Network Rail teams are addressing the issue - disruption expected until 3pm.
All train lines between Axminster and Yeovil Junction are blocked this afternoon (Thursday).
South Western Railway has cited heavy flooding on the lines as the reason.
As a result, train services running through the stations between Axminster and Yeovil could be cancelled, revised or delayed by up to an hour.
Disruption is expected until 3pm.
A spokesman for South Western Railway said: “The control room has been advised of heavy flooding in the Crewkerne area.
“Network Rail response teams have been advised and are attending.
“To reduce the delays to trains, some services may have to be altered or revised at short notice.
Some services may also be diverted via an alternative route.
“We are sorry for the disruption caused to your journey.
The 11.25am Exeter St Davids to London Waterloo service is currently delayed as they area is reported as impassable.
Keep updated on the services on www.nationalrail.co.uk
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