Flood waters in Canterbury and Otago have begun to recede as heavy rain eases, but there's no respite with snow forecast for tonight.

Heavy rain and gales are expected to lash the main islands from tonight, with the MetService warning of one of the "bigger weather events" for some time.

Don't put the umbrellas away just yet. A storm bringing more heavy rain and winds is on its way to parts of the North Island.

Evacuated families have begun returning to their homes after flooding in the Nelson region during the weekend.

Heavy rainfall has left families isolated in the Tapawera area, south-west of Nelson, with 20 households evacuated so far.

Forecast rain today is expected to raise the Lake Wakatipu level, but not beyond its peak, reassures Queenstown Lakes District Council.

Lake Wakatipu's brimming water level rose no further overnight and dropped slightly today, easing the risk of flooding in Queenstown.

Full-to-the-brim Lake Wakatipu is likely to start dropping back tomorrow, but high winds could still push waves of water into the streets.

River flow levels and a minimal rain forecast suggest Queenstown's Lake Wakatipu might only rise by a further 10cm.

More heavy rain is on the way for the Lake Wakatipu head waters before anything starts to improve.

Northland's drought may be endangering motorists - and stock - as hungry farm animals go wandering for food and water.

Queenstown businesses are being warned to brace for potential flooding as more heavy rain is predicted over the next two days.

The brief respite of rain for Northland farmers yesterday is not enough to quench the parched pastures.

More stranded trampers will be flown out of flooded walking tracks a day after 120 were evacuated from the Milford Track.

Trampers were evacuated by air, phonelines cut and bridges washed out last night as the South Island was inundated by rain and flooding.