Another slap from Mother Nature

It was nowhere near as protracted, or as damaging, as last month's storm, but last week's one-in-50-year downpour brought more slips and road closures in the Far North, already facing a $30 million roading repair bill after July's battering.

While the rain that hit particularly hard on the the east coast between Doubtless Bay and Whangarei's eastern hills was short-lived, it was exceptionally intense. At its peak on Tuesday evening it was recorded at 52mm per hour at Kaeo and 49mm per hour in Kerikeri. Anything more than 10mm per hour is regarded as noteworthy.

The deluge triggered slips, flooded highways and sparked a flurry of emergency calls. The Mangonui Fire Brigade was particularly busy, with nine alarms between 5.45pm and 9pm, arising from slips, a flooded shop, downed trees and cars stuck in floodwaters.

Far North Civil Defence co-ordinator Bill Hutchinson said the saving grace was that the downpour coincided with low tide, preventing more serious problems at Kaeo and Kawakawa's Three Bridges. Even so, catchments were so overloaded and the watertable so high that water was pooling along SH10 in places it had never been seen before.

Northland Regional Council hydrologist Dale Hansen said the 50mm/h rain intensity in a narrow band down the east coast was "quite exceptional". The total for Kerikeri was 141.5mm, most of which fell in a three-hour period. Kaeo had 126mm, Whangarei's eastern hills 111mm and Whangarei city 46mm. The Northland Age recorded 51mm.

Slips reduced a number of roads to one lane. Pupuke-Mangapa Road, near Whangaroa, and Snelgar Road, south-east of Kaitaia were closed entirely for a time. At least one farmer lost stock in the Pupuke Valley.

Mangonui's chief fire officer, Peter Sainsbury, said Tuesday night's call-outs included pulling cars from floodwaters on SH10, diverting water from the Cable Bay Store and clearing downed trees, while Kaeo's CFO, Lindsay Murray, said his brigade was called out to help a motorist stuck in floodwaters at Otangaroa Road and to flooding at Mangaiti Marae. The water prevented firefighters from reaching the marae, however.

Kaeo Farm and Fuel owner John Owens said there had been "no dramas at all" there. In other areas, however, including between the fire station and the old Sanfords building, flooding was worse than in July.

The regional council's early warning system, which sends out an automatic email when the river reaches a certain level, worked well. A similar warning by text message could be not sent because Vodafone's transmitter stopped working at 4pm on Tuesday.

Rain continued on Wednesday with localised downpours and a thunderstorm dropping more heavy rain, at around 20mm per hour, in Kaitaia (where the 24 hours to 9am delivered 32mm).

Last month's 293 slips and caused road damage estimated at $30 million across the Far North. The repair bill for Whangarei has been put at $2 million.