Drivers are being warned to take care and expect delays after steady rain overnight has caused flooding and slips in central New Zealand.

The rain has caused surface flooding around Wellington and the Lower North Island and police asked drivers to watch their following distances and to reduce speed while driving.

Overnight slips south of Blenheim closed State Highway 1, the South Island's main route.

The slips blocked both lanes of the highway, about 20km south of Ward.


The road was not expected to reopen until later this morning.

Motorists were asked to detour via Lewis Pass.