People in some parts of the South Island are being told to stay home unless neccessary, with today's severe weather set to worsen before it gets better

Orange warnings are in effect for Canterbury, Kaikoura, Marlborough, Wellington, Wairarapa and eastern Bay of Plenty.

Flooding is blocking several roads, including Fitzgerald Ave in Christchurch and part of State Highway 75 on Banks Peninsula.

Fire and Emergency shift manager Blair Walklin says crews are being kept busy with flooded houses, downed trees, and leaky or lifting roofs.

He says there could be worse conditions still to come.