Testing water lines...

[MountainDon]

If the grass gets greener on the downhill side that'll be a clue somethings gone amiss.

You on a well/pump or municipal system?

[Ernest T. Bass]

Lol! We have a drilled well.

[MountainDon]

Well then,    if the pump starts to cycle when it shouldn't that'll be an even better clue of something gone awry.  

A friend of mine here went away or a month or so and upon returning found their sunken living room (two steps down) full of water.   :'(   A pipe had broken under the slab and the water came up thru a small crack. From the living room it made it's way through the kitchen (one step up) and then into the laundry room and out into the garage where it went down the floor drain. No sign outside at all of any trouble. Just a large water bill that month.  :'(

I have an automatic water shutoff system in place here. I especially like the "away" mode. Place the controller right by the alarm box and when leaving it's a snap to set both.

http://www.flologic.com/Automatic-Water-Shutoff-System.html

another system I considered...
http://www.absoluteautomation.com/watercop/index.html

There was a third, similar to the second one above but I don't know where the link disappeared to. Just thought I'd throw that info out there.