This is what I used some of the soil for. I guess I would call it a washout area. It looks like an old dried out river bed. It does not make sense to take an eroded, low elevation area, and make a swale (make it even lower). So I made just a berm with the excess soil. Its pretty risky but I can fix it if it blows out. There is a lot of Bermuda in there and if I can get it growing, it should hold it together. I also mulched it with hay and seeded it with a food plot mix. Oats, wheat, peas, brassicas.
If you look at the top left you should see a culvert. That road was added by previous owner probably 20 to 30 years ago. The diagonal flow on my property goes through that culvert. This includes overflow of the last pond I built.. This berm is uphill from the culvert so won't be effected by that flow.
It should catch water from a small area. I'll look after a rain but I suspect it will hold 6" of water in an area ruffly 30 yards x 30 yards. It'll take about 200 ft of hose to get a sprinkler to it. Considering the small size of the berm it might be worth doing it to get Bermuda and other roots holding it together sooner.