Cowlitz County, WA Outdoor Lighting: Light Trespass & Shielding (2026)
Key Facts
- Applies to
- commercial/light industrial use in AG-I zone
- Standard
- lighting directed, shielded or screened, § 18.10.502(H)
- Related standard
- stormwater sized for 25-year storm, subsection (B)
- Enforcement tool
- Director/Planning Commission may require monitoring instruments
- Civil penalty
- $1,000 per violation, § 2.06.080
Summary
In unincorporated Cowlitz County's Agriculture-Industrial (AG-I) zone, Cowlitz County Code § 18.10.502(H) requires that lighting on commercial or light industrial development be directed, shielded or screened so it is not cast, directly or indirectly, into adjacent or nearby residential areas or into the eyes of motorists on public or private roads.
The following performance standards apply to any commercial or light industrial use in the AG-I zone, and are in addition to other applicable standards. ... H. Glare. ... Lighting shall be directed, shielded or screened so that it will not be directly or indirectly cast into adjacent or nearby residential areas, or hinder motorists on public or private roads.
Full Breakdown
Section 18.10.502 sets performance standards that apply specifically to commercial or light industrial uses in the AG-I zone district, in addition to the county's general development standards at § 18.10.500 through § 18.10.580. Subsection H, titled 'Glare,' is the county's light-trespass rule: it requires that lighting, including permitted illuminated signs referenced in subsection A, be directed, shielded or screened so that it does not spill into adjacent or nearby residential areas or hinder motorists. The same section pairs the glare standard with related nuisance controls for AG-I development, including a storm drainage standard requiring stormwater plans from a Washington-licensed engineer sized for a 25-year storm event (subsection B), a noise standard requiring compliance with Chapter 173-60 WAC (subsection D), and an air emissions standard requiring compliance with Chapter 70.94 RCW and Southwest Air Pollution Control Authority rules (subsection E).
Subsection I lets the county's Director or Planning Commission require the property owner to install monitoring instruments for glare and other nuisances if a complaint arises. Because § 18.10.502 is written for the AG-I zone's commercial and light industrial development, lighting complaints between two houses in a residential district (RR-1, RR-2, RR-5, SR, UR) are not addressed by this glare standard; those disputes fall to general nuisance law rather than this zoning-specific lighting rule.
Violations & Fines
A commercial or light industrial development in the AG-I zone whose lighting is not shielded, directed or screened away from adjacent residential areas violates the § 18.10.502(H) glare standard, a Land Use Ordinance violation under Chapter 18.10 CCC. CCC § 2.06.040 makes the violation a civil infraction, and § 2.06.080 assesses a $1,000 penalty per violation, doubling for a second violation of the same ordinance within three years.
Frequently Asked Questions
Does Cowlitz County regulate light spilling onto a neighbor's property?
Which properties does the county's glare standard apply to?
Can the county require a business to fix its outdoor lighting after a complaint?
Sources & Official References
Other rules in Cowlitz County
Compare Cowlitz County to another location·View the Washington outdoor lighting overview
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