The giant poplar fell into the Clutha after high river flows in December last year that speeded up erosion of the riverbank.
The operation was led by the Otago Regional Council this morning and also included the Queenstown Lakes District Harbourmaster and Parks and Reserves, NZTA's contractor Aspiring Highways, Go Jets Wanaka and Mike Hurring Logging and Contracting.
ORC's manager engineering Michelle Mifflin said it was a “huge” exercise that was well-executed.
“Because of the inaccessibility of the riverbank where the tree had fallen, as well as the size of the tree and the speed of the Clutha current, we had a very detailed plan and contingencies for all possible risks.
“We looked at a few options for removing the tree, even the possibility of using a helicopter, but settled on the approach of using a bulldozer and excavator upstream on the far bank, and winching the tree across the river.
"It seems complicated, but it was really the best solution for the conditions.”
The poplar needed to be removed for safety and to protect infrastructure, she said.
“It was a bit like an iceberg because a lot of it was invisible under the water, and that could have posed a safety risk to swimmers and kayakers.
"There was also risk that it could damage the riverbank or the downstream bridge if it was mobilised by the current.”
The crew also felled and removed another poplar on the riverside at the same risk of erosion.
