Hounslow West is safe from rivers and the sea, and its flood risk falls out of the sky. None of the area sits in a river or sea flood zone. No flooding is on record. A minority of postcodes still carry a rating for heavy rain. Any water that reaches a house here will have come down the road, with no river involved.
On the Environment Agency's river-and-sea mapping, 0% of Hounslow West's postcodes fall in Flood Zone 3, the highest-probability band, and 0% fall in Flood Zone 2, the medium-probability fringe that lies beyond it. The agency's property-by-property assessment of river and sea risk lists just 2 postcodes in the area with any risk at all, covering 26 properties, and none of them is rated high or medium. One property is rated low and one very low. That is about as close to a clean sheet as a London suburb gets.
Surface water is the measure that matters here. With no river or sea risk to speak of, it is rain falling faster than the drains can take it that puts a street on the flood maps in Hounslow West. That kind of flooding follows dips in the road and low corners of estates, so two houses a few doors apart can sit on either side of the line.
The Environment Agency's climate-adjusted flood zone, which redraws the river-and-sea zones for a wetter future, also puts 0% of Hounslow West's postcodes inside it. Even with the climate allowance built in, the rivers and the sea stay out of the picture here.
For insurance, that clean river-and-sea record should help, because those zones are what many insurers check first. A surface-water rating on a particular postcode can still affect the quote or the questions asked. The useful check is the Environment Agency's long-term flood risk service for the exact address, run before you instruct a solicitor, alongside a quick insurance quote on the same house.
Across all of Hounslow West's postcodes, about 7% rate high on at least one flood measure, about 19% rate medium and about 54% rate low. These postcode ratings fold surface water in with rivers and sea, so they overlap with the zone figures above and are a different measure. Here, almost all of what they pick up is rain. More than half the postcodes register some low-level risk. The 7% at the top is the figure a buyer needs to know about.
On the Environment Agency's modelled flood extents, 0% of postcodes fall in the high-risk extent without defences and 0% fall in it with defences. Defences are not doing any quiet work here, because the modelled river and sea floodwater never reaches the area in the first place. A defence marked on the model only means a structure exists. It never proves that a particular house stays dry.
The nearest tide gauge to Hounslow West is at Portsmouth, where sea level rose by about 2 millimetres a year over the record from 1962 to 2023. That is the rate measured at that gauge over that period. Buyers in Hounslow West can follow the coast's problems on the news from a comfortable distance.
The area has no recorded historic flooding on the Environment Agency's maps. That is reassuring, and it should be read correctly: it means no event was mapped, which is good news but falls short of proof that no street has ever had water in it.
Rivers and the sea are no threat to Hounslow West, but enough of its postcodes carry a surface-water rating to keep the flood picture middling. The street matters more than the district, so the result for the exact house is the one to trust.