IG9: 14 m clear of the highest tide in the London Bridge ledgers

The lowest postcode in IG9, IG9 6ED, stands 14 m above the highest tide in the London Bridge ledgers (5.41 m, 1 February 1953). The highest, IG9 5HQ, stands 72 m above it.
- Ground at eight in ten of its postcodes: between 24 m and 76 m, measured from Ordnance Datum; the middle one stands at 52 m.
- None lies in the Environment Agency's Flood Zone 3 from the sea.
- In Redbridge.