Motorists were stranded in Suswa on Tuesday as floodwaters cut off Narok-Mai Mahiu road.
The water flowed from the Mt Longonot area, where it had rained heavily. It does not rain much in Suswa.
Traffic snarl-ups on both sides of the road were the result, some motorists saying they had been waiting for more than one hour.
One Naomi Mwangi said she and other passengers from Nairobi had been stuck in their vehicle for an hour.
"Motorists are desperately waiting for the floodwaters to subside. This happened yet there hasn't been heavy rain in this area," she said, adding the floodwaters came with debris.
The section of the road that was cut off is the same one that was washed away after heavy rains in 2018.