I am leaning toward the "Dredge don't Divert" if anything is to be done. Spoil from dredging can build strategic land ridges to buffer storm surge and contain salt marshland.
Facts that I read from the reports I directed you to indicate that land loss in Caenarvon is greater area that all deltas built by all freshwater diversions.
dredging is very, very expensive. We should not waste spoil, but you don't just drive around in a dredge gathering up sediment. You are digging out a channel, which can actually accelerate coastal erosion.... Not to say that dredging is bad, but dredging alone is not the solution.