Flooding affected trains on the Portsmouth-Waterloo line today.
South West Trains said that following severe rain at Woking during the night, all lines were open this morning but that services running through the station may be revised.
The company warned that disruption was expected until the end of the day.
A SWT spokesman said: ‘Due to flooding causing issues with railway infrastructure around Woking, it is possible that some delays or alterations may occur. Currently, we are making use of various alternatives and contingency plans, however short notice alterations are still possible.
‘We are sorry for any disruption you experience as a result of this issue.’