How Much Does Main Water Line Replacement Cost in St. Louis? [2025 Data]

The cost of living in Missouri is somewhat lower than the national average. However, the average main water line replacement in St. Louis is $2,231, with a typical range of $1,214 to $3,247, which is higher than national averages. The need to bury water lines deep to protect them from freezing and the location's challenging soil conditions contribute to the higher costs.

Main Water Line Replacement Cost Factors

The primary factors that determine the cost of your main water line replacement are its length, materials, and the installation method. Your local plumber understands the clay-soil challenges and frost-line requirements in the area related to installing underground piping. They're the best resource when choosing who to call if your water main breaks. 

Length

Length is the multiplier that determines the total costs of several of the other main water line pricing factors. Because of this, the distance between your home and the city's water supply pipe can be a significant cost factor. Expect to spend between $50 and $150 per linear foot for most replacements and up to $250 per foot for particularly challenging installation situations. 

Installation Method

Because of the climate in St. Louis, your home's main water line requires installation at least 32 inches below ground level for freeze protection. Your plumber will use one of two methods to achieve that depth. These include either digging a trench or tunneling from the city's water supply line to your home.

Digging a trench to access the water line is the more costly option. Trenchless installation is more budget-friendly and involves creating a borehole or tunneling, which is faster and less intrusive. Most of the St. Louis area has clay-based soil, which is friendly to the tunneling option. However, above- and below-ground obstacles can mean that a combination of the two methods is necessary.

Materials

The per-foot cost of materials is a significant factor in the cost of replacing your home's main water line. However, because of the alkaline soil conditions in most of St. Louis, corrosion is only a moderate concern when choosing materials for the job. Bigger concerns are durability and cost-effectiveness. PEX and PVC are the most common material choices for having both of these attributes.

Accessibility

Accessibility, or how easily your plumber can reach the installation location, is an essential factor in the cost of water line replacement. Landscaping obstacles, driveways, sidewalks, boulders, and tree roots can all create challenges that can increase the job's cost by requiring more labor hours. Expect to pay higher installation costs where these obstacles exist or if trenching is necessary for all or part of the job. 

Additional Services 

After installation, your plumber will need to connect the new line to your home's and the city's water systems. While the associated cost will be part of your pricing estimate, unexpected problems can increase the price of the work. Expect to spend an additional $300 to $1,000 if your home's main shut-off valve requires replacement or retrofitting to accommodate the new line.

Main Water Line Replacement Pro Costs

Replacing your home's main water line isn't a DIY task. The job requires the specialized tools and experience of a water main expert in the St. Louis area. Depending on the installation specifics, your installation may also require other professional services to complete the job. 

Labor

Expect labor costs to make up between 35% and 60% of the total job cost, which equals between $18 and $90 per linear foot, on average. This reflects a labor cost for replacing your water line in and around St. Louis that's in line with national averages. 

Permits

Main water line replacements require your plumber to obtain a permit and manage the inspections for the removal and installation work. The permit price is part of your cost estimate and ranges from $100 to $500, depending on the scope of work. 

Additional Pros to Consider Hiring

If your water main replacement requires trenching or temporary alteration of your landscaping, or your home's foundation needs repair during or after the installation, you may require one or more of these additional services. 

• Landscaping costs: $1,250–$6,300 

• Driveway contractor costs: $3,100–$7,400

• Foundation repair costs: $2,200–$8,100

Does Main Water Line Replacement Increase Home Value?

Because a functioning main water line is a necessary component of a house, homeowners won't experience much of a return on their investment for replacing it when problems come up. However, failing to replace or repair a faulty water line can negatively affect the home's resale value. Additionally, promptly tackling existing main water line problems can reduce the likelihood of experiencing potentially expensive damage to the house, its foundation, or landscaping. 

How Angi Gets Its Cost Data

Home is the most important place on earth, which is why Angi has helped more than 150 million homeowners transform their houses into homes they adore. To help homeowners with their next project, Angi provides readers with the most accurate cost data and upholds strict editorial standards. We survey real Angi customers about their project costs to develop the pricing data you see, so you can make the best decisions for you and your home. We pair this data with research from reputable sources, including the U.S. Bureau of Labor Statistics, academic journals, market studies, and interviews with industry experts—all to ensure our prices reflect real-world projects. 

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