Torrential downpours have hit the region overnight and flooding near Exeter and Tiverton has affected South West Trains, Cross Country and First Great Western services.
The Met Office has an amber warning in force across the South West until 4pm today.
Drivers have been warned of hazardous conditions after nearly half a months rain fell in 24 hours.
The Environment Agency has issued flood warnings on rivers in the region, including the River Clyst from Broadclyst to Clyst St Mary and the River Lowman in Tiverton.
There are flood alerts on the Rivers Creedy, Creedy Yeo, Little Dart, Lapford Yeo and their tributaries, the River Otter, the River Sid and the Middle River Exe from Exebridge to Tiverton and the Rivers Haddeo, Batherm and Lowman.