Restoration of Koggala lagoon: modelling approach in evaluating lagoon water budget and flow characteristics.

Groyne system modification is described related to restoration efforts to Koggala lagoon, Sri Lanka.The large-scale unplanned sand removal at the lagoon mouth shifted the formation of sand bar towards the lagoon and made adverse effects on its ecosystem. After the removal of the natural sand bar, groyne system was constructed to avoid sand deposition in the lagoon and to protect the highway bridge (across the lagoon outlet channel) from the wave attack.