The Floodplain Management Plan divides the Cockrone Lagoon area into six precincts:
- Cockrone Lagoon - Beach Berm High Hazard Floodway/Investigation
- Cockrone Lagoon - Entrance Area High Hazard – Low Hazard
Floodway/Investigation
- Cockrone Lagoon - Storage Area Low Hazard Flood storage
- Cockrone Lagoon - Floodway Area High Hazard Floodway
- Merchants Creek - Floodway Area High Hazard Floodway
- Newell Road Floodway High Hazard Floodway
These precincts have been classified for flood hazard as:
High Hazard - Floodways
- Cockrone Lagoon beach berm;
- Cockrone Gully, from the upstream study boundary to its confluence with Cockrone
Lagoon (identified as Cockrone Lagoon floodway);
- Merchants Creek floodway from the confluence of Merchants Creek with Cockrone
Lagoon to the upstream study extent; and
- an existing open drain through the residential areas bounded by Newell Road and Three
Points Avenue.
High Hazard – Low Hazard Floodway (Floodway Investigation area)
- Cockrone Lagoon at its entrance to the ocean (Floodway/Investigation Area);
Low Hazard - Flood Storage
- Cockrone Lagoon and foreshores excepting high hazard areas above.
These precincts are illustrated on Figures 2 and 3, while Figure 4 provides greater detail in the Cockrone
Lagoon Entrance Area.
Council has adopted a policy of opening the lagoons when water level reaches RL 2.53 m AHD (identified
as the let-out-level). Council has, in the past, also adopted a policy that requires new buildings to have
floor levels above RL 4.3 m AHD. These two policies effectively constitute Council's current floodplain
management practice around Cockrone Lagoon.