COASTAL EROSION PROTECTION WORK

THE BACKGROUND

This coast has been experiencing erosion for the last 4 decades due to the predominant northerly sediment transport. In spite of several measures to rehabilitate the seawall as a protection measure, the problem persisted until the present solution was adopted.

THE SOLUTION

In order to combat further erosion, Prof.V.Sundar, Department of Ocean Engineering (DOE), Indian Institute of Technology Madras has investigated the status of existing seawall, analysed the wave data for the coast, suggested suitable coastal protection measures and verified with numerical model study. The proposed coastal protection scheme consists of shore-connected groins.

After carrying out detailed bathymetry survey, DOE designed the optimum dimensions of the groin cross sections that includes slope on both of its sides, its crest elevation, the size of the stones to be adopted for the different layers, the thickness of the various layers (comprising of armor, under layer, core, filter and the toe) and the width of the crest.

THE IMPLEMENTATION

The implementation of the proposed groin field has been initiated in April’04. Immediate shoreline advancement on the south of the executed groins has been substantiating the most favourable choice and design of the suggested remedial measure. The shoreline advancement is monitored regularly and are well agreeing with the numerical predictions of DOE. Till Oct’04, a beach area to an extent of about 10000 sq.m have been acquired between groins 6 and 5.