Excavation
Backyard Excavation in Tigard: Cost, Slope, and Infill Access
Cojo
April 18, 2026
10 min read
Backyard excavation in Tigard has two distinct personalities. On Bull Mountain and the southern edge of town, the slope is real and the excavation conditions look more like a hillside project than a subdivision job. Down on the flats near 99W, Main Street, and Fanno Creek, the work is more about tight infill lots and drainage than about grade.
Whether you are prepping a patio in Bull Mountain, leveling a backyard off Walnut Street, building an ADU on a Summerfield lot, fixing drainage near Fanno Creek, or doing site prep on an infill lot in Metzger, the variables that drive Tigard backyard excavation cost are slope, access, and how water is going to leave the lot when the job is done.
This guide walks through current market pricing for backyard excavation in Tigard — serving 97223 and 97224 — the Bull Mountain slope realities, infill lot access patterns, and what to expect from an honest contractor quote. The backyard grading cost in Oregon pillar sets the statewide context.
Published averages assume workable soil, side-yard access, and no slope. Tigard often misses on slope in Bull Mountain and on access in infill neighborhoods. Use the ranges below as a starting baseline.
Industry Baseline Range
| Project Scope | Unit | Industry Baseline |
|---|---|---|
| Small backyard leveling / patio pad | flat | $1,800 – $9,000+ |
| ADU pad excavation | flat | $5,000 – $20,000+ |
| Pool excavation (small residential) | flat | $9,000 – $35,000+ |
| Retaining wall excavation | flat | $2,500 – $16,000+ |
| Hillside cut-and-fill (Bull Mountain) | flat | $4,000 – $22,000+ |
| Drainage / French drain integration | per linear foot | $15 – $120+ |
| Per-cubic-yard excavation (flat lot) | per cu yd | $30 – $110+ |
| Per-cubic-yard excavation (hillside) | per cu yd | $45 – $170+ |
| Excavator + operator (mini) | per hour | $150 – $275+ |
| Skid steer + operator | per hour | $125 – $275+ |
| Dump truck haul-off (10–14 cu yd) | per load | $250 – $750+ |
| Disposal / dump fee | per load | $75 – $300+ |
| Mobilization fee | flat | $250 – $800+ |
| Minimum job callout | flat | $500 – $1,500+ |
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.
In Tigard specifically, slope in Bull Mountain and tight access on infill lots are the two multipliers most commonly underestimated. The excavation cost factors in Oregon guide covers how these factors compound.
Tigard backyards routinely carry these hidden conditions:
Duration depends on slope and access:
Tigard backyard excavation is best scheduled May through October. Winter work on Bull Mountain slopes is risky; wet-season flat-lot work is slow and expensive.
Bull Mountain is a meaningful grade. Backyard excavation on a Bull Mountain lot combines slope, tree considerations, and drainage complexity that flat subdivision excavation doesn't have to deal with. Spoil hauling uphill, tracked equipment requirements, and near-universal retaining all drive cost up. Our sloped backyard solutions guide covers the options for these lots. Similar premium hillside conditions show up in our Lake Oswego backyard excavation article.
Tigard has a lot of infill — lots subdivided from older larger parcels — and the resulting access is often narrow. Side gates in the 36- to 42-inch range are common, which forces mini-excavator work. Some infill lots have no side access at all, and spoil has to come through the front. Our Beaverton backyard excavation guide describes similar Washington County subdivision access patterns.
Tigard's clay subgrade is classic Willamette Valley. Any flat-lot excavation that exposes clay will hold water in the new cut unless a drainage plan addresses it. Bull Mountain slopes actually drain better in some cases, but the runoff has to go somewhere that's approved. The backyard regrading for drainage article walks through the drainage piece, and the yard drainage cost guide lays out pricing for the drainage components.
Tigard's building department handles most residential permits, but Washington County codes govern some aspects of stormwater, tree preservation, and slope development. Jurisdictional clarity matters — some Bull Mountain projects need both city and county sign-off.
Properties near Fanno Creek or its tributaries may have riparian setbacks and stormwater rules that affect excavation. Even lots a few blocks away can be influenced by watershed standards. An honest contractor will check the lot location before quoting.
Simple yard leveling generally does not require a permit in Tigard. Permits apply when excavation is part of an ADU, garage, pool, or retaining wall over four feet, when grading changes drainage, or when slope development standards are triggered on Bull Mountain.
DIY may be reasonable when:
Hire a pro when:
| Work Type | Permit? | Typical Cost |
|---|---|---|
| Simple yard leveling | Usually no permit | — |
| ADU pad excavation | Yes (part of ADU permit) | $300 – $1,500+ |
| Pool excavation | Yes | $500 – $2,500+ |
| Retaining wall > 4 ft | Yes | $200 – $1,200+ |
| Hillside development (Bull Mountain) | Yes | $400 – $2,500+ |
| Grading affecting drainage | City/County review | $200 – $1,200+ |
| Work in tree protection zone | Arborist review | $200 – $1,200+ |
| Riparian setback (Fanno Creek) | Yes | $300 – $2,000+ |
For a broader hiring checklist that applies beyond Tigard, read our guide on how to hire a residential excavation contractor.
Tigard backyard excavation pricing cannot be honestly given over the phone. Slope, access, drainage conditions, and watershed status all change the number in meaningful ways. A walk-through takes twenty minutes and saves thousands in change orders.
Cojo provides free on-site excavation assessments across Tigard. We will walk the yard, evaluate slope and access, check watershed status, and provide a written scope that reflects real conditions.
Get a free excavation estimate or learn more about our excavation services. See completed projects on our project portfolio and browse more planning content in our resources section.
Service Area: Primary coverage is Tigard. We also serve nearby communities including Beaverton, King City, Tualatin, Lake Oswego, and Sherwood — ask when booking.
How much does backyard excavation cost in Tigard? Industry baseline ranges for residential backyard excavation in Tigard run roughly $1,800 to $9,000+ for small leveling, $5,000 to $20,000+ for ADU pads, and $9,000 to $35,000+ for small pool excavations. Bull Mountain slope work and tight infill access often push actual Tigard costs toward the top of the range. An on-site assessment is the only reliable way to know.
Why is Bull Mountain backyard excavation more expensive than flat-lot Tigard? Slope changes everything. Spoil has to be hauled uphill before it hits a truck, equipment access is harder, retaining is nearly universal, and erosion control is a code requirement. A similar-scope job can be 50 to 100 percent more expensive on Bull Mountain than on a flat Tigard lot.
How long does backyard excavation take in Tigard? A small flat-lot leveling job takes 1 to 2 days. An ADU pad or patio on moderate slope or tight infill takes 2 to 4 days. Bull Mountain hillside work, pool excavations, or complex drainage projects can run 4 to 7 days or more.
Do I need a permit for backyard excavation in Tigard? Simple yard leveling generally does not require a permit. Permits apply when excavation is part of an ADU, garage, pool, or retaining wall over four feet, when grading changes drainage, or when hillside development standards are triggered on Bull Mountain.
What's the deal with Fanno Creek and my Tigard backyard? Properties near Fanno Creek or its tributaries may have riparian setbacks and stormwater rules. Even lots a few blocks away can be influenced by watershed standards. If the property is anywhere near the creek, an honest contractor will check watershed status as part of the bid process.
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