Kayakers frustrated by Mangahao release failure February 11th, 2020 2017-03-22T08:04:22+13:00 Kayakers from all over the North Island were looking forward to the Mangahao River dam release scheduled for Saturday 18 March, after many years of non-releases, ostensibly to repair the dam gate. Unfortunately at 8am on Saturday the dam operator informed Whitewater NZ that the gate failed to open when required. Unlike the weather (rain events are also problematic for Mangahao releases) that is something that should be controllable, so Whitewater NZ will be talking to Trustpower (who are effectively the new owner) this week on next steps and options to restore reliable recreational releases on the Mangahao. Access