Collecting Water From Road

I'm trying to retain as much water on my land as possible. I'm about to build a road going into my land and thought about maybe making the road's ditch level (rather than sloping toward the main road) and add a berm on the other side of it and planting trees along the berm. I got this idea from Geoff Lawton's swales. Since my land is super flat, I figured this is the only way I could have such an arrangement. What do you guys think...will this work? Or will the water create underground springs under the road itself and cause me problems?

Also, my soil is super clay! Water sits in low spots for days and I think it will evaporate before it soaks in. Would maybe filling the ditch with rocks be a good way to keep the sun from stealing my water before it can soak in?

It's kind of hard for me to really get my head around this idea without seeing the lay of the land.
Since this is a private road vs. a public highway, I see no problem saving all of that water for your own land. In arid/semi-arid land, it seems foolish to watch precious water racing down storm ditches, away from your land.

You might also consider using a subsoiler perpendicular to the road. This would help the water spread onto/into your soil, away from the road. You indicated both infiltration and evaporation issues. This would help the penetration issue, as well as getting the water away from the surface, where the evaporation takes place.

I've attached a graphic of kind of what I had in mind. Since my land is flat, I think this is probably my only chance to capture watershed in this way. I was thinking maybe even connecting this ditch to the main road's (a dirt County Road) ditch if the county allows it so to "steal" the water coming off the main road also.

I like the subsoiler idea. Would it be practical to mix some other type of sand or soil in with the clay after using the subsoiler to improve the water penetration?