Last Updated 07/22/2026
Spokane Stormwater Website
The City of Spokane’s stormwater drainage system is a large, complex network of conveyances that are designed to take rainfall and direct it away from roads, buildings, and other public and private property. It consists of several different components, including:
- More than 300 miles of separate storm sewers that discharge stormwater to infiltration facilities, the Spokane River and Latah Creek at over 100 locations, including many bridges. About 1 billion gallons of untreated stormwater enters the River annually.
- More than 400 miles of combined stormwater and wastewater sewers that carry stormwater to the City’s wastewater treatment plant when it rains. During moderate to heavy rainfall and snowmelt events, a combination of stormwater and untreated sewage can overflow to the Spokane River to prevent overloading the plant.
- Thousands of swale biofiltration treatment facilities that discharge stormwater into the ground after treating the water by trapping sediments, oil, grease, and other pollutants.
Excerpt from Spokane Municipal Code
Title 17D City-wide Standards
Section 17D.060.050 Duties of Property Owners and Occupants – Others – Private Rights Reserved
- Every owner and occupant of premises must install, maintain and keep in good function and order any onsite stormwater facility in accord with applicable requirements. Such requirements may be reflected as conditions of land use or property development in plats, building or special use permits, or other permits, or may be imposed as a consequence of other regulatory action, including code enforcement or nuisance abatement.
- Stormwater facilities shall be installed with adherence to the Best Management Practices referenced in the Spokane Regional Stormwater Manual (SRSM) and the Stormwater Management Manual for Eastern Washington (SWMMEW).
- No party shall obstruct or interfere with the full and efficient function of any onsite stormwater facility.
- Enforcement action taken under this chapter does not affect a right of a party to seek subrogation or further recovery against any other parties determined to be responsible.
Section 17 D.060.070 Enforcement Authority – Implementation
- In accord with SMC 17A.010.070(A)(5), the term “director” in this chapter means the director of wastewater management. The director of wastewater management has overall enforcement authority for this chapter, but may delegate functions to other departments as desired. Actions of other officials listed in this chapter is subject to the overall approval of the director of wastewater management.
- The engineering services department may enforce stormwater design standards and other applicable specifications relating to design and installation of onsite stormwater facilities for commercial developments. Issuance of any permit or approval for commercial developments is conditioned upon acceptable documentation by a civil engineer licensed by the State of Washington of the following statements under penalty of perjury on such forms as may be supplied by the department:
- That the engineer is familiar with all current City of Spokane onsite stormwater facility requirements.
- That the engineer has personally inspected the stormwater facility site and that it fulfills the requirements applicable to the pending development; and
- That the development meets or exceeds all applicable municipal requirements relating to onsite stormwater facilities and applicable stormwater and drainage control, as designed, installed and functioning.
- In lieu of such certification, the director may require an inspection for stormwater by municipal staff, services billed at an hourly rate of fifty dollars per hour, with a minimum charge of one hundred dollars, anticipating two inspections will be needed.
- The building services department may enforce stormwater design standards and other applicable specifications for residential development. In addition to other applicable fees, a building permit applicant for residential development must pay full costs of services. It is anticipated that at least two inspections will be needed.
- The wastewater management department enforces maintenance requirements for onsite stormwater facilities after installation and determines any questions relating to proper functional level and efficiency of said facilities. Said department develops a record of onsite stormwater facilities locations and takes any enforcement action needed to keep them fully and efficiently functioning. Said department reviews plans or design specifications on file or otherwise accessible to determine the nature and extent of onsite stormwater facility requirements applicable to any specific premises, and may conduct further inquiry and/or site inspections as deemed necessary to enforce said requirements and this chapter.
- In evaluating decisions under the chapter, the enforcing official may elect to submit any information available to an outside consultant or civil engineer licensed to practice in the State of Washington selected by the City for review at the City’s expense. An applicant may likewise have such opinion further reviewed by an independent civil engineer licensed to practice in the State of Washington selected by applicant at the applicant’s expense. All final decisions shall be at the enforcing official’s sole discretion.
Section 17 D.060.073 Refusal of Entry – Search Warrant
- To the maximum extent permitted by law, no person shall refuse entry or access to a permitted development project to any authorized representative of the director who provides proper credentials and requests entry for the purpose of conducting an inspection. In addition, no person shall obstruct, hamper, or interfere with any such representative while in the process of carrying out their official duties.
- No one shall hamper or interfere with any other enforcement inspections, entry, or activities of the director or authorized representatives except as permitted by law.
- Inspection requests may be enforced by a search warrant whenever required and in accord with applicable law.
Section 17D.060.075 Enforcement Tracks
This chapter may be enforced through the administrative hearings process or civil infraction process in chapter 1.05 SMC. Normally, simple violations are enforced through the civil infraction process. Normally, violations involving more complicated facts are enforced through the administrative hearings process. The decision of which track to use in any case is within the sole discretion of the enforcing official.
Section 17D.060.140 Runoff and Infiltration Controls
- Runoff and infiltration controls apply in all areas of the City except where exempt or modified.
- Unless otherwise specified, street and alley paving projects funded by local improvement districts are exempt from the provisions of SMC 17D.060.130 and SMC 17D.060.140.
- Drainage plans shall be prepared and submitted for review and acceptance for all proposed plats and land disturbing activities prior to issuance of any permits for site disturbance, including but not limited to grading permits and building permits. The director has authority to waive requirements to the necessity for a drainage plan, but must do so in writing. Factors considered in the evaluation of a waiver request include, but are not limited to:
- soil characteristics and depth,
- number of lots,
- infill development,
- percent impervious area,
- pass-through drainage,
- history and trends of runoff-related problems,
- depth to ground water.
- With respect to drainage plans required under subsection (C) of this section:
- the volume and rate of surface water runoff after new development shall be no greater than the runoff volume and rate leaving the site prior to development, unless the director of engineering services approves the discharge of additional runoff based on a comprehensive drainage plan and down gradient impact study;
- drainage plans for development proposals in SDDs shall not rely upon infiltration to accommodate the additional runoff resulting from the proposed development. However, approval to use infiltration in part or in whole may be granted by the director of engineering services upon a showing, after assessing new, existing, and cumulative impacts from prior developments, that no adverse impact to the side, adjacent, or down gradient properties would occur;
- drainage plans submitted for development proposals shall comply with the Spokane Regional Stormwater Manual and the City of Spokane Design Standards, as approved by and on file with the director of engineering services, for the design of onsite stormwater facilities, including any limitations applicable to any specific SDD;
- drainage plans shall include identification of all properties to be reserved for onsite stormwater facilities and the location of all natural drainage systems.
- The developer, property owner, or other responsible, authorized and designated entity acceptable to the director (e.g., a homeowners association) shall be responsible for accepting and maintaining onsite stormwater facilities. The developer shall provide a perpetual maintenance plan, including funding mechanisms and appropriate financial security for such onsite stormwater facilities acceptable to the director.
- New plats shall expressly identify tracts of land devoted to the conveyance and/or disposal of stormwater flows. The location of all on-site stormwater facilities shall meet the requirements of the Spokane Regional Stormwater Manual.
Section 17D.060.200 Violation of Chapter
In addition to any other provisions, the following actions shall constitute a violation of this chapter:
- Any failure, refusal, or neglect to comply with any requirement of this chapter or any order or enforcement requirement of the director issued pursuant to this chapter, or regulations thereunder.
- Allowing or causing a condition that threatens to injure public health, the environment, or public property.
- Failure to correct ineffective stormwater control facilities after being required to do so by the director.
Section 17D.060.300 Low Impact Development
- The purpose of this section is to provide additional and optional stormwater management techniques beyond the standard best management practices listed in the Spokane Regional Stormwater Manual. These low impact development techniques strive to mimic pre-disturbance hydrological processes by emphasizing site conservation, use of on-site natural features, site planning, and distributed stormwater management practices.
- The Eastern Washington Low Impact Development Guidance Manual is hereby adopted by reference, as hereafter amended. This guidance manual addresses general requirements and may be modified or supplemented in other specific sections. This reference is on file with the director.
- Low impact development is encouraged for site development and redevelopment. Compliance with the Basic Requirements of the Spokane Regional Stormwater Manual shall be met regardless of best management practices used. Certain low impact development techniques may be used to fulfill the basic requirements set forth in the Spokane Regional Stormwater Manual, as approved by the director.
Excerpt from Spokane Regional Stormwater Manual
Maintenance Expectations
2.1.1 REGULATORY THRESHOLD
The regulatory threshold is the “trigger” for requiring compliance with the Basic Requirements of this Manual. This threshold varies from jurisdiction to jurisdiction. In Spokane County and the City of Spokane Valley, it is defined as “the addition or replacement of 5,000 square feet or more of impervious surfaces or the disturbance of 1 acre or more.” In the City of Spokane, the threshold is defined as “the addition or replacement of any impervious surfaces.” The regulatory threshold applies to the total impervious area replaced or added at full build-out. Refer to “common plan of development or sale” definition to determine whether your project will trigger the regulatory threshold.
All projects proposing underground injection control (UIC) facilities must comply with UIC requirements, regardless of whether they trigger the regulatory threshold.
2.2.8 BASIC REQUIREMENT NO. 8 – OPERATION AND MAINTENANCE
Objective
To ensure that stormwater control facilities are adequately maintained and properly operated, documentation describing the applicable preventive maintenance and recommended maintenance schedule shall be prepared and provided to the entity responsible for maintaining the stormwater system.
For drainage ponds and other drainage facilities outside of the public road right of way, the project proponent shall provide the financial means and arrangements for the perpetual maintenance of the drainage facilities.
Proponents shall operate and maintain the facilities in accordance with an operation and maintenance plan that meets the criteria specified in Chapter 11. The operation and maintenance plan shall also include applicable source control BMPs, as described in Chapter 10.
Applicability
All projects that meet the regulatory threshold and that propose drainage facilities or structures shall comply with this Basic Requirement. All projects that propose UIC facilities also must comply with the operation and maintenance requirements, regardless of whether they exceed the regulatory threshold.
11.1.1 INTRODUCTION
Insufficient maintenance of stormwater control facilities can lead to poor performance, shortened life, increased maintenance and replacement costs, and property damage.
The local jurisdiction maintains the stormwater system structures located within the public road right of way and structures located within border easements that serve public road runoff, unless a separate agreement exists whereby the homeowner, property owner or other independent entity is responsible for the maintenance. Drainage tracts created by public projects will be maintained by the local jurisdiction. The project proponent is to provide for the perpetual maintenance of all elements of the stormwater system located outside the public right of way. The high-frequency maintenance of vegetated cover, turf grass and other landscaping within the public right of way and within border easements that accommodate public road runoff is the responsibility of the adjacent property owner. When applicable, the following maintenance-related items shall be submitted with the Drainage Submittal (refer to Chapter 3) for all projects:
- A copy of the conditions, covenants and restrictions (CC&Rs) for the homeowners’ association (HOA) in charge of operating and maintaining all elements of the stormwater system;
- A Financial Plan outlining the funding mechanism for the operation, maintenance, repair, and replacement of the private stormwater system, including contingencies; and,
- An Operations and Maintenance (O&M) Manual.
View State Page
Frequently Asked Questions
What is stormwater compliance in the City of Spokane?
Stormwater compliance in Spokane means following the City’s Stormwater Ordinance, which establishes minimum requirements to protect public health, safety, and welfare across local watersheds. Every property owner and occupant must install, maintain, and keep in good working order any on-site stormwater facility.
Spokane’s stormwater system is particularly complex. In addition to more than 300 miles of separate storm sewers, the City has more than 400 miles of combined stormwater and wastewater sewers. During heavy rain or snowmelt, these combined sewers can overflow untreated sewage to the Spokane River. This makes effective on-site stormwater management especially important in Spokane.
How does stormwater compliance apply to my Spokane property?
In Spokane, compliance is triggered by the addition or replacement of any impervious surface. This is a stricter threshold than most surrounding jurisdictions and means that even small paving, roofing, or grading projects may require a drainage plan and permit review before work begins.
All projects that propose underground injection control (UIC) facilities must also comply with operation and maintenance requirements, regardless of project size or impervious surface area.
If you are unsure whether your project triggers compliance requirements, AQUALIS can review your plans and help you navigate the permitting process before you begin.
Who is responsible for stormwater maintenance in Spokane?
Every owner and occupant of a property is responsible for installing, maintaining, and keeping in good working order any on-site stormwater facility. This is an ongoing obligation, not just a one-time construction requirement.
For commercial developments, a Washington State licensed civil engineer must certify in writing before permit issuance that the stormwater facility meets all applicable requirements and is functioning as designed. If that certification is not provided, the City can require its own inspection at a rate of $50 per hour, with a minimum charge of $100.
For new plats and drainage facilities outside the public right of way, the developer must provide a perpetual maintenance plan, including a funding mechanism and financial security acceptable to the director. AQUALIS can help you prepare the required operation and maintenance documentation and manage ongoing compliance obligations.
Why does stormwater maintenance matter for Spokane property owners?
Spokane’s ordinance makes clear that inadequate maintenance is itself a violation. Three specific actions constitute a violation under the code: failing to comply with any requirement or director order; allowing or causing a condition that threatens public health, the environment, or public property; and failing to correct ineffective stormwater control facilities after being directed to do so.
The Spokane Regional Stormwater Manual also notes that insufficient maintenance leads to poor system performance, shortened facility life, increased future costs, and property damage. These are practical consequences that compound over time, not just regulatory ones.
No person may obstruct or interfere with the function of any on-site stormwater facility. Even actions that seem minor, like grading over a drainage swale or blocking an inlet, are direct violations under the ordinance.
What are the most common stormwater compliance failures in Spokane?
Based on AQUALIS’s inspection experience and Spokane’s ordinance and manual requirements, these are the issues we see most often.
Any impervious surface addition without a drainage plan. Spokane’s zero threshold means even small paving or roofing projects require permit review. Work done without an approved drainage plan is an automatic violation.
UIC facilities without operation and maintenance documentation. All UIC installations require an O&M plan regardless of project size. Properties with drywells or infiltration galleries that lack current documentation are frequently out of compliance.
On-site facilities not maintained in good working order. The ordinance requires every owner and occupant to keep stormwater facilities fully and efficiently functioning. Sediment buildup, clogged inlets, failing vegetation, and deteriorated structures are the most common maintenance failures found during City inspections.
No perpetual financial plan for private drainage facilities. For new plats and commercial developments, a funding mechanism and financial security for long-term maintenance are required. Properties that were developed without these in place have a documentation gap the City can act on.
How do I know if my Spokane stormwater system is at risk of failure or safety violation?
Watch for these warning signs.
Any impervious surface was added or replaced without a permit. In Spokane, this triggers compliance requirements. If work was done without an approved drainage plan, that is an active violation regardless of how long ago it occurred.
Your UIC or infiltration facility is not draining. Drywells and infiltration galleries that are clogged or have lost capacity are not only maintenance failures, they are compliance failures under the operation and maintenance requirements that apply to all UIC facilities.
Your on-site facilities have not been inspected recently. The Wastewater Management Department maintains records of on-site stormwater facility locations and takes enforcement action to keep them functioning. If your facility is on their records and has not been maintained, an inspection could be triggered at any time.
No O&M manual or financial plan is on file. Commercial developments and new plats are required to have an Operation and Maintenance Manual and a perpetual funding mechanism on file with the City. If you cannot locate yours, that is a documentation gap that needs to be resolved.
You see erosion, flooding, or unusual discharge. The ordinance defines as a violation any condition that threatens public health, the environment, or public property. Visible erosion, standing water, or discolored discharge from your property can trigger enforcement action independently of a formal inspection.
Recent property purchase. Maintenance obligations and required documentation in Spokane stay with the property. If you recently acquired a commercial property, an AQUALIS assessment can confirm what facilities exist, what documentation is required, and whether anything needs to be addressed before the City identifies it first.
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.
