The big wet continues for South Canterbury
Rain and floods cause mayhemAL WILLIAMS
The road between Fairlie and Tekapo remains closed this morning after heavy rainfall caused surface flooding.
State Highway 8 was closed until further notice at 4.20pm yesterday. At 7.55am today the road remained closed until further notice, with a condition update expected at 12pm.
State Highway 79 between Geraldine and Fairlie is open with a caution still in place.
An Environment Canterbury advisory for the foothill rivers of South Canterbury this morning said the rivers had peaked and were now receding.
Staff were to be out from first light this morning assessing the condition of stopbanks in the area.
"Stopbanks have become waterlogged and the integrity of them may be reduced during receding flows. People adjacent to the rivers should remain vigilant."
The advisory said there was extensive surface flooding throughout low lying areas in South Canterbury regions as well as overflow onto low lying land from adjacent rivers.
Between 130 to 230mm of rain had fallen in the foothills since Monday evening.
About 8 to 10mm an hour fell yesterday up to 8pm, but started to ease off in the evening.
RAIN CAUSES FLOODING ACROSS SOUTH CANTERBURY
Torrential rain caused flooding across South Canterbury yesterday and by 10pm last night the Te Ngawai had reached a 50-year flood level, flowing at 1000 cumecs.
Wet conditions are forecast for the rest of the week.
Much of the region experienced more than 90 millimetres of rain - significantly more than the 75mm average total rainfall for the month. Rainfall of 180mm was recorded in some areas. Most rivers experienced flows of 10- to 20-year return periods.
High river flows and heavy rainfall throughout the catchment area, especially in the coastal rivers, forced Environment Canterbury to issue a flood warning in the foothills around midday.
Several roads were signposted to alert drivers to water flowing across roads and along culverts at the verges. Most fords were closed and motorists were advised to take extreme care and drive to the conditions.
ECan staff were monitoring the north bank of the Temuka River between State Highway One and the railway last night as the stop bank was leaking.
South Canterbury foothills received 115 mm of rain overnight on Monday, with the heaviest falls in the foothills behind Geraldine yesterday morning.
Ecan reported all South Canterbury rivers rising and they continued to do so throughout the day. The Waihi, Te Moana and Kakahu Rivers in the Geraldine area were particularly affected, with some out-of-river flooding reported.
The Orari, Opihi, Te Ngawai, Pareora and Waihao Rivers rose significantly during the day with the Opihi reaching more than 1000 cumecs by 6pm. Residents at the Pareora Huts were evacuated early last night as a precaution.
Ecan staff said 20 to 40mm of rain was expected overnight.
Farmers were advised to shift stock from low lying areas mid-morning as river levels kept climbing.
The Opihi River had received 47mm of rain by 9am, Hadlow, 45.5mm and Bluecliffs, 49.5mm.
The Temuka River, at the Manse Bridge, was running at 132 cumecs up from around just three by mid-morning.
By mid-morning, at the Saleyards Bridge near Pleasant Point, the Opihi River was running at 94 cumecs, up from 2.4, and the Opihi River at State Highway One had recorded a flow of 244, up from 2.3 cumecs. The Orari River was running at 381 cumecs at the gorge, up from 3.74 cumecs.
By midday the MetService issued a warning advising people to avoid rivers, river floodplains and river mouths until flows subsided.
Some surface flooding due to overland flow was reported and several roads were signposted to alert drivers to water flowing across roads and along culverts at the verges.
Ecan reported significant rainfall by 1pm with Opihi recording 75mm, Hadlow 68mm and 82mm at Bluecliffs.
River flow had tripled in the Temuka River at the Manse Bridge with it running at 306 cumecs around 1pm. By late afternoon flow at the Manse Bridge had increased to 461 cumecs. At the Saleyards Bridge, the Opihi was running a staggering 1190 cumecs.
Conditions started to settle in the evening.
Ecan duty controller Phil Lees said rain rates were forecast to ease. Rainfall intensity had dropped and remained steady at 6mm an hour.
Showers are forecast to ease today with some fine spells.
- The Timaru Herald