[Treemonkey1000]

There are a lot of you folks a lot smarter than I on these type of projects. Just tossing my 2 cents worth in. What about cutting some culvert at the right shape and angle to make a "nose cone" that would go in between the two culverts. Basically to divide the water some what. It would have to project out far enough to be of any use. Then anchor them in concrete to keep from being undermined by the water pressure. I like Eddies Concrete bag approach. Build those up and around enough to form an apron-retaining wall.