French Drain Installation in Bend, Oregon: Cost & Process

French Drains in Bend's High-Desert Soil

Bend sits on the dry side of the Cascades, and people are often surprised that drainage is a problem here at all. It is — just a different kind. Deschutes County's soils sit over volcanic rock: layers of basalt, cinders, and pumice that drain fast in some spots and stop water cold in others. A French drain in Bend is rarely about constant rain. It is about managing snowmelt, channeling runoff away from foundations during the spring thaw, and dealing with the shallow lava rock that traps water exactly where you do not want it.

A French drain is a gravel-filled trench with a perforated pipe at the bottom that collects subsurface water and carries it to a safe outlet. It is one of the most reliable drainage tools available — but in Bend, the soil makes the installation harder than the average online tutorial suggests. This guide covers how it gets done here, what drives the cost, and where Bend's geology changes the job.

For the full menu of drainage solutions, see our guide to property and site drainage in Oregon. For statewide pricing detail, see French drain cost in Oregon.

When a Bend Property Needs a French Drain

• Snowmelt pooling against the foundation — A rapid spring thaw sends water toward the house faster than frozen or rocky ground can absorb it.
• A wet basement or crawlspace — Even in the high desert, subsurface water finds its way into below-grade spaces, especially on lots with a high seasonal water table or a perched layer over basalt.
• A soggy low spot in the yard — Where pumice and fine soil overlie rock, water collects and lingers long after the snow is gone.
• Runoff from a slope or neighboring property — Bend's terrain rolls, and uphill runoff has to be intercepted before it reaches your structure.

How a French Drain Is Installed in Bend

1. Site Assessment and Outlet Planning

Everything starts with where the water will go. The installer evaluates the slope, locates the source of the water, identifies a safe outlet — a dry well, a daylight point downhill, or a storm connection — and probes the soil. In Bend, this probe matters more than almost anywhere in Oregon, because the depth to bedrock decides how the whole job is dug.

2. Trench Excavation

The trench is dug to a consistent depth with a steady downhill slope, typically a 1 percent fall or more. This is where Bend gets expensive: hitting basalt or cemented cinders means switching from a standard excavator bucket to rock teeth, a hydraulic hammer, or in tight spots, hand work. A trench that takes a day in valley clay can take considerably longer through lava rock.

3. Fabric, Gravel, and Pipe

The trench is lined with filter fabric to keep fine pumice and silt from clogging the system — critical in Bend, where fine volcanic soil migrates easily. A bed of clean drain rock goes down, then the perforated pipe (holes down), then more rock, then the fabric is folded over the top.

4. Backfill and Restoration

The trench is backfilled, compacted, and restored to grade. A properly built French drain becomes invisible within a season.

Our excavation services include the rock excavation and trenching these Bend installations demand.

What French Drain Installation Costs in Bend

French drains are priced per linear foot, and Bend's geology pushes installations toward the higher end of the range because of rock. Industry baseline figures commonly referenced are:

Factor	Industry Baseline Range
French drain (per linear foot)	$25–$60
Typical residential run (50–100 ft)	$1,500–$6,000+
Dry well outlet (each)	$1,500–$4,000

In Bend specifically, the cost drivers are depth to bedrock, total length, the type of outlet required, and access. A shallow run through pumice and soil falls near the baseline; a run that has to be hammered through basalt can run well above it. Because rock is so unpredictable, on-site evaluation is the only honest way to price a Bend French drain. See French drain cost in Oregon for the broader breakdown.

Why Bend Installations Need a Local Eye

The single biggest variable in a Bend French drain is the rock you cannot see from the surface. A property two streets over may have eight feet of workable soil while yours has basalt at 18 inches. That difference changes the equipment, the labor hours, and the price dramatically. It also affects the design — where the soil drains too fast, the outlet strategy changes; where rock perches water, the depth changes. A contractor who works Deschutes County regularly will probe before quoting and design around what is actually underground.

Get Your Bend French Drain Quote

Cojo Excavation & Asphalt installs French drains across Bend and Deschutes County, with the equipment to handle the rock that makes high-desert drainage tough. We assess your soil, find the right outlet, and give you a real number based on your property's actual conditions.

Request a free drainage assessment and we will respond within 24 hours. Explore our full range of excavation services for Bend-area homes and businesses.