Originally Posted by Buck_wheat
Here is an imbecile who decided to irrigate a rock garden.
Yes, those are all rocks and get this, he's operating a FIMCO hydro indexing valve to boot.
Aligning the photos posted for easy viewing would be nice.
Actually, I've recommended irrigating hard surface for some water features before, not for the plants, but for supplementing water and promoting moss on the rocks. Although, those would not be rock gardens.
About the only other reason that comes to mind, would be if it was a play or recreation area and is was done for comfort in the summer heat.