A flood alert has been issued by the Environment Agency for the Upper River Colne and Radlett Brook following heavy rain.
The alert was issued this morning and warns of possible flooding to the Borehamwood and Radlett area as ground is saturated.
The Environment Agency says river levels could rise quickly as a result of heavy rainfall and breach their banks, causing flooding to low lying areas and roads.
But the agency also says on its website it does not expect flooding of properties at this stage.
The flood alert is at a level which warns flooding is possible and people should be prepared. An update is expected later today.