How Kennewick Handles Landscaping Rules: A Practical Guide

Kennewick maintains 100 local ordinances across all categories, and 7 of those deal specifically with landscaping rules. Here is a breakdown of what the city actually requires, what is prohibited, and where Kennewick falls on the strict-to-permissive spectrum compared to other cities.

Native Plants

Kennewick has no native-plant mandate or No Mow May exemption. The KMC 9.48.010(4) twelve-inch Weed Hazard rule still applies, but irrigated, living natives generally fall outside the rule because the trigger covers dead or unirrigated vegetation.

Key details: Native-Plant Mandate: None in code. Weed Rule Still Applies: KMC 9.48.010(4). Landscape Chapter: KMC 18.21. Suggested Resource: WSU Master Gardener. KID Conservation: Low-water plant guidance.

Native plantings that go dormant and read as dead vegetation over twelve inches still trip KMC 9.48.010(4) and the 20-day Code Enforcement notice. Native landscape choices for KMC 18.21 plans must still meet the approved planting list at site-plan review.

The rules around native plants in Kennewick lean permissive, but that does not mean anything goes.

Grass Height Limits

Kennewick Municipal Code 9.48.010(4) defines a Weed Hazard as grasses, weeds, or other vegetation that have grown and died or that are not irrigated and exceed twelve inches in length. Maintaining a Weed Hazard is declared a public nuisance.

Key details: Code Section: KMC 9.48.010(4). Trigger Height: Over 12 inches. Status: Public nuisance. Compliance Window: 20 days after notice. Key Exception: Irrigated growth.

Owners get 20 days to cut or irrigate after notice. If the owner does not comply, KMC 9.48 lets the city pursue civil or criminal infractions and recover abatement costs against the property. Agricultural land and natural-habitat areas are exempt.

Tree Trimming

Kennewick requires adjacent property owners to trim vegetation that obstructs traffic signs, signals, intersections, or the public right-of-way. The city's sight-obstruction guidance places the duty on the abutting owner, backed by KMC 9.48 nuisance authority and RCW 7.48 public-nuisance law.

Key details: Owner Duty: Trim ROW & sight lines. Backing Code: KMC 9.48 / RCW 7.48. Power-Line Trees: Benton PUD 509-585-5399. ROW Work: Bonded contractor + permit. Enforcement: Code Enforcement notice.

Failure to trim after notice can lead to a Chapter 9.48 nuisance abatement, with civil or criminal infractions and cost recovery against the property. Doing tree work in the right-of-way without a bonded contractor and ROW permit is a separate Title 5 violation.

Water Restrictions

Most outdoor irrigation in Kennewick runs on Kennewick Irrigation District water, not city potable water. KID activates a mandatory address-based watering schedule during declared droughts under its junior Yakima River water rights, which are governed by RCW 90.03.

Key details: Irrigation Provider: Kennewick Irrigation District. State Authority: RCW 90.03. Even Addresses: Tue / Thu / Sun. Odd Addresses: Mon / Wed / Sat. Exempt Uses: Drip & hose watering.

KID can issue mandatory-schedule warnings and shut off non-compliant accounts during a declared schedule. Out-of-priority diversion of Yakima River water during drought can trigger Washington Department of Ecology enforcement under RCW 90.03.

Weed Ordinances

Inside the city, weed control sits in KMC 9.48 with the 12-inch Weed Hazard rule. Layered on top, RCW 17.10 (the Washington State Noxious Weed Law) gives the Benton County Noxious Weed Control Board authority to order eradication of state-listed Class A, B, and C weeds.

Key details: City Code: KMC 9.48. State Law: RCW 17.10. County Board: 509-943-6005. Class A Status: Eradication required. Cost Recovery: RCW 17.10.170.

Inside the city, 9.48 enforcement starts with a 20-day notice followed by civil or criminal infractions and cost recovery. Failure to control a Class A or designated Class B weed lets the Benton County board file civil infractions and bill the landowner under RCW 17.10.170.

Tree Removal & Heritage Trees

Kennewick does not require a city permit to remove a tree on private property, with three exceptions: trees in the public right-of-way, trees inside an approved KMC 18.21 landscape plan for development, and trees inside a critical area under KMC 18.58.

Key details: Private Tree Permit: Not required. ROW Trees: Title 5 permit + bonded. Critical Area: KMC 18.58 limits. Landscape Plan: KMC 18.21 binds site. State Forest Practices: RCW 76.09 (limited in city).

Removing a tree in the right-of-way without an ROW permit and a bonded contractor is a Title 5 violation. Removing a tree from an approved 18.21 landscape plan without replacement breaches the site plan. Tree cutting in a KMC 18.58 critical area can trigger SEPA and restoration orders.

If you are coming from a city with tighter rules, you will find Kennewick gives residents more flexibility on tree removal & heritage trees.

Composting

Backyard composting for household use is allowed in Kennewick and is not separately permitted in the municipal code. Larger composting facilities are regulated by WAC 173-350 (state solid waste) and WAC 296-301 (workplace safety). Open burning of yard waste is permanently banned citywide.

Key details: Backyard Compost: Allowed, no permit. Yard Waste Pickup: Nov/Dec/Jan, bagged. Open Burning: Banned citywide. Commercial Facility: WAC 173-350 / 296-301. Drift Smoke: RCW 7.48.120.

Burning yard waste inside Kennewick is permanently prohibited and is enforced by Benton Clean Air Agency. Compost piles that create odor, vector, or runoff nuisance violate KMC 9.48 with the standard 20-day notice. Commercial composting without a state WAC 173-350 permit triggers Ecology enforcement.

The Bottom Line

Compared to many U.S. cities, Kennewick gives residents more room on landscaping rules. 2 of the 7 rules here are rated permissive. But permissive does not mean unregulated. There are still requirements, and the city does enforce them when violations are reported.

Keep in mind that Kennewick can amend these rules at any council meeting. For the most current version of any rule mentioned here, check the specific ordinance page, where we track updates as they happen.