Stormwater Committee

Rain Garden fillThe Stormwater Committee shares information and resources focused on reducing pollution from stormwater runoff.

Who is Regulated?

Communities with responsibilities to have water quality permits for stormwater runoff might include:

Municipal Separate Storm Sewer System (MS4)
Phase I Communities

These are the largest communities in Oregon, along with associated partners. The principal communities in Oregon with MS4 Phase I permits include:

  • City of Portland and co-permittees
  • Clean Water Services co-permittees
  • City of Gresham and co-permittees
  • City of Eugene and co-permittees
  • City of Salem and co-permittees
  • Clackamas County and co-permittees
  • Multnomah County
  • Oregon Department of Transportation

Additional information on the MS4 Phase I permitting program is available from the DEQ.

Municipal Separate Storm Sewer System (MS4)
Phase II Communities

Medium-sized Oregon communities are also required to have stormwater permits. See the DEQ inventory of Oregon communities required to have MS4 Phase II permits.



Refer to this map which illustrates the Phase I and Phase II programs in Oregon. Additional information on the MS4 Phase II permitting programs is available from DEQ.

Underground Injection Control (UIC)

Some communities operate UICs or dry wells for managing stormwater runoff. DEQ is in the midst of considering the proper permitting systems for communities with UICs.

Communities may also have stormwater control responsibilities as Designated Management Agencies under a pollution reduction plan developed to meet water quality standards, called a Total Maximum Daily Load (TMDL).

Example Stormwater Manuals

A variety of stormwater design manuals are in use around Oregon.

Examples include:


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