WDC chief executive Simon Weston said it was important to future-proof an airport for Whangārei.
Ruatangata (site nine) has emerged, after eight years of research, as the council's preferred choice for an alternate airport site - by a narrow margin over Ruatangata West (site six) and then One Tree Point West (site 24A).
Stacey Sharp, Beca senior planner, said there had been a very strong level of interest in potential new airport sites.
She said 49 per cent of 610 submissions received wanted to retain the existing Onerahi airport, 45 per cent wanted an alternative airport location investigated and the remainder did not indicate a preference.
Respondents' first choice for a new airport contrasted with that of council's research preference. They selected One Tree Point West (site 24A) as the main new site preference (26 per cent of respondents). Ruatangata was the next new site preference (11 per cent of respondents) then Ruatangata West (5 per cent).
Roberts said WDC needed to be ready, should the Civil Aviation Authority (CAA) dispensation to operate out of Onerahi be removed. The airport does not comply with CAA requirements but has dispensation to continue operating.
He said the CAA would be unlikely to sit back and allow continued Onerahi flights if a plane went off the end of the runway.
Such an incident could happen and although unlikely would have a big impact. The Onerahi airport's 800-metre runway is the shortest Air New Zealand uses in the country.
Roberts said more work was needed on the preferred Ruatangata site before being able to definitely proceed with a new airport there. A possible koiwi burial cave and other cultural features there had been highlighted during consultation. This needed further investigation.
He said if Ruatangata proved unsuitable the council should then move to Ruatangata West as the next option and then to One Tree Point West.
A meteorological station needed to be established at Ruatangata as soon as possible to collect weather data, specifically around fog challenges mentioned by many during public consultation. Roberts said up to five years of weather data would be ideal.
He said an airport was required to have 95 per cent usability, which meant it had only 15 to 20 days disrupted by fog or weather.
Roberts said if the council decided to proceed with a new airport site, it would be eight to 10 years from that decision until the first ground was broken.
This meant WDC could eke out another decade's life from Onerahi airport in preparation.
"If you are able to squeeze a bit more out of the Onerahi lemon and keep it going with Band-Aids as long as you can, if you can push that out, you have effectively got a future-proof option ready and waiting," Roberts told the council.
Roberts said there was no silver bullet airport site location. Each had its challenges.
■ Local Democracy Reporting is Public Interest Journalism funded through NZ On Air
