The main A646 Halifax Road linking Todmorden and Hebden Bridge re-opened after a water main burst forced its closure for several hours this afternoon.
The burst happened at Charlestown and the amount of water swilling across the road meant it had to be closed until Yorkshire Water engineers were able to make a temporary repair.
Late this afternoon the carriageway was open again, but 57 properties were still without water, said a Yorkshire Water spokesman.
Bottled water was being delivered and work was ongoing to restore supplies to those affected, he said.
But he warned motorists would face some unavoidable delays while a full repair was carried out over the next few days, with temporary traffic lights a likely option.
The repair is a complicated one as the water main runs right by a gas main and the situation needs careful assessment before work begins, said the spokesman.