Around 2020, Tony Weir and Lance Stewart set out to locate the enormous landslide visible on the distant hills behind Wainuiomata. The slip may have occurred on Sunday, 7 April 2019, according to a Sunny Grove resident who lodged an insurance claim after floodwaters from Skerrett’s Creek damaged his property.
Measurements taken using Google Earth indicate that the landslide extends approximately 220.4 metres down the steep hillside.
Weather records were obtained for the seven-day period surrounding the flood. The hourly readings, recorded by an automatic weather station on Wellington Road in Wainuiomata, show that 49 millimetres of rain fell on Friday, 5 April, followed by 81.2 millimetres on Saturday and a further 32.6 millimetres on Sunday.
In total, 162.8 millimetres of rain fell over the three days leading up to and including the flood. This sustained period of heavy rainfall was likely a major factor in triggering the landslide and causing Skerrett’s Creek to flood.
Credits
Special thanks to Lance Stewart for providing information about the landslide and storm, and for filming some of the video footage.
Special thanks to Tony Weir for sharing the video.
