At last! I have put up a wiki to debate the Severn Barrage. Wikis are better debating tools than forums IMO because they can build consensually and incrementally. There is no point in being abusive on a wiki, because it can just be deleted.
Severn Barrage Debate: The Severn Estuary
It is mainly aimed for Green Party members, because the Party has, in my opinion, erroneously decided against the barrage. For me the key factor that was left out is that it will keep the sea from flooding 4 major cities and hundreds of square miles of farm land in the future.