Erosion Field Day – Book Book, 11 December 2012

Around 20 people attended a hands-on field day in Book Book this week to learn about low cost methods for controlling erosion. Cam Wilson from Earth Integral demonstrated a ‘log ramp rundown’, used to prevent a gully head cut migrating further up a slope. Attendees came prepared with tools to help set up the demonstration site that will be revisited in coming years to monitor its effectiveness.

Cam Wilson at battered gully head Cam Wilson lines the battered gully head with plastic to protect the highly dispersive sodic soil.

In the afternoon a visit was made to a nearby property with large scale streambank erosion, common in many of the waterways after floods of recent years. Tim Smith, Licencing Officer, NSW Office of Water, spoke about the substantial cost of earthworks to attempt to fix large scale erosion and the risk that costly structures may be ineffective. He suggested that landholders manage waterways as a separate class of land, and that they must accept that erosion is a natural process that cannot be completely controlled and waterways will always continue to move, eroding land some areas and deposition in others.

Cam explains the 'log ramp rundown' structure to protect the eroding gully head.

Cam Wilson spoke about the potential to use vegetation to slow the erosion process in certain areas, directing flow away from vulnerable banks on the outside of bends and generally reducing the force of flood flow in the stream. Using species such as poplar was suggested due to its rapid growth rate and also the additional benefit of its high quality feed value. Fast growing natives such as Casuarina or Acacia could also be used. Cam suggested that landholders plan ahead 5-6 years and plant trees that can later be felled for use in low cost erosion control work.

Peter Lawson describing the flooding in Kyeamba Creek and the resulting streambank erosion on his property.