Engineers are currently working to fix a burst water main that has left a Chorleywood road engulfed with water and one car stranded.
Long Lane was closed after police were alerted to the extensive flooding along the entire stretch of the road at about 2.30pm.
Both the main road and the slip road westbound at Junction 17 of the M25 had to be shut off.
Affinity Water workmen are on site dealing with the burst pipe.
Kevin Barton, Affinity Water spokesman, said: “We would like to apologise for any inconvenience caused by a burst water main on Long Lane, Chorleywood.
“The burst was first reported to us at 2.50pm and our engineers are currently onsite to investigate the incident.
“We would like to thank our customers for their patience whilst we resolve this issue.”