Floods - It happened here - are we prepared and what have we forgotten
In a recent press article, a municipal manager from a SE council made erroneous comments regarding the likelihood or possibility of wide spread flooding in the Dandenong Valley/Carrum Swamp.
History records the major flood event of December 1934 as being the most devastating on record in the South East and South, West and East Gippsland. There were other major events in 1891 and 1952.
On the evening of Thursday 28 November 1934 an active cold front crossed Victoria and centred off the North East coast of Tasmania. It coincided with a king tide. The barometers plummeted and torrential rain fell on central Victoria, the Port Phillip, Westernport and Gippsland catchments. 140mm of rain was recorded as falling in Melbourne. However, totals recorded in the upper Yarra catchment, the Dandenongs, the hills to the east and south Gippsland exceeded 350mm in the same 48 hour period.
The livelihoods of tens of thousands of people was decimated at the peak of the Great Depression. This was despite 50 years of flood mitigation work in the Dandenong Valley/Carrum and Koowerup Swamps.
The worst hit communities ranged from Mordialloc to Seaford (see flood history link) and the communities of the Koowerup Swamp where Kooweerup residents reported 75mm of water in their streets at 8 am Saturday morning. 45 minutes later was over 2 metres deep.
Iona, Catani and other swamp villages were similarly effected as were large areas of the Latrobe Valley. From the Koowrerup area alone, six people were reported drowned and 2000 as being homeless.
Across the state it was estimated that by Sunday night about 5000 were in receipt of emergency aid. 800 were from Chelsea where water was later reported as being approximately 7metres deep.
A Dandenong Valley Authority report of 1965 rated the 1934 conditions as a 1 in 70 year event. In 2004, flows in Dandenong Creek reached 93% of their 1934 levels.
Should we be asking ourselves whether the massive urban expansion that's occurred on both swamps and in their catchments has been adequately factored given that its not a question of if this will happen again but when? - (Thank you Alan H for your help)