In April 1929 a flood occurred in the northern and eastern parts of Tasmania, which are prone to short term intense rainfall periods. Rain began in northern Tasmania on the night of 3 April and reached its peak the following day, finally clearing on 6 April. The highest rainfall totals were recorded in the high country of the north-east and there was a secondary area of very heavy rain south of the Burnie/Ulverstone area. In both cases up to 500 mm of rain fell in three days.

During the floods 22 people drowned. Fourteen people died when the Briseis Dam at Derby burst its banks and a torrent of water travelled three miles through the narrow gorge of the Cascade River to the township of Derby carrying with it trees and tonnes of debris which inflicted serious damage.

In the town of Avoca the river was measured at approximately 17 m above the average summer level. When the waters finally receded, the railway station had disappeared, railway tracks were undermined and twisted, bridges were destroyed and debris blocked the railway line. Many road bridges in the north and north-east were lost.

On the north coast most rivers were severely flooded. At Gawler, near Ulverstone, a truck crashed through a bridge into a flooded river, drowning eight people.

In the Tamar Valley flood waters caused the river to rise to record levels. Flood waters passed through Cataract Gorge and combined with floodwaters from the North Esk, inundated more than 1,000 houses in the low-lying parts of Launceston. Some 3,500 people were evacuated. The power station at Duck Reach was washed away.

In southern Tasmania the rain was substantial and caused rivers to flow across roads and many livestock were lost. Southeasterly gales accompanying the rain swept the Derwent Valley on 4 April, damaging houses and felling trees.

The flood damage to the environment and man-made structures, particularly in the north, took many weeks to repair.