Yes. South Tottenham has a real flood risk, but the danger is mostly rain that has nowhere to drain, with river flooding a smaller part of it. The river-and-sea flood zones cover only a small part of the area. About a third of postcodes still rate high on at least one flood measure. Allowing for climate change, the share in the river zones grows to about a fifth. A buyer who checks only the river map will come away more reassured than they should be.
In the Environment Agency's river-and-sea flood zones, about 3% of the area's postcodes are in Flood Zone 3, which has the highest chance of flooding. Another 9% are in Flood Zone 2, the medium-probability band around it. The two bands are separate, so Zone 2 is the extra fringe beyond Zone 3. Its share is not a total that includes Zone 3. The agency's property-level assessment of flooding from rivers and the sea puts no property here at high, medium or low risk. Every property it lists is in the very-low band. Of the 22 floods the agency has on record, the most recent was in December 1947, when a main river overflowed its channel without raised defences to hold it back.
Surface water is the bigger problem. About 16,500 people live on each square kilometre here, and gardens cover about 24% of the ground. Most of the rest is roofs, roads and paving, so heavy rain runs into the drains with very little soaking away. When the drains are full, the water collects in dips in the road and in basement entrances. The Environment Agency's long-term flood risk service maps surface water separately for each address, and a house's surface-water rating can differ sharply from its river rating.
Looking ahead, the Environment Agency's flood zones allowing for climate change take in about 20% of the area's postcodes, compared with about 12% for Zones 2 and 3 today. Almost all of that extra area is land the agency currently rates as clear.
Insurers price surface-water risk as well as river risk, and they work at the level of the address. In a district where most homes are flats, garden and lower-ground flats are the ones most exposed to water running off the street, and their premiums and excesses tend to show it. Upper-floor flats in the same building usually have less to worry about, though they share the bill if water reaches the foundations.
Looked at postcode by postcode, about 35% of postcodes rate high on at least one of several flood measures, and that set includes surface water as well as rivers and sea. About 29% rate medium on at least one, and about 43% rate low on at least one. One postcode can turn up in more than one band, so these shares overlap and don't add to a total.
The Environment Agency's model puts about 6% of postcodes inside the high-probability flood extent without defences, and the same 6% with defences included. The defences in the model make no difference to that extent at all. A "defended" label in that model means a defence exists on the map. It says nothing about whether a particular house stays dry.
The nearest tide gauge in the Environment Agency's records is at Portsmouth, where sea level rose about 2 millimetres a year between 1962 and 2023. That gauge is on the south coast, and the sea is the least of South Tottenham's worries.
Flood risk is one of South Tottenham's weak points. The danger comes from its streets and drains, and anyone buying a garden or lower-ground flat is the most exposed.