I moved to the Calder Valley in mid 2010, and it's flooded 5 times since then. The works in Mytholmroyd have been taking an eternity, and I think more questions will now get asked as to why things are taking so long. The environment agency are certainly keeping a low profile at the moment, especially considering they were taking walls down last week, not putting them up. That said, some of the completed works do appear to have saved areas that had flooded previously. I understand the works are actually based on modelling of the 2012 floods being a one in a hundred year event, which wouldn't have actually stood up to the 2015 flooding anyway, and may not have stopped yesterday, even if complete. A complete rethink on the frequency of such events needs to be had.
What is really required around here is better management of the uplands to stop so much water getting to the valley bottom so quickly. Stopping all the burning of moorland in the name of grouse shooting, and more upland reservoirs would be a start.
The area you mention that used to hold football pitches is Brearley Fields, and is (or was) the playing fields for Calder High School. The current plans are to create a permanent wetland nature reserve there, however that obviously has a detrimental impact on school sports, not that I understand that they've been anywhere near usable since 2015 anyway.