I just finished reading The Making of the First World War by Ian Beckett: it's a series of vignettes, many of which cover less-well-known aspects of this conflict. It's a fascinating read, which I recommend highly. But I digress.
The first vignette addresses the strategic and intentional flooding of much of Belgium in October 1914 to prevent the Imperial German Army from reaching key channel ports, such as Dunkirk. In no small part, the strategem hinged on utmost secrecy: had the Germans gotten wind of the plan, quite likely it could have been blunted/thwarted entirely.
So let's consider this: suppose the Germans had learned of the plan before it could be executed, and thus had been able to get to the key Channel ports in October 1914? Now the BEF is unable to evacuate should it need to, among other things. How does this capture of the coast affect the development of the Western front and the war in general?