Piha locals told to plan their own emergency escape routes
Piha residents who had their homes damaged in a major flooding event last year will be asked to develop their own evacuation plans to deal with future emergency events.
The plans could potentially work alongside more drastic large-scale engineering options, such as a $45 million tunnel to take the Piha stream straight out to sea, or the building of two dams, which were presented to the Auckland Council yesterday.
In a media briefing on the two independent reports by consultants Tonkin+Taylor into three floods at the west Auckland beach last year, councillors said “community resilience” will be a key part to ensuring lives are saved if flooding occurs.
Glenesk Rd in Piha flooded three times last year. April saw the worst flooding, with 80.5mm of rain falling in four hours, resulting in a catastrophic surge in the stream that swallowed roads and houses. Flooding reached a depth of 2m in some parts of Glenesk Rd, causing residents to flee, and extensively damaging 24 properties.
Craig McIlroy, head of Healthy Waters, said the area around Glenesk Rd stream was unique in that the terrain was “so steep the water gets into the stream very, very quickly, and that creates a situation where, in a heavy rain event, we can go from nothing to a flood situation in 40 minutes”.
In a situation like that, it would be almost impossible for anyone from the council’s emergency management teams to get from the city to Piha in time, so “community resilience”, including personalised evacuation plans, would be key to mitigating disasters.
Authorities would work with property owners to develop personalised evacuation plans, he said.
Waita¯kere councillor Linda Cooper said: “We’ve been working alongside the local board and emergency management to develop individual emergency plans for each home, because everybody’s in a different situation.
“It’s really important that in that really short window of time people need to know exactly what to do and they need to do it quickly. They can’t wait for the emergency services to get there . . . people need to know how to keep themselves safe until people can come and help.”
A number of large-scale engineering options have been suggested as part of the review, including widening the Piha stream, clearing the sandbar to improve the flow of the stream out to sea, damming it, or diverting it by tunnel out to sea.
With 8000 Auckland properties classed as flood-risk, any option chosen for Piha needs to be able to be rolled out across the city, West Auckland councillor Penny Hulse said. “The bigger context for climate change and the increased intensity of rainfall in these areas is something that Auckland is going to have to grapple with, and not just Auckland, New Zealand.”