I am doing just that... ..but because I have to.
Let me explain, I can't afford earth movers and such, so I built swales of cut limbs and other cuttings from the
trees I felled and those are my swales.
They will break down over time, into a hugelkulture swale, as well as be planted, tilled, and everything else by little woodland critters. They are working already in capturing leaves, and small debris making the swale push
water into the ground. As the branches and such break down, it works a little better each day.
Lazy mans way I guess.
However, I believe if I was to make an actual swale, on contour properly, and then built a hugelkulture bed below the swale I would have a nice swampy in a few years.