Thanks, I tried it. I don't have any rocks or gravel, so I used woodchips. I poured water in and not much happened. After about 5 minutes the dirt became mostly saturated, but nothing dripped through to the chips. There was still a lot of water sitting on top. This picture is after waiting 5 minutes. Was that enough time? I assume this means hydrophobic.
The water table varies quite a bit where is live, 50-150ft. There is no exact measurement close to me though.