A flash flood which hit Dannevirke just after 3pm yesterday left Tararua District Council staff stranded in their offices, retailers lifting boxes out of water and a strong smell of sewage in Gordon St.

The force of water flowing from the Mangapurupuru Stream during a torrential downpour blew a manhole cover in Gordon St and as the rain continued, flooding forced council contractors and the police to close the street.

"It's a very long time since this has happened and the force of the water and the stuff which is being blown up through the manhole could damage the road surface," Peter Wimsett, council's manager of strategy and district development, said.

As the water receded, Mr Wimsett confirmed its force had worn an area around the manhole.


"The power of the water was unusually strong, but this has been a relatively isolated weather event," he said.

"However, we've also had flooding in Ormond St, Woodville."

On High St, as water flowed through the back of Derek's Electrical, co-owner Kathy Massey was worried more was to come.

"I've got water in the back room and have had to lift cardboard and polystyrene boxes because they don't go well with water. Right behind the shop is the grille for the underground creek - the water is almost to the top and I'm a bit worried," she said.

As water swept down Gordon St and on to the footpath, council staff were trapped in their offices.

However, Mr Wimsett said he had checked the MetService weather report and the heavy rain was heading east toward the coast, allowing council contractors to get to work cleaning up.

There was a strong stench of sewage in Gordon St, especially close to the Dannevirke News office, and Mr Wimsett said contractors would be washing and disinfecting the footpaths.

Torrential rain also wreaked havoc in Wellington as severe flooding closed schools and left roads submerged in Porirua.

The wet weather was moving north last night, with reports of flooding in Palmerston North.

In Porirua, four people had to be rescued from cars trapped in the water, while about eight schools and several roads were closed due to surface flooding.

Porirua School was one of the schools badly affected by the flood.

Meanwhile, rain was not meant to carry through to more northern parts of Hawke's Bay and was weakening as it headed north last night.