Foundation Drainage in Gresham, Oregon: Keeping Water Out

Protecting a Gresham Foundation From Water

In Gresham, foundation water is not a question of if but when. The eastern Portland metro gets months of steady rain, and the heavy clay soil holds that water against everything below grade. When saturated clay sits against a foundation, it builds hydrostatic pressure — a constant push of water trying to find any crack, joint, or porous spot to get through. Combine that with the long wet season and a lot graded for the building pad rather than long-term drainage, and a wet basement or damp crawlspace becomes almost inevitable without proper foundation drainage.

Foundation drainage is the system that intercepts water before it reaches your structure and carries it to a safe outlet. When it fails or was never installed, you get water in below-grade spaces, mold, and over time structural damage. This guide explains how foundation water threatens Gresham homes and how to keep it out.

For the broader picture, see our guide to property and site drainage in Oregon. For statewide pricing, see foundation drain installation cost in Oregon.

How Water Reaches a Gresham Foundation

Saturated Clay Against the Walls

This is the core problem in Gresham. Clay holds water rather than letting it drain, so during the wet season the soil against your foundation stays fully saturated. That standing water creates hydrostatic pressure that pushes moisture through any weakness in the concrete.

A Long, Relentless Wet Season

Months of steady rain never give the soil a chance to dry. By midwinter the ground around the foundation is fully charged with water, and every additional storm adds to the load on your walls.

Negative Grade Toward the House

If the ground slopes toward the foundation — common on lots graded for construction rather than drainage — every rain sends water straight at the walls and into the saturated clay against them.

Downspouts Discharging at the Footing

Roof runoff dumped right next to the foundation is one of the most common and most fixable causes of foundation moisture in Gresham, concentrating water exactly where you least want it.

How Foundation Drainage Is Done in Gresham

The right system depends on the home and the soil, so an assessment comes first. Common solutions include:

• Footing (foundation) drains — A perforated pipe in a gravel bed at the base of the footing collects water and carries it to a safe outlet. This is the core defense against saturated clay.
• Exterior regrading — Reshaping the soil to slope away from the foundation removes the most common cause of foundation moisture, often at modest cost.
• Curtain drains — On Gresham's foothill lots, a French drain uphill of the home intercepts runoff before it reaches the structure.
• Downspout extensions and drainage — Carrying roof water well away from the footing protects the foundation and reduces the load on every other system.
• Daylight or dry well outlets — Because clay will not absorb overflow, the outlet has to be carefully chosen — daylight downhill where possible, or an engineered dry well.

Our excavation services cover the careful foundation excavation these jobs require.

What Foundation Drainage Costs in Gresham

Foundation drainage is priced by scope — exterior regrading is far cheaper than excavating a full perimeter footing drain. Industry baseline ranges commonly referenced include:

Work	Industry Baseline Range
Exterior footing drain (per linear foot)	$20–$80
Full perimeter foundation drain	$5,000–$15,000+
Curtain / interceptor drain (per linear foot)	$25–$60
Exterior regrading	$1,000–$4,000

In Gresham, cost drivers are excavation depth, the length of the perimeter, the outlet, and the clay itself, which can complicate both the dig and the drainage. A regrade-and-downspout fix sits at the low end; a full perimeter drain runs well above it. Foundation work is high-stakes, so a professional assessment is essential. See foundation drain installation cost in Oregon for the broader breakdown.

Why This Is Not a DIY Job in Gresham

Excavating against a foundation is unforgiving, and Gresham's clay adds a wrinkle: water management during the dig and an outlet that actually carries water away from soil that will not absorb it. Dig too aggressively next to a footing and you can undermine it; choose a poor outlet and the clay just holds the water you collected. A contractor who works Multnomah County evaluates the grade, the clay, and how water is reaching the structure, then designs a system that moves it away for good.

Get Your Gresham Foundation Drainage Quote

Cojo Excavation & Asphalt protects Gresham and Multnomah County homes from foundation water, designed for the heavy clay that makes east-metro drainage relentless. We assess how water is reaching your foundation and recommend the most effective, cost-appropriate fix.

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