How to keep water on the land with sandy soils

We have a 6 acre West facing hillside which is all sand, located in Northern VT. We get about 40" of rain annually. Everything I've read about permaculture is about slowing and sinking water. I see very little evidence of surface water runoff on my land. I think the opposite is occurring, it is so sandy that rain (and nutrients) just disappear into the ground, never to be seen again. I'd like to have swales and several ponds, but will enough water make it to the ponds? Is this a non-issue, or would the addition of a bit of clay, or something else be appropriate to keep the water around?

Thanks!

Jeff

Lots of permaculture success in the desert. Usually included DEEP mulch and organic matter.

Clay and organic matter will both help. Is there a clay deposit somewhere close to you? Maybe someone around you is big into pottery and will give you the extra scraps? What about tree trimmers? You could start making big mounds of chipped trees. Just some thoughts...

I have similiar issue. What about to make rip line on lower part and fill it with clay or organic matter. Maybe this will hold water for longer period?