We actually had it professionally graded and put a three inch layer of “dense pack” down. But that was a little over 3 years ago. I’m going to complete the crown in it tonight and throw another load of dense pack down. It should hold us over at least another three years, partly because I’ve done a better job of re-directing the water flow this time.
BTW, concrete or asphalt is a no-no - it becomes a skating rink in freezing weather. Gravel gives good traction except with thick snow and ice, which we very rarely get.
There are two problems to solve:
1. Break up the power of the flow of water.
2. Make it go somewhere where it won’t be a problem.
Your situation sounds exactly like where my daughter and her family live: On the down side of a steep hill that is not county maintained. Every rain they get washouts...................