Storm Response

Two recent significant storms Marlborough experienced in July 2021 and August 2022 triggered widespread and damaging landslides which left multiple roads and houses impacted.

GNS Science and Marlborough District Council staff analysed the rainfall and landslide data from these storms. In 2021, 400-500mm of rain fell over 54 hours and in the 2022 storm over 1000 mm of rain fell over four days. In total, over the two storms, Marlborough experienced 7597 landslides.

With the assistance of the GNS Landslide response team, the two major storm events resulted in multiple technical outcomes. Marlborough District Council now has access to programmes and tools that can help us assess and map the scale of damage and carry out scientific analysis of landslide mechanisms, impacts and causes.

These include Drone technology that allows the mapping of landslides and can be paired with LiDAR to enable volume measurements. The use of a Rain Radar from Metservice combined with geology, soil, slope, land cover and spatial analysis assists us with assessing the contributing factors.