Yes, and the risk is serious. More than a quarter of the village is in the highest-risk river flood zone. Another large share is in the zone next to it. Most of Laleham comes into the flood zone once climate change is allowed for. Living next to the Thames comes with the Thames's flood risk.
The Environment Agency's river-and-sea flood zones put about 29% of Laleham's postcodes in Flood Zone 3, the highest-probability band. A further 38% are in Flood Zone 2, the medium-probability fringe just beyond it. The two zones don't overlap, so these are different postcodes. One of the possible origins of the name Laleham is the Old English for land in a river bend, so the risk was there from the start.
Surface water, the flooding that comes from heavy rain that can't drain away, isn't counted in those zones. It appears only in the postcode measure further down, alongside river and sea risk.
The Environment Agency also maps a flood zone with an allowance for climate change. About 88% of Laleham's postcodes fall inside it. That's the Agency's planning scenario for the decades ahead, and on that map almost the whole village counts as floodplain.
Insurers price from the same kind of mapping, so in the zones above expect higher premiums, a bigger excess on flood claims and more questions on the application. The Agency has recorded 31 flood events in the area, the latest in February 2014. Ask the seller directly whether the house has flooded or made a flood claim, and get the answer in writing through your solicitor.
At postcode level, about 21% of Laleham's postcodes rate high on at least one flood measure, about 45% at least medium and about 67% at least low. These measures include surface water as well as rivers and the sea, so they overlap with the flood-zone figures. Don't add the two sets together.
Counting homes gives a clearer sense of scale. The Environment Agency's rivers-and-sea mapping lists 918 properties across the 54 Laleham postcodes that carry any risk at all. Postcodes with no risk aren't listed. Of those properties, 114 are at high risk, 187 at medium risk, 476 at low risk and 11 at very low risk. Ninety-four of the high-risk properties are homes.
The Agency's model also asks whether defences change anything. The high-risk flood extent covers about 29% of postcodes with no defences in the model and about 29% with defences in the model. The defences make no difference to the share in that high-risk band. "Defended" only means a defence appears in the model. It says nothing about whether it would keep water out of a particular house.
The nearest tide gauge in the records is at Portsmouth. It measured sea level rising by about 2 millimetres a year between 1962 and 2023. That is a measured past rate at a gauge a long way away. Laleham's flood water comes down the Thames from upstream.
Flood risk is one of Laleham's weakest points. If a home here is otherwise right, check the flood mapping and the insurance cost for that exact house, and decide on that basis.