Hi All,
It would be interesting to know the nature of each break and if there is any offset to them, or if they have a gap as if they were pulled apart, or if they were jammed into each other. If it is ground movement, the whole system of mains may be moving and twisting in the ground causing stress to build up and fractures to occur "down the line" so to speak and not necessarily where the main crosses a known fault. Add to this mixture a changing water table and you have a complex movement in many directions at the same time.

My house is still creaking day and night and has shifted as some doors have jammed and others have become unstuck. The cracks in my walls seem to be opening or pulling apart. It does seem like the ground is moving throughout SoCal for whatever reason. It would be interesting to see if any of the GPS monitoring sites are showing any movement or changes in elevation.

Just thinking out loud.
Bob in Woodland Hills