Storm water runoff at the mouth of Three Mile Creek has been a major cause of erosion of the frontal dunes and foreshore encroaching into the Western Bay of Plenty District Council reserve area and private properties along the beach.
After researching the problem it was decided that that the most effective solution would be to construct training groynes to direct the flow of water seaward of the dunes reducing the erosion around the mouth of the creek.
ELCOROCK® was chosen as the best solution as it was seen as a “soft engineering” option – environmentally and user friendly while being extremely robust to withstand the harsh abrasive conditions found in a coastal environment.
The structure consisting of 2.5m³ containers was constructed over a 4 week period with an additional week either side for site establishment and clean up. A crew of four was able to achieve a filling rate of 5 per hour using the supplied filling apparatus. Hydraulic compaction was achieved by using a generator and pump to saturate the sand with sea water as it moved through the hopper system into the ELCOROCK® containers. Once filled and sealed the containers were placed into position using the specially designed J bin connected to the excavator.