Preventing the Next Disaster

In an attempt to prevent the next disaster, I built a run off area on the back side of the storm drain. My hope is that if the storm drain gets clogged again, the water will have a place to go, other than under the house. It was a lot of work, but hopefully it will make a difference. I lined the side with large stones to direct the water down the hill and away from the house. Once it gets past the house there is a large patch of ivy that the water can disperse in. The next question is, do I need to fill it with stones or will they just wash away?