Flood study centres around the opening of Cockrone Lagoon to the ocean when the water level exceeds the let-out-level of RL2.476m AHD. The policy is aimed at minimising the flooding of properties adjacent to the lagoon.

The investigation process used in this flood study was:

• collection of available data
• assessment of available data
• overview of lagoon behaviour
• assessment of coastal processes
• hydrologic modelling of the catchment to determine flood inflows, and
• hydraulic modelling of the lagoon to assess flood levels from flood inflows