@dwarvenallfather Check your soil types before you bury anything. Expansive soils will crush anything underground like a soda can when it rains if you don't design with them in mind.
@dwarvenallfather Backfill with a couple feet of crusher and you'll be fine. Don't end up like this guy:
@dwarvenallfather It's less the amount of rain, rather the frequency. Desert soils with high clay contents are some of the worst for underground construction since they're bone dry most of the year. When the rain comes, they swell and produce intense pressures.
One good thing the government actually does is survey soils across the US for planning purposes: https://websoilsurvey.nrcs.usda.gov/app/