Yes. Charlton carries more flood risk than most of London's hillier neighbourhoods, and most of it depends on the Thames staying where it is told. About one in seven postcodes is in the highest river-and-sea zone. Allow for a warmer climate and that goes up to nearer one in four. Count the defences and the number of homes at high risk falls close to nothing. The river is the risk here, and the engineering is what keeps it off the map.
On the Environment Agency's river-and-sea flood zones, about 15% of Charlton's postcodes fall in zone 3, the highest-probability band, and a further 4% fall in zone 2, the medium-probability fringe just beyond it. Those postcodes are mostly down by the river in New Charlton, beyond the railway, and the southern end of a major tidal flood defence, operational area and all, stands in the same part of Charlton. The neighbourhood that hosts the defence is also inside the zone it was built for.
Surface water is a separate route in, and it follows the slope. Charlton Village is on high ground, and Charlton Church Lane runs down the hill to the station and the A206, so a heavy downpour at the top has one obvious way to go. The Environment Agency maps surface water on its own indicator, and that indicator is counted in the postcode figures further down.
The agency's climate-adjusted mapping, which tests the zones against a wetter future, puts about 23% of Charlton's postcodes inside the flood zone. That is a modelled forward look built on assumptions about rainfall and sea level, and nobody has scheduled the rain.
Insurers run their own models and will ask about the exact address. A house in zone 3 near the river can attract a higher premium or a higher excess than one up the hill, even when no water has come through the door in living memory. Get an indicative buildings quote for the specific property early, while walking away still costs nothing.
On the postcode indicators, which count a postcode if it rates on any one of several measures including surface water, about 23% of Charlton's postcodes rate high, about 22% medium and about 36% low. A postcode only needs one of those measures to qualify, so the shares describe how widely risk of some kind is spread, and they do not total the river-and-sea zones above.
The count of homes is much less alarming. The Environment Agency's risk-of-flooding mapping for rivers and the sea lists 1,059 properties across the postcodes carrying any risk at all, and puts four of them at high risk, none at medium, none at low and 655 at very low. None of the four high-risk properties is residential. Only postcodes with some risk make the list in the first place, so the homes up the hill are not counted because nothing reaches them.
The defences explain why. About 6% of Charlton's postcodes are inside the high-probability flood extent when the defences are left out of the model, and none are when they are counted. "Defended" means a defence exists in the model, and it is a statement about engineering on a map, with no promise attached about any particular night. The last flood on the Environment Agency's record came in January 1928, when the main river overtopped its defences.
The nearest tide gauge in the record, at Portsmouth, measured sea level rising by about 2 millimetres a year between 1962 and 2023. That is what the gauge recorded over those years, at a harbour some way from the Thames.
Flood risk is one of Charlton's weaker points. A large share of the riverside is in the zones, and the low count of homes at risk depends on defences continuing to do their job.