A Thames Water spokesman says the water is not sewage.
They say it is the result of a burst water main, which had mixed with silt and mud.
Engineers are on site working to manage the problem.
More top news
Police said they are "extremely concerned" for the welfare of a "vulnerable" mother and her two children who have gone missing in Bexley.
It is hoped the 7,400-mile journey will become a cost-efficient and time-saving way of transporting trade between China and the UK.
The Supreme Court is set to decide on whether disabled travellers are legally entitled to have priority use of wheelchair spaces on buses.