The 1934 Flood

It is 75 years since the worst flood on record hit the Koo-Wee-Rup Swamp on December 1, 1934. The original Drainage works on the Swamp were completed in 1897 but later floods in 1901, 1911, 1923 and 1924 saw extra drainage work undertaken including the widening of the Main Drain and additional side drains. None of these works protected the Swamp against the big flood of 1934. 

Cora Lynn in an early flood, perhaps in the 1910s. The building on the right is the E.S.& A bank and the building in the middle is Murdoch's General Store.

Image: Rouse Family collection

There had been above average rainfall in the October and November and more heavy rain fell across the State on December 1. This rainfall caused a flood of over 100,000 megalitres or 40,000 cusecs (cubic feet per second) across the Swamp and this was only an estimate because all the gauges were washed away. The entire Swamp was inundated; water was over six feet deep (1.8metres) in parts of the Koo-Wee-Rup township. At Cora Lynn, three feet of water (about a metre) went through my grandparent’s house in Murray Road. The family, including the four children aged 11, 5, 3 and nearly 1, had to retreat to the roof. This flood also affected other parts of the State, for instance, it was reported in The Argus that there was four feet (120 cm) of water over parts of the Princes Highway between Dandenong and Berwick. Over a thousand people were left homeless as a result. The Koo-Wee-Rup locals were just recovering from this flood when another flood of about 24 000 cusecs hit in April 1935.

Rossiter Road in Koo-Wee-Rup in the 1934 flood. The photograph was taken just near the Railway line, the building on the right is St George's Anglican Church.

Image: Koo Wee Rup Swamp Historical Society

As a result of the 1934 flood, the State Rivers and Water Supply Commission (SRWSC) worked on new drainage plans for the Swamp and these plans became known as the Lupson Report after the complier, E.J Lupson, an Engineer. A Royal Commission was also established in 1936. Its role was to investigate the operation of the SRWSC. The Royal Commission report was critical of the SRWSC’s operation in the Koo-Wee-Rup Flood Protection District in a number of areas. It ordered that new plans for drainage improvements needed to be established and presented to an independent authority. Mr E. G Richie was appointed as the independent authority. The Richie Report essentially considered that the Lupson Report was “sound and well considered” and should be implemented. Work had just begun on these recommendations when the 1937 flood hit the area. The 1937 flood hit Koo-Wee-Rup on October 18^th and water was 60cm (2ft) deep in Rossiter Road and Station Street. The flood peaked at 20,000 cusecs (50,000 megalitres) about half the 1934 flood volume.

Station Street, Koo-Wee-Rup, during the 1934 flood.

Image: Koo Wee Rup Swamp Historical Society

The main recommendation of the Lupson / Ritchie report was the construction of the Yallock outfall drain from Cora Lynn, cutting across to Bayles and then essentially following the line of the existing Yallock Creek to Western Port Bay. The aim was to take any flood water directly to the sea so the Main Drain could cope with the remaining water. The Yallock outfall drain was started in 1939 but the works were put on hold during the Second World War and not completed until 1956-57. The Yallock outfall drain had been originally designed using the existing farm land as a spillway i.e the Main Drain would overflow onto existing farmland and then find its own way to the Yallock outfall drain. Local farmers were unhappy at this, as the total designated spillway area was 275 acres (110 hectares). They suggested a spillway or ford be constructed at Cora Lynn so the flood water would divert to the outfall drain over the spillway. The spillway was finally constructed in 1962, though ironically its opening was delayed by yet another flood, as we can see in the photograph below.

This photograph was taken by my Uncle, Jim Rouse, in October 1962, before the official opening of the Cora Lynn spillway. The building, with the brown coloured roof, is the Cora Lynn Hall. The other buildings you can see in the background are the same as the ones on the other Cora Lynn photograph at the top of this post - the E.S.& A Bank and the general store, then Dillon's store. The road at the top left is the newly constructed spillway and you can see where flood waters have broken through the Main Drain bank and are spilling across it.