Authorities have closed the road in the Shawford area due to a landslide east of the Trafalgar/Copthall junction.
The road closure is between the junction and Trafalgar.
Reports are that half of the road, up to 100 feet, fell into the river in the area on Wednesday morning in an area called Cabanis.
Motortists are being asked to take the Copthall to Wotten Waven Road, going as far a Trafalgar as an alternative route.
Dominica has been experiencing heavy showers of rain in the past few days and the Dominica Met Office says high pressure system is the dominant feature across the region generating a brisk trade wind flow.
It said that low level clouds moving with this wind flow will continue to result in occasional cloudiness and scattered showers across the island chain during the next 24 to 48 hours.