2017 slash investigation report
Cyclone Cook slash investigation
Plantation forestry is a significant land use in Tairawhiti, providing a number of environmental and economic benefits. However, there are also a number of associated issues particularly during the harvest and post-harvest period. A key issue and the one at focus in the report is slash mobilisation events after high intensity rain events.
Ex tropical Cyclone Cook struck Tairawhiti on 12 April 2017. The duration of peak rainfall intensities was a key driver during the event with rainfall of 80mm+ over 3 hours causing woody debris to mobilise. The area of maximum rainfall was in the headwaters of the Uawa and Waiapu catchments. The impacts of the storm were exacerbated by rainfall from Cyclone Debbie occurring just over a week earlier.
Cyclone Cook Slash Investigation Report [PDF, 14 MB]
Appendix A and B of the Report [PDF, 8.5 MB]
Appendices include helicopter flight photos and Tolaga Bay Slash Identification Guide
Limitations - this report compiles and analyses data acquired primarily by Gisborne District Council staff after Cyclone Cook. While it is as comprehensive as possible, resources did not allow to a helicopter overflight over the entire district. Nonetheless, the details obtained are considered to accurately reflect the impacts of Cyclone Cook.