Concrete Retaining Walls in Bainbridge Island, WA

Retaining walls in Bainbridge Island: what to know

The city’s rockery handout, revised October 8, 2014, sets the path. Upland rockeries over four feet need a building permit. A wall under four feet still needs one when it sits in an environmentally sensitive area, when land-use rules call for review, or when it carries a surcharge. Rockeries up to six feet may follow the standard on page two of the handout, and rockeries over six feet must be designed by a Washington State engineer or architect. The handout does not say whether the page two standard covers surcharged walls, so we confirm it first.

The handout defines a surcharge as any load imposed on a retaining wall, and it names a wall at the bottom of a steep slope and a parking area beside a wall as examples. The drainage layer is at least 12 inches of material graded from coarse to fine, and perforated drain tile at least four inches in diameter runs to an approved discharge. Permit drawings show a site plan and a cross section, and the city may require a soil engineer to design any rockery, especially in soil-sensitive areas.

Permits and rules in Bainbridge Island

Each wall is measured from the footing’s underside to its top, and every load is checked, before we confirm the path for your address. Development within 200 feet of the ordinary high water line needs a Shoreline Substantial Development Exemption before a building permit application. The handout is dated 2014, so we confirm it is current with the city’s Planning Division before design.

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

How we approach it

Measure height from the footing’s underside up to the wall top
Record every surcharge, including a driveway, a building footing, or a parking area beside the wall
Check the shoreline distance before the permit application
Set the drain tile outlet to an approved discharge before footings go in

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 Bainbridge Island

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

Questions from Bainbridge Island homeowners

Which Bainbridge Island walls can skip a building permit?

Walls that stand four feet or less, measured from the footing’s underside, can skip a building permit unless a surcharge bears on them. The rockery handout adds that a shorter wall still needs a permit in an environmentally sensitive area, where land-use rules call for review, or with a surcharge.

What counts as a surcharge on a Bainbridge Island wall?

The city’s rockery handout defines a surcharge as any load imposed on a retaining wall. It names a wall at the bottom of a steep slope and a parking area beside a wall as examples, and it lists a driveway and a building footing as well.

When does a Bainbridge Island rockery need an engineer?

Upland rockeries over four feet need a building permit, and rockeries over six feet must be designed by a Washington State engineer or architect. Permit drawings also need a site plan and a cross section, and the city may require a soil engineer, especially in soil-sensitive areas.