River alert as heavy rain looms

Electricity generator Mighty River Power has been urged to spill water from its dam at Lake Karapiro to help the upper Waikato River hydro system cope with rain from a big storm expected to hit tomorrow.

The Environment Waikato regional council called for the spill yesterday after the MetService warned more than 100mm of rain could fall on the Taupo catchment.

"There is a possibility in the higher areas that they could get up to 100mm, with lesser amounts at lower altitudes - significant enough that I imagine it will concern them, given that Taupo is so full," said MetService forecaster Andy Downs.

The MetService was expected to put out severe weather warnings today for the likely effects from a low pressure system forecast to cross southern New Zealand late today and tomorrow.

Last night, its website showed heavy rain in the hills and ranges in the western North Island and down the West Coast of the South Island.

The "active" front will not only bring heavy rain but possibly also northwest gales over northern and central New Zealand.

Heavy rain is likely in the ranges of Westland, Buller, northwest Nelson, the Tararua Ranges and the hilly country from Mt Taranaki to the Central Plateau late today and tomorrow, and the eastern Bay of Plenty, especially near the ranges, will be hit tomorrow and early Saturday.

The council's hazards manager, Adam Munro, said the call was a precautionary measure.

- NZPA