Tairāwhiti's connections to the outside world are severed - power is patchy, a fibre optic cable is down - affecting Internet and phone services; while many roads and bridges are damaged and unusable.
People in Gisborne are being asked to urgently reduce water use, or it will run out.
All schools, kura, and early learning services on the town's water supply have been asked to stay shut until Monday.
Civil Defence controller Ben Green says while information is still being gathered, officials believe there have been no flood related injuries or deaths.
RNZ reporter Kate Green spoke to Max Towle from Gisborne.
