Yes, Teddington has a real flood risk, and nearly all of it lies along the Thames. About one postcode in eleven is in the highest river flood zone. Roughly a thousand properties are rated high risk. The modelled defences hardly move the numbers. Higher ground away from the river is a different conversation, and the riverside is the one buyers need to have.
The Environment Agency puts about 9% of Teddington's postcodes in Flood Zone 3, the high-probability band for flooding from rivers and the sea, and about another 9% in Flood Zone 2, the medium-probability fringe that lies beyond Zone 3. The two are separate bands, so Zone 2 adds to Zone 3 and does not contain it. The river is the source. Teddington Lock is the lowermost lock on the Thames, and the town has its own lifeboat station below it, the only volunteer station on the river.
The Environment Agency has no separate surface-water share for Teddington in the figures here. Rain that overwhelms drains still counts, and it is folded into the postcode measure below. The flood record runs to 16 recorded events, about 3% of postcodes have flooded in the past, and the most recent recorded event was in January 2003, when the main river overflowed a channel with no raised defences.
Once the Environment Agency allows for climate change, the share of postcodes in the flood zone rises to about 22%. That figure comes from a modelled scenario for a wetter future, and its job is to show where the edge of the zone could move.
Insurance follows those maps. Homes in the higher zones can expect higher premiums and larger excesses, and some insurers will ask about past claims before they quote. Flood Re, the government-backed reinsurance scheme, helps keep cover affordable for many older homes at risk, but it does not cover homes built since 2009. The apartment blocks built on the former Teddington Studios riverside site from 2016 onwards are therefore outside it. Get a buildings insurance quote for the exact address while the survey is being done, because the premium is where the flood map shows up in your monthly budget.
A wider measure counts every postcode that rates on at least one of several flood indicators, surface water included. On that basis, about 16% of Teddington's postcodes rate high on at least one of them, 18% medium and 50% low. This measure overlaps with the flood zones, so the two sets of shares should not be added together.
Counting homes says more than counting postcodes. In the Environment Agency's rivers-and-sea mapping for Teddington, 1,018 properties are rated high risk, 177 medium, 1,220 low and 24 very low, out of 2,826 listed. Only postcodes carrying some risk are included, so the rest of the town is missing from those totals. Of the high-risk properties, 935 are homes.
The Environment Agency also models where water would reach with and without defences. About 9% of Teddington's postcodes fall inside the high-risk extent with no defences modelled, and about 9% with them. The defences barely change the modelled picture, and "defended" only means that a defence is shown in the model, which tells you nothing about a particular house staying dry. A sales particular that leans on the word is relying on the paperwork.
The nearest tide gauge in the national record is at Portsmouth, where sea level rose by about 2 millimetres a year between 1962 and 2023. Teddington sits at the point where the tide stops, so that is the trend at the far end of a long estuary, and it says nothing about what comes next.
Flood risk is one of Teddington's weaker points, and it is concentrated on the river side of town, where a buyer needs the address checked, the insurance quoted and the defence questions asked before anything else.