Implications for coastal management

Point Henry, Moolap & Newcomb

The salt works levees are relict; however, they could be inspected by a qualified engineer to determine what would be required to make them effective for flood management purposes. It may be more cost effective to increase the elevation of Geelong-Portarlington Road gradually over time during routine maintenance and resurfacing, and install valves on the drains and flood routes, since the hazard is only significant in the long term. An assessment of the costs and benefits of such actions in future would be required as part of subsequent studies.

The potential development of the salt pans site is an issue in terms of the future inundation hazard, and should be thoroughly considered prior to Council granting any development consents.

Management triggers are presented in Table 6-20.

Table 6-20     Management triggers – Point Henry, Newcomb & Moolap

Hazard Mechanism Estimated scenario under which this is likely to occur Triggers
Inundation

Point Henry

Overwashing of the shoreline due to storm-tide inundation + sea-level rise 1% AEP event + 0.5 m SLR A) Investigation and planning / management when measured increases in sea-level reach 0.2 m above 1990 levels.
InundationNewcomb /

Moolap

Inundation due to storm-tide + sea-level rise 1% AEP event + 0.8 m SLR A) Investigation and planning / management when measured increases in sea-level reach 0.5 m above 1990 levels.

Geelong

Inundation hazards in this area are less significant, and the long-term management of the Geelong waterfront will be the key factor minimising the hazard vulnerability here. The Geelong waterfront is well protected and maintained at present. The location and importance of this as an amenity area will ensure that this is likely to continue indefinitely. The hinterland rises to higher ground, which will limit the risk posed by inundation or overtopping hazards. An increase in the crest height of the shore protection structures over time will reduce the potential hazard significantly.

Eastern and Ritchie’s beaches are sporadically renourished with imported sediments. Erosion losses here are minor, and a programme of beach recycling (i.e. relocation of sediment from downdrift to updrift areas) is being established as part of a separate management project to address the effects of the littoral drift. Management triggers are presented in Table 6-21.

Table 6-21     Management triggers – Geelong

Hazard Mechanism Estimated scenario under which this is likely to occur Triggers
Inundation Overwashing or overtopping of the shoreline due to storm-tide inundation + sea-level rise 1% AEP event + 0.0 m SLR A) Investigation and planning / management required at present day levels. Maintenance of coastal protection structures to continue.

Results

Further investigations & recommendations