Despite the recognition that intertidal surfaces play an important role in dissipating wave height and energy, few previous field measurements have been undertaken to directly quantify this effect. This paper presents the results from a one year data collection campaign in the macrotidal Wash tidal inlet, eastern England, during which wave measurements were taken at lower, mid and upper recording stations along three different shore-perpendicular intertidal transects.

It has been found that the intertidal environment of The Wash is effective in dissipating wave height by, on average, 83% and in dissipating wave energy by, on average, 91% with respect to the incident wave conditions.

Based upon the results from this study, it is recommended that flood defence management practice in The Wash moves away from focusing on the defence of a structural line towards the management of a defence zone, comprising both natural and structural elements.