Erosion-Prone Land Workshop

Following recent intense storm events in the Motueka and Tolaga Bay areas, a workshop was organised by the Forest Owner's Association in Auckland on 2nd August. The purpose was to review current management practices on steep erodible land with a view to minimising downstream impacts, assessing current knowledge and identifying what further gaps or investigation is needed to fill any gaps.

Information on how climate change is causing an increased frequency of more intense storm events was presented with the clear message being that we can expect more of these intense storm events. Hydrology and soils expert advice was that slope failure will occur when such high amounts of rain occur in short periods. Forests provide the greatest level of protection, with pastoral cover the least. There is a window of vulnerability after harvesting and before the replacement crop is well established and how harvesting operations are managed to minimise the impact of intense storms during this vulnerable time is the challenge.

It was acknowledged that greater effort must be taken to reduce the risk of woody material moving downstream on to neighbouring land. Shorter term steps such as improving engagement with neighbours, debris barriers, minimising tree breakage during felling, ensuring woody material is removed from water courses and from mid slope areas at risk of slipping and ensuring debris and wood waste is secured safely on landings or benched areas were identified. Burning of waste is undertaken in some areas and this may be an option for other areas. A number of medium term initiatives were identified including a more proactive approach to finding utilisation options for logging waste and refining the erosion risk zoning so that mitigation measures can be targeted at areas of greatest risk of failure.

The outcomes of the workshop will be discussed with a wider group of stakeholders with the aim of getting agreement on the suggested actions, priorities and resourcing.