SW18: no postcode below a spring high tide, the lowest 0.2 m above it

SW18 on the relief of London, with a tide staff: Its lowest postcode is 0.2 m above a spring high tide.

No postcode in SW18 stands below an ordinary spring high tide at London Bridge. The lowest, SW18 1SF, is 0.2 m above it and 1.2 m below the tide of 1 February 1953.

Ground at eight in ten of its postcodes: between 5.8 m and 23 m, measured from Ordnance Datum; the middle one stands at 10 m.
77 of 1,240 stand lower than the 1953 tide (5.41 m).
123 lie in the Environment Agency's Flood Zone 3 from the sea, mapped without defences.
Mostly in Wandsworth; partly in Merton.

Open SW18 on the map