Staff spent more than two hours sweeping water from the pavements in front of their restaurant after flash floods.
A 10-minute downpour around midday on November 1 caused flooding both east and west of Hampstead Heath in Highgate Road and South End Road.
People on both sides of the heath asked why there was no help from Camden Council or London Fire Brigate as they battled "waves and waves" of water.
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Staff and customers at Bistro Laz, in Highgate Road, spent more than two hours sweeping water away from their entrance and removing leaves and debris from drains.
It is not the first time the restaurant has had to deal with water from blocked drains, and it has bought special rods to clear them.
Ermin Celik, manager of the Mediterranean food and pizza restaurant, worked for hours to clear the path, helped by pizza and pastry chef Ossie Albas and customer Tunay Gungor.
Mr Celik said: "We pay a lot of council tax but we are working instead of the council. This is not our job. This path doesn't belong to the restaurant."
"This is also happening all the time, every time it rains, it's terrible here," he added.
He also criticised lack of response from London Fire Brigade.
He said: "I waved to the fire truck as it passed and they waved back to me.
"For the past two hours we are just doing this. The kids couldn't pass. It was dangerous for everyone."
Camden Conservative Party chairman Don Williams took a video in which he can be heard saying fellow party official David Douglas was "doing his best to get things working with the people from the Euphorium" to clear "a river".
He said: "Camden Council where are you, the police where are you, we need help, fire people where are you?"
London Fire Brigade said they received "several calls" from South End Green and Highgate Road and attended all calls that they received.
A spokesperson added: "We will always respond to flooding incidents where there is a risk to life. Blocked drains are the responsibility of other agencies."
The spokesperson added that when the fire service experiences a high number of flooding calls they can introduce 'batch mobilisation", meaning calls where there is a risk to life are prioritised. This was not needed on November 1.
The Met police said it was "one for the council".
Camden Council has been contacted.
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