Yes, for a part of Richmond, and the part is easy to find. About one postcode in five is in the river's highest-risk zone. Most of the rest are clear of it. The risk follows the Thames, and the Thames wraps round the town. A house up Richmond Hill and a flat on the riverside face two different questions.
The Environment Agency's river-and-sea mapping puts 20% of Richmond's postcodes in flood zone 3, the highest-probability band, and a further 4% in flood zone 2, the medium-probability fringe beyond it. The river is still tidal at Richmond, which is why a half-tide lock was opened in 1894 to keep boats moving at low water. The boats got their engineering. The riverside got the zone 3 label.
Surface water, the rain that floods streets before it ever reaches a river, sits outside those zones entirely. It appears only in the wider postcode measure below, so a home well clear of the river can still carry a surface-water rating of its own.
The Environment Agency also draws an extent allowing for climate change, and about 30% of Richmond's postcodes fall inside it. That is the agency's modelled view of where the zone could reach, set out for planning purposes, and it is a larger patch of town than today's zone 3.
Insurers look up the exact address, and a home in zone 3 can expect more questions, a higher premium or a narrower choice of cover than a house on the hill. An indicative quote for the specific address, run early, settles more than any map.
A broader measure counts how each postcode rates on at least one of several flood indicators, surface water among them. By that test about 12% of Richmond's postcodes rate high on at least one, 18% medium and 47% low. Because any one measure is enough to trigger a rating, these shares run wider than the river zones and should never be added to them.
Counted as properties, the picture is smaller. The Environment Agency's rivers-and-sea mapping lists 117 Richmond postcodes with some risk, covering 2,760 properties. Of those, 30 are at high risk, 21 of them homes, 8 at medium risk, 104 at low risk and 2,054 at very low risk. Postcodes with no risk at all do not appear in that list, so the total is the at-risk slice of the town and nothing more.
On the modelled flood extents, about 12% of Richmond's postcodes sit in the high-risk area with no defence present in the model, and under 1% sit in it with one. A defence in the model means a structure exists on the agency's map. It says nothing about how a particular house fares when the water arrives, and a seller who calls a riverside flat "defended" is quoting a map key.
The nearest tide gauge in the national record is at Portsmouth, which measured sea level rising about 2 millimetres a year over its record from 1962 to 2023. That is a rate already measured on the south coast, some way from a tidal river in south-west London, and it says nothing on its own about the years ahead.
No historic flooding is recorded in the area. That is a fair point in Richmond's favour, though a clean record only covers what someone wrote down.
Flood risk is one of Richmond's weaker points, concentrated along the river and mostly undefended where it is high. Up the hill, the question barely arises.