Dunedin could still achieve dark-sky status despite the installation of 3000-Kelvin LED streetlights across the city, Dunedin city councillors were told yesterday.

Richard Saunders

The council has called for tenders to carry out the city's $13.1 million streetlight upgrade, using 3000K lights.

But there are fears the lights could jeopardise the city's dark-sky ambitions.

A report on the streetlight project was presented to councillors at the infrastructure services and networks committee meeting yesterday.

Council transport group manager Richard Saunders told councillors it was still possible for the city to be granted dark-sky status with the 3000K lights.

Lights installed by the NZ Transport Agency on state highways would be 4000K, he said.

A central management system would allow the city's lights to be dimmed at certain times of the night and for specific events, such as the Midwinter Carnival or significant astronomical events, he said.

It would also allow the council to tailor lighting levels in specific parts of the city, such as near the Beverly-Begg Observatory or in areas with significant wildlife.

Shielding would also limit light pollution, and the tender documents also left room for changes, including lights with lower colour temperatures, he said.

"The central management system gives us a great amount of flexibility and the ability to get there [dark-sky status] if we choose to go down that path.''

In the Mackenzie district, an International Dark Sky Reserve, the NZTA had funded 2200K lights.

But, the Mackenzie district's situation was different from Dunedin and there was no guarantee of funding from the NZTA if the council chose a lower Kelvin bulb, Mr Saunders said.

The agency will subsidise 85% of the project's cost.

Dunedin Dark Skies Group member Michael Broughton said he believed the International Dark Skies Association would not approve Dunedin as a night-sky city when a substantial area of it was illuminated with 4000K lights.

Even the 3000K lights risked non-recognition as the association was in the process of revising its upper colour temperature limit to 2700K, Mr Broughton said.

The dark skies group wanted to work with the council to make Dunedin a "bona fide'' dark-sky city, not something resembling a night-sky city, he said.