Wellington's south coast is to get tsunami safe-zone lines painted on roads in all suburbs potentially under threat.
The blue warning lines were put on roads in the coastal suburb of Island Bay in 2010 and in Houghton and Owhiro bays last year. They will now be added to Lyall Bay, Rongotai and Kilbirnie.
GNS Science says Cook Strait faults have the potential to produce a local tsunami.
It says earthquakes of higher magnitudes than the recent ones off Seddon could send waves up to 15 metres high crashing against the coast.
Wellington Regional Emergency Management Office says all south coast residents need to know where safe higher ground is, and the new lines will be painted in the next few weeks.