Persistent heavy rain is causing rivers to overflow, and bringing surface flooding and road closures in Christchurch.
Christchurch City Council has activated pumps as the rain coincides with a particularly high tide.
"We've had some reports of surface flooding on roads, however we do not expect any flooding of properties at floor levels," says David Adamson, general manager City Services.
There is surface flooding on New Brighton Rd between Locksley Ave and Lake Terrace Rd.
Motorists are advised to take extra care.
Fitzgerald Ave north of Kilmore St is also seeing some minor flooding in the left northbound lane that contractors are likely to cone off to one lane northbound shortly.
There is also surface flooding on Rocking Horse Rd between Godwit and Penguin Sts.
Adamson said the new Dudley Creek bypass pipe and upstream storage facilities on the Heathcote River were coping well with the rain that had fallen to date. However, the Heathcote River has started to overflow around Clarendon Terrace.
Six pumps at Flockton were activated at 3am. A pump at Maces Road was also operating but is struggling to keep up with the volume of water. Other pumps were operating in Southshore, Main South Rd, and Slater St in Richmond.
"With high tide at 8am and the forecast for the rest of the day for steady rain, we don't expect things to get any worse," Adamson said.
"We are asking drivers to take care in the wet conditions. Slow down, and try to avoid driving through surface flooding."
MetService has revised its forecast for the city with 36mm of rain now expected during the day. At 10am between 21mm and 27mm had fallen across the city.
The rain also doesn't bode well for the Canterbury Kings' T20 match against the Northern Knights at Hagley Oval in Christchurch this afternoon.
Canterbury Cricket has posted a photo on Twitter showing a bleak outlook with puddles on the pitch covers.