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Managing stormwater in King County

Resources for environmental managers and annual reporting for King County's Phase I Municipal Stormwater National Pollutant Discharge Elimination System (NPDES) Permit.

Stormwater Management Program (SWMP) plan

Our proposed permit actions for the current calendar year. 

NPDES annual report

Actions we take each year to comply with our Phase I Municipal Stormwater NPDES Permit.

Stormwater Management Action Pan

Information about the Stormwater Management Action Plan (SMAP).

Site management plan

Site management plan (the SiMPla) for County-owned properties.

Stormwater videos

About stormwater in King County.