Man-made coastal structures directly affect sediment balance in the
surrounding beaches. Ongoing South Colombo harbour expansion project has
created 5 km long breakwater affecting the sediment dynamics of the Colombo
beaches. Present study is focussed on quantitatively and qualitatively analyse
the effect of Colombo harbour expansion project on economically important
beaches in an around Colombo city area and to forecast possible consequences
to the Colombo harbour itself. We have taken monthly variations of beach
width, beach profile and the mean grain size of the sediments at mean sea level
from selected 8 beaches. Data was processed and analysed to establish sitespecific
erosion vulnerability. Results shows cumulative beach erosion has high
affinity to erosion causing drastic reduction of beach width after the
construction of the breakwater. This study highlights necessity of proper
mitigation plan to protect the beaches affected by the construction of southern
Colombo harbour expansion project
