Install or Replace a Water Main Cost in Montana in 2026
Most Install or Replace a Water Main projects in Montana cost between $775 and $15,500. The typical price is $3,700.
Labour and materials in Montana run about 3% below the national average. These figures are adjusted for that, so they are not the national average you will find elsewhere.
What drives the price
- Accessible fixture swap versus opening walls or slab
- Pipe material — copper, PEX or cast iron replacement
- Emergency versus scheduled work
- Permit and inspection requirements
Usually included
- Licensed plumber labour
- Pipe, fittings and standard fixtures
Usually extra
- Drywall and finish repair
- Fixtures you supply
- Municipal tap or sewer connection fees