How much does a water main replacement cost in St. Louis?

A water main replacement in St. Louis typically costs $1,587-$7,404, 6% above the $3,500 national average.

What is the cost per linear ft for a water main replacement in St. Louis?

Water Main Replacement in St. Louis typically costs $53-$264 per linear ft.

How long does a water main replacement take?

A water main replacement typically takes 1-3 days. The minimum timeline is 1 day, and complex projects can run 1-2 weeks.

Can I DIY a water main replacement?

DIY feasibility for a water main replacement is rated Very Low - Water main replacement connects to municipal water supply and requires permits, utility locating (811 call), and licensed plumber connections at the meter..

Cost to Water Main Replacement in St. Louis, MO (2026)

If you’re budgeting a water main replacement in St. Louis, most projects run $1,587-$7,404, 6% above the $3,500 national average. What moves that number most is usually one thing: Length of Water Main. On its own it can swing the cost by $500 - $12,000, so that’s the decision to slow down on before you sweat the smaller stuff.

Easiest place to save: Call 811 before any excavation planning - utility locates are free and their location affects your routing and cost.

$1,587-$7,404 in St. Louis

6% above the national average · 1.06x cost multiplier

In St. Louis, a water main replacement runs $1,587 to $7,404 on average - about 6% above what homeowners pay nationwide. The Midwest market's labor costs account for most of the gap, with material pricing and local permitting fees adding to the spread. Use the cost table below to compare budget, mid-range, and premium options side by side.

Cost Breakdown in St. Louis

Line Item	Low	Mid	High
Cost per linear ft	$53	$106	$264
Materials	$376	$846	$1,880
Labor	$1,348	$2,921	$5,617
Permits	$282	$470	$752
Total	$2,006+6% vs. national avg	$4,237+6% vs. national avg	$8,249+6% vs. national avg

Budget

Short run under 25 feet from meter to house, simple trenching in soft soil, new PEX or copper supply line.

Mid-Range

50-75 foot run, standard trenching, new copper or PEX pipe, meter reconnection, permit and inspection.

Premium

100+ foot run, difficult access, landscaping or driveway crossing, full trench restoration, concrete or asphalt repair.

Material Options

Material prices below are national averages; availability in St. Louis may shift costs slightly.

Material	Cost/Unit	Pros	Cons	Best For
Copper (Type K)	$3-$8 per linear ft	50+ year lifespan, approved everywhere, resistant to UV if exposed, proven performance	Most expensive material, price fluctuates with commodity markets, requires soldering	Homes where longevity and maximum reliability are the priorities50+ year lifespan, approved everywhere, resistant to UV if exposed, proven performance
PEX (Cross-Linked Polyethylene)	$0.50-$1.50 per linear ft	Flexible for easy routing, freeze-resistant, corrosion-proof, fast installation	Must be UV-protected if exposed, requires specific fittings, not approved in all jurisdictions for underground	Most residential water main replacements in moderate climates with code approvalFlexible for easy routing, freeze-resistant, corrosion-proof, fast installation
HDPE (High-Density Polyethylene)	$1-$3 per linear ft	Very flexible, ideal for directional boring, long lifespan, corrosion-resistant	Requires heat fusion or mechanical fittings, less common for residential than commercial	Long runs and trenchless (directional bore) installationsVery flexible, ideal for directional boring, long lifespan, corrosion-resistant
Galvanized Steel (Replacement Only)	N/A - being replaced, not installed	N/A	Prone to corrosion and buildup, commonly the cause of replacement, restricted water flow over time	Not recommended - this is what is being replaced in most older homesN/A

Other Projects in St. Louis

Full Kitchen Remodel

Basement Finishing

Roof Replacement (Asphalt Shingles)

Back to national average for Water Main Replacement

St. Louis Estimate

Typical Range

$1,587-$7,404

vs. National Average

6% above national

Cost Multiplier

1.06x

Cost Per linear ft

$53-$264

This 1.06x estimate prices St. Louis labor from BLS Occupational Employment and Wage Statistics (May 2025) and applies a lighter regional adjustment to materials and permits, which vary less by metro than labor does. Actual bids vary by contractor, project scope, and timing.

See national average costs →