The burst in the 12in pipe sent water spilling over the A457 Sedgley Road East in Tipton, leaving some cars stranded in the water.
Pressure from the water was so high, residents reported seeing water pushing up large sections of pavement and sweeping debris down the road.
It resulted in a flood of water in the road which caused several cars to become stuck before the highway was closed in both directions.
South Staffordshire Water was called to the scene at around 8.30am and cut off the supply to the main.
Engineers were attempting to fix the leak before turning the supply back on this afternoon.
The road remained closed at 11am today and only half of the 45-acre Vaughan Trading Estate had seen its water supply come back on.
Frances Hill, who lives on the road, said: "My son called me out front and said that I had to see what was happening.
"I came outside and the road was like a raging river. Water was coming up from both sides of the pavement, it was absolutely amazing.
"At one point one of the cars going through the water began to tilt and was nearly swept down the embankment.
"The road regularly floods when it rains, but I've never seen anything this bad before."
Some residents on the street said they had low pressure in their water supplies this morning.
Resident Paul Hall said: "When I woke up this morning and looked out of my window there was a river running outside the front of my house.
"Luckily the houses are built high up so we haven't really been affected. We have low water pressure at the moment, but there's nothing we can do about it but just wait.
"I've never seen anything like this before."
The busy road that runs between Tipton and Oldbury remains closed in both directions between A461 Dudley Port and Cleton Street.
Sophie Gill, aged 16, was enjoying her half-term holiday when she witnessed the flood.
She said:"I couldn't believe it there was so much water running down the road. I've never seen anything like it before. It's incredible."
Her family and several neighbours braved the cold water to help stricken motorists who has got stuck in the waters that they estimated where almost 2ft deep.
Another neighbour Bradley Pogson, aged 18, added: "The water was coming up and over our cars, we were just worried they were going to get damaged."
Workmen using heavy duty petrol powered cutting discs and diggers were trying to find the source of the water and managed to shut off the main valve supplying the damaged pipe.
Karen Baxter, from South Staffordshire Water, said the water firm was first alerted to the burst at 8.30am. She said the water supply to the Vaughan Trading Estate was cut as a result of the burst, but by 10.30am half of the site's supply was back on.
She said: "We have now got the main isolated. There was some initial flooding which is now being drained away.
"We apologise for any inconvenience but are working as quickly as we can to restore the supply and get the road opened again."
Much of the pavement along the road has been left resembling a rolling sea with several sections lifted up so high that soil and stones have been washed from underneath.
A grass verge further down the road also remains heavily water-logged with pools of water left on the surface.
Although the main was shut off by workmen a small amount of water was continuing to flow from beneath the path on both sides of the road. By 11am, the water only stood a couple of inches deep in a dip in the road. Most of the water had drained away.
The water company hoped to open one side of the road shortly afterwards, but said it would be partially blocked for much of the day as work continues.
It comes a month after a burst water main at the Great Bridge Industrial Estate in Tipton.
Businesses on the estate and 15 homes nearby had their water supply cut for a short time after the pipe burst last month.
And it is the latest burst water main to hit Tipton.
In January last year, homes were left without water and traffic came to a standstill after a pipe burst under Horseley Road, leaving it six inches under water. It was believed the damage was caused by workers and police were called to the scene to help direct traffic.