Enfield Highway carries a moderate flood risk, and it's patchy. Hardly any of it falls in the highest river flood zone. About one postcode in six sits in the medium-probability fringe. Allow for a wetter climate and that share grows a lot. The water that matters most here comes down the drains as well as along the river.
On the Environment Agency's river-and-sea flood zones, about 16% of the area's postcodes are in zone 2, the medium-probability band, and about half a percent are in zone 3, where the chance of flooding is highest. The two bands don't overlap. Zone 2 is the outer band beyond zone 3, so the larger number is the milder one. The River Lee Navigation runs along the eastern edge, and on the agency's maps it keeps nearly all of its high-risk ground to itself.
Surface water is the other half of the story, and older records tell it. About 15% of postcodes here fall within an outline of a flood that has already happened. The Environment Agency's list of recorded floods holds 146 events. The latest on it, in 1947, came from a main river, but local drainage and surface water are given as the cause, which is a reminder that a house well away from the riverbank can still take water from the road outside.
The agency also maps the zones with a climate allowance built in, and on that version about 40% of postcodes are in a flood zone. It is a planning tool for how far the zones could reach, not a prediction for any given winter. It is the map a council will reach for when it assesses a new building nearby.
For insurance, homes in zone 2 or near a recorded flood can expect the insurer to ask more questions and price the answer in, while most of the area will see no difference. Ask for a buildings insurance quote on the exact property early, and look it up on the Environment Agency's long-term flood risk service at the same time, because the two answers ought to agree.
Counting any of the measures, rivers and sea and surface water together, about 7% of postcodes here are rated high on at least one, about 15% medium and about 47% low. A postcode only needs one high rating to count as high, so these shares are wider than any single map.
The rivers-and-sea mapping also counts individual properties. Across the 177 postcodes that carry any risk from rivers or the sea at all, the Environment Agency counts 4,480 properties: 75 at high risk, 15 at medium, 1,193 at low and 1,743 at very low. Of the 75 high-risk properties, 62 are homes. Postcodes with no river or sea risk are left off that list entirely.
Defences make less difference to that picture than people hope. About 0.5% of postcodes fall inside the high-probability flood extent with no defence in the model, and about 0.3% inside it with a defence present. "Defended" means only that the model includes a wall or bank. It says nothing about whether that wall will hold, or whether surface water ever reaches it.
The nearest tide gauge with a long record is at Portsmouth, where the sea rose by about 2 millimetres a year between 1962 and 2023. That Enfield Highway's nearest sea-level record is on the south coast is the best evidence on this page that the sea is not the problem here.
Flood risk here is middling: most homes are clear of the river zones, a few dozen are not, and the drains carry about as much of the risk as the River Lee does.