Snohomish is the old river town. Downtown sits above the Snohomish River, the houses have mature trees, and a lot of the gardens were planted decades ago and then left to get big. The ground near the river stays wet. The hills just south of it do not. A wall on the low ground can trap floodwater against the house or redirect it. We build walls on the bench. We do not dike the river for you.
Snohomish County · ZIP 98290 · 2020 population 10,091
Do not wall off the floodplain
Grade changes up by the house and the drive are normal retaining work: base, drain, a face that fits the house. Down where the river has been, we leave the flow path alone. Fill and a wall there is how you learn about the floodplain the expensive way.
If a small wall is only keeping a bed from slumping onto a path, we build that and we outlet the water to the side.
The ground in Snohomish
Historic lots come with plants nobody planned: a cedar too close to the porch, a lilac that has swallowed the walk, beds that were neat in 1998 and are roots and bindweed now. Pruning and a hard cleanup are often the whole first phase. Bark, used with a little restraint, puts a finished line back on a Victorian front without covering the problem.
Closer to the river, drains matter. Riparian edges want native plants that can take wet soil, not a sod lawn rolled to the bank. We do not haul fill into the floodplain to “raise the yard” without understanding where that water will go next. Uphill, in the newer pockets, the work looks more like the rest of the county: lawns, small patios, and moss.
How we do the work
A retaining wall is a structure. The part you see is the block, the boulder, or the timber. The part that keeps it standing is the base, the batter or the geogrid, and the drain rock behind it. We do not stack block on the sod and call it a wall.
Height decides everything. A low garden wall and a wall holding a drive are not the same detail, the same permit, or the same price. We measure the retained dirt, not the face you wish it were.
What we look at first
- Retained height, at the tallest point
- What is above the wall: a lawn, a drive, a house
- Water coming down the slope
- Access for block or for boulders
Drainage is part of the wall
Rock behind the face, a pipe at the heel, and an outlet you can see. Weep holes alone, stuffed with the native clay, are not a drain. This is the step that gets skipped on walls that lean.
Block, rock, or timber
Engineered block is predictable and what we use when the height or the permit wants an engineered system. Boulders fit the foothills and the older yards. Timber is a short-life choice in the wet, and we will say how many years you are buying.
The base
Compacted rock, buried enough that the first course is not sitting in the organic layer. A wall is not a stack. If the base is soft, we dig out and replace it. There is no fabric or foam that fixes a bad base.
More from this crew
- Retaining walls across Snohomish County
- Rock walls in Snohomish
- French drain installation in Snohomish
- Hardscaping in Snohomish
- Patio installation in Snohomish
- Retaining walls in Monroe
- Retaining walls in Everett
- Retaining walls in Lake Stevens
Sources for the climate and the water
- USDA plant hardiness map for choosing plants that can take a Snohomish County winter.
- EPA WaterSense on watering less once a lawn or a new planting is established.
- EPA Soak Up the Rain on keeping roof and yard water from becoming someone else’s problem.
