MetService is warning of heavy rain in Westland, which could swell rivers as far north as the Waimakariri River in Canterbury.
Heavy rainfall is expected on Sunday evening, ahead of a front which will dump an additional 100 to 150mm of rain in the Westland ranges, south of Otira through till early Monday morning.
MetService says the rain will feed into the headwaters of Canterbury lakes and rivers and people in these areas have been warned water levels are likely to rise rapidly.
