Slips and flooding have closed SH65 near Murchison.
The highway is closed between O'Sullivans Bridge and Shenandoah.
Drivers are asked to avoid the area or delay travel where possible.
The area is under an Orange Metservice Heavy Rain Warning until 1am Monday.
The closure comes amid heavy rain and widespread surface flooding, fallen trees and other slips occurring across the West Coast and the central South Island today.
NZ Transport Agency Waka Kotahi has received reports of flooding on SH6 in the Lower Buller Gorge, on various parts of State Highway 7 between Greymouth and Reefton, and on State Highways 7 and 65 between the Hanmer Springs turnoff and Murchison.
Treefalls have been reported on SH6 at Berlins and Inangahua Junction, and on State Highway 67 near Westport.
