swales - on contour, or to control runoff?

I live on the west coast of California on a sand dune. We are at the top of one with the road below. Horses just found good homes, so I would like to turn the pasture into swales. Do I think contour and then place swales or do I think of runoff and create ways to control that so it goes deeper into the sand? On this property, the only places with plants are the places with a water source nearby, otherwise there are only weeds. Can I create miniswales to keep water uphill to where I have plantings. Since my governator won't support water retention basins, I think private basins may be the only answer.

Howdy Nancy, I hope you are exaggerating when you say you are on a sand dune ?

Could you post some pictures?

Without seeing what you have I would suggest swales on contour with Keyline dams and good spillways. Then planting trees and shrubs on the swales.

Sales on contour are there to control run off. Slow it, spread it and sink it.
Not sure why you are looking at these as separate things?

Swales should control runoff, and soak the moisture into the ground. Keep in mind that swales should primarily be tree growing systems, so if you plan on keeping your pasture without adding trees you might want to look into something along the lines of keyline plowing, cover cropping, mulching, applying compost teas, and reseeding the pasture.