Replenishment Dredging at Maroochy
Overview of Project
The Sunshine Coast Council (SCC) required the dredging of sand within the Maroochy River. This involved the mobilisation of the 450mm Cutter Suction Dredge the “Nu Endeavour” through the Maroochy River mouth and the dredging of 75,000m3 of sand through an existing 400mm diameter pipeline located in the dunes. This sand was used to renourish a 1.5km stretch of beach between the Maroochydore and Alexandra Headlands Surf Lifesaving Clubs.
The Nu Endeavour is a 450mm Cutter Suction Dredge It is 34.78m long and has a maximum digging depth of 15m. It has a total power of 1,454KW (1,500hp) and has the capacity of pumping up to 650m3 of sand per hour up to a distance of 1,000m.
Scope of Works
The requirements particular to the operation included:
- Supply of the 450mm CSD Dredge, Booster and ancillary plant,
- Dredging of 75,000m3 of sand from the approved area within the Maroochy River,
- Placement of 75,000m3 of sand to the approved beach locations and profiles as required by SCC,
- Site rehabilitation and rectification as required.
Challenges
Due to the migration and spawning activities of commercially and recreationally important species of fish within the area. Dredging could not occur during the two days prior, the day of and two days after the new and full moons.
Despite these restrictions and with a four month time frame available, the dredging and beach nourishment works were completed in under 2 months.
