I had a contractor came out and put down concrete and bluestone tiles in the backyard, we had him leave some square holes next to the pergola posts so that we were going have plants crawl over the pergola.

we have noticed that when it rains, or when we hose the tiles down, the water drains away from the house but a good amount of water do go into those holes. here's the problem, the holes don't appear to be draining very well, i talked to him and he claims its normal, it'll go away. But this happens over and over again. My plants are not doing so well in those holes i believe due to water logging.

I started to dig the hole myself to see what's underneath, this is what i've discovered. immediately under the tiles, there's about 2 to 3 inches of concrete, then its just rocks and dirt/aggregate for about 9 to 10 inches, then i can't go any further. It appears to be very rocky, or a huge piece of rock. I am not sure if i am not digging big enough (about a 5 inches hole at the bottom), or is that just the end (did the builder build our house on top of rocks?)

here's a picture

You might ask this under the structures forum or landscape design. I don't believe there is an irrigation question in there. Even though I would dig a wider hole and a few more around the area to determine the extend of the subbase problem. GL Aloha