Heavy rainfall triggered flash flooding and a series of minor accidents across the Mid North yesterday morning.
The worst-affected stretches of highway included SH10 between Kerikeri and Pakaraka, and SH1 between Pakaraka and Moerewa.
Most problems stemmed from blocked drains which were cleared by volunteer firefighters and roading contractors. There were no road closures, though police and contractors were stationed along the highways urging motorists to proceed with caution.
Surface flooding north of Pakaraka reduced SH10 to one lane while a blocked drain a few kilometres south of the junction spread floodwaters and debris, including large rocks, across SH1.
The road was cleared and the drain unblocked by volunteers from the Kawakawa Fire Brigade about 9.30am. Another blockage sent a torrent of water across SH1 about halfway down Turntable Hill, north of Moerewa.
Otiria Stream, at the bottom of Turntable Hill, was high but still a metre below the bridge. The Otiria Stream bridge is often the first point on SH1 to close in heavy rain. A Far North District Council spokesman said no local roads were closed as a result of the weather.
Weather-related accidents included one on Matauri Bay Rd about 9.30am when a car slid off the road.
MetService rain radar shows a band of rain covered Northland from about 11pm on Wednesday to 4am yesterday, followed by intense bursts yesterday morning along the east coast and the Bay of Islands.
Meteorologist Lisa Murray said Kerikeri copped 75mm of rain in the 24 hours to 2pm yesterday. Over the same period Whangarei had 33mm and Kaikohe 44mm. The rain all but bypassed Kaipara with Dargaville receiving just 15mm.
The highest intensities, 26mm/hr, were over Puketi Forest yesterday.
The rain, and the run of humid nights, was caused by moist tropical air pulled over New Zealand by a low over the Coral Sea. The same weather system brought heavy rain, thunderstorms and flooding to the South Island's west coast, Nelson and Marlborough earlier in the week.