A tanker trailer of fresh water was brought into the town on Sunday by the Clutha District Council and Kaitangata and the Wangaloa rural water scheme users were urged to conserve water on the same day.
"The reason for the shutdown and reservoir level dropping was due to the failure of the main site programmable logic controller (PLC), a small computer, which shut the plant down", council deputy chief executive Jules Witt said.
"However, it did not shut down the raw water pumps which continued to pump from the Clutha River up to the plant, resulting in the plant overflowing."
A temporary replacement PLC was sourced from another site and installed.
Additional time was then needed to get the plant running again within specification, to demonstrate full compliance with the necessary drinking water rules.
As of 4pm yesterday, the reservoir was 63% full.
The council will look at removing the tanker once it reached its normal operating level, generally between 75% and 90%.
— Nick Brook
