Barely, and never from a river or the sea. No postcode is in a river or sea flood zone. A few show some risk from surface water. There are no recorded floods. In West Horsley the thing to watch is the drains.
On the Environment Agency's river and sea mapping, 0% of West Horsley's postcodes are in Flood Zone 3, the highest-probability band, and 0% are in Flood Zone 2, the medium-probability fringe beyond it. The two zones don't overlap, and here both are empty. These figures cover river and sea flooding only. Surface water is measured separately on this site with a different indicator.
That leaves surface water, from heavy rain that the ground and the drains can't take fast enough, and it is the only kind of flood risk this village really has. It shows up postcode by postcode and doesn't follow any river, so the figures further down are where it appears. When West Horsley does get water where it shouldn't, it has fallen out of the sky first.
The Environment Agency also models how the river and sea zones change with climate change, and 0% of West Horsley's postcodes are in the climate-adjusted zone either. Even the Environment Agency's projections for a wetter, warmer climate leave the village out of reach of rivers and the sea.
For insurance, a village with no postcodes in the river and sea zones and no recorded flooding is the kind of place insurers tend to quote without much fuss. The exception is any house that sits on a surface-water flow route, where insurers look at the precise address. For the house you're looking at, put the address into the Environment Agency's long-term flood risk check, and read the surface-water result as carefully as the river one.
The wider postcode measure counts a postcode if it shows risk on at least one flood indicator, surface water included. On that basis 3% of West Horsley's postcodes are rated high, 8% medium and 12% low. These bands overlap with the zone figures above, which measure only rivers and the sea, and they shouldn't be added together. They describe a small minority of postcodes picking up some rain-driven risk, and a village-wide average can't tell you which ones.
On the Environment Agency's modelled flood extents, 0% of postcodes are in the high-risk extent with defences and 0% are in it without defences. Nothing here relies on a flood defence, because the model doesn't find anything needing defending. A "defended" label would only mean a defence appears in the model, and in West Horsley it doesn't apply.
The nearest tide gauge is at Portsmouth, which recorded sea level rising by about 2 millimetres a year between 1962 and 2023. That is the rate measured at that gauge over those years. That the nearest tide gauge is in Portsmouth tells you how far West Horsley is from the sea.
The Environment Agency's historic flood map records no past flooding anywhere in West Horsley. That is reassuring, because recorded floods tend to come back. It only covers floods that were recorded, though, and a single soaked garden doesn't always make it into the record.
Flood risk is one of West Horsley's smaller worries, with rivers and the sea out of the picture altogether. The modest exception is surface water on a few postcodes, and that is worth checking for any particular house.