Bay of Plenty tsunami evacuation maps updated with simplified blue ...
An updated Bay of Plenty tsunami evacuation map shows an area previously listed as “safe” is at risk of being inundated.
But new refuge sites have also been identified in the Pāpāmoa suburb where residents worried they could be effectively “trapped”.
Released today, revised maps for Bay coastal communities have blue “go” zones that should be evacuated in an event, replacing previous multicoloured evacuation zones based on different tsunami scenarios.
The maps are based on data sets from the region’s seven councils that have been collated, reviewed and incorporated into new tsunami evacuation information.
Online maps and tsunami signs at beaches and waterways throughout the region will be updated from today.
Letters will also be distributed to Pāpāmoa East residents this week, where there are significant changes to evacuation areas.
The previous Pāpāmoa East evacuation zone, with various levels of risk, covered almost the entire suburb and stopped at the Tauranga Eastern Link/State Highway 2. Previous maps stated that beyond this was largely a “tsunami safe zone”.
Now, the at-risk area stretches over the highway into a large part of that zone.
The map, however, also indicates new safe areas on Te Okuroa Drive near Te Manawa o Pāpāmoa School and in the southeast of Golden Sands.
Other large areas in highly populated Pāpāmoa and Mount Maunganui were also blanketed in blue, and tsunami risk zones at Whakatāne and Ōpōtiki were expanded.
Emergency Management Bay of Plenty director Clinton Naude said his team did not want to scare people “but if the blue makes a bigger impact — that’s great”.
Previously, tsunami evacuation maps had yellow, orange, and red evacuation zones for different scenarios, with safe areas in green.
“People have told us that having three different-coloured zones was confusing, and we agreed, so we hope this is clear and easy to understand.
“The reality is that you don’t muck around with that if there is a potential tsunami, you advise everyone in an evacuation zone to move inland or to higher ground, so it made sense to have a single go/no go zone”, Naude said.
“Blue means go.”
On March 5, 2021, an 8.1 magnitude Kermadec earthquake triggered a tsunami warning for the Bay east of Matatā, prompting many to evacuate. Cars were seen leaving Ōhope and people fled to Whakatāne’s hills.
“Fortunately, that event did not result in loss of life, but it focused our attention on how to make sure our coastal communities are as well-informed and prepared as possible,” Naude said.
“In a big tsunami generated near our coastline, we might not have a lot of time before the first wave hits … that’s why we say ‘long or strong, get gone’, and why people should act immediately and not wait for official warnings.”
While the probability of a tsunami was low, it was still a “high-risk hazard” for the Bay. Fatal tsunami activity had been recorded in New Zealand before “and our coastline is far more densely populated these days”, Naude said.
Naude said any means of evacuating that did not contribute to traffic congestion should be considered, including walking.
“... Even if you are walking quite slowly, you can get over a kilometre inland in just 20 minutes. Even if that doesn’t take you all the way out of the evacuation zone, you would be far far safer than if you stayed nearer the coast. And the most powerful waves may take longer than that to arrive, so please never think ‘that’s too far for me to walk’ because every step you take inland or to higher ground is a step towards safety.”
A new QR code that can be scanned for “you are here” imagery and other tsunami information will be included on the signs.
Other areas that use blue to indicate evacuation zones include Waikato, on maps, and Wellington, which has lines painted on roads.
In November, Pāpāmoa Eastern Corridor Alliance and ratepayer advocate Philip Brown highlighted concerns with the existing tsunami-safe locations at Parton Rd bridge and Gordon Spratt reserve, saying these may not be suitable for the area’s fast-growing population nor effective depending on the size of a potential tsunami.
He also cited concern about people potentially trying to cross the highway to get to higher ground, saying residents were effectively “trapped”.
Asked how the two new Pāpāmoa East safe zones were discovered, a Tauranga City Council spokesperson said the previous modelling was done before much of the area’s recent development.
Newer modelling accounted for changes in the landscape “and we have great confidence in final elevations, which identifies these areas as not being flooded”.
The areas were suitable for people to evacuate to as they were set back from lower swales and streams, which would likely channel the water, the spokesperson said.
Bay of Plenty Civil Defence Emergency Management Group chairwoman and Kawerau Mayor Faylene Tunui said Bay of Plenty families needed to know what to do and where to go to keep safe in an emergency.
The updated maps communicated this more effectively and provided the same consistent messaging for the Bay’s coastline, she said.
The group is governed by a committee of representatives of local councils.
Kiri Gillespie is an assistant news director and a senior journalist for the Bay of Plenty Times and Rotorua Daily Post, specialising in local politics and city issues. She was a finalist for the Voyager Media Awards Regional Journalist of the Year in 2021.