Palmers Green has a small river problem and a much bigger rain problem. Hardly any postcodes fall in the river flood zones. Close to three in ten carry a high rating once surface water is counted. Nothing is on record as having flooded. The danger here comes down from the sky and along the gutters, and very little of it comes out of a riverbank.
The Environment Agency's river-and-sea flood zones cover very little of Palmers Green. About 1% of the area's postcodes fall in Zone 3, the highest-probability band, and about 6% fall in Zone 2, the medium-probability fringe beyond it. The two bands do not overlap, so the second figure is the ring around the first, not a bigger version of it.
Surface water is the risk those zones leave out. It is the rain that cannot drain away fast enough in a heavy downpour, and it settles in dips and low roads with no help from any river. A map drawn for rivers and the sea was never going to show it, which is why the postcode figures further down look so different.
The Environment Agency also models what the river zones might look like with an allowance for a changing climate, and on that version about 8% of postcodes fall inside them. That is a modelled forward look built on assumptions, and a buyer can take it as the direction of travel the agency plans for.
For insurance, a home in a river zone or on a high surface-water rating can cost more to cover, and the excess can rise with it. Get a quote on the exact address early, while the price still has room to move. "Flood Zone 1" in a listing answers the river question and leaves the rain question unasked.
At postcode level, each postcode is rated on several flood measures at once, including surface water, and counted by its worst one. On that basis about 29% of Palmers Green's postcodes rate high on at least one measure, about 31% medium and about 48% low. Those bands overlap and run on a different measure from the river zones above.
Counting homes in place of postcodes makes the river risk look smaller again. The Environment Agency's rivers-and-sea mapping lists 1,602 properties, and only postcodes with some risk make that list at all. Of them, 6 are at high risk, 182 at medium risk and 812 at low risk. Two of the six high-risk properties are homes. For anyone buying in Palmers Green, the useful question is whether the house is one of the 182 or one of the six.
The defences question gets a dull answer. About 1% of postcodes fall inside the high-risk river extent when the model leaves defences out, and about 1% still fall inside it when the model puts them in. The model's defences make no visible difference to that share. A defence that exists in the model is a line on a map, and it says nothing about whether a wall stands at the end of the garden.
The nearest tide gauge with a long record is at Portsmouth, which measured sea level rising by about 2 millimetres a year between 1962 and 2023. That is the rate the gauge recorded over those years, at a gauge on the south coast. It is about as clear a sign as any that the sea is somebody else's worry.
No historic flooding is recorded anywhere in Palmers Green. That is real comfort, though a clean record means nothing serious was written down, which falls short of saying it never rained hard enough to fill a cellar.
Flood risk is a weak spot for Palmers Green, mostly because of the rain and hardly at all because of the rivers. Buyers should check the surface-water rating on the specific address and not stop at the river zone.