Flood warning - Canterbury alpine rivers

Rain has been falling along the main divide since Tuesday morning, and the Canterbury alpine rivers (especially the Rangitata, Rakaia, and Waimakariri) have been flowing at higher than normal levels. A burst of heavier rain yesterday afternoon has pushed flows higher again overnight.

The Waimakariri River has peaked around 550 m³/s in the upper reaches early this morning, and these flows will pass through the lower reaches today. There is no threat of any ‘out of river’ flooding from the Waimakariri.

The Rakaia River and Rangitata River both also peaked in the upper reaches early this morning, with the Rakaia rising to around 2100 m³/s and the Rangitata to around 1100 m³/s. These flows will pass through the lower reaches today. Overflows from either river are unlikely, but landowners adjacent to these rivers should monitor their own situation. Environment Canterbury staff will monitor vulnerable locations to check for any issues during the day.

The Ahuriri River in the south and Hurunui and Waiau Uwha rivers in the north will also be carrying higher than normal flows today, but we do not expect these rivers to cause any ‘out of river’ flooding.

Recreationalists or contractors using any of the alpine riverbeds in the region should monitor their own situation and remain wary of rising water levels.