They said the state of emergency declared just after the category five storm is to continue.
The latest situation report from the National Emergency Management Office says 11 of the families in shelter are on 'Eua which is thought to have got the worst of the storm.
NEMO said electricity services are almost completely restored on Tongatapu, while all schools' water tanks on both islands have been purified.
The office said some homes need spraying urgently to control mosquito larvae and the threat of dengue and the state of emergency will continue to apply until March 12th.
The government, with help from the World Bank, plans to undertake an assessment to quantify the damage caused by Gita and provide data for recovery planning.