The New Zealand Red Cross is heading to Tonga to deliver a unit that turns salt water into fresh water to the island of Niuatoputapu.
Nine people died on the remote island of about 15-hundred people in last week's tsunami.
An emergency delegate for the Red Cross, Carl Burr, says the few water springs on the island were damaged in the disaster, and locals have been relying on water being shipped in.
He says the unit being delivered to the island can provide three-thousand litres of clean drinking water per day.
The Red Cross says it's the first time the device has been used in the field since it was designed last year.