Excavation
Foundation Drain Installation Cost in Oregon
Cojo
April 18, 2026
10 min read
A foundation drain — also called a footing drain or perimeter drain — is a pipe that sits at the base of a house's footings, collecting groundwater before it can push into the crawlspace or basement. It is the single most important drainage component for the long-term health of an Oregon home's foundation, and it is also the one most commonly missing, damaged, or failed on properties built before modern drainage codes.
This guide covers what foundation drain installation typically costs in Oregon, how clay soil changes the design, and why new-construction drains and retrofits price very differently. If you are dealing with a wet crawlspace, efflorescence on foundation walls, or a basement that floods in winter, this is the drainage project that actually solves the underlying problem. For surface water pooling because of slope rather than subsurface saturation, a small-lot drainage regrade or French drain may be the right first step.
Foundation drains are one of those jobs where the cheapest bid is almost always the most expensive bid in the long run. Cutting corners here means opening the trench again in five years. The variables that move every residential dig price are covered in our excavation cost factors guide.
The ranges below reflect published industry averages for foundation drain installation in Oregon. Sump pumps, interior waterproofing, landscape restoration, and permits are separate.
Industry Baseline Range
| Scope | Typical Depth | Cost Per Linear Foot | Typical Project Cost |
|---|---|---|---|
| New construction perimeter drain | 3 – 5 ft | $25 – $80+ | $3,500 – $15,000+ |
| Retrofit perimeter drain (exterior) | 4 – 8 ft | $40 – $150+ | $6,000 – $35,000+ |
| Partial-side footing drain | 4 – 6 ft | $35 – $130+ | $3,000 – $18,000+ |
| Curtain drain (hillside intercept) | 3 – 6 ft | $25 – $110+ | $2,500 – $18,000+ |
| Interior basement drain | 1 – 2 ft below slab | $35 – $160+ | $3,500 – $22,000+ |
| Sump pump + discharge add-on | — | — | $1,500 – $6,500+ |
The industry baseline ranges above represent ideal conditions — easy access, workable soil, shallow depth, minimal haul-off. In practice, actual project costs frequently exceed published averages by 2 to 3 times when complications arise. Oregon's clay soils, rocky terrain, unmarked utilities, permit requirements, and disposal fees can all push costs well above baseline figures. The only reliable way to know your actual cost is through an on-site assessment.
Small foundation drain jobs — partial-side fixes and extensions — typically carry a $500 – $1,500+ minimum callout.
Retrofit foundation drain work is one of the most surprise-heavy excavation categories in Oregon:
Foundation drain work is a multi-day project:
Permits, inspections, and weather add calendar time.
A code-compliant foundation drain in Oregon typically includes:
Skipping filter fabric is the single most common way foundation drains fail in clay. Silt infills the rock, the rock loses drainage capacity, and the pipe clogs.
Willamette Valley clay: Clay is the dominant reason foundation drains are so important in western Oregon. It holds water against foundations, doesn't drain naturally, and pushes hydrostatic pressure into crawlspaces and basements. Drain envelopes need to be wider and fabric-wrapped more completely in clay than in sandy soil. The same clay drives the pricing and sequencing of water line trenching and sewer lateral work on the same properties.
Central Oregon rock: Drains through rock are slower and harder, but rocky soils often drain naturally enough that drains aren't always required. When they are, expect the upper end of per-foot ranges.
Rainfall volume: Western Oregon's 35 – 60+ inches of annual rain demand properly sized pipe (4-inch minimum, 6-inch for larger systems) and adequate discharge capacity.
Discharge options:
Wet-season window: Foundation drain work is possible year-round but much cheaper and cleaner May through October.
CCB licensing: Excavation work requires an Oregon CCB license; any storm sewer tie-in typically requires a licensed plumber.
DIY is not realistic for foundation drain installation. Trenches at footing depth are 3 – 8 feet deep, OSHA trench safety rules apply, and the consequences of getting slope, bedding, or fabric wrapping wrong are a drain that fails and a foundation that pays for it. Retrofit work specifically requires exposing the footing safely without undermining it.
Hire a pro for: every foundation drain, new construction or retrofit, exterior or interior. This is not the DIY category. Our contractor hiring guide walks through the license, insurance, and scope questions that matter most on footing-depth work.
Foundation drain work often requires:
Portland, Eugene, Salem, and Bend each handle foundation drain permits slightly differently. Check the local jurisdiction before scoping the job. The mini-excavator vs skid steer guide covers how equipment choice affects tight-access retrofit work along foundation perimeters.
Foundation drains are the drainage project that actually protects the structure. Done right, they extend the life of a home by decades. Done poorly, they quietly fail and the problem shows up again five years later in a wetter crawlspace. Cojo handles foundation drain installation and retrofit across Oregon, with scopes built for clay, rain, and the realities of existing homes. See our full excavation services to scope related trenching work in the same mobilization.
See examples of our work on our project portfolio, browse our full services, or get a free excavation estimate. More Oregon property owner guides live on the resources page.
How much does a foundation drain cost to install in Oregon? Published industry averages run roughly $25 to $150+ per linear foot for exterior perimeter drains, with typical projects landing between $3,500 and $35,000+ depending on new-construction vs retrofit, depth, discharge, and site access. Retrofit work in clay with mature landscaping routinely runs past baseline.
How long does a foundation drain last? A properly installed foundation drain with 4-inch rigid PVC, clean drainage rock, and filter fabric wrapping typically lasts 30 – 50 years. The most common failure is clay or silt infill when filter fabric is omitted or undersized.
Do I really need a foundation drain in Oregon clay soil? Almost always, yes, if your home was built before modern drainage codes or has any history of crawlspace or basement moisture. Clay holds water against foundations and generates hydrostatic pressure that pushes water through concrete block, cracks, and floor-wall joints. A properly designed perimeter drain relieves that pressure.
How deep does a foundation drain have to be? At or just below the top of the footing. That typically means 3 – 5 feet on a crawlspace foundation and 6 – 8 feet on a basement foundation, though exact depth depends on the footing and the site.
Can a foundation drain tie into my existing French drain or storm sewer? Sometimes, but only when the downstream system has the capacity and the jurisdiction permits it. Tying a new foundation drain into an undersized or failing existing system just moves the problem. A drainage assessment determines whether the existing downstream path can carry the new flow.
Plan your French drain installation budget with 2026 Oregon pricing. Covers interior and exterior drains, yard drainage, and foundation waterproofing costs.
Understand land clearing costs per acre in Oregon for residential, commercial, and agricultural projects. Pricing by terrain, vegetation density, and disposal methods.
Compare drainage solutions for standing water. Ranked by effectiveness, cost, and suitability for Oregon's climate. French drains, regrading, dry wells, and more.