Tsunami sirens could be activated too late for Western Bay residents in the event of a locally triggered wave.
A tsunami triggered by movement in the Kermadec Trench would reach the coast in about 50 minutes _ but it could take more than an hour for official warnings such as sirens to be activated, according to a draft tsunami survival guide created by Tauranga City Council.
Tsunami Survive project coordinator Katharyn Roxburgh said warning sirens may not have been activated by the time the wave hit if an official warning had not yet been issued.
"Sirens could be going off within the 50 minutes but it depends on the quality of the information. It's knowing what is the right information to do it with,'' she said.
"Chances are there won't be an official warning because there just won't be time. We're trying to preserve life.''
That is why Tauranga City Council has been undertaking extensive consultation on a tsunami survival guide.
Ms Roxburgh said the guide will not be a traditional Civil Defence document as Civil Defence procedures may not have time to take effect if a tsunami originated in the Kermadec Trench or closer.
Duty officers need to be notified and scientists need to evaluate the information before the warnings can be publicised.
A planned evacuation of Tauranga, Mount Maunganui and Papamoa could take up to six hours.
The draft guide was put to councillors and community group representatives yesterday.
It outlines steps Tauranga, Mount Maunganui and Papamoa residents should take in the event of a tsunami.
The document instructs people to take action based on natural warnings, such as intense or prolonged shaking and unusual sea level changes, and informal warnings, such as phone calls from friends and family, news reports and social media, rather than waiting for an official evacuation announcement.
Papamoa Progressive Association chairman Steve Morris said the sirens are an excellent final warning as long as people are educated and do not wait for the sirens before making a move.
"It's a great warning of last resort and it's got the potential to save lives. It's valid having them as long as people realise it's a last resort not a first resort otherwise they will be more at risk.''
Tauranga City Council emergency management co-ordinator Barry Somers said for people in coastal areas such as Mount Maunganui and Papamoa the best way out is likely to be by foot.
He said those in costal Papamoa should drive to the back of the urban area and walk to higher ground from there as the worst place to be stuck would be in a car on Papamoa Beach Rd.
"Most people will be looking at about half an hour in terms of walking,'' Mr Somers said.
But people need to make sure they do not end up stuck in the low area on the western side of the Tauranga Eastern Link, as water is likely to pool there. Mr Somers said people need to have considered the next safest option if they do not have time to get far enough inland or to higher ground.
High dunes along some parts of the coast may lessen the effect of the wave and the top floors of strong building may increase your chances of survival, he said.
Bold Blue Lines Mark Evacuation Paths
EVACUATION LINES: Blue lines in Wellington streets mark evacuation paths in the event of a tsunami. Local Tsunami Survive project co-ordinator Katharyn Roxburgh said the lines were a highly visible way to get the message across.
Bold, blue lines could be painted on roads around Tauranga's inner harbour to mark the safe zone for a tsunami evacuation.
A draft tsunami survival document for Tauranga, Mount Maunganui and Papamoa suggests installing the lines to denote clearly who should evacuate_and where they need to go to.
About 120 lines have been suggested around the inner harbour at a cost of about $500 each.
The strips only work in protected harbours where the water is not expected to go too far inland.
Those living in Mount Maunganui or Papamoa should get as far inland or as high as possible as those areas would be likely to be hit by the full force of a tsunami.
Wellington already has a number of the blue lines and Tsunami Survive project coordinator Katharyn Roxburgh said it was a highly visible way to get the message across.
"It's a very visible and an high impact way of showing people where the safe zone for evacuation is. People that live below the blue line know where they have to go and people who live above a blue line don't have to go anywhere.''
The lines are likely to ease congestion as people in the safe areas are less likely to be trying to get out as well, she said.