A burst water main flooded a large part of Kilburn High Road with several inches of water today.
Businesses and commuters were affected by ankle-deep water which started pouring onto the street this morning.
Police advised people to avoid the area. The road was closed to traffic for four hours.
The road was later deemed safe to be opened to traffic after the flood water was drained.
Thames water said in a statement: "A burst main is causing traffic disruption on Kilburn High Road and Kilburn tube station.
"You may experience interrupted water supplies while our engineers work to fix the problem.
"We are really sorry to those affected."
Actor Tom Kane, 21, was held up on his way to work this morning by the flood water.
He said: "I was on the bus and it was diverted so I had to get off and walk back to get on the Tube.
"People were struggling with water up to their knees in places. Shopkeepers were trying to sweep water away from their front doors. There was a fire engine and they were grabbing sandbags."
Mr Kane, who is acting in film Now is Good starring Dakota Fanning, added: "I think the water stretched for about half a mile up the street."
Twitter user Camilla Eden wrote: "Burst water main on Kilburn high road. It's like a lake - they've closed the road. I'll have to swim to to the overground station."
Another user, Gareth Abbit, wrote: "I see they have a ZiL LAKE in KilburnHigh Road."
Stuart Clarke wrote: "It appears that Wimpy in Barking has suffered the same fate as Kilburn High Street this morning. Knee deep in water "
Simon Morris wrote: "Wow, Kilburn high street is a river today."
