Environment Canterbury’s Flood Room has been on alert overnight after more than 30 hours of persistent heavy rain in South Canterbury.
The rain has caused extensive surface flooding in the region, saw the Tengawai River reach a 50-year flood level of about 1000cumecs, several other foothills rivers reach 10 to 20-year peak flows and led to the evacuation of residents at the Pareora Huts.
Duty Flood Controller Phil Lees said more than 200mm of rain had fallen between 3pm Monday and 9pm last night (Tuesday), triggering flood room staff and Environment Canterbury staff in the field into action yesterday morning.
“The result of all this rain is some of the biggest flows in some of our region’s rivers for at least 10 years.”
Residents at Pareora Huts were evacuated early last night as a precaution in case the river breached the stopbanks overnight.
Late last night Mr Lees was predicting that the rivers may have been peaking but added that there was no room for complacency.
“This is the first significant rain we’ve had for about four months and although at first the ground was soaking it up well South Canterbury is now saturated. Although the rain is easing, there could be between 20mm – 40mm more rain from now until first light Wednesday so river levels will remain high.”
Yesterday (Tuesday) Environment Canterbury advised farmers to shift stock from low-lying areas. Environment Canterbury personnel, along with Civil Defence staff and South Canterbury police were closely monitoring rivers. Those of most concern were the Pareora, Tengawai, Temuka, Hakataramea and Waihao rivers.
“We’re paying particular attention to the Temuka River stopbank below the State Highway 1 Bridge,” Mr Lees said.
“Environment Canterbury staff will be out at first light today (Wednesday) assessing river stopbanks at key points. We advise everyone, whether they are property owners and or residents in low-lying areas to remain vigilant as with river levels staying high there’s the potential for damage to be caused to stopbanks.
“There also could be significant surface flooding on roads so motorists should also take extreme care,” Mr Lees said Tuesday night.