[nate_meurer]

It would be pretty ridiculous if a little water could short out a buried transmission line. Do you really think generations of engineers haven't figured out how to protect buried lines from ground water?

I don't know what PG&E will use in this case, but all buried power and transmission lines lines are robust against water infiltration. Solid-dielectric cables are rated for direct burial, and cooled lines are encased in steel conduit. Both types are sometimes further protected in concrete.

[bluGill]

Engineers encase the cables in rubber or plastic, which degrades over time. Or steel pipes which rust over time. there are things we can do about this, but they just add time. When you only have a little bit of cable odds are it lasts, when you have thousands of km odds are there will be constant problems.