Flooding closed State Highway 83 and a rock fall reduced SH82 to one lane on Saturday night, as a short burst of rain hit the Waitaki Valley and South Canterbury.
Surface water forced the closure of SH83 between Doveys and Black Point Rds to light vehicles, just after 8pm.
''We had it closed for a short period of time ... open to 4WD and heavy vehicles,'' NZTA Otago Southland duty manager Graeme Hall said.
''There was very little rain in Oamaru at the time, but there must've been a burst up the hill and water has come running down.''
SH83 was opened to one lane for all traffic later that night, but an area warning remained in place and motorists were advised to take extra care or avoid the area, if possible.
There was also surface flooding along Island Cliff Duntroon Rd and some motorists chose this route as a detour.
The warning was lifted yesterday morning.
Rockfalls and a slip near Ikawai reduced SH82 to one lane about 7.15pm on Saturday.
NZTA Canterbury West Coast duty manager Lee Wright said contractors worked through the night to clear the road and both lanes were open yesterday morning.
