IG11: 307 of 1,017 postcodes stand below a spring high tide

The ground at 307 of IG11's 1,017 postcodes (30%) 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 2.2 m and 8.4 m, measured from Ordnance Datum; the middle one stands at 5.5 m.
• 502 of 1,017 stand lower than the 1953 tide (5.41 m).
• 403 lie in the Environment Agency's Flood Zone 3 from the sea, mapped without defences.
• Mostly in Barking and Dagenham; partly in Redbridge.