Municipality of Metaponto – Design intervention to mitigate coastal erosion in the Metaponto area
Client: Appointed Commissioner Delegate
Period of implementation: 2013
Total value of works: Euro 2.965.688,72
Value of our services: Euro 98.585,36
For the works to mitigate coastal erosion in the Metaponto area, undertaken by the Special Commissioner appointed for the implementation of works for the mitigation of the hydrogeological risks in the Basilicata Region, Acquatecno provided the final and executive design between 2012 and 2014, on the basis of the preliminary design that was the basis of the tender notice.
In recent years, the area of the works, located on the Ionian coast of Basilicata, in the Province of Matera, has been undergoing considerable erosion phenomena causing a serious risk with regard to natural disasters (storm surges, seawater incursion, erosion etc.).
In 2014, work started on the design drafted by Acquatecno, approved at the Conference Service and contracted by the Client, and the monitoring and inspection activities are under way.
The planned work involved the construction of 7 submerged breakwaters 140 m long, 0.50 m below mean sea level and interspersed with gaps of 75 m along a stretch of coastline of 1600m.
The dimensioning was performed on the basis of a thorough study of the wave, taking the Crotone buoy as the point of reference. This study was then integrated with a statistical analysis of the wave patterns, identifying the wave for the design using a return period of 50 years.
The study was also supported by a complex phase of bathymetric and topographic updated more time phases of design to take account of annual shoreline.
During the drafting of the project, numerical simulations were conducted, one for the estimate of currents induced between the entrances of the barriers, in order to study the evolution of the seabed and to prevent the dispersion of sediment out to sea, and one to determine the long-term evolution of the coastline to verify the scenarios resulting from the works themselves.
In terms of the materials chosen for the realization of the cliffs, on the basis of the wave incident on the structure of defense it was adopted a double layer of natural boulders from 6 to 8 t. with a core of natural boulders of equal size – 50 1000 Kg.
Special care has been taken for the study of wave transmission patterns on the rear of the cliffs, assessing the amount of dissipation they produce, and checking the wave run-up level, the identity of the sea level rise on the coast.
In order to improve the geotechnical conditions of the soil, or to prevent the core material from sinking or dispersed in water, the project involved the creation of a fund with a nonwoven geotextile fiber. Along the side edges of the submerged barriers are been included in berms natural boulders of I category (50-1000 kg) to prevent the undermining to the foot and the destabilization of the cliffs due to the action of waves and currents induced by it. In terms of security, the barriers that were conducted were buoyed floating in agreement with the requirements of the Port jurisdiction, in order to inform the boats and wet of the presence of such works as the submergence
