Renton, WA Environmental Rules: Stormwater Management (2026)
Key Facts
- Enforcing official
- Public Works Administrator
- Design standard
- City of Renton Surface Water Design Manual
- Drainage review types
- 5 tiers: simplified to large project
- Core requirements
- 9 required elements per project
- Illicit discharge
- Banned outright under RMC 4-6-030.K
- Record retention
- 5 years for illicit discharge records
- Violation penalty
- Misdemeanor under RMC 4-6-110/RMC 1-3-1
Summary
Renton regulates surface water runoff and drainage under RMC 4-6-030, requiring drainage review for development projects and banning illicit discharges into the storm sewer system. The Public Works Administrator enforces the chapter, applying the City's Surface Water Design Manual and King County's standards to protect creeks, streams and groundwater from pollution.
B. ADMINISTERING AND ENFORCING AUTHORITY: The Administrator of the Public Works Department or their designated representative(s) ("Public Works Administrator") is responsible for the general administration and coordination of this Section... All provisions of this Section shall be enforced by the Public Works Administrator. C. ADOPTION OF SURFACE WATER DESIGN MANUAL: The Surface Water Design Manual, as it exists or may be amended, is adopted by reference by the City of Renton for consistency with the current version of the King County Surface Water Design Manual. K. STORMWATER POLLUTION SOURCE CONTROL AND DISCHARGE PROHIBITION: 1. Prohibition of Illicit Discharge: Materials, whether solids or liquids, other than surface water and stormwater shall not be spilled, leaked, emitted, discharged, disposed, or allowed to escape into the storm sewer and/or drain system, surface water, groundwater, or watercourses.
Official source re-checked September 8, 2026: no newer edition of the code had been published (publisher’s edition: current through Ordinance 6197, passed August 10, 2026).
Full Breakdown
260 and the NPDES Phase II Municipal Stormwater Permit. The Public Works Administrator holds general administrative and enforcement authority over the section, while the Community and Economic Development Department reviews and inspects development permits tied to it. The City adopts the King County Surface Water Design Manual by reference as its own Surface Water Design Manual, filed with the City Clerk and posted on the City's website. Any project subject to a City development permit must go through drainage review, scaled to project size and impact: simplified (small project), targeted, directed, full, or large project review.
Projects that qualify must meet nine core requirements covering discharge at the natural location, off-site analysis, flow control facilities, conveyance systems, construction stormwater pollution prevention, maintenance and operations, financial guarantees, water quality facilities and on-site best management practices, plus special requirements such as flood hazard delineation and aquifer protection where applicable. Subsection K bans illicit discharge outright: materials other than surface water and stormwater cannot be spilled, leaked, emitted, discharged, disposed of, or allowed to escape into the storm sewer system, surface water, groundwater or watercourses.
Violators responsible for an illicit connection or discharge must remedy it at their own cost; if they don't act, the Public Works Administrator can enter the property, install monitoring wells, and order cleanup, billing the responsible party. An illicit discharge is declared a nuisance under RMC 1-3-3. Records related to any illicit connection must be retained for five years.
Violations & Fines
Unless otherwise specified, violations of RMC Chapter 4-6 are misdemeanors under RMC 4-6-110 and RMC 1-3-1. Illicit discharges are separately declared a nuisance under RMC 1-3-3, letting the Public Works Administrator order remediation at the responsible party's expense and, for violations posing an imminent hazard, impose immediate penalties without waiting on the standard education and notice process.
Frequently Asked Questions
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Sources & Official References
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Stormwater Management in Nearby Cities
How other cities in King County handle stormwater management.