Lots of things can cause pipes to break, but almost all are related to stress changes. Ground shrinkage, landslides, subsidence (due to drought?)and other pressure changes can stress pipes enough to crack them. If these pipes are new, they might not meet the stress standards that were expected.

In the LA are aright now, it COULD be drought. I would guess that the flow through the pipes may not be constant, but this is not my area of expertise.

A few years ago, I noted that some oil pipelines in the Bakersfield area were breaking...and sure enough, there was a quake that followed. Wish that I remembered all of the details on this! Currently have plenty of experience with this up here in the cold winter country! But ice will NOT be a problem in the LA area as it is up here.

Keep watching.