We live in San Antonio in a ranch style home. I have a sprinkler system that has always caused some minor vibration (I am guessing water hammer) that occurs while it is running. It stops when one zone stops and starts when the next one begins. Over the last few months we have noticed it has become louder and three weeks ago my next door neighbor let me know that their pipes make noise when my sprinkler system runs. I am going to check the pressure today. Any other thoughts would be greatly appreciated.