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Stormwater and surface water management

Information and resources for stormwater and surface water management in King County.

Report a problem

Report a flooding, drainage, or water quality problem in unincorporated King County.

Stormwater services and information

Resources and technical guidance to help manage stormwater.

Surface Water Management fee

Information about the King County Surface Water Management fee, and the current rates and discounts.

Stormwater drainage problems and assistance

Information about assistance that is available to help drainage problems in King County.

Surface Water Design Manual

Requirements and standards for designing surface and stormwater management systems in King County to mitigate the impacts of new development and redevelopment on natural and existing man-made drainage systems.

Stormwater pollution and prevention

Resources for preventing pollution at your home and business.

Stormwater Management Program

Reports, documents, and resources for our Phase 1 Municipal Stormwater National Pollutant Discharge Elimination System (NPDES) Permit.

Capital Services Unit

Projects that protect public health, property, and natural resources from flooding, soil erosion, and drainage problems caused by flooding.

Stormwater glossary of terms

Definitions for words about managing stormwater.