The road was closed to traffic because of the flooding caused after 5,000 cubic metres of rock from a cliff above the Imbach AG gravel quarry fell into the Kleine Emme river, the 20 Minuten newspaper reported online.
“I heard a loud rumble in the night, it was like an earthquake,” a Wolhusen resident told the daily.
The incident occurred around 3am, blocking the river, which sent water coursing through the village’s main street.
Rocky cliffs overlook the road, around 12 kilometres west of the city of Lucerne.
Nobody was reported injured but local school classes were cancelled, 20 Minutes said.
Motor vehicle traffic was diverted via Rengg while crew worked to remove the blockage in the river, broadcaster SRF said.
Electrical utility CKW said that power was cut at three substations in the nearby village of Werthenstein shortly before 8am as a result of the flooding.
It said local power was being restored with the use of a generator.
The Nueue Luzerner Zeitung reported that the flooding had severely impacted operations of the Imbach quarry and concrete plant.
“Water is flowing through the whole area of our plant,” managing director Brigitte Imbach told the newspaper.
The company’s office building and garage were under water, along with its gravel and concrete works, she said.
The flooding has prevented employees from working, Imbach added.