French drain installation in the Portland metro area typically costs between $1,500 and $6,000+ for a residential project. The total depends on trench length, depth, site access, soil conditions, and where the water needs to be routed. Here’s what Portland homeowners can expect to pay in 2026.
French Drain Cost by Project Type
Not all French drains are the same size or scope. Here’s how pricing typically breaks down for residential projects in the Portland area.
Single-run French drain (30 to 60 linear feet): $1,500 to $3,500. This covers a single trench along one side of a foundation, across a soggy lawn section, or at the base of a slope. It’s the most common residential French drain project we install.
Foundation perimeter drain (80 to 150+ linear feet): $3,000 to $6,000+. A full perimeter drain wraps around two or more sides of the house to intercept water before it reaches the foundation. These projects involve more linear footage, more gravel, and more complex discharge routing.
French drain combined with other drainage systems: $4,000 to $15,000+. Many Portland properties need a French drain paired with catch basins, grading corrections, downspout routing, or E-Z Flow drains in tight-access areas. When multiple systems work together, the project is priced as a complete drainage solution rather than individual components.
What Drives French Drain Cost in Portland
Two properties on the same street can have very different French drain costs. Here are the factors that move the price up or down.
Trench Length and Depth
French drains are priced partly by the linear foot. A 40-foot run costs less than a 120-foot run. Depth matters too. Standard residential French drains are trenched 18 to 24 inches deep, but foundation drains or drains intercepting a high water table may need to go deeper, which means more excavation and more gravel.
Portland’s Clay Soil
Clay is harder to dig than sandy or loamy soil, which increases excavation labor. Clay also requires more gravel backfill because the trench needs a larger drainage channel to compensate for the soil’s inability to absorb water. Most Portland properties sit on clay, so this is a factor on nearly every project we quote.
Site Access
If the trench runs through a backyard with a fence, narrow side yard, mature trees, or limited equipment access, the work takes longer and may require hand digging instead of machine trenching. Properties in older Portland neighborhoods like Sellwood, Laurelhurst, and Hawthorne often have tighter access than newer subdivisions in Happy Valley or Damascus.
Discharge Routing
Every French drain needs somewhere to send the water it collects. If the discharge point is close and downhill, the routing is straightforward. If the water needs to travel a long distance, cross hardscape, or connect to the city’s storm system, the additional pipe and labor add to the cost. Some properties in Beaverton, Tigard, and Milwaukie require a dry well or pop-up emitter when there’s no natural discharge point available.
Grading and Surface Restoration
After the trench is backfilled, the surface needs to be restored. If the drain runs through a lawn, that means regrading and reseeding or resodding the disturbed area. If it crosses a patio, walkway, or planting bed, those need to be repaired or rebuilt. Restoration is included in our estimates, but the scope of restoration affects the total.
French Drain vs. Other Drainage Options: Cost Comparison
French drains aren’t the only drainage solution, and they’re not always the right one. Here’s how they compare to other systems we install on Portland properties.
E-Z Flow drain: $1,200 to $3,500. E-Z Flow uses a pre-wrapped pipe that eliminates the need for bulk gravel, making it faster and less expensive to install. It’s a good alternative to a traditional French drain in tight side yards, garden beds, and areas where minimizing excavation matters.
Catch basin system: $800 to $3,000. Catch basins collect surface water at low points and route it through solid pipe to a discharge point. They handle surface runoff that French drains can’t reach. Many Portland projects combine catch basins with French drains for a complete system.
Yard regrading: $1,500 to $6,000. Regrading reshapes the ground surface to direct water away from structures. Sometimes grading alone fixes the problem without any pipe. Other times, grading is the first step before installing a French drain.
For a full breakdown of all drainage options and pricing, visit our drainage solutions page.
How to Get an Accurate French Drain Estimate
Online pricing guides (including this one) give you ranges, not quotes. Every property is different, and the only way to get an accurate number is to have someone walk the site, see where the water is going, and measure what it takes to fix it.
We provide free on-site drainage consultations throughout the Portland metro area. We’ll assess your property’s soil, slope, and water flow patterns and give you a detailed written estimate with line-item pricing. No pressure, no obligation.
Call (503) 847-9110 or request your free estimate online.
Learn More About Drainage
5 Signs Your Portland Yard Has a Drainage Problem — How to spot drainage issues before they cause serious damage to your yard or foundation.
French Drain vs. Catch Basin vs. E-Z Flow — A side-by-side comparison of the three most common drainage systems we install on Portland properties.
Do You Need a Permit for Drainage Work in Portland? — What triggers a permit and who handles it.
Can You Install a French Drain Yourself? — What’s involved, what goes wrong, and when to hire a pro.
Backyard Drainage and Grading Planning Guide — How to evaluate your yard, identify drainage problems, and understand your options.
Pricing ranges last verified 2026. All estimates are based on typical Portland metro residential projects. Your actual cost depends on site conditions assessed during the free consultation.
