Hillside lots are everywhere in Snohomish County, and a well-built retaining wall turns an unusable slope into a flat yard, a driveway shelf or a level building pad. Reach Dirt Works builds retaining walls, rockeries and terraces for homeowners and light commercial properties, with the excavation, base and drainage done right so the wall lasts.
What’s Included
- Excavation and base prep. We cut the slope, set a compacted base and bury the bottom course as the design requires.
- Wall construction. Modular block walls, boulder rockeries and terraced walls, built to the design for your site.
- Drainage behind the wall. We place drain rock, fabric and drain pipe where the design calls for them, so water doesn’t build up behind the wall.
- Backfill and compaction. We backfill in lifts behind the wall.
- Grading above and below. Shaping the ground to finish the terrace or yard (grading).
Common Projects
- Terracing a sloped backyard into usable flat space
- Cutting a driveway or parking shelf into a hillside
- Walls at the edge of a new building pad
- Replacing failing timber walls or rockeries
- Light commercial walls along parking areas and property lines
Local Considerations
When a wall needs a permit. In unincorporated Snohomish County, a building permit and engineered plans are required for any retaining wall over 4 feet in total height, measured including the buried portion of the wall. A building permit is also required for a wall of any height that supports a surcharge, meaning extra load on or behind it such as sloped fill, a driveway or a structure. Walls 4 feet or less with no surcharge are generally exempt. Depending on size and location, the project may also need a Land Disturbing Activity permit, especially in or near a critical area. Cities apply their own building codes and review, so check with your city if you’re inside city limits.
Small blocks have limits. Snohomish County cautions that small home-improvement-store blocks have limited uses: under 4 feet total height including buried blocks, no surcharge, and adequate drainage. Taller or loaded walls need a proper design.
Water is the enemy. With rainy winters and dense glacial till soils that don’t drain well, water pressure behind a wall is the most common cause of failure. Drainage is part of every wall we build.
Slopes and critical areas. Steep slopes may be geologic hazard areas, and walls near wetlands or streams may fall inside buffers. Your site plan and any engineering will show what’s allowed.
Retaining Wall FAQ
How tall can a wall be without a permit? In unincorporated Snohomish County, up to 4 feet total, including the buried part, as long as nothing extra is loading it. Anything taller, or any wall holding back a driveway, building or sloped fill, needs a building permit and engineered plans.
Do you work from an engineer’s design? Yes. For walls that need engineering, we build to the stamped plans. For smaller walls, we’ll talk through layout and drainage with you.
Can you fix a failing wall? Often the best fix is to remove the old wall and rebuild with proper base and drainage. We’ll look at it and recommend options.
What wall types do you build? Modular block walls, rockeries and terraced walls, matched to the height, load and look you need.
Areas We Serve
We work within about an hour of Snohomish, including Snohomish, Monroe, Lake Stevens, Marysville, Everett, Arlington, Granite Falls, Mill Creek, and unincorporated communities such as Machias, Cathcart, Clearview and Maltby. See all areas we serve.
Get a Free Quote
Reach Dirt Works is family owned and operated in Snohomish, WA. We’re licensed, bonded & insured (WA contractor license #REACHDW771Q7) and rated 5.0 stars on Google.
Call 360-512-2225 or request a free quote. Tell us where the property is and what you’re planning, and we’ll set up a site visit.
