Hide Alert

ALERT: none at this time

Municipal stormwater permit guidance

Municipal stormwater permits require local stormwater management program implementation. 

Jump to detailed information on this page:


Stormwater Management Program (SWMP) elements

Public education and outreach
Illicit discharge detection & elimination (IDDE)
Operation and maintenance
Annual reporting
Coordination opportunities

Other Guidance

Secondary Permittees

Our municipal stormwater permits generally cover cities and counties. However, there are other public entities (such as ports, prison complexes, parks and recreation districts, universities, or diking and drainage districts) that own or operate a stormwater sewer system located in a Phase I or Phase II city or county.

These stormwater sewer systems are also known as municipal separate storm sewer systems (MS4). A public entity with an MS4 may be required to get a secondary municipal stormwater permit.

Do I need a permit?

Does my district/facility need a NPDES MS4 permit?
What if I don't think my district needs the NPDES MS4 permit?

If, upon reviewing the permit language, you determine that your MS4 does not require a permit from us, then you do not need to take further action. If you are unsure, you should contact the regional MS4 Permit Manager.

How do I apply for a NPDES MS4 permit?
Stormwater Control Transfer Program