Excavation & Site Prep in Durham, Oregon: 2026 Guide

Excavation and Site Prep in Durham, Oregon

Durham is a small city between Tigard and Tualatin in Washington County, set along the Tualatin River and Fanno Creek on the south metro edge. Excavation here happens in a built-up, creek-side setting rather than open country, and that changes the work. Lots are tight, buried utilities run everywhere, the low ground near the water holds moisture, and the valley winters are wet. Site prep in Durham is about managing water on low ground, working carefully around existing structures and utilities, and meeting the oversight that comes with an incorporated metro city.

Cojo Excavation & Asphalt serves Durham and the surrounding south metro from our Willamette Valley base, an easy run in. This guide explains what site prep involves on this ground and what the creek, the rain, and the tight setting mean for your project.

What Excavation and Site Prep Covers

Excavation is the dirt work that comes before construction. In Durham the core tasks are:

• Site grading — Shaping the ground for a level pad and setting enough slope that water runs off, which takes care on the flat, low ground near the creek.
• Drainage — Critical on low-lying ground. Swales, French drains, culverts, and catch basins that move water off a site that holds it.
• Utility trenching — Digging lines for water, sewer, power, and other services, carefully, in an area dense with existing buried utilities.
• Land clearing — Removing brush, trees, old structures, and pavement to open buildable ground.

For statewide context on pricing, see our excavation cost in Oregon guide and our site grading cost in Oregon breakdown.

Durham's Ground: What Makes It Different

Low Ground and a High Water Table

Durham sits along Fanno Creek and the Tualatin River, and the low ground near the water holds moisture, with a high water table in places. Building on low, wet ground takes drainage that moves water away and a base that handles dampness. On the lower properties, managing water is the central task. Ignore it and a site sees standing water, saturated ground, and settling.

Wet Winters

The valley's long wet season keeps low ground saturated for stretches. Saturated soil works and supports differently than dry ground, and timing matters. Some site work goes better in the drier months, and a contractor who knows the metro plans around the weather and soil moisture.

Tight Lots and Buried Utilities

Durham is built up, so properties sit close together with limited room to work and a dense network of buried utilities underneath. Excavation here calls for careful staging, equipment that fits the space, and real attention to utility locates. There is little margin for error when lines run close together in a small lot. This is where 811 locates and a careful crew matter most.

Permits, Stormwater, and 811 in Durham

Durham is an incorporated Washington County city, and the metro setting brings more oversight than rural work. Plan for:

• Grading and stormwater permits — Earthwork, fill, and stormwater management can require permits, and the creek and rain make stormwater a real consideration.
• Right-of-way and utility coordination — Work near public roads or existing utilities may require coordination and approval.
• 811 locates — Oregon law requires calling 811 before digging so existing utilities get marked, and in a built-up area like Durham this is essential, not just routine. We confirm locates before any digging starts.

A contractor who knows the local process pulls the right permits, coordinates with utilities, and sequences the work so nothing stalls the project.

What Affects the Cost of a Durham Excavation Job

Site work pricing turns on conditions more than catalog rates. Industry baseline ranges exist, but a given Durham site can land outside them. The biggest drivers:

• Drainage — The defining factor on low, creek-side ground. The drainage a wet site needs costs more than simple grading.
• Access and staging — Tight metro lots take more careful staging than open ground.
• Utility complexity — A dense network of buried lines calls for careful, slower trenching.
• Permitting — City and stormwater requirements add steps.
• Timing and soil moisture — Wet-season work on saturated low ground can be slower.

We do not quote firm numbers without walking the site, because on this ground the water, the access, and the utilities decide the real scope. Owners in the wider area can also read our Tigard excavation services overview for the neighboring market.

Why Hire a Contractor Who Knows the Metro

Site prep in Durham rewards crews who manage water on low ground and work carefully in tight, utility-dense lots. Cojo brings the equipment and the experience to drain low ground, stage work in close quarters, coordinate utility locates, and meet the city's oversight. We plan the water and the access before we dig, because in this setting that is what keeps a project on track and a finished site sound.

If you are planning a home pad, an addition, a driveway, or any project that starts with site work in Durham, we can scope it with the creek, the rain, and the tight setting in mind.