Detours are in place for SH23 to Raglan due to the road closure. Photo: Twitter / Waka Kotahi
State Highway 23 between Whatawhata and Raglan remains closed after the major storm event.
Waka Kotahi says the heavy rain caused serious cracks and slumping on the highway.
"We know this closure will have an impact on local communities, and we're working hard to get the road back to full use."
The official detour was Ohautira Road, Waingaro Road, Herschel Street, Ellery Street, Whatawhata Avenue, Ngāruawāhia Road, and Horotiu Road to re-join SH23, it said.
The journey takes about 58 minutes but has tight, winding sections, the transport agency said so it advises people to be careful and drive to the conditions.
It advises against using the Te Pahu Road, Limeworks Loop Road, Fillery Road, and Waitetuna Valley Road route, as there may be slips and flooding in places.
Old Mountain Road was closed to through traffic.
Waka Kotahi said drivers travelling from the north to Raglan should exit the Waikato Expressway at Taupiri, following the VMS signs through to Ngāruawāhia to access the detour.