Cost to Water Main Replacement in Seattle, WA

$1,920–$8,960 in Seattle

28% above the national average · 1.28x cost multiplier

In Seattle, a water main replacement runs $1,920 to $8,960 on average — about 28% above what homeowners pay nationwide. The West Coast 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 Seattle

Line Item	Low	Mid	High
Cost per linear ft	$64	$128	$320
Materials	$512	$1,152	$2,560
Labor	$1,536	$3,328	$6,400
Permits	$384	$640	$1,024
Total	$2,432+28% vs. national avg	$5,120+28% vs. national avg	$9,984+28% 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 Seattle 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 Seattle

Full Kitchen Remodel

Full Bathroom Remodel

Composite Deck Building

Back to national average for Water Main Replacement

Seattle Estimate

Typical Range

$1,920–$8,960

vs. National Average

28% above national

Cost Multiplier

1.28x

Cost Per linear ft

$64–$320

Estimates apply Seattle's 1.28x regional cost multiplier to national averages. Actual bids vary by contractor, project scope, and timing.

See national average costs →