Constable Peter Graham, of Winton, said the truck was delivering two shipping containers full of domestic rubbish from Gore to a landfill near Browns when the front container became unbalanced and hit the side of a bridge over the Makarewa Flood Channel on State Highway 96 near the intersection with Channel Rd about 5pm.
The driver stopped the truck, but as it came to a halt the container fell off in to the stream.
The movement of the container unbalanced the cab which then also tipped over the side of the bridge and landed upside-down on top of the dislodged container.
The trailer of the truck, with the other container on it, remained connected to the swinging truck, but on the bridge.
The driver was uninjured, Const Graham said.
The driver, who was the owner-operator of the truck, declined to comment.
SH 96 was closed until 9.30pm
