The road between Makarora and Haast had been closed after heavy rain.
And while it was still raining heavily yesterday, MetService has predicted mostly calm and sunny conditions for the next few days, although a few showers were expected on Sunday.
The heavy rain also caused delays to the scheduled reopening of the Bailey bridge at Waiho, which was damaged during the earlier floods.
The NZ Transport Agency advised travellers delays were expected around the Diana Falls area and advised to take care while driving.
Extensive road safety work was completed in the same area five years ago.
A spokeswoman said a "catch fence" needed to be emptied after the last bout of bad weather so it could do its intended job.
The fence was part of $8million of work done after a huge slip of 40,000cu m in September 2013 and is capable of catching a 16-tonne boulder travelling at 90kmh.
Up the road the Department of Conservation is reopening the storm-ravaged access road to Franz Josef Glacier, but already it is starting to look for alternative viewing points further back.
The access road was washed out by the Waiho (Waiau) River during the same storm that destroyed the State Highway 6 bridge further downstream.
The Fox Glacier access road was already shut and may never reopen because of ongoing damage from the largest landslip in the country.
This means the only way to view the ice now is generally by helicopter.
Conservation Minister Eugenie Sage visited both glaciers at the weekend and acknowledged the "huge significance" of the glacier valleys.
She told the Greymouth Star the Department of Conservation was now looking for alternative viewing points because maintaining access was challenging.
