City of West Linn

West linn stormwater laws & regulations

The City of West Linn regulations are compliant with the National Pollutant Discharge Elimination System (NPDES) through municipal regulation City of West Linn Municipal Code 4.070. The city’s portion of the Clackamas County Group Municipal Separate Storm Sewer System (MS4) requires West Linn to administer and enforce compliance with stormwater discharge permits in an effort to decrease stormwater pollutants and increase overall water quality. The Stormwater Branch within the West Linn Public Works department administers the stormwater program.


EXCERPT-City of West Linn Municipal Code

4.070 Private Responsibilities.

(1) Storm drainage facilities to be managed by the person responsible include but are not limited to:

(a) A storm drainage facility not located on City owned property, City right-of-way, or City easement;

(b) A private parking lot storm drain;

(c) Any roof, footing, or area drain;

(d) A storm drainage facility not designed and constructed for use by the general public;

(e) An open drainage way;

(f) Access drive culverts in the public right-of-way or on private property;

(g) A detention, retention or treatment system, in the construction of which the City did not financially participate.

(2) Any person responsible shall keep open drainageways on property which they possess or control cleared of debris and vegetation as required by Sections 5.400 to 5.430.

(3) Any person responsible for non-public storm treatment and detention facilities such as catch basins, manholes, filter systems, rain gardens, etc., shall enter into a maintenance agreement with the City, and maintain such facilities so as to prevent flooding or damage to other property not possessed or controlled by the person responsible and to prevent injury to any person or property not owned or controlled by the person responsible.

(a) The maintenance agreement shall be recorded in the deed records of Clackamas County, Oregon.

(4) Any person responsible shall not alter a detention, retention or treatment system from its original properly functioning condition or intended design without prior approval of the City Engineer.

Private parking lots and private streets must be swept or cleaned at least semi-annually. Prior to the sweeping or cleaning, bio-filter bags (or filter fabric inlet sacks) must be installed to prevent pollution during the maintenance effort from entering the City’s storm drainage system and impacting downstream water quality. The property owner or manager must certify every year through a cleaning contractor that the inspections and cleanings have been completed.

(6) The failure of any person responsible to comply with the obligations stated in subsection (1), (2), (3), (4) or (5) of this section is in violation.

(7) The conditions on private property which may result in situations proscribed by subsection (2), (3), (4) or (5) of this section are declared to be a danger to public health and safety and therefore are a nuisance to be abated as provided in Sections 5.400 to 5.430.


EXCERPT-Operation and Maintenance for Private Property Owners

Inspection Schedule: How often?

It is recommended that you inspect your facility at least:

•Quarterly for the first two years

•Twice a year thereafter, and

•Within 48 hours of major rainfall events (more than one inch of rain over a 24-hour period). Some inspections are recommended more often, as noted in the following text.

For at least the first two years, you should conduct inspections with the facility drawings to help you

understand how the facility is supposed to function. This section will help you recognize signs that

indicate diminished performance (for example, sediment accumulation, vegetation die-off, or ponding

water for more than 24 hours after a storm).

Inspection and Maintenance Logs

City Code requires you to keep inspection and maintenance logs for your facility. In general, the logs

should note inspection dates, the facility components inspected, and any maintenance or repairs made.

It is also a good idea to track the rate of sediment accumulation and record visual observations about

the facility and its components. We encourage you to use the sample log on the following page. If you

have a manufactured facility or have a maintenance contract with the manufacturer, assure that their

maintenance logs generally include the same type of information and level of detail.



West Linn Stormwater Website
Low Impact Development Approaches Handbook, July 2009
West Linn Stormwater Maintenance Agreement


Stormwater Permit Application Forms and Fees
Stormwater Contacts