The number of dwellings at risk is in this area is the highest out of all London boroughs - at 59,632 homes - with Newham close behind with 39,665 homes under threat.
The study, conducted by the UK's leading authority on environmental land risks, cites houses that have more than a 1 in 1,000 risk of flooding as 'high risk' houses.
Drew Hardy, research manager at Groundsure, warned that the risk is only getting higher as sea waters rise and climate change continues.
“The Thames Barrier is being used more, and more and more,” he said. “It is also getting closer to the end of its operational life which means the protection it offers will reduce over time.”
Properties of a high risk status will soon be able to insure their property against flood damage when the new ‘Flood Re2’ agreement which comes into effect on April 1.
The ‘Flood Re’ agreement aims to help the estimated 350,000 'high risk' households to insure at an affordable set price.
However, this will not apply to properties built after 2009, leasehold properties, commercial properties, and Bed and Breakfast establishments.
Groundsure advises potential home-buyers to review a property's land flooding history before making a house purchase.
Dan Montagnani, managing director at Groundsure, said: “It is essential that you consider the history of flooding in the area you are thinking of buying a home - not just from rivers but also how the land, and sewer systems have coped with sudden deluges.
“We also believe the Flood Re agreement should be universal to all - the current agreement puts many small business owners at increased risk if they cannot afford to insure their livelihood.
“We all remember the human stories from flooding that everybody wants to avoid.
"Insurance is essential but it can’t replace those precious photos or months of disruption while your home dries out.”