This report details the investigations carried out to determine design flood levels for Cockrone Lagoon and the floodplain adjacent to the lagoon within the study area.

Cockrone Lagoon is a small, shallow coastal lagoon located behind MacMasters Beach. The lagoon entrance is normally closed due to the action of coastal dynamic processes which result in the formation of a beach berm across the entrance. The lagoon is perched some 2.5 metres above mean sea level.

Gosford Council has adopted a maximum water level for the lagoon, termed "let-out-level" of RL 2.476 m AHD. The lagoon entrance is normally opened when the water level in the lagoon rises above the let-out-level.