Concrete Retaining Walls in Vashon Island, WA

Retaining walls in Vashon Island: what to know

A wall that stands four feet or less from the bottom of its footing to the top, carries no added surcharge, and impounds no Class I, II, or IIIA liquid sits on the exemption list in King County code section 16.02.240. The county’s permit guidance says most walls of four feet or less need no permit unless critical areas are present, and a bluff behind a wall may raise a critical area question. Excavation of five feet or more in one spot, or fill of three feet or more in one spot, can each call for a clearing and grading permit, and a cumulative total above 100 cubic yards can too.

Drains on bluff walls are routed to a point the parcel allows, traced on the site plan before the footing is cut, and kept away from the shoreline bank. Each load that could reach the wall face, such as a drive, a parked vehicle, a structure, or the bluff itself, is logged on the survey, and we ask King County whether it counts as a surcharge under the code. Where a route would cross public ground, the county is asked before any trench opens.

Permits and rules in Vashon Island

We check every wall from footing to crest, and we confirm each load and cut-and-fill figure before a drawing is released. Walls outside the exemption go to King County for written review, and the reply travels with the drawing. The outlet route is traced against the grade readings before the footing is set, so the fall can be verified on site.

Rules change and vary by parcel, so we confirm the current requirements with the city before we start.

How we approach it

Read each wall from its footing up to the crest before sorting it
Log every load that reaches the wall face on the survey
Send any wall outside the exemption to King County for review
Trace the drain outlet and its fall before the footing is set

For the full process, see our Retaining Walls page.

Building in the cold months? See our guide to winter concrete pours.

Our retaining walls work, serving Vashon Island

Examples of our work. We build retaining walls in Vashon Island and the cities around it. See all of our work

Questions from Vashon Island homeowners

Does a Vashon Island wall at four feet need a permit?

The county’s exemption covers a wall of four feet or less that carries no added surcharge and impounds no listed liquid. A taller wall, or a shorter one with a load on its face, is put to King County for review, so we confirm the reading before the drawing is final.

Which loads on a Vashon Island wall get checked with the county?

A drive above the wall, a parked vehicle, a structure within reach, or a bluff behind the face can each raise the question of whether a surcharge applies. The site survey logs each one, and where a load is unclear we ask King County in writing.

Where does the drain behind a Vashon Island bluff wall discharge?

To a point the parcel allows, kept clear of the shoreline bank and marked on the site plan before the footing is cut.