Rock bags are a product developed in 1987 by Kyowa in Japan to protect against erosion from hydraulic processes in riverine, lake, coastal and marine environments. Within Australasia, the rock bags are imported and distributed by Bluemont Pty Ltd. However, the behaviour of rock bags in shallow water, coastal environments had not previously been assessed in a physical modelling study. This is despite the use of rock bags since 2020 as a temporary or emergency coastal protection unit for seawalls located at the back of some beaches in Australia (e.g. Wamberal Beach and Collaroy Beach). Since this is an emerging erosion protection application for rock bags, Bluemont wanted to assess their hydraulic stability in this arrangement using scale model laboratory tests. The UNSW Water Research Laboratory was engaged by Haskoning Australia to partner in carrying out a physical modelling study for Bluemont for shallow water seawalls constructed from rock bags.
