More heavy rain is expected to fall on the Gisborne region tonight with a red severe weather warning for up to 7am tomorrow

Tairawhiti is under a state of emergency - after flooding, rescues and evacuations - and about 600 homes reportedly without power.

Gisborne District Council says the city's sewer network is at capacity - and they're receiving reports of overflows onto roads.

It says it's more than likely emergency valves will be opened in the next few hours to release pressure in various areas of the sewer network.