The Ross Creek reservoir dam remains secure after two days of steady rain had no impact on cracks along the surface of the 145-year-old structure, the Dunedin City Council says.
Council staff conducted their regular weekly inspection of the dam yesterday, but found no signs cracks in the structure had deteriorated after this week's rain, council acting water production manager Peter Brownie said.
The inspection regime included plans to increase monitoring of the dam from weekly to daily, if the area received more than 40mm of rain in 24 hours, he said.
About 30mm had fallen in the area in one 24-hour burst, and more than 40mm this week, but the dam had been unchanged, he said.
''Everything's as per normal. There's been no changes at all noticed,'' he said.
The dam was completed in 1867, making it the oldest in the country, and it continued to do a ''remarkable'' job,Mr Brownie said.
In 2010, superficial cracks were discovered on the dam's surface following torrential rain, leading to half the water being drained from the reservoir.
Council staff have since drawn up plans for a multimillion-dollar refurbishment of the reservoir, as part of work to secure the city's water supply.
That work was still scheduled to begin next summer, Mr Brownie said.
