30-Nov-2011

Elastocoast is a polyurethane product used in Europe and developed by BASF principally for coastal seawall protection. It is used to bind hard rock aggregate together to form a solid surface. In 2009 it was introduced to Australia for the first time for erosion control purposes in South East Queensland (SEQ).

An example of using elastocoast is for construction of a Leaky Weir. A Leaky Weir is a structure designed to reduce the velocity of water from a catchment draining into the main River as well as reducing the sediment load. Elastocoast forms a porous structure but in a storm flow will pond water behind it for a period of time. At this site the water will pond back around an eroding corner. Because the water virtually stops it will start to drop sediment that hopefully over time will repair this particular gully.

A leaky weir was recently constructed using ‘elastocoast’ in the Upper Bremer as part of the Healthy Country project. The leaky weir was tested by a storm on the night that the structure was finished and it proved to be successful as it had drained completely by the next morning. In the picture the debris line is marked high on the structure and there is evidence of possibly some sediment on the floor above the weir.

It is expected that elastocoast can last for a minimum of 20 years. The cost of elastocoast is said to be competitive with a traditional rock structure and expected to be very successful in stabilising erosion sites. It is however still at a trial phase and runoff events over the next few years will provide many learning experiences and determine to what extent it could be used for erosion purposes in SEQ.