Yard Drainage in Beaverton, Oregon: Fixing a Soggy Lawn

Why a Beaverton Yard Stays Soggy

Beaverton sits where the Tualatin Valley floor meets the west hills, and a soggy lawn here usually traces back to one of two things: heavy valley clay that will not let water through, or runoff coming downhill from higher ground. Often it is both. The Pacific Northwest wet season brings months of steady rain, and on Beaverton's slow-draining clay — or on a lower lot catching runoff from above — that water has nowhere to go but your lawn.

A perpetually wet yard kills grass, breeds mosquitoes, makes the space unusable for half the year, and threatens the foundation when the water sits near the house. The cause is almost always a combination of grading, soil, and where the water originates, and each has known fixes. This guide explains what is happening beneath your lawn and how to dry it out.

For the full picture of how water moves on a property, start with our guide to property and site drainage in Oregon. For statewide pricing, see the yard drainage cost guide for Oregon.

What Causes Yard Drainage Problems in Beaverton

Heavy Clay Soil

Washington County's clay packs tightly and lets water pass slowly, so rain that should soak away instead lingers near the surface. On the flatter valley parts of Beaverton, this is the main reason a lawn stays spongy long after the rain stops.

Hillside Runoff

On Beaverton's slopes and the lots below them, water flows downhill and collects at the bottom. A lawn that drains fine on its own can flood simply because it is receiving runoff from higher ground — including a neighbor's property.

Flat or Negative Grade

If the yard slopes toward the house or sits dead flat, water pools instead of flowing to a low point and away. Many Beaverton lots were graded for the building pad and never optimized for yard drainage.

Downspouts and Hardscape Runoff

Roof water dumped at the foundation and runoff from patios and driveways concentrate water onto soil that is already saturated, overwhelming it quickly.

How Yard Drainage Gets Fixed in Beaverton

The right solution depends on where the water comes from, so an assessment comes first. Common approaches include:

• Regrading — Reshaping the yard to create positive slope away from the house and toward an outlet is the foundation of most fixes.
• French drains — A gravel-filled trench with perforated pipe intercepts subsurface water and carries it away — and on slopes, an interceptor drain stops runoff before it reaches the yard.
• Dry wells — Where daylight drainage is not available, a dry well collects water and releases it slowly, sized for clay conditions.
• Channel and catch-basin drains — Surface inlets capture water from patios, downspouts, and low spots and route it underground.
• Downspout extensions — Carrying roof runoff well away from the foundation solves many soggy-yard complaints on its own.

Our excavation services cover the grading and trenching these solutions require.

What Yard Drainage Costs in Beaverton

Yard drainage is priced by the type and length of system, not a flat rate. Industry baseline ranges commonly referenced include:

Solution	Industry Baseline Range
French drain (per linear foot)	$25–$60
Dry well (each)	$1,500–$4,000
Channel / trench drain (per linear foot)	$50–$150
Yard regrading (per project)	$1,000–$5,000+

In Beaverton, cost depends heavily on whether the problem is local clay or incoming runoff. A simple regrade or downspout fix sits at the low end; a hillside interceptor or a French drain to a dry well runs higher. A site assessment is the only way to budget accurately. See the yard drainage cost guide for Oregon for the broader breakdown.

Why a Site Assessment Comes First

The first question in Beaverton is always where the water is coming from. A soggy yard caused by local clay needs a different fix than one flooded by hillside runoff — the first calls for a drain to an outlet, the second for an interceptor uphill. Get the diagnosis wrong and you spend money draining a yard that keeps refilling from above. An assessment checks the slope, evaluates the soil, traces the water to its source, and finds a viable outlet. That diagnosis is what separates a lasting fix from a patch that floods again next winter.

Get Your Beaverton Yard Drainage Quote

Cojo Excavation & Asphalt helps Beaverton and Washington County homeowners dry out soggy lawns for good, with solutions matched to valley clay or hillside runoff. We assess your grade, soil, and where the water originates, find the right outlet, and recommend a fix matched to your property.

Request a free drainage assessment and we will respond within 24 hours. Learn more about our excavation services for Beaverton-area properties.