Otago Regional councillors have sought assurances from staff the council will not become the "dam policeman".
A new policy on enforcing the building code for dams in Otago was approved by councillors this week.
Environmental engineering and natural hazards director Gavin Palmer said under the Building Act the council was required to enforce its provisions, but had some "discretion" on how it chose to exercise that responsibility.
The council could not ignore its responsibilities, as during undertaking work in the region staff often saw dams.
"Being aware, we must act on it," he said.
Under present legislation all dams had to comply with the building code, but dams which were 3m or more in depth and held 20,000cu m or more required a building consent.
Developments in the Building Amendment Bill which was being considered by Government meant there were likely to be changes to the height requirements of up to 4m or 20,000cu m in volume for dams not needing a resource consent, he said.
It was similar to a change the regional council had lobbied the select committee for.
"It's a significant win," chairman Stephen Woodhead said.
The council was proposing to assess all dams constructed after July 1, 1992, which did not have building consent for compliance with the building code.
It would give priority to dams thought to be "high risk" and would "promptly" investigate any complaints about non-compliance or the lack of safety.
To do this, a register of dams in the region would be compiled using aerial photographs although non-compliance could only be found by a site visit, he said.
If a dam was found to be non-compliant a "notice to fix" would be issued under the Building Act requiring the owner to remedy the problems.
The dams at greatest risk in the council's experience were those at a depth of just less than 3m and holding more than 20,000cu m.
"Such dams have usually been configured by the owner in a way that avoids the need for a building consent, professional engineering advice, and regional authority scrutiny."
Cr David Shepherd said the manner in which the council went about enforcement was key, and the council needed to be transparent in its views to avoid causing alienation among landowners.
Mr Woodhead said it would be a test for staff to find non-complying dams given the many "duck pond-sized" dams around the region.
Cr Duncan Butcher said he was concerned about the council becoming the "dam policeman".
Chief executive Graham Martin said the council would be "done like toast" if it did not enforce the legislation.
"As a council, to say we didn't know won't wash with insurance companies or anyone else."
