Heavy rain eased in Timaru on Monday evening, providing some relief for residents whose basements have flooded.
The Fire Service was getting six to eight calls an hour earlier in the afternoon, mostly for minor flooding in basements and yards.
Earlier a Fire Service spokesperson said it received calls from residents in Timaru, Washdyke and Oamaru, whose homes and garages were being affected by heavy rain.
The spokesperson says the flooding was particularly bad around Hassall Street in the Timaru suburb of Watlington.
About 20 homes in South Canterbury were without power, and Alpine Energy said some might not have power restored until Tuesday.
Christchurch braces for rain
Meanwhile, the Christchurch City Council has sandbags ready to give to people in high risk flooding areas, as the band of rain moves up the island.
MetService has severe weather warnings in place for North Otago, Dunedin and Canterbury, but Christchurch is now expected to receive 30-50mm of rain, less than the 80mm earlier predicted.
A Christchurch City Council spokesperson says contractors are clearing storm water drains and sumps in the most vulnerable areas, but flooding is not expected to reach to floor level.
The low should move east off New Zealand by the middle of the week.
