http://www.bbc.co.uk/news/uk-26078592

The relevant section is buried at the bottom:
"Mr Winkworth said Lord Smith told him the reason the area was not dredged, as was promised a year ago, was because the £400,000 set aside was not enough and they were waiting for other agencies to contribute."

The EA is just one of five or six agencies responsible for flood management on the Somerset Levels. Due to Treasury rules, the maximum they could put forward for dredging was £400K. The other agencies declined to put in anything, so the dredging didn't happen.

But all this talk of dredging is just part of the political blame game. The people with the real answers to this problem are the scientists, engineers and hydrologists. We should get are advice from these people, not politicians!