longest clapper bridge in Britain at nearly 55 metres, has been dismantled by floodwater five times in nine years. The most recent destruction came during storms Austen and Boelo, when over eight centimetres of rain fell overnight and the River Barle rose by nearly two metres. The medieval structure — 17 arches of unmortared gritstone slabs weighing up to two tonnes each — is held together by nothing but bulk and gravity, a design that worked for centuries but now faces a climate regime it was never built for.

The acceleration is the story. The bridge famously survived a dramatic ice-flood event in January 1940 when the Barle froze solid and then released ice floes that battered out its central section. That was treated as a once-in-a-generation catastrophe. Now equivalent damage occurs roughly every two years. The numbered stones get hauled back into place, the bridge reopens, and the next storm knocks it down again. This is not maintenance; it is Sisyphean repetition. The scene after storms Austen and Boelo tells the structural story plainly. The middle section was gone entirely, with massive rock slabs jumbled across the riverbed. Heaps of fallen trees and timber swept downstream were caught against the bank, torn branches smashed and wedged into the remaining piers. Bridge and ford remain closed for the immediate future, with winter making reconstruction impossible for months. Exmoor itself is changing around the bridge. Red kites, still fairly uncommon on the moor, are pushing westward with increasing numbers. Pheasant populations are rising too, driven by the spread of game-shooting estates rather than ecological recovery. The landscape is being reshaped by both climate and commercial land use simultaneously. The deeper question is whether heritage structures designed for a stable climate can survive in an unstable one. Tarr Steps is a medieval improvement of a bronze age crossing — possibly the oldest continuously used river crossing in England. Its unmortared construction is both its historical significance and its fatal vulnerability. Every restoration preserves the form but cannot address the intensifying hydrological forces destroying it. With each rebuild, the cost-benefit calculus shifts. The numbered stones can be reassembled, but the labour, equipment, and road closures accumulate. At five collapses in nine years and accelerating, the question is no longer whether the bridge can be saved but whether the current approach — rebuild, wait, rebuild — constitutes a plan or a refusal to acknowledge the new normal. Sara Hudston's book 'A Life Outside,' about Exmoor nature writer and artist Hope Bourne, is available from the Exmoor Society. The bridge it overlooks may soon require a fundamentally different kind of care.