More New Zealand medics leave on Tuesday (NZT) for Samoa as the focus there shifts towards limiting the spread of infectious and communicable diseases.
The confirmed death toll from last week's tsunami stands at 176. Most of these are from Samoa, but there are still at least 12 people unaccounted for.
Seven of the dead have been confirmed as being from New Zealand.
The New Zealand Government says it has been advised of a high demand for ongoing wound care and a growing need for mental health personnel.
A plastic surgeon and a psychiatrist are among the 19 medical specialists already working in Tonga.
More are due to depart on a Defence Force flight at midday on Tuesday.
New Zealand Navy divers reconnected the water mains to Manono Island on Sunday (local time).
Three breaks have been repaired in about 3km of the PVC piping, off the coast of the main island, Upolu.
The Ministry of Natural Resources and Environment says running water has been restored in some villages.
It says the water is not yet to drinking standard and people should use it only for washing and bathroom needs.
Distributing drinking water remains a priority and the ministry says RNZAF helicopters have been invaluable in delivering aid to areas that are hard to reach.