Most of Weybridge is dry, and the wet part is the part the town is named after. About one postcode in twenty is in the highest river flood zone. About one in nine rates high on at least one flood measure. Several hundred homes appear on the river map. The river gave the town its name and has never fully let go of the land beside it.
In the Environment Agency's river-and-sea flood zones, about 5% of the Weybridge area's postcodes fall in zone 3, the highest-probability band, and a further 4% fall in zone 2, the medium-probability fringe beyond it. The two bands are separate, so the second figure adds to the first. The pattern follows the geography: the town centre is close to where the Wey joins the Thames, the land by the rivers is low, and the ground rises to the south towards Brooklands and St George's Hill. The Desborough Cut opened in 1935 mainly to give the Thames more room for floodwater, and the island it created lies entirely inside Weybridge.
Surface water is the other half of the story, and the available measure for it is folded into a combined postcode rating covered further down. On the Environment Agency's recorded history, about 6% of the area's postcodes fall within past flood outlines, across 109 recorded events, the most recent of them in February 2014.
Looking forward, about 10% of postcodes fall inside the Environment Agency's flood zone with its climate-change allowance added. That is the agency's planning view of where the river could reach as conditions change, and it is the wider of the two maps.
For insurance, the risk is concentrated enough that most of the town should find ordinary cover, while homes near the rivers can expect insurers to ask more questions and price more carefully. Ask the seller directly whether the property has flooded or had a flood claim, and get a buildings insurance quote on the exact address early, because a riverside quote is the one most likely to change the sums.
On a broader measure that combines surface water with rivers and sea, about 11% of the area's postcodes rate high on at least one flood indicator, about 18% medium and about 28% low. These bands overlap with the flood-zone shares above, so the figures are different views of the same ground, never totals to be added together.
Counted as properties, the Environment Agency's rivers-and-sea mapping lists 1,453 properties in postcodes that carry some risk. Of those, 287 are at high risk, 224 at medium, 615 at low and three at very low. Of the high-risk properties, 245 are homes. Postcodes with no river or sea risk are left off the list entirely, so these counts describe the exposed corner of the town, never the whole of it.
On the defended question, about 5% of postcodes fall inside the high-risk extent with no defence present in the Environment Agency's model, and about 4% inside it with a defence present. A defence in the model means a structure exists between the river and the property, and says nothing about whether it holds in a given flood. "Defended" is a word about engineering, and buyers who hear it as a promise have done the translating themselves.
The nearest tide gauge is at Portsmouth, where sea level rose about 2 millimetres a year between 1962 and 2023. Weybridge is on the non-tidal Thames, well upstream of Teddington Lock, so the sea is a distant relative here and the rivers are the immediate family.
Flood risk in Weybridge is middling: low across most of the town, real and well mapped along the Thames, the Wey and the island the 1935 cut created. Buyers who keep away from the rivers are mostly clear, and buyers who want the riverside are buying the risk with it.