For most of Berrylands, no, but the streets nearest the water carry real risk. Only a small share of postcodes fall in the river flood zones. Surface water reaches far more of them. A man-made brook runs through two of its green spaces. The risk depends heavily on the exact address, and most of the suburb stays dry.
The Environment Agency's river-and-sea mapping puts about 4% of Berrylands postcodes in Flood Zone 3, the highest-probability band. Another 4% sit in Flood Zone 2, the medium-probability fringe just outside it. Those are two separate rings around the water, not one inside the other. In Berrylands the water in question is the Hogsmill River, which runs along much of the border with New Malden, plus its man-made tributary. That brook runs through the nature reserve on the old Surbiton Lagoon site and then through Alexandra Park. The Hogsmill is small, and small rivers are easy to underestimate.
Surface water, meaning rain with nowhere to drain, has no separate figure in the Environment Agency's river-and-sea zones. It is counted in the postcode measures further down. What the record does hold is 19 recorded flood events. The most recent was in 1968, when an ordinary watercourse carried more water than its channel could hold. About 5% of postcodes fall inside an area that has flooded at some point.
With the Environment Agency's allowance for climate change added, the share of postcodes in the flood zones goes up to about 8%. That is the modelled outline for a wetter future, drawn around the same small rivers.
For insurance, the few streets inside the zones are the ones likely to see higher premiums or more questions from insurers. The rest of Berrylands should be quoted much like any other inland suburb. Put the exact address into the Environment Agency's long-term flood risk checker, and get an insurance quote for that address early in the purchase.
Counting all flood measures together, surface water included, about 13% of Berrylands postcodes rate high on at least one measure, 19% rate medium on at least one and 35% rate low on at least one. These bands overlap one another and the zone figures above. They are a separate, wider net, and adding them together gives a meaningless number.
Counted by property, the Environment Agency's rivers-and-sea mapping lists 1,272 properties in the 38 Berrylands postcodes that carry any river or sea risk. Postcodes with no risk are left off entirely. Of those, 139 properties are at high risk, 124 of them homes, along with 150 at medium risk and 234 at low risk. A street-by-street number like that is more useful than any percentage, because the only question that matters is whether one particular house is on the list.
The modelled high-probability flood extent covers about 4% of postcodes with defences included in the model, and about 4% without them. Along this stretch, the Environment Agency's model finds no defence that makes the worst-hit area any smaller. Even where a defence does show up in a model, it only lowers the odds. It does not keep the water out.
The nearest tide gauge to Berrylands is at Portsmouth, where sea level rose about 2 millimetres a year over its record from 1962 to 2023. Berrylands' water arrives by river and brook, so the coast is the least of its worries.
The flood risk here is middling: low across most of Berrylands, and real for the minority of homes beside the Hogsmill and its brook. Whether a particular home is fine depends entirely on which street it is on.