Stormwater Permit Process

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Clean Water Services (the District) is a service district formed under ORS Chapter 451 with lead responsibility for urban surface water management in urban Washington County, including all of the incorporated cities. To better protect water quality within its service district, the District has adopted rules that affect how and where “development” can occur by requiring vegetated corridors, enhancement, and mitigation for impacts to “Water Quality Sensitive Areas”.

Water Quality Sensitive Areas are land features which serve as water quality filtering systems, protect aquatic communities, or otherwise function to improve the water quality and quantity management of the storm and surface water system, and include any drainage system with a basin greater than 10 acres, wetlands, rivers, streams, springs, lakes and ponds. However, various types of man-made stormwater facilities are not considered sensitive areas. The “Vegetated Corridor” is a corridor adjacent to a Water Quality Sensitive Area that is preserved and maintained to protect the water quality functions of the sensitive areas.

This summary is intended to provide general information about Clean Water Services’ water quality regulations. However, it is not a substitute for the regulations themselves. If you have any questions or concerns about how these new regulations may affect you, please contact Clean Water Services.

When did the rules go into effect? Who is subject to the water quality regulations? Are permits required? How do I obtain a Pre-Screening Determination? How do I obtain an Initial Site Assessment? How do I obtain a Natural Resource Assessment? How do I obtain a Stormwater Connection Permit? Where do I find more information?

Q: When did the rules go into effect?

A: On February 22, 2000, and updated February 3, 2004, these water quality protection rules went into effect for all of urban Washington County, including the incorporated cities of Banks, Beaverton, Cornelius, Durham, Forest Grove, Hillsboro, King City, North Plains, Sherwood, Tigard and Tualatin.

Q: Who is subject to the water quality regulations?

A: These rules apply to all new “development”, as defined below.

"Development" under these rules refers to all human-induced changes to improved or unimproved real property including:

Construction of structures requiring a building permit if such structures increase the impervious surface footprint on the real property;
Land division, including subdivisions, lot line adjustments, expedited land partitions and minor land partitions. “Land Division” does not include plats for the sole purpose of converting existing buildings to condominiums;
Drilling;
Site alterations resulting from surface mining or dredging;
Grading that would require an Erosion Control Permit;
Construction of earthen berms;
Paving and roadway construction;
Excavating that would require an Erosion Control Permit;
Clearing when it results in the removal of trees or native vegetation that would require a permit from the City/County or notification to the Oregon Department of Forestry;
Redevelopment;
Construction of utility infrastructure.

Section 1.02.14, Design and Construction Standards (PDF, 22MB) Resolution and Order 04-9 (R&O 04-9).

As noted in the definition, “development” includes a wide range of activities such as land divisions, the construction of structures requiring a building permit, grading, and excavating. However, the definition of “development” does not include the construction on a lot of record within a subdivision which is inside the urban growth boundary and which was approved by a local government decision on a land use application under an acknowledged comprehensive plan after September 9, 1995.

Q: Are permits required?

A: A Stormwater Connection Permit is required by the District for all “development”. However, prior to issuance of the Stormwater Connection Permit, you will need either:

A Pre-Screen Site Assessment by the District or local jurisdiction that states that no Water Quality Sensitive Areas are on or within 200 feet of your development site; or
A Service Provider Letter from the District, which states that the District has reviewed and concurs with your proposed site plan. (NOTE: A Service Provider Letter must be included with your land use or building permit application to the City or County.)

In order to get a Service Provider Letter and a Stormwater Connection Permit from Clean Water Services, you must comply with the current Design and Construction Standards (PDF, 22MB). This means that if you are proposing a project that meets the definition of “development”, you must complete a Pre-Screen Site Assessment and may be required to complete a Site Certification and Natural Resource Assessment.

Q: How do I obtain a Pre-Screen Site Assessment?

A: Submit a completed Pre-Screen Site Assessment Form (PDF, 283KB) and request that City or District staff make a determination of whether your property is likely to require a Site Certification under the current Design and Construction Standards (PDF, 22MB). Based on mapped information and other available resources, City or District staff will tell you whether or not it’s likely that there are Water Quality Sensitive Areas on or within 200 feet of your property and provide you with documentation of their determination.

If the pre-screening determines that it is likely that there are Water Quality Sensitive Areas on or within 200 feet of your property, you must complete a Site Certification.
If the pre-screening determines it is not likely that there are Water Quality Sensitive Areas on or within 200 feet of your property, you may obtain a Stormwater Connection Permit and proceed with the land use or building permit application process.

NOTE: The pre-screening does NOT eliminate the need to evaluate and protect Water Quality Sensitive Areas if they are subsequently discovered on your property.

Q: How do I obtain a Site Certification?

A: The applicant or authorized agent shall conduct a Site Certification to determine if there are Water Quality Sensitive Areas present on or within 200 feet of the site and complete the Sensitive Areas Site Certification Form (PDF, 373KB). The Site Certification shall include at a minimum; a site reconnaissance, the proposed site plan (with dimensions) and photographs documenting the location of the potential sensitive areas (keyed to the site plan).

If the Site Certification indicates that there are Water Quality Sensitive Areas on or within 200 feet of your site, you must complete a Natural Resource Assessment.

If the Site Certification indicates that there are no Water Quality Sensitive Areas on or within 200 feet of your site, submit the completed Sensitive Area Site Certification form, your proposed site plan, and supporting documentation to Clean Water Services. If the District concurs that there are no Water Quality Sensitive Areas on site or within 200 feet, the District will issue a Service Provider Letter and Stormwater Connection Permit. A copy of this letter should be submitted to the City or County with your land use or building permit application.

Q: How do I obtain a Natural Resource Assessment?

A: If there are Water Quality Sensitive Areas on or within 200 feet of your site, you must complete a Natural Resource Assessment to determine appropriate Vegetated Corridors. Depending on your proposed site plan and level of encroachment into the Vegetated Corridor, the Natural Resource Assessment may include an Alternatives Analysis. You will need to submit your Sensitive Areas Site Certification Form (PDF, 373KB), Natural Resource Assessment, Alternatives Analysis (if required) and Site Plan to Clean Water Services. Details of the requirements of Site Certification and Natural Resource Assessment can be found in Appendix C of the Design and Construction Standards (PDF, 22MB). Please contact Clean Water Services at (503) 681-5100 for further information.

Q: How do I obtain a Stormwater Connection Permit?

A: Prior to obtaining your building permit or site development permit, present your Pre-Screening Determination or Service Provider Letter to the District with your proposed site plan. The District will review the information to be sure that the plan meets the District’s requirements for water quality protection and issue the Stormwater Connection Permit Authorization.

Q: Where do I find more information?

A: The complete text of the current Design and Construction Standards (PDF, 22MB) is available for download. Chapter 3 contains the regulations pertaining to Water Quality Sensitive Areas. Appendix C outlines the Natural Resource Assessment Methodology, and Appendix D provides information on Landscape Standards.

You may also go to our Permit FAQs for answers to common questions. For additional questions about Clean Water Services’ water quality protection regulations or the process, contact:

Clean Water Services
2550 SW Hillsboro Highway
Hillsboro, OR 97213
Phone: (503) 681-5100
Fax: (503) 681-4439