Nothing like an exciting climax to "planned" opportunities! In the last couple of days of yard work we realized that recent water department work had brought our supposedly disabled yard sprinkler system to life. We bought the house 2 years ago, and understood from the previous owners that everything was turned off. We are at the top of a hill, and the first house on the line. Said another way, when the water department works on anything down the line they must turn off the water right in front of our house. This means we get a lot of air in the line when they work for a half day or so, which they did early in the week. In addition to the explosive pressure that comes into the house once the water line is fired up again, we found water leaking out the front of the lawn. I suspect the air blew open a zone valve enough to allow about a gallon a minute of water to seep out the front sprinkler line. Strangely enough the main valve for the whole sprinkler system was NOWHERE to be found. I spent my exciting Friday of Staycation June 2009 guessing, digging holes, and looking for a mystery.