The 1980 Taieri Plain flood is considered one of the most devastating to hit the area and has shaped the level of flood protection there since.
The 1980 flood caused widespread damage to both East and West Taieri, highlighting the inadequacies of the West Taieri flood protection system developed in 1929.
It left the Otago Catchment Board and Regional Water Board scrambling to come up with a more comprehensive scheme and in 1985 one was technically approved - although it was not until 1988 that the Government approved financing for it.
The scheme was designed to protect most of the plain against flooding from the Taieri River by any event up to the 2500-cumec size of the June 1980 flood and worked on the principle of controlled storage in ponding areas.
Otago Regional Council engineering manager Ramon Strong said the concern from 1980 was that the water levels in the ponding areas built up too early in the event, leaving not enough storage for the peak of the flood.
Modification works were designed to ensure the ponding areas "kicked in" at a higher threshold.
Since 2004 the upper pond has filled three times. The lower pond was designed to take the pressure off the upper pond in bigger events.
Much of the work proposed after the 1980 flood was not completed as government subsidies for the work reduced as the political scene changed, Mr Strong said.
"The issues around funding were rather political and contentious at the time. As the subsidy disappeared they cut back elements."
They had originally proposed to build eight new pumping stations but only two became a reality.
"At the time it was an ambitious works programme and these modifications were the last river works to receive significant central government funding."
