How deep does a water line need to be buried?

Model codes require underground water piping to be buried at least 12 inches deep and at least 6 inches below the local frost line, according to the International Code Council's explanation of the International Residential Code. The frost line is set by each jurisdiction when it adopts the code, and local conditions can call for deeper burial. Frost depth in Texas varies a lot: for manufactured home foundations, Texas designated 40 counties, mostly in the Panhandle and West Texas, as frost-line counties with a 12-inch frost depth. Ask your local building official or utility for the required depth before trenching.

Check your local rule. This varies by state, county or city. Your permitting office has the final word; the official lookup pages below show you who that is.

Sources

• Build It to Code to Minimize Damage from Frozen Water PipesInternational Code Council (ICC)
• Federal Installation Requirements for New Homes (frost line counties)Texas Department of Housing and Community Affairs, Manufactured Housing Division