Snoqualmie soils, exemptions, and right-of-way lines
The USDA soil survey describes Snoqualmie soils as formed in alluvium on low river terraces. The series is somewhat excessively drained, with very slow runoff and very rapid permeability, and the survey notes common, brief flooding from November through April.
The city’s permit page exempts retaining walls not over four feet from footing bottom to top, unless they support a surcharge or impound Class I, II, or III-A liquids, and it exempts uncovered decks 30 inches or less above grade. The building exemption list in SMC 15.04B.090(C) also covers fences up to six feet and driveways, sidewalks, and steps accessory to residential buildings built under the International Residential Code, where they sit 30 inches or less above adjacent grade. The permit page does not mention patios or driveways.
Work inside the public right-of-way needs a Type A right-of-way construction permit under SMC 12.19.030(A), whose examples include driveways, curbs, stormwater infrastructure, sidewalks, and retaining walls. Clearing and grading needs a clear and grade permit unless SMC 15.20.030 exempts it. That section covers grading under 100 cubic yards, or adding impervious surface under 2,000 square feet, outside critical areas and flood-hazard areas.
Nearby, we also build in North Bend, Fall City, Duvall, and Carnation, and we serve the rest of western Washington.