We have used big round bales to divert water.  A few in the bottom to slow it down.Also unroll them and run over them with brush hog. Then a pass with a roller to stake the straw down.Spread winter wheat or rye along with grass seed. Few water bars along the way and it should hold.   I would also have a few breaks to let any large amounts of water out without ruining the waterway. Kind of emergency spillways.  Easier to fix than the whole thing.   Seemed like a good idea when they broke the levees. Don't see why it would be a problem with the Gov..