Opotiki Harbour Development

WRL completed 2D, quasi-3D and full 3D physical modelling of twin 400 m long training wall breakwaters to stabilise a dynamic river mouth at Opotiki in New Zealand.

Year: 2021
Client: Tonkin + Taylor

The Opotiki Harbour Development (“OHD”) is the first river port to be constructed in over 100 years in New Zealand. The OHD scheme comprises of twin 400 m long training wall breakwaters requiring a multi-stage approach to physical modelling.

A combination of 2D, quasi-3D and full 3D modelling was used to assess the complex river entrance processes, optimise and validate the proposed design: 

  1. 2D physical modelling of key sections of the training wall trunks.
  2. Quasi-3D physical modelling of the breakwater head.
  3. Full 3D physical modelling of the two complete structures.

Physical model tests at a 1:40 scale allowed for the determination of actual KD numbers, using a placement methodology and density specified for construction, a range of wave conditions including normal and 45 degree incident waves.

The armour units used were Hanbars, an Australian invention that can be found on many breakwaters along the NSW coastline. With over 3,000 individual blocks placed by hand, the Hanbar layouts were tested in the full 3D physical model to assess and validate the performance of the design layout.
Larry Paice, UNSW Water Research Laboratory

For further information contact:

Dr Francois Flocard | Director, Industry Research | f.flocard@wrl.unsw.edu.au