Here is a full overview of the relevant code requirements and the factors that influence how deep your water line has to be.
Running Water Lines to the Barn and Garden
Yard Hydrant Basics: Things You Should Know
Indiana Water Service Line Costs: How Much Does It Cost to Repair
How Deep To Bury Water Pipes To Prevent Freezing UK
How To Find Your Utility Lines – Forbes Home
Bored Wells
How Deep Should A Water Line Be Buried? (Find Out Now
How Much Does Water Line Replacement Cost? (2024)
Should You Bury Your Sump Pump Discharge Pipe, or Not?, Thrasher
How Deep Does a Water Line Need to Be Buried?
2015 International Plumbing Code and Commentary (IPC) - Chapter 3: General Regulations - 305.4 Freezing.
Best Practices for Underground Copper Piping Installation