TW9: 18 of 597 postcodes stand below a spring high tide

The ground at 18 of TW9's 597 postcodes (3%) is lower than an ordinary spring high tide at London Bridge (3.9 m above Ordnance Datum).

• Ground at eight in ten of its postcodes: between 4.5 m and 9.0 m, measured from Ordnance Datum; the middle one stands at 6.8 m.
• 93 of 597 stand lower than the 1953 tide (5.41 m).
• 120 lie in the Environment Agency's Flood Zone 3 from the sea, mapped without defences.
• In Richmond upon Thames.