More than 200 people have self-evacuated to Haumoana School and authorities say they may need to stay away from the coast for as long as 12 hours.
Residents were asked to self-evacuate just before 9am this morning after tsunami alerts were sparked by an 8.8 Richter scale earthquake near Chile.
While the initial waves were small, the pattern from Chatham Island and Gisborne indicates that waves will grow in size over the next few hours.
Historically, the largest waves are seen at around six to 12 hours after the initial wave.
Hastings Civil Defence controller David Fraser says people should plan to spend the day away from the coast and lower reaches of rivers.
“If the waves continue beyond this afternoon welfare arrangements will be put in place by Civil Defence and will be advised through the media,” Mr Fraser says.
Residents should listen to their radios for further instructions.
Police have reported that people have been rubbernecking at Haumoana and Waimarama beaches and officers have had to ask them to leave.
Authorities are strongly urging people to stay away from the waterfront.
The Ministry for Civil Defence and Emergency Management says people should:
Stay off beaches
People should not go sightseeing in coastal areas
Stay away from coastal areas including, tidal estuaries, rivers and streams for 24hours, as even small waves create dangerous currents
Boats are generally safer in water deeper than 30m than closer to shore
Share this information with family, neighbours and friends
Listen to the radio or television for updates
Follow the instructions of local Civil Defence