Last Updated 07/22/2026
Excerpt from City of Seattle Municipal Code
Chapter 22.803 - MINIMUM REQUIREMENTS FOR ALL DISCHARGES AND ALL REAL PROPERTY
22.803.020 - Minimum requirements for all discharges and real property
A. Requirement to provide documentation and to map infrastructure. The owner is required to make plans, procedures, and schedules required by this subtitle available to the Director when requested. When requested to aid in applying the Stormwater Code, the owner must provide to the Director a complete map of all drainage, side sewer, and plumbing infrastructure on the property.
B. Requirement to report spills, releases, or dumping. A responsible party is required to, at the earliest possible time, but in any case within 24 hours of discovery, report to the Director of SPU a spill, release, dumping, or other situation that has contributed or is likely to contribute pollutants to a public drainage system, a private drainage system, or a receiving water. This reporting requirement is in addition to, and not instead of, any other reporting requirements under federal, state or local laws.
C. Requirements to maintain facilities. All treatment facilities, flow control facilities, drainage control facilities, and drainage systems shall be maintained as specified in rules promulgated by the Director in order for these facilities and systems to be kept in continuous working order.
D. Requirements for disposal of waste from maintenance activities. Disposal of waste from maintenance of drainage control facilities shall be conducted in accordance with federal, state and local regulations, including the Minimum Functional Standards for Solid Waste Handling, Chapter 173-304 WAC, guidelines for disposal of waste materials, and, where appropriate, Dangerous Waste Regulations, Chapter 173-303 WAC.
E. Requirements to maintain records of installation and maintenance activities. When a drainage control facility is installed, the party having the facility installed shall make records of the installation and shall identify the party (or parties) responsible for maintenance and operations. The parties shall retain a continuous record of all maintenance and repair activities, and shall retain the records for at least ten years. If a transfer of ownership occurs, these records of installation, repair, and maintenance shall be transferred to the new property owner. These records shall be made available to the Director of SPU during inspection of the facility and at other reasonable times upon request of the Director of SPU.
22.803.030 - Minimum requirements for source controls for all real property
For all discharges, responsible parties shall implement and maintain source controls to prevent or minimize pollutants from leaving a site or property. Source controls that are required for all real property include, but are not limited to, the following, as further described in rules promulgated by the Director:
A. Eliminate illicit connections and illicit discharges.
It is the responsibility of the property owner or other responsible party to ensure that all plumbing connections are properly made and that only connections conveying stormwater or permissible discharges pursuant to Section 22.802.030 are connected to the drainage system. When requested to aid in applying the Stormwater Code, the owner must provide to the Director a complete map of all stormwater and plumbing infrastructure on the property.
B. Perform routine maintenance.
All drainage system components, including, but not limited to, catch basins, flow control facilities, treatment facilities, on-site BMPs, and unimproved drainage pathways shall be kept in continuous working order.
C. Dispose of fluids and wastes properly.
Solid and liquid wastes must be disposed of in a manner that minimizes the risk of contaminating stormwater.
D. Proper storage of solid wastes.
Solid wastes must be stored in a manner that minimizes the risk of contaminating stormwater.
E. Spill prevention and cleanup.
All property owners having the potential to spill pollutants shall take measures to prevent spills of pollutants and to properly clean up spills that might occur.
F. Provide oversight and training for staff.
For businesses and public entities, annually train all employees responsible for the operation, maintenance, or inspection of BMPs, assign oversight responsibilities, and maintain records.
G. Property maintenance.
For businesses and public entities, locate pollution-generating activities away from stormwater pathways where feasible and engage in proper site maintenance to prevent pollutant transport off site, including but not limited to sweeping paved areas and inspecting loading, unloading, storage and parking areas.
H. Rooftop dog runs.
Dog runs located on private property on rooftops or above-grade plazas must prevent stormwater from the dog run from discharging directly or indirectly to a public drainage system, private drainage system, or receiving water body.
A. For all discharges, source controls shall be implemented, to the extent allowed by law, by businesses and public entities for the following specific pollution-generating activities as specified in the joint SPU/SDCI Directors’ Rule titled “Seattle Stormwater Manual” at “Volume 4—Source Control,” to the extent necessary to prevent prohibited discharges as described in subsection 22.802.020.A through subsection 22.802.020.D, and to prevent contaminants from coming in contact with drainage water or being discharged to the drainage system, public combined sewer, or directly into receiving waters:
-
- Fueling at dedicated stations, for new or substantially altered fueling stations.
- Mobile fueling of vehicles and heavy equipment.
- In-water and over-water fueling.
- Maintenance and repair of vehicles and equipment.
- Concrete and asphalt mixing and production.
- Concrete pouring, concrete/asphalt cutting, and asphalt application.
- Recycling, wrecking yard, and scrap yard operations.
- Storage of liquids in aboveground tanks.
Source controls include, but are not limited to, segregating or isolating wastes to prevent contact with drainage water; enclosing, covering, or containing the activity to prevent contact with drainage water; developing and implementing inspection and maintenance programs; sweeping; and taking management actions such as training employees on pollution prevention.
B. For all discharges except those that drain only to the public combined sewer, source controls shall be implemented, to the extent allowed by law, by businesses and public entities for specific pollution-generating activities as specified in the joint SPU/SDCI Directors’ Rule titled “Seattle Stormwater Manual” at “Volume 4—Source Control,” to the extent necessary to prevent prohibited discharges as described in subsection 22.802.020.A through subsection 22.802.020.C, and to prevent contaminants from coming in contact with drainage water or being discharged to the drainage system or directly into receiving waters. Source controls include, but are not limited to, segregating or isolating wastes to prevent contact with drainage water; enclosing, covering, or containing the activity to prevent contact with drainage water; developing and implementing inspection and maintenance programs; sweeping; and taking management actions such as training employees on pollution prevention.
22.803.040 - Minimum requirements for source controls for businesses and public entities for specific activities
22.805.070 - Minimum requirements for on-site stormwater management
A. Applicability
The requirements of this Section 22.805.070 apply as required in Section 22.805.030 to Section 22.805.060.
B. Requirements
On-site stormwater management shall be installed to the extent allowed by law and maintained in compliance with the rules promulgated by the Director to receive flows from that portion of the site being developed and shall comply with either:
a. Subsection 22.805.070.C (On-site performance standard); or
b. Subsection 22.805.070.D (On-site lists).
C. On-site performance standard
If the existing hard surface coverage is less than 35 percent and the project discharges to a listed creek, or to the drainage basin of such creek:
a. The post-development discharge durations shall match the discharge durations of a pre-developed forested condition for the range of pre-developed discharge rates from 8 percent of the 2-year peak flow to 50 percent of the 2-year peak flow.
For all other projects:
a. The post-development discharge durations shall match the discharge durations of a pre-developed pasture condition for the range of pre-developed discharge rates between the 1 percent and 10 percent exceedance values.
D. On-site lists
This ordinance is not intended to modify or repeal any other ordinance, rule, regulation, or other provision of law. The requirements of this ordinance are in addition to the requirements of any other ordinance, rule, regulation, or other provision of law, and where any provision of this ordinance imposes restrictions different from those imposed by any other ordinance, rule, regulation, or other provision of law, whichever provision is more restrictive or imposes higher protective standards for human health or the environment shall control.
22.807.090 - Maintenance and inspection
A. Responsibility for maintenance and inspection. The owner and other responsible parties shall maintain drainage control facilities, source controls, and other facilities and implement landscape management plans required by this subtitle and by rules adopted hereunder to keep these facilities in continuous working order. The owner and other responsible parties shall inspect permanent drainage control facilities, temporary drainage control facilities, and other temporary best management practices or facilities on a schedule consistent with this subtitle and sufficient for the facilities to function at design capacity. The Director may require the responsible party to conduct more frequent inspections and/or maintenance when necessary to ensure functioning at design capacity. The owner(s) shall inform future purchasers and other successors and assignees to the property of the existence of the drainage control facilities and the elements of the drainage control plan, the limitations of the drainage control facilities, and the requirements for continued inspection and maintenance of the drainage control facilities and for implementation of a landscape management plan, if applicable.
B. Inspection by City. The Director of SPU may establish inspection programs to evaluate and, when required, enforce compliance with the requirements of this subtitle and accomplishment of its purposes. Inspection programs may be established on any reasonable basis, including, but not limited to: routine inspections; random inspections; inspections based upon complaints or other notice of possible violations; inspection of drainage basins or areas identified as higher than typical sources of sediment or other contaminants or pollutants; inspections of businesses or industries of a type associated with higher than usual discharges of contaminants or pollutants or with discharges of a type more likely than the typical discharge to cause violations of state or federal water or sediment quality standards or the City’s NPDES stormwater permit; and joint inspections with other agencies inspecting under environmental or safety laws. Inspections may include, but are not limited to: reviewing maintenance and repair records; sampling discharges, surface water, groundwater, and material or water in drainage control facilities; and evaluating the condition of drainage control facilities and other best management practices.
C. Entry for inspection and abatement purposes
- New installations and connections. When any new drainage control facility is installed on private property, and when any new connection is made between private property and a public drainage system, sanitary sewer or combined sewer, the property owner shall grant, pursuant to subsection 22.807.020.B.1.c (Memorandum of drainage control), the City the right to enter the property at reasonable times and in a reasonable manner pursuant to an inspection program established pursuant to subsection 22.807.090.B, and to enter the property when the City has a reasonable basis to believe that a violation of this subtitle is occurring or has occurred, and to enter when necessary for abatement of a public nuisance or correction of a violation of this subtitle.
2. Existing real property and discharges. Owners of property with existing discharges or land uses subject to this subtitle who are not installing a new drainage control facility or making a new connection between private property and a public drainage system, sanitary sewer, or combined sewer shall have the option to execute a permission form for the purposes described above when provided with the form by the Director of SPU.
Chapter 22.808 - STORMWATER CODE ENFORCEMENT
22.808.010 - Violations
A. Civil violations
- The following are civil violations of this subtitle, subject to a maximum civil penalty of up to $5,000 per day for each violation.
- General. It is a violation to not comply with any requirement of, or to act in a manner prohibited by, this subtitle, or a permit, approval, rule, manual, order, Notice of Violation, or Voluntary Compliance Agreement issued pursuant to this subtitle;
- Aiding and abetting. It is a violation to aid, abet, counsel, encourage, commend, incite, induce, hire or otherwise procure another person to violate this subtitle;
- Alteration of existing drainage. It is a violation to alter existing drainage patterns which serve a tributary area of more than one acre without authorization or approval by the Director;
- Obstruction of watercourse or public drainage system. It is a violation to obstruct a watercourse or public drainage system without authorization or approval by the Director;
- Dangerous condition. It is a violation to allow to exist, or cause or contribute to, a condition of a drainage control facility, or condition related to grading, drainage water, drainage or erosion that is likely to endanger the public health, safety or welfare, the environment, or public or private property;
- Interference. It is a violation for any person to interfere with or impede the correction of any violation, or compliance with any Notice of Violation, emergency order, stop work order, or the abatement of any nuisance;
- Piecemeal of projects. It is a violation for any person to knowingly divide a larger project into a set of smaller projects specifically for the purpose of avoiding minimum requirements;
- Altering a posted order. It is a violation for any person to remove, obscure, or mutilate any posted order of the Director, including a stop work or emergency order; and
- Continuing work. It is a violation for any work to be done after service or posting of a stop work order, except work necessary to perform the required corrective action, until authorization is given by the Director.
B. Criminal violations
- The following are criminal violations, punishable upon conviction by a fine of not more than $5,000 per violation or imprisonment for each violation for not more than 360 days, or both such fine and imprisonment:
- Failing to comply with a Notice of Violation or Director’s order issued pursuant to this subtitle;
- Failing to comply with a court order;
- Tampering with or vandalizing any part of a drainage control facility or other best management practice, a public or private drainage system, monitoring or sampling equipment or records, or notices posted pursuant to this subtitle; and
- Anyone violating this subtitle who has had a judgment, final Director’s order, or Director’s review decision against them for a prior violation of this subtitle in the preceding five years.
22.808.030 - Enforcement actions
A. Investigation. The Director may investigate any site where there is reason to believe that there may be a failure to comply with the requirements of this subtitle.
B. Notice of Violation
-
- Issuance. The Director is authorized to issue a Notice of Violation to a responsible party whenever the Director determines that a violation of this subtitle has occurred or is occurring. The Notice of Violation shall be considered an order of the Director.
- Contents.
a. The Notice of Violation shall include the following information:
-
-
-
- A description of the violation and the action necessary to correct it;
- The date of the notice; and
- A deadline by which the action necessary to correct the violation must be completed.
-
-
b. A Notice of Violation may be amended at any time to correct clerical errors, add citations of authority, or modify required corrective action.
3. Service. The Director shall serve the notice upon a responsible party either by personal service, by first-class mail, or by certified mail return receipt requested, to the party’s last known address. If by first-class mail, service shall be deemed complete upon the third day following the day upon which the notice is placed in the mail, or if the third day falls on a Saturday, Sunday or legal holiday, then on the next day following that is not a Saturday, Sunday or legal holiday. If the address of the responsible party cannot be found after a reasonable search, the notice may be served by posting a copy of the notice at a conspicuous place on the property. Alternatively, if the whereabouts of the responsible party is unknown and cannot be ascertained in the exercise of reasonable diligence, and the Director makes an affidavit to that effect, then service may be accomplished by publishing the notice once each week for two consecutive weeks in the City official newspaper.
4. Nothing in this subtitle shall be deemed to obligate or require the Director to issue a Notice of Violation or order prior to the initiation of enforcement action by the City Attorney’s Office pursuant to subsection 22.808.030.E.
C. Stop work and emergency orders
-
- Stop work order. The Director may order work on a site stopped when the Director determines it is necessary to do so in order to obtain compliance with or to correct a violation of any provision of this subtitle or rules promulgated hereunder, or to correct a violation of a permit or approval granted under this subtitle.
a. The stop work notice shall contain the following information:
-
-
-
- A description of the violation; and
- An order that the work be stopped until corrective action has been completed and approved by the Director.
-
-
b. The stop work order shall be personally served on the responsible party or posted conspicuously on the premises.
2. Emergency order
a. The Director may order a responsible party to take emergency corrective action and set a schedule for compliance and/or may require immediate compliance with an emergency order to correct when the Director determines that it is necessary to do so in order to obtain immediate compliance with or to correct a violation of any provision of this subtitle, or to correct a violation of a permit or approval granted under this subtitle.
b. An emergency order shall be personally served on the responsible party or posted conspicuously on the premises.
c. The Director is authorized to enter any property to investigate and correct a condition associated with grading, drainage, erosion control, drainage water, or a drainage control facility when it reasonably appears that the condition creates a substantial and present or imminent danger to the public health, safety or welfare, the environment, or public or private property. The Director may enter property without permission or an administrative warrant in the case of an extreme emergency placing human life, property, or the environment in immediate and substantial jeopardy which requires corrective action before either permission or an administrative warrant can be obtained. The cost of such emergency corrective action shall be collected as set forth in Section 22.808.060.
3. Director’s review of stop work and emergency order. A stop work order or emergency order shall be final and not subject to a Director’s review.
D. Review by Director
-
- A Notice of Violation, Director’s order, or invoice issued pursuant to this subtitle shall be final and not subject to further appeal unless an aggrieved party requests in writing a review by the Director within ten business days after service of the Notice of Violation, order or invoice. When the last day of the period so computed is a Saturday, Sunday, or federal or City holiday, the period shall run until 5 p.m. on the next business day.
- Following receipt of a request for review, the Director shall notify the requesting party, any persons served the Notice of Violation, order or invoice, and any person who has requested notice of the review, that the request for review has been received by the Director. Additional information for consideration as part of the review shall be submitted to the Director no later than 15 business days after the written request for a review is mailed.
- The Director will review the basis for issuance of the Notice of Violation, order, or invoice and all information received by the deadline for submission of additional information for consideration as part of the review. The Director may request clarification of information received and a site visit. After the review is completed, the Director may:
a. Sustain the Notice of Violation, order, or invoice;
b. Withdraw the Notice of Violation, order, or invoice;
c. Continue the review to a date certain for receipt of additional information; or
d. Modify or amend the Notice of Violation, order, or invoice.
4. The Director’s decision shall become final and is not subject to further administrative appeal.
E. Referral to City Attorney for enforcement. If a responsible party fails to correct a violation or pay a penalty as required by a Notice of Violation, or fails to comply with a Director’s order, the Director may refer the matter to the City Attorney’s Office for civil or criminal enforcement action. Civil actions to enforce this subtitle shall be exclusively in Municipal Court.
F. Appeal to Superior Court. Because civil actions to enforce Title 22 are brought exclusively in Municipal Court, notices of violation, orders, and all other actions made under this subtitle are not subject to judicial review under chapter 36.70C RCW. Instead, final decisions of the Municipal Court on enforcement actions authorized by this subtitle may be appealed under the Rules for Appeal of Decisions of Courts of Limited Jurisdiction.
G. Filing of Notice or Order. A Notice of Violation, voluntary compliance agreement, or an order issued by the Director or court may be filed with the King County Recorder’s Office.
H. Change of ownership. When a Notice of Violation, voluntary compliance agreement, or an order issued by the Director or court has been filed with the King County Recorder’s Office, a Notice of Violation or an order regarding the same violations need not be served upon a new owner of the property where the violation occurred. If no Notice of Violation or order is served upon the new owner, the Director may grant the new owner the same number of days to comply as was given the previous owner. The compliance period for the new owner shall begin on the date that the conveyance of title to the new owner is completed.
View State Page
Frequently Asked Questions
What is stormwater compliance in the City of Seattle?
Stormwater compliance in Seattle means following the City’s Stormwater Code, which applies to all real property in Seattle regardless of whether you are doing any construction or development. Every property owner is required to keep all drainage control facilities in continuous working order, prevent prohibited substances from entering the drainage system, and report spills that could contaminate stormwater within 24 hours of discovery.
Seattle’s stormwater rules apply whether or not a permit is required, and whether or not any development is occurring. If your property has stormwater infrastructure, you are responsible for maintaining it to the City’s standards at all times.
Who is responsible for stormwater compliance in Seattle?
Seattle’s Stormwater Code defines “responsible party” broadly. It includes owners, operators, and occupants of property, as well as anyone causing or contributing to a violation. This means a tenant, contractor, or business operator on your property can be held responsible alongside you as the property owner.
What does Seattle require property owners to do on an ongoing basis?
Seattle’s Stormwater Code establishes several baseline requirements that apply to all property owners at all times, even when no construction or development is happening.
Maintain all drainage facilities. All treatment facilities, flow control facilities, drainage control facilities, and drainage systems must be kept in continuous working order per the rules set by the Director.
Keep maintenance records for 10 years. Property owners must maintain a continuous record of all installation, maintenance, and repair activities for drainage control facilities, and make those records available to Seattle Public Utilities upon request. When a property changes hands, these records must be transferred to the new owner.
Report spills within 24 hours. Any spill, release, or dumping that has contributed or is likely to contribute pollutants to a drainage system or receiving water must be reported to the Director of SPU within 24 hours of discovery.
Provide drainage maps when requested. If the City asks, you must provide a complete map of all drainage, side sewer, and plumbing infrastructure on your property.
What are the most common stormwater compliance failures in Seattle?
Based on AQUALIS’s inspection experience and Seattle’s Stormwater Code requirements, these are the issues we see most often for commercial and industrial property owners.
Prohibited discharges reaching the drainage system. Wash water, cleaning products, food waste, oils, and other non-stormwater substances entering catch basins or drains are among the most frequently enforced violations. Seattle’s list of prohibited substances is extensive and covers many everyday commercial activities.
Illicit or legacy connections to the drainage system. The code prohibits all connections that convey anything other than stormwater, including connections made under older rules that were permissible at the time. Legacy connections discovered during an inspection are treated as current violations.
Drainage facilities not maintained in continuous working order. Catch basins, treatment facilities, and flow control systems that are clogged, sediment-filled, or otherwise degraded are a direct violation of the code’s baseline maintenance requirement.
Missing or incomplete maintenance records. Seattle requires 10 years of continuous maintenance and repair records, and they must transfer with the property on sale. Properties that cannot produce these records are exposed to enforcement action regardless of the physical condition of the system.
Spills not reported within 24 hours. The 24 hour reporting requirement applies to any spill that has or could contribute pollutants to stormwater. Failure to report is an independent violation separate from the spill itself.
How do I know if my Seattle stormwater system is at risk of failure or safety violation?
Watch for these warning signs.
Your drainage facilities are not draining properly. The code requires all facilities to be kept in continuous working order. Standing water, slow drainage, or overflow after rain are signs your system is not meeting that standard.
You have outdoor commercial activities without source controls in place. If your property involves washing, fueling, outdoor storage, food handling, or other activities that could generate pollutants, Seattle’s code requires source controls to prevent those materials from reaching the drainage system. Businesses without these controls in place are likely out of compliance.
You cannot produce 10 years of maintenance records. Seattle requires a continuous record going back a decade, and those records must have transferred with the property if it changed hands. Gaps in documentation are an active compliance issue the City can act on during an inspection.
You have drain connections of unknown origin. Any connection carrying non-stormwater to the drainage system is prohibited, including those installed under older rules. If you are not sure where all your drainage connections lead or what they carry, that uncertainty needs to be resolved.
A spill occurred and was not reported. If a release of pollutants reached or could have reached the drainage system and was not reported to Seattle Public Utilities within 24 hours, that is an independent violation that may still be addressable before it becomes an enforcement action.
The information on this page is provided for general informational purposes only and is not legal advice. Regulations change frequently — AQUALIS makes no warranty as to the accuracy or completeness of this content, and any reliance on it is at your own risk. Consult a qualified professional or your local regulatory authority to confirm requirements applicable to your specific property.
