Ilford's flood risk is moderate: low from the river, higher once rainwater is counted in. Only a small fringe of the town is in the river flood zones. About one postcode in ten is rated high on at least one flood measure. A few hundred homes are at high risk from rivers. For most of Ilford, flooding is a localised problem and nowhere near a town-wide one.
In the Environment Agency's river-and-sea flood zones, about 3% of Ilford's postcodes fall in flood zone 3, the highest-probability band, and a further 2% sit in flood zone 2, the medium-probability fringe beyond it. The River Roding runs along the town's western edge, and in 1737 it was made navigable for barges as far as Ilford Bridge. That tells you how far up the river the water has been reaching for nearly three centuries.
Surface water changes the numbers. On the site's postcode-level flood indicators, which fold surface water in with rivers and sea, about 10% of Ilford's postcodes are rated high on at least one measure. That is a different measure from the flood zones, so the two shares can't be compared directly, but it shows where most of the extra risk comes from. A town built mostly of terraces and tarmac has to send its heavy rain somewhere.
Looking ahead, the Environment Agency's climate-adjusted flood zone takes in about 9% of the area's postcodes. That is the zone mapped with an allowance for wetter conditions, and it is a modelled projection.
For insurance, a home in the river flood zones or on a high-rated postcode is likely to cost more to cover and may get fewer quotes. Get a buildings insurance quote on the exact address while the conveyancing is still running, because a flat on a third floor and a ground-floor flat in the same block are very different policies.
On the postcode-level indicators, about 13% of Ilford's postcodes are rated medium and 36% low on at least one of the measures. Each one counts a postcode if any single measure flags it, so a postcode marked low may be safe from the river and only exposed to heavy rain, or the other way round. These shares overlap with the flood zones and shouldn't be added to them.
Homes are the more useful count. The Environment Agency's rivers-and-sea mapping lists only the 86 Ilford postcodes that carry some risk, covering 2,764 properties. Of those, 483 are at high risk, 407 of them homes, while 128 are at medium risk, 639 at low risk and 28 at very low risk. The great majority of the town's homes are in postcodes that never appear on the list.
Whether anything holds the water back is the harder question. About 3% of postcodes sit inside the high-risk modelled extent with no defences assumed, and about 3% sit inside it with defences counted. "Defended" in that model means a defence exists in the model, and that is all it means. The Environment Agency has 10 recorded floods in Ilford, the most recent in December 2000, when a main river rose higher than its channel could hold and there were no raised defences to stop it. "Defended" on a property description describes a wall in a computer model, and a model has never had to dry out a kitchen.
The nearest tide gauge with a long record is at Dover, where the sea rose by about 2 millimetres a year between 1961 and 2010. That is the rate measured there over those years and says nothing about what comes next.
Ilford's flood risk is middling. Most of the town is in the clear, and a few hundred homes near the river and in the low spots carry real risk that their buyers will have to price in.