Spilling record alpine rain will cause Waitaki to flood
South Canterbury rivers seem to have coped with heavy rain over recent days with the Waitaki River the only one causing fears of ‘‘out-of-river flooding’’.
Environment Canterbury duty flood manager Chris Fauth said while river levels in the Mackenzie District are dropping, the Waitaki River is expected to continuing rising and out-of-river flooding can be expected.
‘‘In the lower Waitaki River below the dam, we are now expecting spill flows from Waitaki dam.
‘‘Water will spill over the dam in excess, at a flow of 1000 cumecs for at least the next two days.’’
The Waitaki was running at 900 cumecs late yesterday afternoon, and Fauth said landowners needed to monitor their situation as it will run 800 to 1200 cumecs for a few days. The mean annual flood level is 1050 cumecs.
Fauth said the Rangitata River (at the gorge) was running at 1100 cumecs and was expected to peak last night. He said there is a 10-hour delay from the gorge to the lower river and ‘‘we expect the river to be high all day and tomorrow.’’
The Orari River, running at 420 cumecs, had elevated flows yesterday but ECan had not experienced any problems on the river.
‘‘We are keeping a close eye on certain areas on the river which were damaged by the floods last year.’’
The MetService recorded 405mm of rain in the Mt Cook Village from 7am Monday to 7am Tuesday while Timaru’s airport received just 6mm of rain in the same period.
MetService meteorologist Tui McInnes said it was a ‘‘very impressive amount of rain’’ for Mt Cook Village as their usual threshold for a rain warning is 100mm in 24 hours.
Almost all the power outages that struck the region on Monday have been repaired. Seadown was the latest repair completed but the supplies to Ikawai, cut at 1.30pm on Monday is still off to 16 customers, while 11 customers are with
out power on Levels Plain Rd, Timaru.
State highway closures landlocked Ō mā rama yesterday with SH8 closed from the township to Tarras (Lindis Pass), SH83 to Kurow, and SH8 to Twizel. SH80 between Ben Ohau and Mt Cook was also closed until further notice due to a slip.
Waka Kotahi NZ Transport Agency has asked motorists to avoid those areas or delay journeys if possible.
A road snowfall warning from the MetService for the Lindis Pass was in place until early this morning.
The Timaru District Council said Hanging Rock Bridge, which crosses the Opihi River between Winchester Hanging Rock Rd and Opihi Rd, has been closed due to damage from the high river levels.
The council said its roading team will be assessing the bridge as soon as water levels have receded.
The Waimate District Council said Waihaorunga and Waikakahi catchment water supplies have been temporarily shut down due to the deterioration of water quality caused by the rain.
The council also advised consumers to conserve water where they can and inform all staff, tenants and neighbours about the shutdown.
The council also said the Hakataramea Pass has been closed until further notice due to flooding.
‘‘The gates have been shut at Round Hill Station at the bottom of the pass,’’ the council said.
Other road closures in the Waimate District include McHenrys Rd – between Foveran Station and Wrights Crossing Bridge; Adamsons Rd – closed between Lower Hook Rd and the ford, due to dangerous trees.
Mackenzie District Council, on its information page, said Braemar Rd, Clayton Rd from Monument Corner, Glen Lyon Rd from the ford, Hakataramea Pass, Hayman Rd, Jack Lovelock Track, Kerrs Rd, Lilybank Rd, Mackenzie Pass, Mt Cook Station Rd, Opuha Dam Rd, Seddons Rd, Stanton Rd and Stoneleigh Rd were all closed.
The council said surface flooding is widespread around the district.