I had a chat with an old friend of mine, earlier this evening. He works for the 'Environment Agency' and had previously worked for all their predecessors, going right back to the 'Essex River Board' days, in the late 1960's. Somehow, the conversation got round to water levels and I mentioned the often discussed 'clearance beneath Potter Heigham Bridge' subject. Without wishing to restart the 'discussion' as to the reasons for the reduced air draft beneath the bridge, he did come up with a r