We are just back from a fabulous weekend of camping. We had a great time and everything went smoothly all weekend. This morning we were told that no one was coming in to our site, and that the group we were camping with could enjoy a late check out, free of charge. We stayed thru lunch time, and then started to pack up at a leisurely pace. A little while later, we heard a fellow camper ask if we had water, and low and behold, we did not. My husband went to the office to investigate, and was told that the water was on a timer and shuts off every Sunday at noon. There was no warning, and we saw nothing posted about this anywhere. My husband was told that they would get the water turned back on shortly. We continued to break camp, but my husband was still thinking about the water issue. He had already connected the reverse flush connector to the sewer line and the hose to the water line, in preparation for dumping and flushing, before we realized the water was shut off. He had not yet opened any valves. But here is our question. What if someone else was doing the same thing, and actually had their black tank valve open for flushing. When people down hill from us unknowingly used their water, would the loss of water pressure cause suction through the water lines of the campground, possibly causing contamination from open black tank valves? My husband thinks turning the water off with no notice to campers was a bad practice. Is this all far fetched? Should we flush out our water lines in the camper just to be on the safe side?