Coppicing is used a lot in my neighbourhood (and in the Netherlands as a whole) on willows close to water banks; I don't know if the wood is used for anything, but the trees have deep and sturdy roots that stabilize the soil, without the tree growing to a size where it might fall over in a storm or drop a lot of materials in the water.
(I'm Dutch) I don't think this is true. It may have been true in some instances, but I can't find anything about that. Dikes are reinforced using rocks, stones, and tarmac.