Seven Kings has some flood risk: light across most of the area and serious for a few hundred homes. About three postcodes in every hundred fall in the highest river-and-sea zone. Around one in ten rate high on at least one flood measure once rain is counted. In the official model, the defences make no difference to the high-risk area. For most of Seven Kings flooding never comes up, and for a few streets it is a permanent feature of the paperwork.
In the Environment Agency's river-and-sea flood zones, about 3% of Seven Kings postcodes are in zone 3, the highest-probability band, and another 7% are in zone 2, the medium-probability fringe beyond it. The two bands don't overlap, so zone 2 is extra ground around zone 3. Taken together, the river-and-sea map leaves most of the area in the lowest zone.
Surface water means rain the drains can't keep up with, and it gets no separate figure for Seven Kings. It is folded into the wider postcode measure further down.
The Environment Agency also draws a flood zone with an allowance for climate change, and about 19% of Seven Kings postcodes fall inside it. That is a modelled look at a wetter future, and insurers are more likely to have read it than buyers.
For insurance, most homes in Seven Kings should notice nothing. A property in zone 3, or rated high on the surface-water measure, is the kind of risk insurers ask about, and it can push up premiums or excesses, or make a buyer look for a specialist policy. The postcode is only the starting point. The thing to do is put the exact address into the Environment Agency's long-term flood risk service and ask for an insurance quote on that address while the sale is still young.
On a wider count that combines several flood measures, including surface water, about 9% of Seven Kings postcodes rate high on at least one of them, about 17% medium and about 47% low. A postcode only needs one high reading on one measure to count as high, so this net catches more than the river map does.
Counting homes instead of postcodes, the Environment Agency's rivers-and-sea mapping lists 3,084 properties in Seven Kings postcodes that carry some risk. Of those, 267 are at high risk, 114 at medium, 983 at low and 46 at very low. Postcodes with no risk at all are left off the list completely, so the 3,084 counts only the streets the map is worried about. The high-risk group is a short list, and the Environment Agency holds every address on it.
The Environment Agency models the high-risk extent twice, once ignoring flood defences and once allowing for any defences in its model. In Seven Kings both runs put about 3% of postcodes in the high-risk extent. A defence appearing in the model is not the same as a dry house anyway. Here the model found nothing to take off.
The nearest tide gauge in the record is at Dover, where sea level rose about 2 millimetres a year between 1961 and 2010. That is the rate measured on the Kent coast over those years. When the nearest gauge to your house is in Dover, the sea is not your main worry.
Flood risk in Seven Kings is middling: it barely matters for most homes and is very real for the few hundred the Environment Agency has flagged. The individual address decides which group a buyer is in.