Kennewick, WA Fence Regulations: Retaining Walls (2026)
Key Facts
- Permit-exempt height
- Under 4 feet
- Guardrail trigger height
- 60 inches or more
- Required guardrail height
- At least 36 inches
- Exempt-height exception
- Not if supporting surcharge/liquids
Summary
Kennewick exempts retaining walls under four feet from a building permit, but any wall 60 inches or more above grade on a lot line needs a guardrail or fence at least 36 inches high.
(c)Retaining walls which are not over four feet (1,219 mm) in height measured from the bottom of the footing to the top of the wall, unless supporting a surcharge or impounding Class I, II, or III-A liquids....(3)If a retaining wall is 60 inches or more above the adjacent grade and is located along a lot line, a guardrail or fence not less than 36 inches high must be placed along the top of the wall.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 19 Update 2).
Full Breakdown
Two Kennewick sections govern retaining walls together. KMC 15.08.060(1)(c) exempts a retaining wall from needing a building permit if it is not over four feet high, measured from the bottom of the footing to the top of the wall, unless it supports a surcharge or impounds Class I, II, or III-A liquids. Separately, KMC 18.27.050(3) requires that any retaining wall 60 inches or more above the adjacent grade, sited along a lot line, carry a guardrail or fence at least 36 inches high along its top edge for fall protection.
Violations & Fines
Skipping the required building permit above four feet, or omitting the top guardrail on a wall 60 inches or taller, violates KMC 15.08.060 and 18.27.050(3), enforceable as a Title 18 misdemeanor under KMC 18.54.090.
Frequently Asked Questions
Do I need a permit for a retaining wall in Kennewick?
Does a tall retaining wall need a guardrail in Kennewick?
Sources & Official References
Other rules in Kennewick
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