June Cummings reports
Queensland Premier Anna Bligh has lived up to her election promise by funding the $500,000 first stage operation. Council will manage the project and use its own day labour for traffic control, because of the many pathways and parks in the zone and the need to maintain access to beachfront residential properties.
In a first for the Gold Coast, the surfing fraternity has primarily dictated the re-shaping of the shoreline to restore ‘the break’, which will remove sand from the lee of the Kirra Point groyne. The excavation area is an open beach, shore wash zone between high and low tide. Sand will be taken to two destinations – one a short distance, the other long distance.
This will preclude any downtime for the beach excavation machinery. The closest sandfill, only 1km from excavation work, will fill in lagoons at the back of Kirra Beach caused by recent storm surges. The residue will be trucked north to Palm Beach to build a bund on the existing seawall to house a pipeline to be used for beach nourishment with sand supplied from dredging operations.
Neumann Dredging has been contracted for the dredging works, which will remove sand from the mouth of Currumbin Creek and pump it by pipeline to replenish southern and northern areas, up to 11th Avenue, of Palm Beach. Sand will be delivered within 2km from the dredge.
Council says it did its costing for the restoration of the Kirra break and sand distribution project using comparisons between hourly rates and cubic metre removal rates. Because of the economic climate, prices were good and hourly rates were chosen.
State government has promised $1.5m for long term beach replenishment. One proposal is for a fixed pipeline from the Tweed River sand bypass scheme with multiple outlets, allowing distribution to flexible locations and quantities of sand.
It would mean establishing a new coastal outlet further north, which is beyond the capacity of the existing Tweed River pump station, so a booster station would be needed. This would require dual state negotiations to establish new rates, how often required, amounts and whether a fixed pipeline is the answer.
The Griffiths Centre for Coastal Management at the Gold Coast Griffiths University campus has been commissioned to do a study in conjunction with the Danish Hydraulic Institute.
Other issues to be addressed by the study are the heights of shoreline dunes, which have been lowered in line with the seawall to allow a view or vista out across the ocean. Could sand, which is in oversupply because of dredging works from estuaries and waterways, be used to build artificial high dunes and spoil views. The big question is, according to council, what to do with the sand long term – sacrifice views, or dunes, or store it.
Council’s short term plan is to distribute it along beaches to maintain activities. The study is to come up with a long term strategy for placement of sand and the longevity of the foreshore. Few of Australia’s east coast beaches have a ready endowment of replenishment sand to offset the predicted rise in sea levels.
