DO SEAWALLS CAUSE BEACH EROSION ?
This is a Question that has often been asked by Planners and Decision makers regarding whether proposed protective structure should be allowed or not- A body of opinion exists that insists that seawalls promote and accelerate the erosion process in front and adjacent to the seawalls. To answer this question, GRIGGS et al (1991) have monitored for over four years the beaches in the protected and the unprotected coastal areas in Central California, USA- Their findings are valid for a coast which is not undergoing any net retreat with time. They find that seawalls properly located had no impact on the erosional behaviour of the beaches in front or adjacent to it. Some scour was observed at the down drift end of each structure and the extent of this scour was controlled by the end section orientation, angle of wave approach and the wave characteristics.CONCLUSIONS Karnataka coast experiences erosion at isolated regions in the monsoon season. However these erosions do not cause any net retr
