The region's emergency services say drivers are putting themselves in danger by ignoring road signs and deliberately driving through flood water.
It follows widespread flooding over the past few days, affecting a number of counties in our region.
Hertfordshire Fire and Rescue Service says it has been dealing with hundreds of flood-related calls over the past few days.
It says high water levels have been causing problems across the county including Bishop's Stortford, Puckeridge and the Hadhams.
As well as dealing with flooded homes and businesses, fire crews have been called out to help drivers they say are taking unnecessary risks.
Assistant Chief Fire Officer Darryl Keen said: "There are people that were taking significant risk by driving through flood water where clearly they'd been asked not to or actually where they should have known better from the point of view of their awareness of the road they were driving along.
"I think we can only urge people to be sensible about flood water, it's not something to take lightly."
Fire officers are reminding drivers there is still a lot of water on our roads. They say some road closures could remain in place until the end of the week.