The Making of a Gravel Beach (Cavo, Elba Island, Italy)

Abstract

This paper presents the history and evolution of the different projects carried out from 1999 to 2008 at Cavo beach in the Elba Island, Italy. The village of Cavo almost completely lost its beach in the 1970s due to the reduction of sedimentary input, and the backing coastal road was defended by a revetment and two detached breakwaters. Such severe erosion processes continued in the following years and impeded any possibility of beach tourist development. In 1999, a project based on the removal of existing breakwaters and beach nourishment works based on the use of gravel as borrow sediment and the construction of two short groins to maintain nourished sediment, raised environmental concern and did not find the approval of the stakeholders. They were worried about the characteristics of the sediments, i.e., waste materials from iron mining rich in red silt and clay. Such sediment fractions made the sea red during the nourishment and deposited on the Posidonia oceanica meadow in front of the beach, with a potential environmental impact. Furthermore, they cemented the gravel fraction forming a beach rock. Between 2006 and 2008, these materials were covered with better quality gravel, extending and raising the beach profile, which required the elevation and lengthening of the two existing groins. Beach evolution monitoring following the second project, based on morphological and sedimentological data acquired before, during and after the works, demonstrated the great stability of the newly created beach. The wider beach has allowed the construction of a promenade and the positioning, in summer, of small structures useful for seaside tourism, increasing the appeal of this village. Data presented in this paper shows an interesting study case, since few examples exist in international literature regarding gravel nourishment projects monitoring and evolution.