Static equilibrium bays in coast protection

As part of the 2004 Hythe to Folkestone Harbour coast protection scheme, two static equilibrium bays were formed using rock headland structures and shingle imported as part of the beach renourishment phase of the scheme. The development of this element of the scheme and the appraisal process that led to these bay forms being chosen as the most appropriate form of coast protection are discussed. The performance of the bays has been continually monitored since their construction and the measured plan-shape of each bay has been compared with the theoretical predictions. This has shown that there is good agreement between the crenular planforms predicted by the mathematical models and the theoretical methods, which are founded on the log-spiral curve that has been shown to represent the crenular planform of naturally formed bays. Observations based on the survey data collected over the 20 months since the completion of the scheme have shown that the measured planform is in relatively good agreement with the theoretical predictions. The bays do, however, exhibit distinct yet small differences from the theoretical form, but nevertheless are approaching an equilibrium state