Under new dam regulations that came into force yesterday, dam owners have until August 13 to submit the potential impact classification ratings — low, medium or high — of dams that are 4m or more in height and store 20,000cum of water to the Otago Regional Council.
A city council spokesman said the council owned nine dams that met the threshold for classification.
At Ross Creek Reservoir, Mt Grand storage pond and Sullivans Dam at the headwaters of the Leith the council owned three dams with "high" potential impact classifications, the spokesman said.
West Taieri, Deep Stream and Deep Creek all had dams with low potential impact classification ratings.
The council ran an ongoing dam safety assurance programme to make sure it complied with the building (dam safety) regulations, the spokesman said.
The cost of that work included $50,000 to $150,000 a year to hire dam safety specialists to support council staff work, as well as staff time and operational, repair and maintenance costs.
A Clutha District Council spokeswoman said the council-owned Moa Flat raw water reservoir, in rural West Otago, met the threshold for a classification, but to date no investigation of its potential impact classification had been done.
A spokesman for the Queenstown Lakes District Council said council staff were working to classify council-owned infrastructure as required.
"We’ll be able to share more information once we’ve completed this process prior to ORC’s submission deadline of August 13," he said.
A Waitaki District Council spokesman said the council had one classifiable dam and staff were working towards the August deadline.
The Central Otago District Council owned no dams that met the threshold for classification, a spokeswoman said.
The regional council said of the 132 dams in Otago that would require investigation, 71 were owned by private landowners and 61 were owned by councils or companies.
Dams that were assessed as being medium or high impact would need to comply with additional dam safety assurance programme and annual dam compliance certificate requirements, the council said.
— Staff reporter
