BR3: 20 m clear of the highest tide in the London Bridge ledgers

The lowest postcode in BR3, BR3 1FB, stands 20 m above the highest tide in the London Bridge ledgers (5.41 m, 1 February 1953). The highest, BR3 6PQ, stands 67 m above it.
- Ground at eight in ten of its postcodes: between 30 m and 54 m, measured from Ordnance Datum; the middle one stands at 40 m.
- None lies in the Environment Agency's Flood Zone 3 from the sea.
- Mostly in Bromley; partly in Lewisham.