SE4: 8.7 m clear of the highest tide in the London Bridge ledgers

The lowest postcode in SE4, SE4 1JF, stands 8.7 m above the highest tide in the London Bridge ledgers (5.41 m, 1 February 1953). The highest, SE4 2NU, stands 40 m above it.
- Ground at eight in ten of its postcodes: between 20 m and 36 m, measured from Ordnance Datum; the middle one stands at 28 m.
- None lies in the Environment Agency's Flood Zone 3 from the sea.
- Mostly in Lewisham; partly in Southwark.