I one time for a particle joke built a moat at a friends house while he was out of town...ok...so it was a crescent moat, as I did not have time to make a full circle.
This reminds me of a story.
In the mid 90's I would pull weekend duty catching emergency calls for a local water utility. On a really cold Saturday I recieved a call from the answering service that a customer was out of water. I drove to the pump station, verified that it was operational and the headed over to the customers house. After letting the home owner know that I was there I started to walk towards the curb stop (buried shut off valve). The trick with these valves is to listen on them. You place a 'key' down inside a valve box and put your ear to it. If you hear any noise like rushing water you have a leak. The louder the hiss the smaller the leak.
I was about 10 steps away from the curb box when the ground began to ripple.
Their water service leaked for so long that it had flooded up against the frost line. The grass undulated like a water bed. One more step and I would have been up to my hips in mud.
That was a mess to repair.