Lake Roxburgh. Photo supplied.
Sediment is being flushed from Lake Roxburgh in order to
reduce the risk of flooding in Alexandra, Contact Energy
Contact generation manager Graham Quinn said the lake would
be out of bounds while flushing was being carried out and the
company had locked the access gate to the Roxburgh dam boat
ramp and put up warning signs at the Alexandra boat ramp.
It was expected the flushing would be finished in three to
five days, subject to the flow of the river, Mr Quinn said
The flushing moved sediment which had deposited in the upper
reaches of Lake Roxburgh further downstream, reducing the
potential effects of flooding in Alexandra, he said.
During the flushing, the level of Lake Roxburgh at the
Roxburgh dam site was lowered from its usual level of 132m
above sea level to about 126m above sea level.
Sediment flushing was carried out during periods of high
river flow, with opportunities coming about about once a
year, he said.
Flushing was permitted under the company's resource consents
and Otago Regional Council was being kept informed.