- Public Works Home
- About Us
- The River Starts Here
- Catch Basins/Drain Inlets
- Erosion Control
- Healthy Watersheds Program
- Permits, Plans and Reports
- Stormwater Program
- Sedimentation Ponds
- Stormwater Maintenance
- Stormwater Interactive Map
- Public Rights of Way & Management
- Street Sweeper Naming Contest - 2020
The City's new stormwater code and the Lake Oswego Stormwater Management Manual are now in effect. Manual files are available using the links below.
Missed our March 11 briefing on the new stormwater requirements for development and other construction projects? Review the presentation digitally.
In the early 1990's, the Federal Clean Water Act was amended to require select urban areas to have a municipal stormwater (or MS4) permit. In Oregon, this program was delegated to the Oregon Department of Environmental Quality (DEQ). Clackamas County was one of the jurisdictions required to obtain an NPDES permit, and the City of Lake Oswego is one of the 13 co-permittees on the Clackamas County permit. The City of Lake Oswego received their NPDES stormwater permit from DEQ in 1995. The NPDES Permit has subsequently been renewed in 2004 and in 2012, and is due for renewal again on March 1, 2017.
The permit requires the City to:
1. Manage stormwater at City facilities and on the City right or way
2. Require stormwater management on private parcels as they develop or redevelop
3. See that stormwater facilities are properly operated and maintained
4. Provide additional oversight for high pollutant-load generating areas (industrial & commercial)
5. Control erosion from construction
6. Control non-stormwater discharges to the storm drainage system
7. Provide public and staff education and outreach around stormwater best practices
8. Provide opportunity for public involvement and participation, particularly at the time of permit renewal
9. Undertake targeted evaluations of specific issues as required by DEQ
10. Monitor the stormwater system; and
11. Report annually on City activities related to the permit. (Recent annual reports are available online.)
Stormwater Management Manual
This Manual, and related amendments to the City’s drainage and surface water utility codes, is a requirement of our current NPDES stormwater permit (part of Item 2 in the list above). The Manual emphasizes the use of infiltration-based approaches to stormwater management where possible, along with other low-impact development (LID) techniques to minimize runoff from roofs, streets, driveways, and other impervious surfaces. The manual applies to the design of newly developing and re-developing sites, and has requirements based on different thresholds of impervious surface area. The City Council approved the stormwater code amendments on February 16, 2016. The new Manual document, with appendices, is available at the links below.
- March 2016 version of the Lake Oswego Stormwater Management Manual.
- Lake Oswego Stormwater Management Manual Appendices (March 2016).
For those of you wanting more information on Low Impact Development (LID) Techniques for stormwater management work, check out this video: Reduce Runoff: Slow It Down, Spread it Out, Soak It In [8:43 minutes]
Buy, Use, and Dispose of Household Products Wisely to Help Protect Our Water
The products you use for cleaning contain ingredients that may harm you, your family and the environment. Using household products incorrectly can allow dangerous chemicals to enter Oregon’s streams and rivers.
The City of Lake Oswego's obligations toward our stormwater permit ("municipal separate storm sewer" or MS4) and related water quality ("total maximum daily load" or TMDL) are outlined in a number of plans and progress reports, provided as Supporting Documents. These Supporting Documents are prepared by the City in response to the MS4 permit and TMDL analyses.
Stormwater runoff occurs on dispersed land surfaces including pavements, yards, driveways, and roofs. Runoff picks up pollutants that are then transported down curb and gutters, pipes, and ditches to our streams and Oswego Lake. Improving water quality requires that we are careful about what we allow onto the land surface, either intentionally or unintentionally.
Lake Oswego is committed to protecting the environment of the city and the surrounding area through its Stormwater Management Utility. In an effort to further protect our water sources, Erosion Control Permits are required for construction projects under any of the following circumstances:
In an effort to proactively keep illicit discharges from happening, the City implements a program of inspections, dry weather field screening, and monitoring to detect any potential illicit discharges to the Stormwater System.
The City of Lake Oswego has developed an inventory of all industrial and commercial sources of stormwater discharge in the City.
The City of Lake Oswego conducts a variety of activities focused on the prevention of typical stormwater pollutants (sediment, hydrocarbons, trash and debris, nutrients, metals) from entering the MS4 system. Such activities include the maintenance and repair of City streets; the maintenance of public parks and recreational areas with the intent of minimizing fertilizer and pesticide use; the maintenance of municipal facilities; control of potential cross-connections from the sanitary sewer system; and master planning for stormwater quality improvement.
The City of Lake Oswego Planning, Public Works, and Building divisions share review responsibilities for development applications.
The City provides opportunities for public participation in the development, implementation, and modification of the policies, practices, procedures, and codes that comprise the City’s Stormwater Management Plan (SWMP) and pollutant load reduction benchmark development.
The City of Lake Oswego conducts a variety of activities focused on the prevention of typical stormwater pollutants (sediment, hydrocarbons, trash, debris, nutrients and metals) from entering the M