Hertfordshire Council has closed St Johns Road, between Woodford Road and Clarendon Road this morning - and say it could remain shut for up to four days.
The council added: "It is possible that by exposing the hole and then subsequently back-filling, this will cure the problem. A small section will be resurfaced upon completion.
More top news
The family of a father-of-three from East Ham have made a fresh appeal to catch his killer 20 years after he was murdered.
The Metropolitan Police has paid £45,000 in damages in an out-of-court settlement following the 'unlawful arrest' of a black motorist.
John Cantlie, who worked for a number of Fleet Street newspapers, is thought to have been taken hostage in November 2012.