Excavation & Underground Utilities · Greater Seattle area

Site Development,
Grounded in Four Decades.

From complex underground utilities to precision grading, we apply four decades of local ground intelligence to take risk out of your site — with our own crews and equipment on the ground.

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1982Established
40+ yrsIn the Ground
In-HouseCrews & Equipment
What We Do

Comprehensive Site Development

From concept to completion, we deliver the full horizontal package — one accountable team from the first cut to final restoration.

Riverton fleet grading a large site pad
01

Site Prep & Grading

Land clearing, mass excavation, cut and fill, and grading to subgrade — raw ground brought to plan, with export handled in-house.

Underground utility pipe installed in an open trench
02

Underground Utilities

Water, sanitary sewer, and storm drainage — mains, services, manholes, and structures installed to spec and built to pass inspection.

Deep shored excavation for a utility vault
03

Excavation & Foundations

Precision digging for utility and foundation work — proper shoring, bedding, and engineered, compaction-tested backfill.

Slope protection and erosion control on a Riverton site
04

Erosion Control

TESC setup, stormwater protection, and full site restoration — kept compliant and inspection-ready from mobilization to closeout.

Excavator and trucks preparing a commercial site pad
05

Civil Site Prep

Complete civil preparation for tract developments and commercial pads — dependable groundwork that keeps the build on schedule.

Riverton excavator and crew on a road utility job
06

Pre-Construction & Takeoffs

Planning, quantity takeoffs, and design-build solutions — ground intelligence applied before the first machine mobilizes.

All Services →
Selected Work

Ground We've Moved

Real sites across the Greater Seattle area — earthwork, utilities, stormwater, and finished infrastructure, from clearing to closeout.

Storm outfall structure and shoring in a deep excavation

Storm & Culvert

Deep Drainage Installation

 Two excavators working a deep underground utility excavation

Underground Systems

Pipe & Structure Install

 Excavator and dozer on a large mass-earthwork site

Mass Earthwork

Cut, Fill & Haul

 Underground infiltration chambers on geotextile liner

Stormwater Storage

Infiltration & Detention

 Dozer grading a large engineered slope

Fine Grading

Slope & Subgrade Work

 Utility pipe laid in an open trench

Utility Trenching

Water, Sewer & Storm Lines
Riverton excavator digging a deep foundation excavation on a Greater Seattle site
Why Riverton

We Don't Just Move Dirt

We engineer the financial and physical success of your project through systematic technical mastery. Founded in 1982 and running our own crews and owned equipment, Riverton gives you a single point of accountability and the hard-won experience to get tough sites out of the ground.

  • ✓
    Full horizontal package, one point of contactWe coordinate grading, utilities, and site prep with our own crews and equipment — tighter schedules, single-point accountability.
  • ✓
    Four decades of Greater Seattle ground intelligenceWe know the soils, jurisdictions, and inspectors — so risk gets solved before the first shovel hits the dirt.
Our Story
Mastering the Ground Since 1982

Four Decades In, And Building For What's Next.

A new generation of ownership carrying forward a four-decade reputation for getting hard sites out of the ground — on schedule, to plan, and built to last.

What Clients Say

Reviewed & Recommended

★★★★★
Read our Google reviews →
★★★★★

"Riverton ran our site work start to finish and hit every date. Their crew knew exactly how to handle our soils, and the underground work was dialed in. Real pros."

M
MainVue Homes
Residential Developer
★★★★★

"We needed an experienced site development team to come in on a complicated project. We called Riverton, and they executed exactly like we knew they would."

R
RM Homes
Normandy Heights · 2026
★★★★★

"Four decades of experience shows. They solved problems before they became problems and the quality of the work was exactly what we needed."

S
Segale Properties
Regional Developer
Trusted Partners & Coverage

Serving the Greater Seattle Area

Headquartered in the Greater Seattle area with our yard in Orting, WA, Riverton delivers excavation, grading, and underground utility work across Pierce County and South King County.

MainVue HomesKB HomesSegale PropertiesCornerstone GC
Established 1982 100% Hispanic-Owned WA Certified DBE Licensed & Insured
Ready to Break Ground?

Let's Engineer Your Site's Success

Send your plans or walk us through the site. You'll get a straight, competitive number from a team that's been mastering Greater Seattle ground since 1982.

Request Technical Review Call 253-891-2733
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