As a result of the vegetation loss on the slopes, the fire exposed highly erodible loess soils as well as a significant amount of ash. The sensitive receiving catchment was subjected to a significant risk as well as an increased sediment loading during autumn rain events washing into the Cashmere Stream and subsequently into the Avon/Heathcote Estuary.
For a large portion of the catchment, vegetation began to restablish, where fire damage had not damaged dormant seed or plant roots. However, on the most highly impacted areas there are no signs of revegetation occurring. Leading into winter, where rainfall is at its highest in Canterbury, there was a push to stabilise those most “at risk” areas.
Applications of Vital Bon-Matt Stonewall IGD were undertaken to specific areas to provide immediate point source stabilisation of exposed slopes. The areas were chosen based on an assessment of their erosion potential, as well as their proximity to sensitive waterways.
Vital Bon-Matt Stonewall IGD applications were also undertaken to support the establishment of aerial seeding where specialist seed blends were used to promote revegetation by pinning seed to soil, strike is improved and seed is less prone to wind & rain damage.
The employment of Vital Bon-Matt Stonewall IGD to over 8Ha to immediately & effectively stabilise at risk areas on the Port Hills will improve sustainable environmental outcomes by minimising erosion, leading to a reduction in loss of soil and loess, which in turn will reduce the sediment loading entering sensitive waterways whilst promoting long-term stabilisation & revegetation.
